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08 Aug 08 - 07:24 AM (#2408298) Subject: BS: Chevrolet torque specs. From: kendall Here's something new, does anyone know what the torque specs. are for a 235 straight 6 Chevy engine? Spaw? |
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08 Aug 08 - 08:31 AM (#2408336) Subject: RE: BS: Chevrolet torque specs. From: Bobert What's ya' need to torque, Capt'n... If it's the head 55 lb's will do just fine but be sure to torque it in the proper sequence and take it to 40 pounds first... The sequence is somewhat flewible but you need to alternate bolts and work the entire head rather than starting at the front and work to the back... If it's not the head then use good judgement... Like the manifolds certainly won't like 55 pounds... Maybe 20 or so pounds and then if you have a leak youi can always tighten 'um a little more but 55 will break 'um and then you'll be drilling and easyoutin' (which it ain't)... Motorhead/bluesman Bobert |
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08 Aug 08 - 08:44 AM (#2408343) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe Years ago My Fiat 128 had available for it 'special' gaskets which were (apart from being more expensive) more tolerant of torqueing down. |
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08 Aug 08 - 09:12 AM (#2408358) Subject: RE: BS: Chevrolet torque specs. From: kendall I had to replace the manifold gaskets, and I guessed at 20 pounds.I used a torque wrench. I used to be able to remember all kinds of specs. for old Chevrolets, but I'm out of practice, and I don't have a manual. Yes, I followed a basic sequence. This is a 1940 model that has never been restored. 58 K miles, no rust except under body surface rust. The clock still works, I get an owners manual and a title. She rides like new and handles so much better than that Model A Ford I traded. |
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08 Aug 08 - 09:59 AM (#2408383) Subject: RE: BS: Chevrolet torque specs. From: Beer I envy you Kendall. What a hobby to have. Or is it a hobby? Best of luck with it. Beer (adrien) |
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08 Aug 08 - 12:52 PM (#2408530) Subject: RE: BS: Chevrolet torque specs. From: kendall It is a hobby, but sometimes I forget that when I burn my arm on a muffler or whack my head on an engine compartment cross bar. |
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08 Aug 08 - 01:28 PM (#2408565) Subject: RE: BS: Chevrolet torque specs. From: GUEST,number 6 I have a scar on my arm from a 'muffler burn' ... used to have old Jeeps that I loved working on ... gave that 'hobby' up 18 years ago ... the only time I open an engine bonnet these days is to add windshield washer fluid. biLL |
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08 Aug 08 - 02:10 PM (#2408597) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 Looks like you already have it but "Half A Turn Before It Breaks" is always pretty good(;<)) Actually if I were to have cast iron construction 6 rule of thumb I'd figure about 30-35 ft/lbs on the intake and 25-30 on the exhaust.......head bolts 60-65. Without a pattern I'd work inside-out, working equally in each direction in a circular pattern and use a three step sequence to the final on the head and a two step on other parts (intakes, exhausts, oil pans, rocker covers, etc. Also worth a recheck a few pounds higher after the engine has gone through a heat/cool cycle. But you knew all that so I'll shut up!!! Spaw |
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08 Aug 08 - 08:50 PM (#2408957) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Spaw has it right: "a half turn before it breaks." The safest method would be to find a service manual for the engine you're working on, but if you believe in the designers just about any manual for a similar engine in a near year will give nearly identical torque specs for the same bolt in the same use. For the theoreticians: The indentical specs for a given bolt are because a bolt tightened to less than "80% of yield" will almost always back itself out eventually, especially if no "retention method" such as locking nuts, sticky goop, or (per British specs) cotter pins in every nut, is used, which sets a minimum safe clamping force for a particular bolt. In "high stress" areas, or where there's lots of "thermal cycling" or vibration, the common setting is intended to be around "112% to 120% of yield" so that the bolt is actually "stretched into place" and is "springy" against the load. Since you'll probably go the "extra half-turn" if you try for anything over 120% of yield, you'd break the bolt, so that's a "maximum in any case." Since theoretically, the "high stress" bolt (a.la. Head Bolt) is actually stretched a bit each time it's installed, for some "fussy applications" it may be a good idea (or a legal requirement) to use a new bolt each time the thing is put back together. "Fussy mechanics" in less fussy applications (i.e. when the FAA isn't looking over your shoulder) may insist on at least a magnaflux inspection before a bolt is re-used. (A new bolt may be cheaper than the inspection.) Most autoshops go by the "use what's there" theory, with little trouble; but a "visual" to replace any bent or "obviously twisty" bolts would be worth considering. The "yield point" for a bolt is for the longitudinal load (i.e. the "clamping force") and can be easily calculated from the area of the bolt cross section and the "yield stress" for the bolt type. Unfortunately there is no reliable way to calculate what torque must be used to get the intended/wanted clamping force, so most large shops use "torque tables" worked up from tests or plagiarized from a "possibly reliable source." These tables are the source for the torque tables in the service manuals. THE BOTTOM LINE is that for a given bolt the torque spec is one or the other of two values, depending (sometimes) on the place where it's used. Even the ambiguity between the "80%" and "112%" values isn't as ambiguous as it could be, since the higher stress levels are used (usually, at least, in cast iron block times) only with SAE Class 5 or Class 8 bolts, and the lower values will more likely be a Class 3 (but sometimes a Class 5). Going back to "theory" again, you should be able to tell the Class of the bolt from the markings on the head. For "instructional