Is the weight savings of an aluminum block beneficial for pro-touring? I am looking to build a new BBBC this summer and I have a friend who will give me a great deal on an aluminum block. It is still more expensive that an regular block, but it is a great deal. I have never had my car to a track, but I do drive it alot on the street. I think I put about 9k miles on it last year. any opinions would be great.

Aluminum blocks are certainly very nice for weight savings but do give up a few HP to iron blocks from thermal efficiency & stiffness reasons. Pretty minor HP loss though, and especially with a big block I'd gladly give up a few HP to shed that much weight over the front axle.

However, if starting fresh on an engine today I personally wouldn't go with anything other than a modern LS series of engine. Why not take advantage of the factory's latest and greatest efforts? Very efficient engines with fantastic cylinder heads. If you still want big block cubes you could build a 454 LSX or something similar. Just thought I'd throw out another option.

if your not racing it, its not going to be a big difference, other than cost. look into the lsx blocks. although iron, the tall deck that is coming out will allow for 500+ cubes out of a small block. bad ass in my opinion.

Its a block for a 540. I do like the LS series engines, but there is some draw about the BBCs thst I just can't get away from.

GM advertises the standard Corvette to run 12.40s at 117 mph, also 26 mpg US. 117 mph would be well into the elevens with some slicks. That would be some engine in a '66 Chevy II of similar weight. They have come a long way in the power department since 1960.

They must get these times in mineshaft air with good tuning. My turd hasnt had a problem putting those away. Impressive car for the money though.

To the OP. If thats what you want, go for it. I reeeealy wanted one in mine and at the time had the $$ but my machinist had nothign good to say about running an aftermarket aluminum block on the street. Betting tech has come around more since then though.

Ifit were me Id go Iron block/aluminum heads.

Wait, I lied. POLISHED in/out aluminum block and heads. and everythign else....Like one big piece of chrome.... Im sick like that. :hurray::D

If you've got the funds. Absolutely!

Dollar for dollar, I'd take a big CID BBC over a LSX anyday. More HP for the money.

markm, very true on cost. im looking at 11k already to build an lsx. but a 450+ ci small block will get my head to turn faster than a big block anyday. 600+ hp is VERY easy with a lsx, and any more than that is just a waste on the street unless you have the ability to hook it up. plus the weight of a bb aluminum and small block iron cant be that far off.

bb vs lsx is really not apples to apples though.

also, ive read nothing but bad things about the aftermarket aluminum blocks. again that is reading, and i dont have any experience with them. enough to keep me away though.

LS1's make 350hp stock, LS6 405hp, LS2 400, LS3 430, LS7 505...

That said. You can find a cheap LS1 <$1500, and having it up around 500+hp for less than $5k...

JMO

It's a brodix block, not sure if anyone has experience with there blocks or not.

It's a brodix block, not sure if anyone has experience with there blocks or not.

Their SBC aluminum blocks are very nice. I don't have any experience with their BBC blocks, but I would have similar expectations.

Brodex stuff is fine, I see lot of them in Drag Race sportsman classes. I expect someone will tell me I am wrong but I would not build a street car, push rod style engine with an aluminum block and non hydralic lifters. The engine grows so much the valve clearence will be changing .012" to .015" as the engine warms up, a hydralic roller would make a nice combination, a solid would be a nightmare

Brodex stuff is fine, I see lot of them in Drag Race sportsman classes. I expect someone will tell me I am wrong but I would not build a street car, push rod style engine with an aluminum block and non hydralic lifters. The engine grows so much the valve clearence will be changing .012" to .015" as the engine warms up, a hydralic roller would make a nice combination, a solid would be a nightmare

Dave, I agree with you 100% when it comes to using aluminum SBC / BBC aluminum blocks on the street. You're talking a 50+ year old cast iron design that has been translated to aluminum. All the wall thicknesses, deck thickness, block geometry, etc, were intended and designed around the material properties of cast iron. You simply can't pour aluminum into the same mold and expect it to work right and perform the same-- changes must be made. I'm not saying the aluminum blocks don't work, but there are many issues that must be considered. As you said valve clearance is one of them, bearing clearances are another. Because of the much greater thermal expansion of aluminum, to have a proper bearing clearance on an engine at operating temperature means that bearing clearances when cold are tighter than nominal... so beating on a cold aluminum engine can result in bearing scuffing or failure.

