aluminum block and power loss?

[Stan Weiss]

I don't about today. But 50 or so years ago. NHRA Pro Stock BBC Iron block was 15 HP up on same combination in Alum block.

Stan

[hoffman900]

I don't about today. But 50 or so years ago. NHRA Pro Stock BBC Iron block was 15 HP up on same combination in Alum block.

Stan

If F1 can get 50%+ thermal efficiency and make it last for 3000 racing miles, with more than double the cylinder pressure of any NA engine, it’s really a question of not the material, but how the block is designed. And yeah, I get they have the resources, but it’s something that block designers should aspire to.

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.

And a few hundred lbs off the nose of the car can now be ballast you put anywhere.

So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

[Warp Speed]

I would bet an iron block, of the same configuration, would make measurably more power, but then we get into the "what shows on the dyno but not the track thread".............lol
And that would follow suit all the way down to the oem level.
Would it be much? Not these days, but certainly measurable at F1 level testing.
I'm sure they model for a best case, no movement scenario, and from there try to minimize losses from there.....?

[hoffman900]

I would bet an iron block, of the same configuration, would make measurably more power, but then we get into the "what shows on the dyno but not the track thread".............lol
And that would follow suit all the way down to the oem level.
Would it be much? Not these days, but certainly measurable at F1 level testing.
I'm sure they model for a best case, no movement scenario, and from there try to minimize losses from there.....?

Probably, but even still, those blocks are stress members with the whole rear suspension bolted to the cylinder heads, along with dealing with those cylinder pressures.


The cam cover:

55B9C672-155B-4075-A313-51CAE63B62DD.jpeg

So somehow they’re making an aluminum alloy work from an engine standpoint and a loading standpoint. A 1800lb car pulling 4g’s is a lot of load to put into those valve covers.

[Tom68]

If F1 can get 50%+ thermal efficiency and make it last for 3000 racing miles, with more than double the cylinder pressure of any NA engine, it’s really a question of not the material, but how the block is designed. And yeah, I get they have the resources, but it’s something that block designers should aspire to.

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.

And a few hundred lbs off the nose of the car can now be ballast you put anywhere.

So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Of course those cylinder pressures are resisted by the deck thickness not at the water jacket level.

[hoffman900]

If F1 can get 50%+ thermal efficiency and make it last for 3000 racing miles, with more than double the cylinder pressure of any NA engine, it’s really a question of not the material, but how the block is designed. And yeah, I get they have the resources, but it’s something that block designers should aspire to.

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.

And a few hundred lbs off the nose of the car can now be ballast you put anywhere.

So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Of course those cylinder pressures are resisted by the deck thickness not at the water jacket level.

Depends how far down they go.

[Tom68]

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.
So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Of course those cylinder pressures are resisted by the deck thickness not at the water jacket level.

Depends how far down they go.

Far enough if they've been designed to do the job.

460 block here ranges from 1 to 1.25" deck thickness.

[hoffman900]

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.
So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Of course those cylinder pressures are resisted by the deck thickness not at the water jacket level.

Depends how far down they go.

Far enough if they've been designed to do the job.

460 block here ranges from 1 to 1.25" deck thickness.

A built out 460 is probably weighs as much as an entire Formula Car. A quick online search says a fully dressed one is 720lbs

Again, many are doing that thing where we forget engines live in cars and weight is a HUGE component and 15hp on the dyno can easily be made up by saving hundreds of pounds off the nose (either ditching it if rules allow or relocating it).

[Tom68]

A built out 460 is probably weighs as much as an entire Formula Car. A quick online search says a fully dressed one is 720lbs

Haha, maybe not now that FIs have batteries.

Built to do the job, 460 needs an inch for the long stroke, maybe the Fi needs a band a half inch high around the top of the bore that is possibly freestanding anyways.

[hoffman900]

A built out 460 is probably weighs as much as an entire Formula Car. A quick online search says a fully dressed one is 720lbs

Haha, maybe not now that FIs have batteries.

Built to do the job, 460 needs an inch for the long stroke, maybe the Fi needs a band a half inch high around the top of the bore that is possibly freestanding anyways.