purposes only," you can look at http://www.americanfastener.com/technical/grade_markings_steel.asp for samples of head markings. Auto engines in cast iron days would likely have used SAE J429 style markings, with the good ones quite a ways down the list. The ASTM specs are mostly identical to the SAE, and the same markings from either spec will generally mean "the same bolt." To be "the same bolt," the bolt "diameter," "thread class and pitch," and "material spec" must ALL match. Safest is to look for the same bolt head markings. Note that "all bets are off" once you get into Al blocks, since the "torques" used for the bolts in cast iron heads may strip the threads in an Al block long before "bolt clamping capacity" is reached. "Sticky goop" and other specialized "retention methods" are fairly frequently used with the bolts at lower tension/torque. Studs are perhaps more commonly used as well, since the stud half that screws into the Al block can be installed at low torque/zero tension, and is thus fully engaged in the threads before the nut goes on and applies the tension. (It should be noted that the "nut torque" may be somewhat different than the "bolt torque" to get the same "clamping force," so the actual engine spec is more critical for Al block work. None of this, of course, is particularly useful to those who asked the questions; but perhaps the bit of theoretical stuff may be of some interest to a couple of our stranger members. Just remember that even when there are "rules" there are also "creative designers" so don't expect anything to work all the time. John |
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08 Aug 08 - 09:02 PM (#2408962) Subject: RE: BS: Chevrolet torque specs. From: GUEST Like John says: I'd find a manual and get the sequence right. I've screwed up a lot of head gasquets trying to guess at it. |
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08 Aug 08 - 09:35 PM (#2408980) Subject: RE: BS: Chevrolet torque specs. From: Amos John: Your are truly a wonder. I have never seen this issue discussed with such great clarity and elegance. Count me as a fan. A |
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08 Aug 08 - 09:45 PM (#2408984) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas *** such great clarity and elegance *** Or of so little use? You must be one of the "stranger members" if you actually read it.(?) But I'm blushing again, anyway. John |
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09 Aug 08 - 01:55 AM (#2409079) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe "the bit of theoretical stuff may be of some interest to a couple of our stranger members" John, I'm always truly amazed just how much useful stuff you know, and surprised that I actually read about most of it once in passing somewhere (I hate electronic library indexes - I always have been a 'stack browser') and forgotten most of it... "You must be one of the "stranger members" if you actually read it.(?)" Really strange, mate - I understood it all... :-P I once owned a Healy 100/4 (NOT an Austin Healy!) which I was restoring - till my mum drove me mad and I disposed (to stop the nagging) of it still in bits. Cost $440 - cash received -$200 - vale nowadays $55,000..... "Just remember that even when there are "rules" there are also "creative designers" so don't expect anything to work all the time" and the mongrels now write software for Microsoft ... :-) |
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09 Aug 08 - 03:01 AM (#2409091) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Foolestroupe - I take exception to you calling the Microsoft mongrels "creative." I was not using the term pejoritively. They're more like most modern artists. I see virtually no "creativity" in their stuff. Just nasty little perverts trying to scam a buck without working very hard. Some of the artists admit it's a scam, but most just say "you must be too stupid to understand it," and let the know-nothing critics "search for the hidden meanings" and invent preposterous "explanations of nothing" to make it sell. When it doesn't work, Microsoft just says "You're too stupid to see that's a feature." Then the critics (a.k.a. "editors") try to explain that you really should like that feature, and tell you why you want it to not work. Same theory. John |
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09 Aug 08 - 07:30 AM (#2409170) Subject: RE: BS: Chevrolet torque specs. From: kendall All good advice but this old "Stovebolt six" has both intake and exhaust manifold in one piece so the torque has to be either or. Also, the whole thing is cast iron.To make things a little more hairy, there is no way to get the head of a torque wrench down between the ports. The nuts on each end are brass and I expect they would strip before the steel bolts. I must have done it right because the engine runs smooth, 22 pounds of vacuum and no leaks. Anyway, I came across a catalog of old Chevy parts in Georgia, and I just ordered a shop manual. |
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09 Aug 08 - 08:15 AM (#2409191) Subject: RE: BS: Chevrolet torque specs. From: Bobert Well, Capt'n, I have some additional thoughts now that I realize it's the manifold... First, there is a product called "never-seize"... It's kinda silvery pastey stuff and I'd highly recommend using it on the bolts because it will not only allow you to thread them easier but also will also keep them from siezing from the heat... Also, there is kinda this rule of thumb on torque that has to do with the size of the bolts... Like a 1/2 bolt won't take 30 pounds... Yours are probably 5/8s if I had to guess which can easily take 30-35 pounds... You just kinda have to feel the bolt as you tighten... It will let you know what's what... Plus, do not use air tools to tighten because they mask the amount of torque... Long rachet handles also mask the torgue... For initial tightening use a hand rachet with no more than about a 10" handle before the final torquing... Wish I was up there myself... We'd have 'er purrin' like a kitten in no time at all... Sho nuff would... Also, once you get it torqgued and purrin' I'd recommend re-torquin' it after a few hours of running... Heat does some starnge things to new gaskets on old cast iron engines... Good luck... B~ |
