What's the appeal of an aluminum engine block?

[blykins]

Fickle means that they have a greater chance of developing leaks. Fickle means that there are warm-up and operating guidelines that are a little more strict because of bearing clearance.

A Shelby block is stronger than an original FE block. Not stronger than an aftermarket cast iron block. You do have reduced ring seal from the aluminum block just because things move around so much.

We're not driving Porsches.

Thanks for the 11 pages of backing-and-forthing. I feel better.

[patrickt]

Originally Posted by blykins

Thanks for the 11 pages of backing-and-forthing. I feel better.

Now, if you would just do exactly as I tell you, you will be healthier, wealthier and wiser than RodKnock will ever be.

[RodKnock]

Originally Posted by patrickt

Now, if you would just do exactly as I tell you, you will be healthier, wealthier and wiser than RodKnock will ever be.

I don't think so.

Why does everyone post in 3's? That's another complaint of mine. There was "power, reliability and quality" and now Patrick is posting "healthier, wealthier and wiser." What's up with that? Do all of you have OCD or something?

[patrickt]

Originally Posted by RodKnock

Why does everyone post in 3's?

Because it stems from the three ethical principles of Zoroastrianism. Simple, really.

[Dimis]

I go to sleep and wake up to - BOOM! 4 more pages of fun.

I'd still choose an all AL engine, not because I'm really going to notice the difference driving, I doubt I'd notice 100HP less, but merely because it was an advancement on iron. I use the term advancement here because its lighter and does the same job. If a billet block was available, I'd have gone for that too.

Given the choice, I also wouldn't swap it for an iron build.

If I was planing a truck, sure, I'd no issue with an Iron block. But in a car that's claim to fame is BIG Engine in Light Car, then maximising the philosophy is what I'd try to do. AL block is therefor fit for purpose. True, there are lighter big engines, but for those keen on keeping an FE under the hood, then those are ones choices.

Originally Posted by RodKnock

You're making the Pond and Shelby blocks sound like Pepsi/Coke cans. People use aluminum pistons, rods, cylinder heads, intakes, rocker arms, etc. Until I see at least a good statistical sample of equally built FE engines, built with both cast iron and aluminum blocks, I call BS.
"

Hey RK just a little note for you, they are recycled Pepsi & Coke cans.

The theory does suggest that for the exact same build, Iron block will make more HP. If nothing else, simply because they have a higher density there is less distortion during detonation.
In simple terms, when the fuel goes boom, on a microscopic level there is less flex in the cylinder wall. This flex is potentially amplified the bigger the boom. Hence the claim for larger gains in HP with iron at the higher numbers, and why Barry opts for iron when building for Engine Masters Challenge (EMC). It's fit for purpose, its on an engine stand, so who cares how much it weighs?

This doesn't mean that AL Blocks can't be made to achieve the same HP numbers as iron block, its just more effort in prep and technology, and in the end, in the range we are discussing for a cobra, a few HP is mostly irrelevant. If one wanted more HP one would look at a 385 series BBF.

YES. They use AL for pistons, rods, cranks and other moving parts, because the a reduction in weight is amplified when trying to overcome inertia. Distance of weight from the Centre of Mass (CoM) is relevant in moving parts.
Weight alone is not everything, the distribution of the weight plays a factor.

In simple terms some of the energy that otherwise goes into microscopically flexing an AL Piston head, during the explosion in the cylinder, is outweighed by the gains in overcoming the lighter weight of these parts, particularly as these parts have most of their way a fair distance away from their CoM.

Reducing the weight of moving parts by "x" has a much greater impact that simply removing "x" from a non-moving part. The same logic applies and explains why one tries to minimise unsprung weight in suspensions, or the desire for Magnesium wheels, and so forth. Fit for purpose.

Enjoy...

Originally Posted by blykins

I would think that a $$$$ "aftermarket" block would be an ego-booster. Not solely focused on aluminum.

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......

PS: Brent Its at Starbucks speed where I notice the lighter engine most. It's easier to turn those front wheels while parking baby!

Originally Posted by patrickt

Because it stems from the three ethical principles of Zoroastrianism. Simple, really.

Patrick is in one of those moods again... Making me laugh, and educating me at the same time. Thanks Professor, I had to google that.

[RodKnock]

Originally Posted by Dimis

The theory...

Ya lost me after "theory."

Yes, it's all hot air, er, I mean "theory", to me.

Everyone here got a chemistry set when they were kids. I was out getting exercise at the local school playground.

[Dimis]

Originally Posted by RodKnock

Ya lost me after "theory."

Yes, it's all hot air, er, I mean "theory", to me.

My gift to you for Thanks Giving I threw "theory" in there for you deliberately.
I thought it nice to offer you a "get of jail card", because once you read those facts, there's no further retort.
You're welcome and enjoy your holidays

[cycleguy55]

Originally Posted by Dimis

PS: Brent Its at Starbucks speed where I notice the lighter engine most. It's easier to turn those front wheels while parking baby!

Or you could just install power steering - though that adds weight and parasitic power losses...

[RodKnock]

Originally Posted by blykins

We're not driving Porsches.

And you're likely not driving Toyota's, Subaru's, Miatas, RX-7's, Corvette's, BMW's, etc. either, but the "hot rod" consumer desires lightweight parts.

Since the dawn of time, tennis rackets, baseball bats, wiffle balls, engine blocks, have become lighter. Why? To go faster, hit the ball farther, etc.

One word. Plastics.