What's the appeal of an aluminum engine block?

[blykins]

352 and 390 blocks are still pretty plentiful. 427's and 428's are getting a little harder to find, but they're still out there.

Since the aftermarket stash has been dried up this year, I've done quite a few factory block builds.

[Dimis]

Originally Posted by blykins

If the Cup guys can go 200 mph at 9500 with a cast iron block, you guys can drive 5 miles to Starbucks without nosing over and missing your turn......

By that account, may as well take a Prius.

...and by the way, 5miles to Starbucks is about as far as I can go on a tank anyway, but it's the best 5miles I get!

[Barry_R]

Its been a long time since I posted here - "life" has kept me a bit busy...

I can back up a few statements. Nobody has any aluminum blocks. I have not seen one shipped for months. I get promises - and unfortunately have repeated them to customers - and then I get no parts. If there were an alternate I would go to another supplier. But out of the FE block suppliers - Side Oiler Garage (former Genesis), Pond, Shelby, Dove, BBM - none of them have a block to ship. I have already paid one of those guys for five blocks in advance and received nothing in return.

We have a vacuum impregnation facility here in the Detroit area - out by the airport. Very nice guy who is justifiably proud of his services. Every single aluminum block I do will get impregnated from now on (Bill - your's was done too) after I had an issue a few years ago. The cost is added into the build, but I do not call it out because customer get nervous about a process the might not understand. This place does a bunch of military and OEM transmission stuff.

The weight savings is nice and I can fully understand the desire. The blocks themselves seem to be consistently inconsistent in quality. I have always been able to build them into good engines but they are always a challenge and I kind of agree with the sentiment - they should cost 20% more for labor because of the extra effort required. Every single fastener needs to be retightened after they run - the aluminum growth seems to loosen them all up. They leak - probably for the same reason. I suspect that the OEMs use better alloy and a much more sophisticated process for fasteners, seals and gaskets to avoid these problems.

The 427 stuff is definitely cool - given the choice I would prefer to build an iron block every time. We pretty much never have any issues with 390 based 445 builds, and we do them at a rate of two or three per month.

[eschaider]

My suspicion is the power differences whichever way they cut are non starters because our cars are so light to start with, as others have already mentioned.

If you do not do your own engine builds once the engine is in the car, iron or aluminum is not likely to make a measurable difference. If you do, do your own builds I would rather wrestle with aluminum pieces than iron pieces.

When you go to sell your car the buyer and market will probably place a premium on the aluminum bullet rather than the iron equivalent. Premiums are real interesting critters, most people recognize them and why they are charged. Many fewer buyers are willing to pay for them.

In the end like most choices on these cars it becomes a personal decision, it is not a rational decision. What do you want for your toy?

As an aside doesn't BBM offer an aluminum block version of the FE?


Ed

[moore_rb]

Originally Posted by Phx Mike

Not sure why you would say it is technical ignorance. ....

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"

I wasn't talking about you... I already knew why you chose an aluminum engine for your car... It fits a theme with your car's overall styling- I get that.

But Brent's original points are very valid- aluminum makes perfect performance sense for cylinder heads... but not engine blocks; unless weight is the most important factor to you (which it clearly must be to many, many guys out there)

- Not knockin, just sayin...

And yes- Until your car has a time slip from a drag strip, or a road course (or has generated a fist full of cash from an illegal Saturday night out on some road in boonies, sorry to say- You're a bench-racer.

But that's ok- I'm a bench racer, too... My best days throwing a car around a track are probably behind me... I can tell whenever I get a little punchy in my Cobra that my eyesight and my reflexes aren't what they were 15 years ago....

And I never said bench-racing wasn't fun

[olddog]

Originally Posted by blykins

Power to weight ratio....

2400 lbs vs 600 hp - 4 lbs / hp

2300 lbs vs 600 hp - 3.83 lbs / hp.

You'd never know the difference.