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09 Aug 08 - 08:49 AM (#2409202) Subject: RE: BS: Chevrolet torque specs. From: frogprince "no way to get the head of a torque wrench down between the ports" Don't ya got a little socket extension, 4" or so? (Probably you do have, but there's some reason that I don't know about why it wouldn't work. Maybe too hard to keep everything from tilting and skinning off the nuts.) |
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09 Aug 08 - 10:21 AM (#2409257) Subject: RE: BS: Chevrolet torque specs. From: kendall What I did was to bathe the bolts in "weasel piss" (penetrating oil) and let it set overnight. I was surprised that those 68 year old bolts came out so easily. The size of a bolt is important, but so is the tensile strength.. |
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09 Aug 08 - 11:07 AM (#2409290) Subject: RE: BS: Chevrolet torque specs. From: gnu Odd! After reading John's post... actually, before I was done reading it... I thought, I am gonna post sommat about this and then I see Amos and Robin had the same thought, although they put it far more eloquently than I had in mind... Jaysus, man!! Do you know EVERYTHING? |
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09 Aug 08 - 03:34 PM (#2409460) Subject: RE: BS: Chevrolet torque specs. From: dick greenhaus Kendall-- A Chevy 6? Wasn't there a song about that vehicle..."Drive Dull Car Away" or something like. |
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09 Aug 08 - 05:12 PM (#2409498) Subject: RE: BS: Chevrolet torque specs. From: John MacKenzie Shy Torque? |
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09 Aug 08 - 05:19 PM (#2409503) Subject: RE: BS: Chevrolet torque specs. From: kendall Good one, Dick! |
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09 Aug 08 - 06:03 PM (#2409527) Subject: RE: BS: Chevrolet torque specs. From: Bobert Yeah, the 40 Chev weighed ibn a a couple tons and with that 6 cly. in it Motor Trend clocked 0 to 60 in just under a calendar year... Lol... Awww, I'm jsut messin' wif ya' Kendall... But a 40 Ford with a flathead 8 woulda torn up the Chev... I know... What's the hurry??? Good point... B~ |
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09 Aug 08 - 08:57 PM (#2409621) Subject: RE: BS: Chevrolet torque specs. From: kendall Dream on Bobert. I've made more than one Ford eat dust with a Chevy. I don't know about the 40s but in '37 the Ford and the Chevy both had 85 HP. The Ford was slightly faster out of the gate, but at high speed the Chevy was king. High speed, 85 to 90 mph. |
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10 Aug 08 - 09:00 AM (#2409809) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe "The size of a bolt is important, but so is the tensile strength" That's what my ex-girlfriend mechanic used to say... "Maybe too hard to keep everything from tilting and skinning off the nuts.)" Funny, that's what my... "What I did was to bathe the bolts in "weasel piss"" Funny, that's what my... |
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10 Aug 08 - 09:45 AM (#2409823) Subject: RE: BS: Chevrolet torque specs. From: John MacKenzie Do the job properly and replace the bolts too, they stretch. JM |
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10 Aug 08 - 10:10 AM (#2409839) Subject: RE: BS: Chevrolet torque specs. From: Bobert Ummmmmm, I hate to bring it up, Capt'n, but the only dust-eatin' Fords from '32 on were the ones with the little old lady behind the wheel who had no interest in dustin' off Chevy's... I had a '49 with that same stock flathead V-8 with overdrive and there wasn't 6 cly. Chevy around that could touch it at any speed... Not in a quarter mile, not in a hundred miles and not to the moon... Fords ruled... Now don't get me wrong, I liked alot of them Chevys, especially the late 40's Chevys and kinda have my eye on a certain '47 Chevy right now if I get somethin' sold but I ain't lookin' at fir nuthin' other than it looks one heck of alot better than any of the pre-49 Fords for a decent bluesmobile... B~ |
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10 Aug 08 - 10:26 AM (#2409844) Subject: RE: BS: Chevrolet torque specs. From: maeve John, that was indeed an elegant and interesting post. I read it all and understood it, too. I'm enjoying this discussion. One day I'll get to visit Kendall's Chevy. |
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10 Aug 08 - 11:05 AM (#2409853) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Zero Products Torque Chart gives a somewhat typical treatment of "general torque values" for a variety of fairly common bolt types. As with quite a few such sources, a "formula" is given, but my personal advice would be that you not rely on this formula, or most other similar ones. The discussion there about variations due to "lubricant" condition is valid, but note that the "formula" does not include any adjustment for the thread pitch – although the table gives different torque recommendations for UNC and UNF threaded bolts1. If you actually used the formula as it's described, you'd get the same torque for both. This is the clue that the advice given is "partly based on magic" (i.e. things not revealed) which doesn't always work reliably for "nuts and bolts" work – unless you're the magician, know the "hidden details," and do some additional "adjustments" to the result. 1 The unexplained correction also is in the "wrong direction" if you believe the "explanation" since he shows a higher torque for the fine thread than for the coarse one. (6 ftLb for 1/4-20 and 7 ftLb for 1/4-28). The lower pitch of the fine thread usually will develop the same bolt tension at a lower torque than for a coarse thread of the same diameter. The "error" in torque values is because he's actually used the thread root diameter to calculate his "bolt cross section area" without explanation, so we'll be forgiving and say it's not an error, just a "difference due to sloppiness." Note also that in several places in the table the x/y bolt diameters appear as x1y, indicating the author didn't have a proof reader. (114-20 is 1/4-20, 112-13 is 1/2-13 and 112-20 is 1/2-20) A minor quibble – to be a torque the value must be INCH-POUNDS (InLb or LbIn doesn't matter) or FOOT-POUNDS (FtLb or LbFt). "Pounds" alone doesn't cut it, although most of the shade tree mechanics probably will (usually) assume the "foot" value. Many US service manuals for more recent models do give the spark plug torque – for the "gasketless tapered-seat plugs – in INCH-POUNDS, and if you use the number with a FtLb torque wrench you almost certainly will strip the threads. For metricized work, torques are usually Newton-Meters (Nm or mN) or Dyne-Centimeters. You may see kg-m specs, but those are technically incorrect and indicate an "uninformed" source. "Uninformed" is common and shouldn't be too disturbing. You are unlikely to see dyne-cm values in auto maintenance/rebuild, since one dyne-cm is approximately equal to "100 flea fart angstroms" in actual value (i.e. – it's not very much torque). Both intake and exhaust manifold bolts typically will use the 80% of yield torques. (The table at the link says 75% which is "in the range of common practice.") About the only common engine bolts that used the "full yield" torque values were older engine head-bolts, and sometimes for crank/rod bearing caps. Usually, even in very old engines, the bearing cap bolts used the lower torque values with a "bend over" retaining washer or other "anti-backout" device. On "more modern" engines even the head bolts generally use the lower values with a "liquid gasket" or other zero-compression method that eliminates the need to bend the bolts. "Head gaskets" almost don't exist in recent engines, at least in forms like the old-style "compress-until-the-cracks-are-gone" kind. John |
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10 Aug 08 - 11:59 AM (#2409879) Subject: RE: BS: Chevrolet torque specs. From: Bobert I think it is also important when using torgue wrenches that the cheapies ain't all that exact... If you have a friendly Snap-On toolguy he'll take yer wrench and check it for accuracy... This is more important on newer engines with aluminum and alloyed components as they are less forgiving than the old cast iron engines where you could get by nicely without a torque wrench as long as you had developed "the feel"... BTW, John, I used to build air cooled VW engines and the torque requirement for the flywheel gland nut was 275 ft pounds... Purdy tricky 'cause you had to use a 4 foot long pipe extension to crank 275... And ya' also had to have someone with a foot on the No's 3 & 4 Cyl. head to keep that side of the engine from lifting up from the torgue... No fun.... B~ |
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10 Aug 08 - 12:03 PM (#2409880) Subject: RE: BS: Chevrolet torque specs. From: kendall Bring on your flat head Ford, Bobert; I'll take you like Grant took Richmond! LOL |
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10 Aug 08 - 12:44 PM (#2409894) Subject: RE: BS: Chevrolet torque specs. From: Bobert Ahhhhhh, Grant didn't take Richmond, Capt'n... The joint was burnin' by the time he got there and it had nuthin' to do with the Yankees... Seems that a few folks busted into the whiskey wharehouse down in the Shockoe tobacco district and accidently caught the city on fire... Speakin' of accidents, the only way I could loose to yer yer Chev would be if some Taylor Geetar playin' knothead ran a red light and took the Ford out on our way up to Maine...lol... And thems is the truth... No brag, just fact... Bobert;~) |
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10 Aug 08 - 02:29 PM (#2409956) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Bobert flywheel gland nut was 275 ft pounds I had a Chrysler truck running tests at Flagstaff AZ that ran into a tree stump and broke off a suspension arm. The factory airlifted1 a replacement part, but they sent the suspension arm and the ball joint as unassembled parts. The ball had a "self-tapping" thread on it, about 3 7/8 inch diameter, and the hard-tempered Al arm was a smooth bore. We put the arm in a reallybig vise at the Ordnance Depot railroad maintenance shop, put a twelve foot "cheater" on a wrench (for 4 7/8" hex nut) that the shop had. Put four pretty husky guys on the wrench end, and still skidded the 18 foot long (railroad tie top) bench a few feet with the other two guys tryin' to hold it down. Back at home base I asked the factory rep (who was unavailable for the installation) what kind of torque they used at the factory, and he called the factory for us. Their answer was "we don't really know 'cause we've got this hulkin' big hydraulic thingamajobby that puts 'em in; but we'd guess about 3700 ftLb." (I think they missed by about a 2x factor. I'd already made my estimate that we used something a little over 4800 ftLb. It "looked seated" but wasn't really all the way in at that.) Since they sent both parts, it occured to me that they could have used their "hulkin' big hydraulic thingamajobby" to put them together before they sent them to us like they did before they sent them to the install line at the factory; but apparently they never had that idea. 1 "airlifted" is a euphemism. They sent the parts from Yuma in an L19 (max rated operational altitude 8,000 ft.) Flagstaff field, 8,300 ft. I didn't see him come in, but the pilot had brown pants when we met him in the coffee shop. When he left (empty), he used all of the runway, cleared the 3 foot fence at the end, and went DOWN out of sight tryin' to pick up flying speed. Fortunately the ground went down in that direction too - all the way back to Yuma. ( John |
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10 Aug 08 - 02:40 PM (#2409968) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas XM410E1 Truck All-wheel independent suspension with a push-button automatic transmission. John |
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10 Aug 08 - 04:35 PM (#2410026) Subject: RE: BS: Chevrolet torque specs. From: kendall Ok, true story. When I was in the service my ship was in dry dock at Portsmouth shipyard in New Hampshire. Whenever I had liberty I would drive to Portland to be with my wife. I remember one time a shipmate had a '46 Ford 8 and we were racing on the Maine Turnpike. I passed him and afterwards he said he was doing 100 mph. When I went by my speedo said 90 mph. That's not the only time I saw such a difference in speedos. Looks to me like Henry made the speedo that way to fool Ford owners into thinking they were faster than they really were. By the way, I knew about Richmond, but I like the saying. It bugs southern gentlemen. And, leave my Taylor out of this! Don't make me come down there! |
