BS: Motor/gearhead thread

Subject: BS: Motor/gearhead thread...
From: Bobert
Date: 09 Jul 12 - 08:17 PM

Okay, I'm a motor/gearhead'er from way back...

So I was lookin' as some pics I took when I went to a major car show at Charlotte Motor Speedway last summer and...

...there was a 60's Chevy truck with a 454 and not one ***but two*** GM 671 blowers on top of it?!?!?!?!?...

I swear!!! One mounted on top of the other with 2 fours on top of that...

Sheet fire!!!

B~

Subject: RE: BS: Motor/gearhead thread...
From: Richard Bridge
Date: 09 Jul 12 - 08:51 PM

The legendary BRM v16 used two stage supercharging - but ran on pure alcohol to deliver 600bhp at 12,000 rpm out of 1500cc.

I'd have expected that setup that you describe, Bobster, to deliver a MASSIVE detonation problem - if it ran on stock petrol.

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 09 Jul 12 - 08:58 PM

Gotta turn up the octane, Richard, or set your timing back a degree or two to catch it at the right point...

B~

Subject: RE: BS: Motor/gearhead thread...
From: Rapparee
Date: 09 Jul 12 - 11:00 PM

Wimp! We ran 'em on hydrazine and alcohol!

Subject: RE: BS: Motor/gearhead thread...
From: Richard Bridge
Date: 10 Jul 12 - 12:50 AM

I can't see hydrazine being useful for that purpose, since it combusts hypergolically and is so exothermic it would very likely melt the engine. Or am I missing something?

Subject: RE: BS: Motor/gearhead thread...
From: JohnInKansas
Date: 10 Jul 12 - 01:46 AM

Spectacular performance?

Massively overblown engines run better as diesels, and vague recollections are that GM foisted off a "slightly modified" 454 as a diesel in a couple of passenger cars around that time. Are you sure the 454 in the truck wasn't a diesel? (With enough positive manifold pressure you could get diesel ignition without even changing the mechanical compression ratio, and the fuel can't burn any faster than it's injected - so who cares if it explodes instead of burning?

John

Subject: RE: BS: Motor/gearhead thread...
From: Richard Bridge
Date: 10 Jul 12 - 03:53 AM

I remember the Ford Navistar Diesel and think that the current 454 GM diesel is the Duramax, but I can't place the "back then" reference.

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 10 Jul 12 - 09:27 AM

I gotta a picture of it, John, and I'll see if it's got any spark plug wires... I'm kinda sure I would have noticed if it had no ignition system but I'll go back and look at the pics...

The GM 350 diesels, BTW, were junk for many years... Bad everything... Rosa Master injection pumps were good for about 25K miles and done... Heads leaked and cracked so GM put more bolts on 'um... Then the cranks gave out...Junk... I don't know why GM didn't just buy dependable IH engines??? I mean, they uses Isuzu diesels in some of the Chevettes...

B~

Subject: RE: BS: Motor/gearhead thread...
From: Rapparee
Date: 10 Jul 12 - 09:38 AM

Did I say it worked? The car just sat there like a molten lump.

(It did for the Germans towards the end of WW2 -- hydrazine and alcohol was called, I believe, "C-Stoff" and used to power rocket planes.)

Subject: RE: BS: Motor/gearhead thread...
From: Richard Bridge
Date: 10 Jul 12 - 10:00 AM

That is not a compression engine, Rap. And you are right, it was the ME262 I think.

Subject: RE: BS: Motor/gearhead thread...
From: Rapparee
Date: 10 Jul 12 - 10:03 AM

Actually, hydrazine was used by some idiots in California back in the '60s as a fuel for dragsters. Well, it worked...until the explosions started.

Subject: RE: BS: Motor/gearhead thread...
From: Richard Bridge
Date: 10 Jul 12 - 11:50 AM

How long was it until the explosions started?