If weight is not object, then what are container ships running?

A F1 car is bloated these days, but it’s still a sub 1800lb car with driver. Makes a 1000hp with the PU + hybrid unit.

[Stan Weiss]

I don't about today. But 50 or so years ago. NHRA Pro Stock BBC Iron block was 15 HP up on same combination in Alum block.

Stan

If F1 can get 50%+ thermal efficiency and make it last for 3000 racing miles, with more than double the cylinder pressure of any NA engine, it’s really a question of not the material, but how the block is designed. And yeah, I get they have the resources, but it’s something that block designers should aspire to.

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.

And a few hundred lbs off the nose of the car can now be ballast you put anywhere.

So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Bob,
Unless someone builds and tested an F1 iron block engine we will need know what the difference in HP is at that level. I don't follow F1. Is there a min vehicle weight, and could an iron block F1 engine even make that weight?

Stan

[hoffman900]

I don't about today. But 50 or so years ago. NHRA Pro Stock BBC Iron block was 15 HP up on same combination in Alum block.

Stan

If F1 can get 50%+ thermal efficiency and make it last for 3000 racing miles, with more than double the cylinder pressure of any NA engine, it’s really a question of not the material, but how the block is designed. And yeah, I get they have the resources, but it’s something that block designers should aspire to.

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.

And a few hundred lbs off the nose of the car can now be ballast you put anywhere.

So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Bob,
Unless someone builds and tested an F1 iron block engine we will need know what the difference in HP is at that level. I don't follow F1. Is there a min vehicle weight, and could an iron block F1 engine even make that weight?

Stan

I mean sure, maybe an iron block would be better from a sealing standpoint, theoretically, but last I checked this was “speedtalk” not “stationary engine talk”. If we’re going to ignore weight, then we might as well start including locomotive engines and mine lift pump engines.

That said, you don’t get over 50% thermal efficiency without it not being tight.

-shrug-

[Stan Weiss]

250 bar peak is approaching what nitrous Pro Mod engines see, except they’re used on a road course, has water jackets, and need to last 3000 miles or so, and weight matters to them.
So I guess my point for the rest of us is, don’t look at the material so much as look at the block design, and that’s the bigger variable. An aluminum copy of an iron block is going to be flimsier, sure, but if designed correctly, it clearly works in really extreme racing conditions.

Far enough if they've been designed to do the job.

460 block here ranges from 1 to 1.25" deck thickness.

A built out 460 is probably weighs as much as an entire Formula Car. A quick online search says a fully dressed one is 720lbs

Again, many are doing that thing where we forget engines live in cars and weight is a HUGE component and 15hp on the dyno can easily be made up by saving hundreds of pounds off the nose (either ditching it if rules allow or relocating it).

Bob,
This does depends on the type of racing. Running pounds per ci and a having min % of car weight one end maybe not.

Stan

[hoffman900]

A built out 460 is probably weighs as much as an entire Formula Car. A quick online search says a fully dressed one is 720lbs

Again, many are doing that thing where we forget engines live in cars and weight is a HUGE component and 15hp on the dyno can easily be made up by saving hundreds of pounds off the nose (either ditching it if rules allow or relocating it).

Bob,
This does depends on the type of racing. Running pounds per ci and a having min % of car weight one end maybe not.

Stan

Stan, weight matters in all racing. You’re accelerating a vehicle through time / space, and even if you can’t drop minimum weight, being able to put it wherever you want and not wherever the engine has it is huge as well, as now you can effect distribution, CoG, etc.

Even in drag racing… there is a reason dragsters came to be.

[JC565Ford]

One thing i didn't mention is i have a center counter weighted crank to help reduce stress and distortion. I have no idea on what it is worth, but the dyno numbers seem pretty good for the heads i have. My only clues are vacuum with a moroso pump spinning at 80% is only holding 7inch vacuum at best, pulled 9to 10 with my iron block. But those numbers could easily be skewed by leakeage beyond rings.

Maybe a good part of that ring seal can be recovered with 20" of vac vs running 12-15" ? Maybe?