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10 Aug 08 - 05:58 PM (#2410069) Subject: RE: BS: Chevrolet torque specs. From: Bobert Well, if ya' do, bring the Chev, Capt'n... I'll let ya' take a crack at my Craftsman ridin' mower... That oughtta be a little closer a race... lol... BTW, I know yer buddy an' he swears he was still in 2nd gear when he let you around... Lol, part B... Sorry about the Taylor shot... I'm just kinda bored today and, plus, the devil made me do it... B;~) |
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10 Aug 08 - 07:10 PM (#2410109) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe My Grandad ran a service station. In my tool collection I have a open end spanner. It's nearly 3 foot long, and while I can't quite fit my head in it, I suppose JiK might... at the top any way.... :-P |
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10 Aug 08 - 07:13 PM (#2410113) Subject: RE: BS: Chevrolet torque specs. From: kendall What?????that does not compute |
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10 Aug 08 - 07:21 PM (#2410119) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe I'm not at home right now, so can't get it - but it weighs an awful lot, It was supposedly for getting flywheels off trucks or something. He was a carrier before he went into the service station - was once a big wig in the VACC. |
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10 Aug 08 - 07:48 PM (#2410133) Subject: RE: BS: Chevrolet torque specs. From: Bobert Yo, F-Troupe... You say yer spanner is 3 feet long??? Jaysus, mah man!!! That is one heck of a spanner ya got there!!! "Big wig of the VACC"??? Well, I'll say he was... Whaddayahtink, Kendall??? Bobert w/ ****grin**** |
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10 Aug 08 - 08:52 PM (#2410164) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe "You say yer spanner is 3 feet long" I'm not making this up, ya know... No, it belonged to my dad's dad spanner. He used it, then my dad used it. but I never had a need to use one that big, and anyway, I'm getting too old to need to use it anymore... |
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10 Aug 08 - 08:54 PM (#2410167) Subject: RE: BS: Chevrolet torque specs. From: The Fooles Troupe Ah - stuffed that one up... "You say yer spanner is 3 feet long" I'm not making this up, ya know... No, it belonged to my dad's dad. He used it, then my dad used it. but I never had a need to use one that big, and anyway, I'm getting too old to need to use it anymore... |
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10 Aug 08 - 11:17 PM (#2410215) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Kendall - Some time back, anything within plus/minus about 10% was considered "within tolerance" for speedometers, although most new cars "delivered" with 5% or better when new. The gear where the cable came out of the prop shaft usually was available with around 17 to 23 teeth on it, odd numbers only, and you could only add or drop two teeth at a time, so the only adjustment that could reasonably be made was about 17/19 = .89, 19/19 = 1.00, 21/19 = 1.11, if you started at the 19 that was common. In the early 60s, US automakers sized the tires to get an average of 10,000 miles on the tread. This was considered a minimum that buyers would tolerate, and let them use the smallest tire "almost big enough" to improve "ride" and to save about $3.00 per tire. (No comment on which was most important.) (The use of undersized and overloaded tires, invariably bias-ply, also contributed somewhat to the sales pitch that "radials are better" and helped drive the switchover to (almost) universal use of radials. Coincidentally(?), radials are cheaper to make than bias ply ones, once the manufacturing equipment switchover is made.) My '64 Buick Special came with 6.70x15 tires, and they were pretty well shot at 10,000 miles - so I replaced the set at about 14,000. In the replacement I went up to a 7.10x15, still bias ply, sized to carry the load with "flat wear" on the tread - the "proper size for my vehicle" according to the Tire & Rim Mfrs Assn Handbook. That set got well over 38,000 miles and were replaced mainly because of "sidewall rot" (almost 6 years later) rather than tread wear. The tire size change unfortunately put my speedometer "quite a bit out of spec" so I had to drop two teeth in the gear to bring it back to within a little less than 3%. Tire changes, and poor pressure maintenance, can easily affect speedo calibration enough to account for the difference seen; and, especially for older cars, sometimes they just weren't really all that close to reality to start with. John |
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11 Aug 08 - 07:21 AM (#2410409) Subject: RE: BS: Chevrolet torque specs. From: kendall I just checked the speedo on my '40 Chevy and it is off by 5 mph.The Police set up a speed warning contraption on Sawyer road and I saw that I was going 5 mph faster than the speedo said. The Hyundai is right on the money. Years ago I had a '56 Chevy and for some reason, I put oversize tires on it. That threw the speedo off by 10 mph. I warned my wife to watch it, but did she listen? Do pigs fly? Well, you guessed it, she got a ticket for speeding. We took the car to have the speedo calibrated and sure enough it was off by 10 mph.She got off by submitting the report and she only paid court costs. |
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12 Aug 08 - 10:02 PM (#2412152) Subject: RE: BS: Chevrolet torque specs. From: kendall The manual I ordered has not arrived yet, and I have the oil pan off ready to install a new rear main seal. I'm going to guess that the rear main bearing is about 75 pounds torque. |
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12 Aug 08 - 11:01 PM (#2412182) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 How about these from a 47 Stovebolt 235? Cylinder Head Bolts: 90-95 Intake Manifold: End Clamp Bolts: 15-20, Center Clamp bolts: 25-30 Exhaust Manifold: End Clamp Bolts; 15-20, Center Clamp bolts:: 25-30 Rocker Arm Shaft Bracket: 25-30 Rocker Arm Cover: 25 inch lbs. Connecting Rod Cap Bolts: 35-45 Main Bearing Cap Bolts: 100-110 Flywheel to Crankshaft: 50-65 Spaw |
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13 Aug 08 - 07:50 PM (#2413016) Subject: RE: BS: Chevrolet torque specs. From: kendall I say again, there is no way to get a torque wrench down between the ports of the manifold.A box end will just fit. This engine has never been apart. Two shims on each rod bearing. |
