What's the appeal of an aluminum engine block?

[RodKnock]

1. Big blocks are heavy and lightening the front end to make the car more nimble was certainly the main factor in choosing an aluminum block.

2. There was a certain symmetry with having an aluminum block in an aluminum body with a billet aluminum suspension and wheels and an alloy differential.

3. Back in 2008, there wasn't a shortage of aluminum blocks and, from memory, Genesis was one of the only producers of new iron FE blocks and they were having casting/porosity issues with their blocks at that time.

4. The price difference was relatively negligible. New FE blocks were roughly $3,500-$4,000. The Pond alloy block was $4,000-$4,500. And the Shelby alloy block $5,000-$5,500. I can't remember the figures exactly, but that's ball park.

5. The rumor mill or "I had heard" that the mating of alloy heads to the cast iron block caused metallurgical issues, which in turn caused sealing problems and oil leaks. And most sports cars today have all alloy engines, so that was somewhat comforting at the time.

6. Bragging rights. Yes, we all have egos.

Would my decision be different today? Maybe, even probably, depending on various circumstances like shortages, block casting problems, etc. Today, I'd be more likely to choose a cast iron block than 8 years ago.

[Dimis]

For me, these cars are ALL about the engine...

I could have paid less for a car that was faster, and more reliable, and more durable, and more comfortable... but meh, where's the joy in that?


Brent, to answer your question as per my decision making process, in order of priority for me:

1. The engine HAD to match the car.
If I had bought an SPF or ERA I'd have chosen different engines, but with an Aluminium car, Alu Body, Alu billet bits everywhere, etc, there was really only one obvious option, an all Alu engine.


2. Weight - Is the enemy of anything that needs to move and accelerate. It's what makes Lotus, Lotus, and Porsche, Porsche. If its good enough for car manufactures to delete carpet, radios, door handles, and change glass to polycarbonate, or steel to Aluminium, and then to carbon fibre, so be it. Designers and Engineers bust a nut trying to shave ounces, so dropping 100lbs by using an Alu block, is a no brainier, particularly 100lbs on a sub 2000lbs car. The fact most all probably aren't able to tell the difference, is NOT relevant, if the placebo is.
My BMC road race bike weighs 6kgs (just over 13lbs). I can feel and tell the difference when I ride it compared to my 6.8kg (15lbs) road bike, my Strava times aren't that much different, but the pleasure off riding the BMC is just blissful. It's not even a full 2lbs difference.


3. Advancement / Progression - The automotive manufacturing world has followed this advancement and progression with intakes and heads. Iron out, Alloy in, and before you know it to Carbon or Carbon fibre wherever possible. Why stop at just heads and intake?


4. Durability - If you recall we discussed this at the time, and the truth is for a car that sees so few miles and heat cycles per year, opting for the more exotic, fully optioned specs, was a no brainier. Remember, I twisted your arm to upgrade to the forged SCAT crank, and the titanium bits. My car will never see 100k miles, the world would have run out of oil 3 times over by then. Further, AFAIK Alu blocks have been beat on and tested in many high end motorsports. So theoretically, any durability quotient should have well and truly be met. The fact they may not produce the same max HP wasn't irrelevant. The car is grossly overpowered as it is... Thanks for that by the way!


5. It was new and pretty... meaning we didn't have to go hunting in graveyards for a solid but seasoned block. Nor be held to ransom (time and money) for a virgin 427 Side Oiler that had been sitting all these years just waiting for me, if it even exists.


I hope that helps with your survey

[patrickt]

Originally Posted by Dimis

I hope that helps with your survey

... and if the engine had exploded in to a supernova on its first dyno run?

[Large Arbor]

I bought the car which had an aluminum block.

Having noted that, I have noticed two significant advantages. 1) They cool off really quickly which is great in hot weather. 2) the weight savings is significant.
3) if you have a good engine builder the risks can be mitigated.

Phil

[jhv48]

Originally Posted by Large Arbor

3) if you have a good engine builder the risks can be mitigated.
Phil

And away we go!

[patrickt]

Originally Posted by jhv48

And away we go!

Yes, I didn't want to say it at the time, but that remark implies that if you can't mitigate the risks, then you are not a good engine builder.

[Large Arbor]

Please don't confuse what I am saying. I think Brent is a great engine builder. I am saying it helps to have someone that has built multiple aluminum engines rather than having a first time builder do an aluminum one. My engine builder preferred Shelby blocks above others as he said there was less block work to do when he received it.

I said also "mitigate" which is risk reduction but not elimination. I don't think you can eliminate all of them. I also am not saying they are superior to a steel block.

I think there are pros and cons to each direction. I can tell you things do move around on the aluminum block worse than a steel block.

Phil

[Dimis]

Originally Posted by patrickt

Yes, I didn't want to say it at the time, but that remark implies that if you can't mitigate the risks, then you are not a good engine builder.

A good builder (or professional in any field) mitigates against the known issues. Experience counts here. It doesn't mean they mitigate EVERY single possible issue. You just can't know the unknown.


EDIT By the time I finish my thoughts, get distracted by the NBA game, then interrupted by work sheesh... and type them up, Phil has already quite eloquently summed it up for me... Yeah, what he said. ^

[Dimis]

Originally Posted by patrickt

... and if the engine had exploded in to a supernova on its first dyno run?

Well, it really could have... but it could have if iron too.

In the end I trusted the guy who put it together... It turned out ok.

At the same time if it went bang, I guess Brett (and or I) would have had to find the time, money and energy to chase up the supplier... Not easy in a one man band. So I understand his headache.

Despite there being plenty of fat factored into the price, eg: when you pay the manufacturer $5K for recycled coke-cans in the shape of a block, or $2K for heads, it doesn't mean the manufacturer would be prepared to stand by their faulty product or workmanship. Its worse again with NOS parts. NO chance of a warranty there.

Originally Posted by blykins

I have made the decision to not accept any more all-aluminum FE build orders.

Originally Posted by blykins

As some of you know, aftermarket FE blocks have been non-existent this year. I've been waiting on blocks since February and still have not received any. Foundries have changed, designs have changed, and until things settle down

By the way not accepting any more orders is just prudent and practical in light of the fact blocks are just not available. I didn't see him say he wont ever build them again in the future.