I look at it differently:

2400 lbs / 600 hp = 4 lbs / hp

2300 lbs / 575 hp = 4 lbs / hp

The 100 lb saving is 25 hp I do not need to have for the exact same acceleration, plus better handling in the corners.

Now compare an all cast iron FE (original) to an all aluminum 5.0 based stroker with a 4.125 bore. That isn't apples to apples but the smaller engine does not have all the issues that an aluminum FE has.

[olddog]

I think the issues you have with aluminum FE engines is partly the size. The bigger the part the more thermal expansion you have to deal with. In the case of aluminum, bigger is not better. On a cold day you have almost zero clearance in your bearings.

Secondly you are dealing with a replaceable sleeve design. Go talk to the diesel builders and see what they have to say. I don't think they are begging for aluminum blocks. They do deal with sleeves moving, and they know some things.

I read many years ago how Ford was casting the sleeves into the 4.6 modular blocks. The outer surface of the sleeve is knurled or grooved and the molten aluminum is cast around them. There is no way for the sleeve to move it is trapped. It makes replacing them difficult. You have to bore it out until the wall is paper thin. Then bend it until it comes out. Certainly design plays a roll.

One of the properties of aluminum is that when a force is applied to it, it slowly creeps over time. That is why you torque lugs down on aluminum wire once. It would tighten more, if you re-torqued them yearly. Eventually you would pinch the wire off. There are hug differences in different grades of aluminum. I'm not certain that the people who are designing aluminum blocks are choosing the right grade for the design.

I have been told porosity in aluminum has to do with humidity. It cannot be cast with humidity above a certain amount. GM had problems with porosity in the Cadillac north star for years. If GM fought it, it isn't simple to do.

I think aluminum and replaceable sleeves on a large engine is challenging to do right.

You might want to talk with Barry, Craft, and some of the other builders. Together all of you may be able to impact what the block manufactures are doing. The solution to your problem is at the manufacturers. It is not uncommon for users of a product to partner with the supplier to resolve issues. When all the players have a seat at the table, better decisions are are usually made.

[fordracing65]

Originally Posted by moore_rb

I wasn't talking about you... I already knew why you chose an aluminum engine for your car... It fits a theme with your car's overall styling- I get that.

But Brent's original points are very valid- aluminum makes perfect performance sense for cylinder heads... but not engine blocks; unless weight is the most important factor to you (which it clearly must be to many, many guys out there)

- Not knockin, just sayin...

And yes- Until your car has a time slip from a drag strip, or a road course (or has generated a fist full of cash from an illegal Saturday night out on some road in boonies, sorry to say- You're a bench-racer.

But that's ok- I'm a bench racer, too... My best days throwing a car around a track are probably behind me... I can tell whenever I get a little punchy in my Cobra that my eyesight and my reflexes aren't what they were 15 years ago....

And I never said bench-racing wasn't fun

Not true. Brent does not like FE blocks because of the consistency in casting them. Every other aluminum block is fine. OEM blocks go over 100,000 miles easy with no problems. 90 percent of daily drivers use them. It's the quality of the FE blocks.

[fordracing65]

If there was a market for FE stuff the blocks would be fine because they would be sold in such high quantity they would be able the get someone to do it right. But with the cost to do that and such low FE interest nobody will. Or so it seems.

[Dominik]

In the 90s I used a (old!) Chevy 4.44" block in my car. PITA... Granted, it was old and showed weaknesses. I would never offer such engine for a customer, unless you want to get married to him.

As for the weight "in the front", most Cobras have a weight distribution of 50/50. When I replaced the alu motor with a a cast iron one, I had to drop the front and rear suspension equally.

The ally blcok cools better. Probably too good for street use, even on German Autobahn.

A 454 cui Small Block with aluminium heads would be a sensible compromise. Or, for FE look a 390 stroker.