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13 Aug 08 - 07:57 PM (#2413020) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 Why are you saying it again? All I did was post some specs I found that included your mains. If you like or they offend you I can delete them. Otherwise I figure YOU need a torque wrenching yourself cause you got something loose.............. Spaw(;<)) |
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13 Aug 08 - 08:50 PM (#2413047) Subject: RE: BS: Chevrolet torque specs. From: Bobert Well, gol danged, Capt'n.... If ya gotta use an open end or box end and we're talkin' 15-20 pounds you can use the torque wrench on one you can get to then back it off an 1/8th turn, retorque it with an open end and then you will have a feel for how much pull you gotta put on the inner ones... Like I said earlier, or maybe I didn't, bolts is alot like womens... Once you got the feel then the rest is gravey... That's a-bolt it from here... B~ |
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14 Aug 08 - 11:59 AM (#2413622) Subject: RE: BS: Chevrolet torque specs. From: kendall Get up on the wrong side of the ditch, spaw? |
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15 Aug 08 - 01:25 AM (#2414275) Subject: RE: BS: Chevrolet torque specs. From: Lonesome EJ When I saw the thread title I knew you'd be all over this one, Spaw..er, Grease. |
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15 Aug 08 - 02:52 AM (#2414304) Subject: RE: BS: Chevrolet torque specs. From: Gurney A couple of bits of generalised information which may be useful to tinkerers: 'Foot/pounds' means pounds weight at 1" from the bolt centre. Just in case you don't have a torque wrench. Head and manifold tightening patterns are usually in an outward clockwise spiral beginning at the centremost bolt. Taper-roller bearings. No-one has a torque wrench for these, it is a tiny specialised tool. Usually in the front hubs of rear-drive vehicles. For cars, start with everything clean, tighten to about as much as you would if it were a 1/4" bolt (to seat the bearings,) back off the tension and remove the socket wrench, grip the socket with your HAND and tighten as hard as you can. As hard as a male mechanic can. |
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15 Aug 08 - 05:26 AM (#2414370) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Gurney - It's Foot Pounds, not Foot per pounds, (Foot/pounds), and one foot pound is the torque from one pound applied ONE FOOT from the centerline of the bolt. Last I heard 1" isn't a foot (except maybe in the UK - I've had some experience with their "standards.") (Dang those typos can be embarassing!) Several methods have been used for "wheel bearings" but what my older overhaul manuals usually said was "make sure the bearing is clean and well-greased, torque to some low value while rotating the wheel to take the slack out, and then back off the nut until the cotter pin goes through the slot in the castle-nut - and cleanly through the hole in the axle." Sometimes they added that if the pin goes in "at torque," the nut should be backed off the 1/6 turn to the next slot. I don't recall the torque values recommended for seating, but recollection is that they were about what you'd put on a 1/4" bolt, or sometimes even a little less. Some "shade tree mechanics" I've known said they just torqued the nut down "until there's drag when you turn the wheel," and then do the back off to the hole bit. They probably never saw a torque wrench (not based just on this particular procedure, but on general performance in other areas as well). John |
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15 Aug 08 - 07:22 AM (#2414434) Subject: RE: BS: Chevrolet torque specs. From: kendall Turn it down one half turn before it strips. I like that. |
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15 Aug 08 - 09:12 AM (#2414518) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 Kendall, can I ask you about your posts? I always wonder who the hell you're responding to. Just above you say: Turn it down one half turn before it strips. I like that. Who are you responding to? Or a few posts up you thought I might have gotten out on the wrong side of bed. I wasn't upset or anuthing, again I was wondering who you were reponding to when you said: I say again, there is no way to get a torque wrench down between the ports of the manifold.A box end will just fit. Who was that meant for? See, I thought it was for me and I never said a thing about trying to get a torque wrench on a bolt, just specs I found and posted. I'm still not upset or anything at all, just curious that many times in threads you make a comment that seems to be about another post but the post it most relates to is several days back up the thread.....LOL....Always confuses my dumb ass. I love ya' like a brother but I think the fumes from that leather coat are addlepating your melon. Spaw |
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15 Aug 08 - 03:26 PM (#2414850) Subject: RE: BS: Chevrolet torque specs. From: kendall I forget who posted that, "Turn it down until half a turn before it strips". It just popped into my mind. And the other post I was responding to, someone mentioned again a torque wrench, not you.I appreciated your posting of those specs. |
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15 Aug 08 - 04:33 PM (#2414912) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas Spaw - He's probably a bit distracted 'cause he's workin' on that engine about 60 feet under water, which probably requires more than usual concentration. When you suck all of the air out of something the most you can get is about 15 pounds (per square inch assumed) of "vacuum" (at sea level, in air, on planet earth) so his 22 pounds of suck on the manifolds must mean he's deep under water or on Jupiter. (yeah, quibble quibble quibble) I'd bet his gage says inches of Mercury (inHg), and 22 inches is still pretty respectable - admirable even, for an old - - - piece of hardware. John |
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15 Aug 08 - 06:59 PM (#2415019) Subject: RE: BS: Chevrolet torque specs. From: kendall 20 inches of vacuum is standard on these old engines.When you rev it up it drops to 15 or less, then it pops up to 22. |
