alu blk weight saving
Thread Starter
Team Owner
Joined: Nov 2004
Posts: 20,708
Likes: 25
From: Sorrento Italy
alu blk weight saving
my engine builder is claiming, and i dont have any reason not to believe him, that weight saving for an alu blk ,instead of steel, in a 383ci (good for about 450/475 hp) is of 129 lbs, really not bad! the wild side of the iussue is its cost: 3.900 usd extra on top of the engine cost built with a standard 4 bolt main gm blk...
these figures are coming out from the quotation requested to 'american speed engines' of Ill. (quite a reputable builder) for a SM for my 2.300lbs griff 500. of course 129lbs referred to a 2.300 lbs car are quite more substancial then same weight saving on an over 3.000 lbs vette...
comments
?
these figures are coming out from the quotation requested to 'american speed engines' of Ill. (quite a reputable builder) for a SM for my 2.300lbs griff 500. of course 129lbs referred to a 2.300 lbs car are quite more substancial then same weight saving on an over 3.000 lbs vette...
comments
?
Tech Contributor
Joined: Jun 2004
Posts: 20,847
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
Originally Posted by Shark Racer
Every pound counts, and 129 is quite a lot to shave in one blow... especially when you realize there's no functional compromise,other than cash. 
I've been working like a dog over the years trying to pull weight out of my '69, while still trying to maintain a street driven look. (It annoys the well heeled types at the track when a 38 year old car is making life difficult for them.) I think a lot of forum members can relate to the challenges of weight reduction without cutting the crap out of the basic car. I'm slowly parting with some infrequently used toys to free up some cash for an aluminum block. The weight difference for a bbc is around 160 pounds, or about 5% of the total vehicle weight. Lap times aren't always directly related to vehicle weight, but a five percent weight reduction ought to take a couple seconds off the lap times at several tracks.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
If low-weight is paramount ... and you're considering a $3900 Al gen 1 sbc block ... I think that'd be false economy ... and you'd be better served by building upon a late model LSX platform. In general, most LSX prod motors have Al block & heads ... most stock LSX heads have about 15* valve angles w/ superior flow ... most have 6-bolt mains ... and have long 6.1" rods ... and taller deck about 9.25" leaves lotsa room for more stroke/taller pistons/longer rods. Virtually any kind of upgrade you might desire for Gen 1 sbc is also available for LSX.
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Thread Starter
Team Owner
Joined: Nov 2004
Posts: 20,708
Likes: 25
From: Sorrento Italy
the alu block would be for a chevy engine to transplant into my mistress' round tube frame...she's so light (2.300lbs) and now has a 5 ltr V8 all alu, so if i go with a SB standard will find abot 200 lbs more right in the front, would un-balance the whole ride and will be difficult to compensate in other ways...so it seems to take (the alu blk engine) or forget about the transplant altogether...
Race Director
Joined: Dec 1999
Posts: 16,945
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Originally Posted by jackson
If low-weight is paramount ... and you're considering a $3900 Al gen 1 sbc block ... I think that'd be false economy ... and you'd be better served by building upon a late model LSX platform. In general, most LSX prod motors have Al block & heads ... most stock LSX heads have about 15* valve angles w/ superior flow ... most have 6-bolt mains ... and have long 6.1" rods ... and taller deck about 9.25" leaves lotsa room for more stroke/taller pistons/longer rods. Virtually any kind of upgrade you might desire for Gen 1 sbc is also available for LSX.
Team Owner
Joined: Apr 1999
Posts: 21,953
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
GUI - I broke my crank in my 350 journal size 427 motown small block. It came very close to destroying the $2300 block. I'm now going to have to run two main journals with a bearing spacer on the block side. I had to buy two new main caps.
the aluminum version of my 427 is only $4000. the repairability of aluminum is worth the $1700 difference in price. They could have just welded up the main saddles and remachined the crank shaft main bores.
I have an repaired aluminum head from AFR. It had a broke off intake valve that completely destroyed the chamber and even tore out the valve seat. When i got the head back it was so perfect that I could not tell it from the good head. I just put in a new piston and fired my 427 back up.
If i had it to do over again I would have went with the taller deck raised cam aluminum block and installed a 4.125 stroker crank and instead of having only a 427 ci I would have had a 441 ci without an over bore or a 448 ci with a .030 over bore
the aluminum version of my 427 is only $4000. the repairability of aluminum is worth the $1700 difference in price. They could have just welded up the main saddles and remachined the crank shaft main bores.
I have an repaired aluminum head from AFR. It had a broke off intake valve that completely destroyed the chamber and even tore out the valve seat. When i got the head back it was so perfect that I could not tell it from the good head. I just put in a new piston and fired my 427 back up.
If i had it to do over again I would have went with the taller deck raised cam aluminum block and installed a 4.125 stroker crank and instead of having only a 427 ci I would have had a 441 ci without an over bore or a 448 ci with a .030 over bore
