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Thinking about an aluminum block....


Mikelly

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I'm thinking about purchasing an aluminum 350 block for my next build.... Dart is selling them, as are a few others... Anyone got any good info on these? Additional precautions for building them up???

 

Mike

 

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"I will not be a spectator in the sport of life!"

mjk

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Guest iamjackal

If I had gobs of cash I would want that aluminum block but they are rediculously expensive,but for good reason I guess.If your just wanting it because of the weight issue then why dont you just use that cash for real horsepower goodies.Build up that bottom end and put on a good Nos system. More bang for your buck.But your choice.Later

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Well I'm currently running a brand new 383 stroker with aluminum heads, full roller valve train, and all the go fast goodies, and nitrous is not an option for me. I'm not as much into the 1/4 mile thing as some. I prefer road courses and top end stuff. This aluminum block project would be just for the heck of it.... Plus I'm sure I could sell the motor I currently have later on or put it in something else....

 

Just curious if anyone else has done research on aluminum blocks and what needs to be done... don't want any surprises!

Mike

 

------------------

 

"I will not be a spectator in the sport of life!"

mjk

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Guest Anonymous

John Scott looked into a 4.3L V6 aluminum block which is basically a SB V8 with 2 cylinders missing. He was told that there was some real problem with flexing in the block (most noticeable in the main journals). JS...you out there??? What is the full scoop on this? I'm sure the info is relevant to a SB aluminum block decision.

 

SpencZ

MonsterZ Cont.

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Guest RyalC

How about an LS1. You have an all aluminum engine that makes 345hp stock wink.gif Add a hefty cam, a stroker crank, a little re-programming and you are up to 450hp again.

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I suppose that like most upgrades, this one comes down to a matter of personal preference. About a year ago I was also thinking about an aluminum block - aluminum big block, that is. GM performance parts had reissued the much-vaunted ZL1 "aluminum cylinder case", and Merlin (World Products?) has a whole line of aluminum big and small blocks. The cheapest aluminum BB is around $4-5k; SB may be around $3K. Costs aside, one issue is how to mount the bearing caps. The GM LS1 is cross-bolted, which I was told works very well, although another chorus claims that LS1's are notorious for spinning crank bearings. The earlier generation blocks are 4-bolt, which may or may not be a weak point. The other problem is cylinder sleeves. The Zl1, for example, has cast iron sleeves, essentially poured into the aluminum, as opposed to pressed in. That evidently solves the leakage issues that caused head gasket failures, as in the original Chevy Vega ( 4 cyl.).

 

I tend to side with the folks that consider an aluminum block to be more trouble than it's worth. The economy of scale just isn't there yet. The blocks themselves are expensive, and machine shops don't feel comfortable handling them. At least, that's my impression. The only truly successful aluminum block is the severely modified Chrysler Hemi, run in pro drag racing. And those guys have essentially infinite parts and repair capacities.

 

If weight - or rather, weight placement - is a significant concern, consider relocating the firewall further back, giving yet more room for engine setback. That's been my approach.

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  • 2 weeks later...
Guest Anonymous

I think you'd be disappointed after actually weighing an aluminum block. They need to be so much beefier in order to maintain strength (they're usually sold as race pieces) that they often weigh as much as a production iron block.

 

In the case of small Fords, the beefy, 4-bolt main aluminum blocks weigh more than their production counterparts (albeit 40lb less than the race, 4-bolt iron blocks). If such a block were made with only the same strength as a production block, the weight savings might be significant.

 

I'm certainly not against evolution, revolution, or technology of any kind, but when it comes to engines, "high tech" is often laughable. Maybe design by committee is the reason...

 

Take the 32V 4.6L Ford. The block is not only strong, very strong, but also light (at roughly 100lb). But then they design in flaws, like a small bore (somewhat offset by 4V per cylinder, but leaving the 2V models dead in the water), and such huge cylinder heads that the whole engine takes more space than a 460 (and weighs more than an all-iron 302).

 

Good ol' "American Iron" really is that good. Lightweight, compact engines for enormous power and displacement capability. Keep in mind I grew up in Europe and cut my teeth as a mechanic in Italy, so it's not just blind bias I'm spouting...

 

All that said, between you and me, I've been lusting after an aluminum block myself... wink.gif

 

 

 

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Michael Sen-Roy

Houston Performance

281-893-6080

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I've also wanted one for a long time - since I first got the V8 Z bug over 20 years ago after seeing the HOTROD article on the red ScarabZ.

 

I then learned from Z buddies that the V8 conversion (the only known way then was the Scarab position of the drivetrain) made the car plow. So I came to the conclusion that an AL block would solve that. Too bad I couldn't think outside of the engine placement box and see that a set-back engine would solve the nose-heavy problem.

 

I still think a light AL V8 would be cool, but hey, an iron Ford SB V8 would be lighter too.

 

Oh well, I guess practicality will keep that old fashioned iron block SBC in my car!

Heck, I ought to upgrade those old iron 462 Heads to AL first! wink.gif

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