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15 Aug 08 - 08:16 PM (#2415074) Subject: RE: BS: Chevrolet torque specs. From: Bobert Kendall's on Jupiter??? Danged, that explains alot... Aww, jus' funnin' wid ya... But really, Capt'n, if you'll just do as I suggested you'll have that Chev purrin' like a kitten... And here's yet another tidbit... Torque it down as I suggested and then start it and if it runs smooth then leave it alone... If it doesn't, spray some carb cleaner around the manifold gasket and if there is one place where you spary the stuff that makes it run smooth then tighten the bolts around that area and all will be well... Geeze, do I have to come up there and get that sumabich'n Chevy runnin'??? Cause I can... Yiu need a passport to get in??? I ain't got a current one... Shots??? No, no... Here's a better idea... Tow it down to the Getaway and the two of us will get it runnin'... Yeah, that's a gooder idea... B;~) B;~) |
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16 Aug 08 - 03:52 AM (#2415272) Subject: RE: BS: Chevrolet torque specs. From: Gurney JohniK, you are correct, I was following the usual (when I did it) English terminology. Then usually typed lbs/' or lbs/ft. BUT I typed pounds at one INCH from the bolt. I plead that it is 35 years since I thought in feet and inches, and the abbreviations are growing fuzzy. And I didn't proofread carefully enough. The information on taper-roller bearings is from personal experience. I once was the poor sod who fitted hubs in a car factory, and I had a tiny torque-wrench to be sure. Japanese cars, they are very punctilious. "You will tighten to 13lbs/' while turning the hub (forgot that), slacken off, and tighten to (whatever it was.) I developed a personal method of getting the same result without the tiny torque-wrench. Never known to fail. Kendall's method of tightening is like my method of cooking. 'Stop before it burns!' |
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16 Aug 08 - 07:28 AM (#2415321) Subject: RE: BS: Chevrolet torque specs. From: kendall Bobert, you old hillbilly, I've done all that. She purrs like a kitten. Maybe I should mention that I started working on cars at the age of 16, and I've been doing it ever since. My older brother gave me a car, 1937 Chevy, when he went to Korea in 1951. My younger brother got pissed at me for some reason and yanked all the plug wires out of the engine and threw them all over the yard. One of my neighbors was a mechanic at the time, and he drew me a diagram of the firing order. I did as he said and she fired right up. Now, if you want to see for yourself why a torque wrench won't work on the manifold bolts, come on up. I can teach you a thing or two about good cars.LOL By the way, my new John Deere lawn tractor can take your flathead Ford any day. |
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16 Aug 08 - 08:41 AM (#2415338) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 Listen.....Y'all are more than free to use anything I say but let's get it right.......The expression is "Half a turn before it breaks." Professional Mechanics have a long list of commonly used expressions in the trade. If you'd like to use any others let me know so they pass down correctly in the tradition. Among the many available are for instance: "RCH" and "Half an RCH"......used in clearance measurement "Slicker than a mini's peter".......a smooth fit,easily assembled "Hard to tell where the first explosion occurred"......long laundry list of problems "French Jack"........leaking hydraulic jack that keeps going down on you "The length of my dick"......long linear measurement "About the length of your dick"......a short linear measurement "Half the length of your dick".....an even shorter length "Jack up the radiator cap and slide a new car underneath it"...car not worth repairing "Put some hair around it".....when having difficulty in starting a bolt into it's bolthole "Non-Ambulatory Case C"...backyarder's car brought in on the hook with many parts in a cardboard box Many more are available and free for the using but please check so as to get them right. Spaw |
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16 Aug 08 - 10:11 AM (#2415364) Subject: RE: BS: Chevrolet torque specs. From: Bobert Whoa, Spawz... Toomany references to "dicks" in there... Must be a Yankee thang... Down south we know that you got tools for cars and truck and you got this other tool fir, ahhhhh, not cars and trucks... But now we maybe a bunch of redneck hillbillies but we know the difference... Sho nuff do... Ya'll must get snowed in alot to come up with all them other uses fir various tools... Like mah daddy taught me, "Don't us force, son, jus' use the proper tool..." Speakin' of snow, seems like the poor ol' Capt'n got bored last winter an' stuff a 327 in his John Deer 'cause he says he's ready to take my '49 fire breathin Ford with it??? Well, I guess that is one thing I do find amusin' with Yankees... When them boys get snowed in at least they ain't out drenkin' 'n fightin' behind the Seeet Springs store ike we do in the winter... They are stuffin' 327's in their lawn mowers??? Ya' leave the mower deck on, Kendall??? Bet you can mow yer lawn in just under 12 seconds with that 327... Of course, a 271 hp high performance Ford motor would getcha into the 11 second bracket but then you'd have to play with the big boys... lol... B~ |
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16 Aug 08 - 10:17 AM (#2415368) Subject: RE: BS: Chevrolet torque specs. From: kendall Bobert, I don't play with boys. You really shouldn't advertise such proclivities in public. Spaw, we don't use such crudities up here. Most of us went to school and learned English. Put 'em up, put 'em up! LOL |
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16 Aug 08 - 10:50 AM (#2415378) Subject: RE: BS: Chevrolet torque specs. From: Bobert See what you've done now, Spawzer??? Ya' gotta poor ol' Kendall's fir up... Next thing ya' know he'll be tellin' us that not only did Columbus use a Chevy engine to motot the Mayflower to the New World but that he was in charge of keepin' it runnin'???... lol... B~ |
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16 Aug 08 - 11:31 AM (#2415402) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 You guys need to get your time frames right for any of those. While both were respectable in their class at different times, it wasn't until the late 50's that you ever saw much of a time period where both brands were sharing the same stage. Prior to that, a long string of notables held the coveted positions such as Packard, Hudson, etc. If you wanted a fast and powerful Ford for 'shine, you put in a Caddy mill (ask Junior). Spaw |
