What's the appeal of an aluminum engine block?

[jetblue69]

I guess it just boils down to showing everyone how big your, ahem, "fritter" is...

Or isn't

[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

[Detroit Bill]

It is weight, cool factor. Most guys buying this stuff are buying themselves a gift.

Refusing aliminum is fine. You might lose a couple but not all sales are good sales.

[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.

[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.

[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. ^

[Mark IV]

Originally Posted by Detroit Bill

It is weight, cool factor. Most guys buying this stuff are buying themselves a gift.

Refusing aliminum is fine. You might lose a couple but not all sales are good sales.

What Bill said.............

[patrickt]

Originally Posted by Mark IV

What Bill said.............

Wait a minute, who puts an aluminum FE in an SPF anyway?

[Phx Mike]

Originally Posted by moore_rb

I'm with this guy...- Most dudes are going to tell you they want aluminum instead of iron for both the reasons you mentioned - Weight, and for the "cool factor"

But my personal opinion is that these 2 reasons mask the real rationale, which is technical ignorance, augmented by a fat checkbook...

"A fool, and his money, are soon parted"
- Benjamin Franklin.

It's the same reason that guys are coming to you asking for a 700hp solid roller, for a car that they put 500 miles a year on, driving around to car shows and parking lot meets.

Bench racing is fun, without being nearly as scary, or time consuming, as the real thing...

Not sure why you would say it is technical ignorance. The aluminum block weighs about 60 lbs less than the iron block. That's not insignificant if you care about weight. And if you choose an iron block and aluminum heads you have to consider the thermal expansion differences and what issues that may or may not create. Going with the iron heads adds more weight.

I made a very conscientious decision to choose aluminum for the engine block in my car due to the resale value and because it is in keeping with the "technology" and low weight focus of the Kirkham product design (billet suspension components etc). I don't think that makes me a "fool" or a "bench racer".

There is no question that aluminum sand castings have more porosity issues than cast iron components - this is a problem in the aerospace parts world also and the associated casting yield gets built into the cost of the parts. There are ways to help mitigate it such as hipping, mold and core design, mold heat and pouring technique but none are foolproof nor inexpensive and certainly not approaches that are well suited to low volume production.

It will be interesting to see 3D printed parts when the additive manufacturing machines get large enough to make them.

[blykins]

I know it probably wasn't meant to sound that way, but this is not an engine builder experience issue. I've built more all-aluminum FE's than I can remember right now.

When you get a fresh block out of the box and it doesn't pass a pressure test, there's really not any experience that needs to be involved there....unless it involves going with another block manufacturer. However, there have been issues with all of them at one time or another.

What it comes down to for me is that I'm really not willing to be a guinea pig for new foundries or new block manufacturers, especially when I've had issues in the past. I understand that cast iron blocks are probably cast using the same foundries, but as the others have pointed out, the aluminum blocks have more of a chance for porosity.

[Phx Mike]

I agree with you Brent. I would not want to take the chance either and you no doubt have more experience than most/any of us. I was just weighing in on why someone might prefer aluminum.

[blykins]

Yeah, I had to look up "mitigate".

[66gtk]

If you have customer who wants an aluminum block why not simply charge him time and materials to pass the risk onto him?

[scottj]

Independent rear suspensions don’t produce the anti-squat that solid axles can produce, so forward bite has to be achieved by other means. Personally, I want as much rear percentage as I can get and there’s really only two ways of achieving that. The way I chose is to use the lightest engine available that will make the HP I can use. Since 1999 I’ve run 430+ cid all-aluminum small blocks and get 57%-59% rear depending on fuel load. A Dart Iron Eagle tall deck block would be a few percent less rear and a BB would probably be close to 50%-50% in my car. Yes, the iron block versions of my engines would probably make a little more power, but I’m already at the limit of what I can hook up with 59% rear. Because I’m more about percentages than overall weight, the weight I save with the aluminum block allows me to run that boat anchor T-56 6 spd that I know you’re so fond of Brent. Oh, and the other way to get the rear percentage I want would be to hang a bunch of lead on the back of the car. But, since these things are challenging enough to drive already I would not want to deal with the effect that would have on the polar moment of inertia.

[fordracing65]

Originally Posted by Phx Mike

Not sure why you would say it is technical ignorance. The aluminum block weighs about 60 lbs less than the iron block. That's not insignificant if you care about weight. And if you choose an iron block and aluminum heads you have to consider the thermal expansion differences and what issues that may or may not create. Going with the iron heads adds more weight.

I made a very conscientious decision to choose aluminum for the engine block in my car due to the resale value and because it is in keeping with the "technology" and low weight focus of the Kirkham product design (billet suspension components etc). I don't think that makes me a "fool" or a "bench racer".

There is no question that aluminum sand castings have more porosity issues than cast iron components - this is a problem in the aerospace parts world also and the associated casting yield gets built into the cost of the parts. There are ways to help mitigate it such as hipping, mold and core design, mold heat and pouring technique but none are foolproof nor inexpensive and certainly not approaches that are well suited to low volume production.

It will be interesting to see 3D printed parts when the additive manufacturing machines get large enough to make them.

Pond website. Iron fe block 285lbs. Aluminum fe block 135lbs. That's a 150lbs difference. You're about 90lbs off.

[Phx Mike]

Originally Posted by fordracing65

Pond website. Iron fe block 285lbs. Aluminum fe block 135lbs. That's a 150lbs difference. You're about 90lbs off.

It says the weight of the original iron block was 195 lb which is what I was using as a reference.