This is why my preference would be to use an LSX based block if you want an aluminum engine-- they were engineered and intended to be made from aluminum from the very start. All the thermal expansion, clearance issues, and material properties were taken into account and designed around from the day of conception by a very well financed GM engineering team and the designs were tested for hundreds of thousands of hours with test mules. Take advantage of all the money that GM spent in R&D and testing. :)

What I would really like to see come down in price is CGI (compated graphite iron) blocks in the traditional SBC / BBC configurations.

There is no substitue for better front to rear weight balance then taking weight off the nose, especially engine weight. Weather it be a drag car, Pro Touring car, Road Coarse car, reducing front weight is a huge advantage. So we run Aluminum blocks in all our personal Pro Touring Cars. personally I am a fan of big cube, big horse, lightweight engines. If we can avoid blowers, turbos, intercoolers (all real bad weight), it makes for a much better balanced car.

I will never forget mocking up the Aluminum 540 CI in Michael's Project Prodigy with just the bare block, and reaching over the fenders and lifting the block out of the car impressing some onlookers in the shop with my strength. Only weighed 140LBS naked! The 535 CI Pontiac block in Lisa's car is only 125 LBS.

We did a 55 Chevy for a customer a while back with a Bill Mitchell 427 CI small Block. Total weight of the 427 SB in the 55 Chevy we did is only 375 LBS for the entire motor!

We also did a couple of all Aluminum 572s recently for (2) briothers inlaws. One is a 57 Chevy, the other in a 67 Chevelle. The Chevelle is of most interest to you guys I am sure. With a Full hotchkis TVS Kit, 17" tires, the car drives around and fell like a small block balance wise, but has 754 HP / 704 TQ to let you know this is NO SMALL BLOCK!

Simply cannot beat it.

Here are some pics of some of our aluminum motor projects. All these projects run either solid or hydraulic rollers and are driven. A couple get a lot of miles. We have had no issues related to the aluminum material instead of aluminum

http://i169.photobucket.com/albums/u212/ProdigyCustoms/YearOne0612.jpg
My son Michael's Project Prodigy

http://i169.photobucket.com/albums/u212/ProdigyCustoms/SEMA10315.jpg
Project Prodigy's 540 CI Aluminum World Products block, 684HP / 622TQ

http://i169.photobucket.com/albums/u212/ProdigyCustoms/ProdigyFront.jpg
Cool shot of Project Prodigy going together

http://i169.photobucket.com/albums/u212/ProdigyCustoms/DSC_1138.jpg
My wife Lisa'a Project EmptyNest

http://i169.photobucket.com/albums/u212/ProdigyCustoms/DSC_1025.jpg
Project EmpyNest 535 CI Aluminum All Pontiac block and Tiger heads, 812HP / 803TQ

http://i169.photobucket.com/albums/u212/ProdigyCustoms/DSC_0125.jpg
Our customer Robert's 57 Chevy

http://i169.photobucket.com/albums/u212/ProdigyCustoms/DSC_0147.jpg
All Aluminum 572 CI Bill Mitchell 572CI / 758HP / 712TQ

http://i169.photobucket.com/albums/u212/ProdigyCustoms/DSC_0059.jpg
Our customer Bruce 67 Chevelle SS

http://i169.photobucket.com/albums/u212/ProdigyCustoms/DSC_0002.jpg
All Aluminum 572 CI Bill Mitchell 572CI / 754HP / 704TQ

Thanks for the pics. From me he is only asking $2500 for the block. I may have to just bite the bullet and buy it. I was thinking a hydralic roller just to keep it streetable. The only time my car will see the track is when my chevelle club goes, but that is just for fun. no pressure to win.

Frank those cars look great.