Aluminium SBC

[customcam]

I was on Engine Masters website and seen the article Mark stielow did on an
Aluminium sbc. GM Block, 400 ci, Chapman heads,FInj, 600 hp dynoed
What do u guys think about the aluminium motor rather than cast iron blocks?
Wheel to Wheel built the motor! benefits or negatives?? thanks

[Steve Chryssos]

I have seen reliablity issues with all aluminum GEN 1 engines both small and big block in street applications. More so with big blocks. Specifically, I'm referring to ring seal issues (due to block rigidity) and head gasket issues (due to expansion). One all aluminum big block we built had an 11.625" deck height aluminum block. I swear you could almost see the thing flopping around like a boneless chicken!! An extreme example for sure.
That's not to say that these problems appear consistently. But way more frequent that with all iron or iron/alum engines. So you need to make sure that your engine builder knows what he is doing. Head studs, head gaskets, o-ringing. And the end user needs to appreciate the higher maintenance of an aluminum block (i.e. checking the torque of the head bolts on a regular basis)
Whereas the LSx engines have been designed from the start with aluminum castings in mind, GEN 1 stuff may be iron parts cloned in aluminum. Aluminum castings--particularly water jacketed castings--need additional ribbing.

Given the price of aluminum blocks, I personally would not consider an aluminum small block unless it is LSx based. I assure you that Stielow's shallow valve angle, raised runner, all aluminum, forged everything, fuel injected small block would cost big money to duplicate--Close to 10K in castings alone and it still does not have cross bolted mains. An LSx engine has all of those attributes and can be found growing on trees for under 10K complete. It blows my mind, too. But I get it now.

I'm not selling anything here. Just stating that if I build another Gen 1 it will be iron block'd. If I want all aluminum, it will be LSx based.

[Blown353]

What Steve said.

It's hard to successfully take a design that was originally intended to be cast in iron and duplicate it in aluminum without major changes; there are substantial material property differences that must be taken into account. Some of these issues can likely not be designed around satisfactorily when you're limited by the dimensions and packaging and internal components of the original iron design. With such a substantial material change, it's best to start with a clean slate and design around the new material.

All the aluminum Gen-1 blocks (SBC and BBC) I've dealt with "move around' quite a bit. This comes with the territory. Valve adjustments, head bolt torques, etc, they all seem to move around and have to be checked far more frequently than an iron block.

Now if the block was originally designed in aluminum, then you're OK; the LSX series would be the logical choice. Since it was designed out of aluminum originally you don't have to worry about possible shortcomings of a "modernized" old design; since the designers are not limited by the constraints of being backwards compatible with the old stuff they can take full advantage of aluminum and also work with and around its inherent drawbacks over iron (greater CTE, lower yield strength, finite fatigue life, etc.)

Troy

[USAZR1]

Man,I've always wanted to build a replica ZL-1 for my El Camino,using a Donovan alum BBC block. Now,you guys have done gone & peed in my Post Toasties.

[jonny51]

I have an Aluminum 540 and a aluminum small block no regrets here

[customcam]

ive read that there is Cast aluminium Blocks from GM,Dart,World, street blocks! Then theres Race blocks?
Then iv read full aluminium blocks? WTF!
"coz of my inexperience"!
Gm Block was 90 pounds instead of cast iron block that was 220 pounds? big difference in weight? Thay say you have to get them really warmed up before driving! What about prices difference in parts etc? SBC preferred

[Steve Chryssos]

Having worked for World Products, I can tell you that race block does not necessarily refer to the part's ability to support greater output. Rather, "race block" generally refers to a semi-finished state that permits engine builders to custom blueprint to a particular spec (i.e. semi finished lifter bores) That's not to say that race blocks are without their perks. A race block may feature billet main caps while a standard high performance block will feature nodular iron caps.

I believe World has built an aluminum SBC block with the help of an eager foundry that results in a lower than normal price. I will have to look into it further. But cheapER may mean $2500-$3000

[MarkM66]

I plan on running an alloy sbc, someday, .

I've looked into is some, and for the price, the Brodix block looks to be the best.

If you want what looks to be the ultimate al. sbc, check these out,

http://www.cnblocks.com/splaysbc.htm

LS-what?

[CraigMorrison]

FWIW, we are going to use one of Mitchell's 427 aluminum SBC on our 60 Vette project. I'll keep you posted of the good/bad/ugly.

[jonny51]

Mark,I have the brodix aluminum small block I will let you know how it turns out