[RodKnock]

Originally Posted by Barry_R

But out of the FE block suppliers - Side Oiler Garage (former Genesis), Pond, Shelby, Dove, BBM - none of them have a block to ship.

It begs the question. Why isn't there a single new FE block anywhere? Was there a run of purchases (demand outstripped supply) and sellers were caught off guard? Are there manufacturing problems at every foundry? Or are the foundries really not interested in making 50-100 blocks per year when they have other larger orders that are higher priority because of size and fixed contracts.

From Brent's remarks, the lack of blocks has been a year long problem. These really are just rhetorical questions, but if I were building a Cobra, Mustang, Fairlane, I'd be a little upset because 352's, 390's, 427's and 428's just wouldn't do it for me at the prices these engines sell for.

[fordracing65]

From what I hear the foundries being used. the quality got so bad they had to look elsewhere which takes time and effort. It amazes me in this big world we live in nobody can make an aluminum fe block that is satisfactory for the consumer and builder. Kinda like tires for these cars. One company makes a good set Avon and that's it. Even Shelby changed foundries and they only make aluminum blocks.

[fordracing65]

Craft racing bought everything Pond had in aluminum and are using them for their complete engine builds. They won't sell just the block right now. They had 3 of the new run and said they looked fine. They have 8 more coming soon they said. BBM says end of January for their new aluminum block. But few have seen or used one so people are skeptical.

[razerwire]

Don't know much of anything but FWIW had a surprise when Rex Racing Engines dynoed refresh of engine out of Bennett car. When I took engine out of car and took it to them it was 427 cast iron block with mr cast iron heads. They had built engine 20 years ago and it made 450 hp with 1- 4 barrel carb on sidewinder intake. I have 2 extra sets of TWM 8 stack fuel injection setups so they suggested lets put one on and get rid of one four barrel setup. Engine had cast crank out of 428 so it was 454 cubic inches? I had billet crank setting in there shop already and had planned to put it in already. Surprise came when on dyno, it put out 357 hp a 3500 rpm and 532 lbs tq. tq climbed to 633 lbs at 4800 rpm and hp 658 at 5900 rpm. Big surprise because all aluminum shelby block and heads in csx car built by Kroyer Engines, 468 cubic inch, was not much different. 660 hp with 560 lbs tq. REx Engines suggested new Edelbrock heads on cast iron block so that what was used. I have to agree with post's by builders here that iron block seams way to go. Also have to say that I have had no trouble with leaks or engine built by Kroyer. Have set of dove mr heads if any one has interest and also 1 set of mr cast iron heads if someone has interest. Will keep two side oiler 427 blocks for what idk.

[Phx Mike]

Originally Posted by RodKnock

It begs the question. Why isn't there a single new FE block anywhere? Was there a run of purchases (demand outstripped supply) and sellers were caught off guard? Are there manufacturing problems at every foundry? Or are the foundries really not interested in making 50-100 blocks per year when they have other larger orders that are higher priority because of size and fixed contracts.

From Brent's remarks, the lack of blocks has been a year long problem. These really are just rhetorical questions, but if I were building a Cobra, Mustang, Fairlane, I'd be a little upset because 352's, 390's, 427's and 428's just wouldn't do it for me at the prices these engines sell for.

Aluminum sand castings are difficult - period. The weight saving benefits due to the superior strength to weight ratio of aluminum vs iron makes it an essential element in a modern car (fuel economy). But the big guys (OEM's) are able to spend a lot of time and money optimizing the part designs and casting processes to improve the yield of the parts. They have to do this in order for the economics to work (you can't survive the cost impact otherwise). It is more than just the alloy used - aluminum is poured at much lower temps than iron or steel or titanium castings and it cools quickly. If the mold designs and temp and the pour process are not perfect, you get splashing, asymmetric cooling and all kinds of other issues that result in voids. Some times you don't detect these voids until you start machining the casting and get a break-out. I see this in the aerospace industry also. Sometimes you can get 100 good parts in a row and then something very subtle changes and you can't seem to get a good part. Very stringent process control in the foundry is needed to minimize this. It is hard to justify this when you are making a few hundred parts per year.