Subject: RE: BS: Motor/gearhead thread...
From: catspaw49
Date: 10 Jul 12 - 12:35 PM

Never had any experience with dual supercharging although I did spend one summer with the Unlimited Hydro team of Miss Circus Circus. That was a bit different though as they used dual staged supercharging, a bit of a different proposition. I was just a part time hand on race weekends but it was one of the best times I ever had though.......


Spaw

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 10 Jul 12 - 07:10 PM

Found the pic, John...

Memory failed me... It looks like a 350 engine, not a 454... Twin blowers, however with one mounted on top of the other and plugs wires...

B~

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 10 Jul 12 - 07:12 PM

BTW... both blowers are spun with a single toothed belt...

B~

Subject: RE: BS: Motor/gearhead thread...
From: Rapparee
Date: 11 Jul 12 - 04:50 PM

Can you use them to blow stuff off your driveway?

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 11 Jul 12 - 07:06 PM

Ahhhhhh, Rap... This is a truck... I mean, if you got the guns to pick the sumabich up, hold it on its side and let them exhaust headers blow off the drive way then have at it... I'll stick with my 13 pound Craftsman, thank you...

B~

Subject: RE: BS: Motor/gearhead thread...
From: JohnInKansas
Date: 12 Jul 12 - 09:14 AM

The GM 350 diesels, BTW, were junk for many years ...

Back about then, the Director for Engine Research at the GM Research division claimed that the engines were good enough for the intended use, and that 100% of the engine failures that were inspected at the Research labs were caused by improper use of 10W40 engine oil, which was specifically NOT APPROVED for use in that engine.

He stated then, and the few operating manuals I checked agreed, that GM had NEVER listed 10W40 as approved for use in ANY GM Engine.

He made a very plausible argument for why it wasn't good - for any engine. (A decent explanation would be "longish.") And he was one of the first technical people I can recall who put the blame on "the big oil corporations."

At least one of his ideas seems to have taken hold, but the "public" still thinks that when the book says 10W30 then 10W40 is better because "it's an even bigger number."

John

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 12 Jul 12 - 09:40 AM

When that engine came out I was an assistant service manager at the largest Chevy dealer in Richmond... I know better... We had customers who bought these and had them maintained at our dealership who went thru the nightmare of these engines... The injector pumps gave out on most of them at 25,000-30,000 miles... So we replaced them under warranty... The heads were next to go at 45,000-50,000 miles...

Then in 1981 when GM went to computers we had massive problems with "Check Engine" lights on some of the cars... There were some that were downright possessed... They'd set a code and we'd replace whatever the brain said to replace and have it back in the following day with the "Check Engine" light on??? We eventually figured out that the cars were lying to us so we had to do brain transplants on them...

Drove me crazy... Decided that GM was not for me and left and opened up a VeeDub repair shop... No brainer (pun intended)...

B~

Subject: RE: BS: Motor/gearhead thread...
From: catspaw49
Date: 12 Jul 12 - 11:19 AM

Ya' know John, if you took 39 automotive engineers working in small groups, committees, and on their own, for 2 years, at the end of that time they will not have produced a plan for a 2 car funeral. The head of the group, the "director," would then justify why one sub-compact driven in reverse is the best option.

The GM diesels in both the 5.7 and the 6.2 were both utter crap. The list of problems on the 5.7 is a bit longer, but only a bit and their performance capabilities were pathetic equaled by the piss poor mileage. In the world of diesels, these two had no redeeming value.


Spaw

Subject: RE: BS: Motor/gearhead thread...
From: Richard Bridge
Date: 12 Jul 12 - 11:37 AM

I'd like to see that explanation. It does not immediately sound probable. And my first degree is in mechanical engineering.

Subject: RE: BS: Motor/gearhead thread...
From: Bobert
Date: 12 Jul 12 - 02:02 PM

It was so bad in the late 70's early 80s at GM that the factory tech people were afraid to come to the dealerships and spend a great deal of time telling us to read the bulletins... Well, the root word in bulletin is "bull" and that's all we got out those bozos... And got lousy warranty book time for our labor... Shoot, you could spend an entire day trying to fix the sumabiches and at the end of the day get paid for 2.1 shop hours...

Grrrrrrr....

B~