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16 Aug 08 - 05:53 PM (#2415626) Subject: RE: BS: Chevrolet torque specs. From: Bobert Well, I guess so, Spawzer... Them Caddie moters had about a hundred cylindars in 'um... But them was all long strokers that wouldn't turn up too fast... Yeah, good torque but that was about it... Big pistons and short strokers now??? Different idea... Mah dad worked for Ford Motor Company as a district rep and he could get just about anything that Ford could think up as company cars... In 1956 he got a Crown Victoria with a 312 with multiple carbs and than sumabich was fast... I wish I had that car now... It was one of a kind 'cause they built it with a plexiglass sunroof in the hood so you could see the engine with the hood closed... Purdy cool... B~ |
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16 Aug 08 - 07:30 PM (#2415702) Subject: RE: BS: Chevrolet torque specs. From: kendall I received my new shop manual for that old bucket today, and would you believe it? NO torque specs! |
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16 Aug 08 - 07:35 PM (#2415705) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 Well you keep saying that you can't get a torque wrench to fit! LOL!!!! Spaw |
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16 Aug 08 - 09:05 PM (#2415746) Subject: RE: BS: Chevrolet torque specs. From: kendall Spaw, try to keep up, I said only the manifold bolts. |
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16 Aug 08 - 10:01 PM (#2415782) Subject: RE: BS: Chevrolet torque specs. From: catspaw49 Yeah I know Kendall but I think you have a head bolt loose. Spaw |
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16 Aug 08 - 10:39 PM (#2415802) Subject: RE: BS: Chevrolet torque specs. From: Amos ANd maybe about tuh blow one of them gaskets.... A |
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16 Aug 08 - 10:57 PM (#2415812) Subject: RE: BS: Chevrolet torque specs. From: Riginslinger "I received my new shop manual for that old bucket today, and would you believe it? NO torque specs!" That's really hard to believe. I would think that would be one of the basic peices of information you would need. Years ago, we used to go down to the public library and look things like that up in "Motors Manuels." You could find automobile specs, and even some trucks, industrial engines, and tractors. |
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16 Aug 08 - 11:57 PM (#2415829) Subject: RE: BS: Chevrolet torque specs. From: JohnInKansas The "Motors Manual" was a very popular book with auto shops, and generally covered all the US cars for about 10 years back from the year you got yours. My recollection is that my first copy was ca. 1950, and would have had the specifics wanted here; but since I also had kids with delusions of being "mechinically inclined" it no longer exists. There were a couple of independent publishers who produced books for individual "models" and everybody had one of them; but the typical one of these was about 350 pages of "boiler plate" that never changed from one model to another, with only about 23 pages more or less specific to the particular car for which you got your copy. One ca. 1965 "aftermarket" manual I got had the same pictures and text in the boilerplate as some I looked at (and didn't bother to get) around 1998. The "changeables" were generally in about 20 pages (or fewer), usually at the back of the book, and that's where you might find the "clearances and torques." The manufacturers' manuals were pretty good, and very specific up until about 1970(?) when they (at least GM) "outsourced" the printing, although I can't comment on what ones before about 1950 looked like. When the manufacturers started hiring outsiders rather than publishing them in-house, instead of one manual for basic service and one for overhaul, to get a "full set" you had to (probably still do) get one for scheduled services, one for engine and drive train, one for electrical, one for emissions, one for body and trim, and often a separate one for ventilating and air conditioning - and in some cases there are/were "supplements" available (at extra cost) for less common "options." The full set of manuals would cost you at least as much as adding the "surround sound stereo AM/FM radio with CD player and digital clock and coffee maker" to your new car in place of the "basic" AM/FM that was standard equipment. The three "basic volumes" for my 1995 GM were about $95, as I recall. I've actually used about four pages that had info that was helpful, but I'm unlikely ever to do any engine/tranny rebuild since you have to saw the frame apart to pull the engine and cut in a different place to yank the tranny out. (I'd have to get a welder to put it back together.) John |
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17 Aug 08 - 06:27 AM (#2415923) Subject: RE: BS: Chevrolet torque specs. From: kendall Spaw, I believe your "Muffler" is not attached properly. |
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17 Aug 08 - 07:52 AM (#2415948) Subject: RE: BS: Chevrolet torque specs. From: Bobert Look closer, Capt'n... Spawzer runnin' without a muffler... |
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17 Aug 08 - 08:34 AM (#2415962) Subject: RE: BS: Chevrolet torque specs. From: Riginslinger Better than "Running on Empty," I suppose! |
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17 Aug 08 - 10:07 AM (#2416007) Subject: RE: BS: Chevrolet torque specs. From: Bobert Not to worry, Rigs... For good or fir bad, Spawzer always has somethin' his tank... Might of fact, I wouldn't be a bit surprised if he didn't share a little (or alot) with the good folks here at any time... B~ |
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17 Aug 08 - 11:34 AM (#2416071) Subject: RE: BS: Chevrolet torque specs. From: kendall This thread has just about run its course.Time to let it die? |
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17 Aug 08 - 11:49 AM (#2416080) Subject: RE: BS: Chevrolet torque specs. From: Bobert Me thinks that Spawzer is workin' on a fittin' end to it, Kendall... lol... |