None of this is the fault of or can be controlled by the engine builder. The foundry processes and basic part design are the drivers.

[blykins]

When there are not *high* quantities involved, pretty much anything is game.

I can receive 5 sets of heads and they can all be a different shade of "aluminum". Some are a little darker than others (which I kinda like LOL). I suppose that's from the mold release agent. I've also got different aluminum blocks in that were a different shade as well.

Fun stuff.

[Blue66]

Originally Posted by RodKnock View Post
It begs the question. Why isn't there a single new FE block anywhere? Was there a run of purchases (demand outstripped supply) and sellers were caught off guard? Are there manufacturing problems at every foundry? Or are the foundries really not interested in making 50-100 blocks per year when they have other larger orders that are higher priority because of size and fixed contracts.

From Brent's remarks, the lack of blocks has been a year long problem. These really are just rhetorical questions, but if I were building a Cobra, Mustang, Fairlane, I'd be a little upset because 352's, 390's, 427's and 428's just wouldn't do it for me at the prices these engines sell for.

I agree ! I really don't see the foundry getting excited just to do a 100 blocks . We have a little V6 Turbo block that cast in aluminum now to. Guys were crying to get someone to invest $1000's to get the build goin.. Ran a small batch an guess what !!!! Not many people can threw when it came to shellin out the $$$. These were goin for $4500. Never mind the $6k for a FE.
Sooo my car is goin up in value with an alum block !!

[patrickt]

Originally Posted by Blue66

We have a little V6 Turbo block that cast in aluminum now to. Guys were crying to get someone to invest $1000's to get the build goin.. Ran a small batch an guess what !!!! Not many people can threw when it came to shellin out the $$$. These were goin for $4500.

We saw that around here, year after year after year, when it came to the magnesium wheel issue. You have lots of guys that say "Oh yeah, I'd be interested in magnesium wheels." But then when someone tries to actually accumulate a little seed money to place an order, those birds disappear in to the bush. That's just life in the big city, and there's no shortage of bullshi! around these parts.

[Jaydee]

I remember years ago working on V6 Volvo who used a Renault v6. The casting was very thin near the oil galleries. Then when the cooling system wasn't maintained properly, it would corrode into the oil gallery and fill the entire cooling system with high oil pressure. Destroying the radiator, heater core and a hell of a mess to clean up. Just removing heads was tricky, if you bumped the sleeve it would break the paper gasket at the bottom of the sleeve.
JD

[eschaider]

I think you guys are way overthinking this issue. The brass tacks simply come down to;

1. How big is the real market for these blocks,

2. How much does it cost the entrepreneur to create the block,

3. Could he make more money with his money doing something else,

4. Like patrick so accurately pointed out

Originally Posted by patrickt

... But then when someone tries to actually accumulate a little seed money to place an order, those birds disappear in to the bush. That's just life in the big city, and there's no shortage of bullshi! around these parts.

It is sort of like Lucy, Charlie Brown and the football. Charlie Brown has yet to kick the football. The FE block sales phenom is exactly the same. With small volume you will never be able to get the quality that large production runs provide. If you loose you shirt once or twice (financially speaking) on one of these boon-doggles You're damn sure not likely to piss away another quarter million bucks — which might be low when you consider engineering, tooling and fixturing costs.

We and our market appetite are our own biggest enemies, in particular the guys who say they will buy and then flake out or the guys who can not come to grips with the costs involved with bringing one of these components to the market for resale.

This is not a technology problem. It is a market size problem, a cost to manufacture problem, and a flake out problem where someone is hot to trot, set to get and flakes out when it comes time to pony up the bucks. Think about it — the enthusiast and market size are the real problem.


Ed