[hurryinhoosier62]

Originally Posted by Elarson

The Pontiac community is very much a "build it and they'll come" market as long as the pricing is moderate. Prices don't have to be claimer-engine cheap nor will most Pontiac people spend high-dollar Pro Mod sort of prices.

Look at blocks for instance. When Indian Adventures came out with the first aftermarket cast iron block, some detractors were quick to jump on the negative bandwagon and proclaim that factory blocks were all we needed. Fast forward to now and AllPontiac has 4 types of blocks, KRE has 3 and LSM will carve up a billet one for you.

So I'm cautiously optimistic that a cast iron aftermarket head market can be created.

Eric

Same here, Eric. The Kiwis have the technology to produce a limited run of quality head castings. All someone has to do is produce the casting master that meets the criteria that Mike has laid out.

[slowbird]

Originally Posted by hurryinhoosier62

Cite the date of the article. Hot Rod has made many assertions over the years that proved to be WRONG.

https://www.motortrend.com/how-to/cc...er-heads-test/

Also season 5 episode 57 of Engine Masters aired in March 2020 test it also

[MatthewKlein]

Originally Posted by hurryinhoosier62

You are missing the point. Build the same engine with aluminum and cast iron heads. You WILL have to run one to one and one half point higher compression in the engine with the aluminum heads to make the SAME power as the engine with the iron heads.

You are missing the point.

If I can run more compression with the same cam and octane fuel I have a better overall running engine.

[MatthewKlein]

Originally Posted by wbnapier

You can sand cast aluminum. Die casting is more expensive, but more precise. My experience in this is based on ornamental castings in China which may or may not apply.

Thank you

[Jay S]

A wrong assumption is that a change to an aluminum head has linear gains in any aspect other than weight. The 1.5 SCR difference is not at all correct as a blanket number. The thermal efficiencies of the engine’s static compression change the outcome. If some aluminum heads were swapped on an 8:1 engine and you kept the compression the same, the thermal efficiency is lower, and the aluminum heads change almost nothing for octane requirements or power. The percentage of change is small compared the the engines total thermal efficiency.

Then on the other end, if your compression is 14:1 with iron heads, and you swap to aluminum and make it 15.5. The thermal efficiency is higher from the SCR increase, but that gain in power is a small fraction of what it would have been if you increased the compression from 8 to 9.5 with the iron to aluminum swap.

I recall a circle track class that the cars started to go to fast, the sanctioned body knocked all the engines down from 12:1 to 9.5:1 hoping too knock 40 HP off the cars to slow them down. Instead of loosing 40, they only lost about 12 HP. Just like it is a wrong assumption that all compression changes yeild the same results in all combos, it is also a wrong assumption that when swapping from iron to aluminum that increase in compression is all do to the aluminum heads, and not attributing any of those increases to the heads design.

Below is a screen shot of super stock and stock for a 1969 440 Mopar which they allow an aluminum E head to race as a replacement head. Look at the HP changes, there barely is any difference. The HP index actually goes slightly higher for super stock for the aluminum head, but is slightly lower than the iron head for stock. Basically no difference. If you took a E head and cast it in iron instead of aluminum, there would be very little difference in octane requirement for the same engine. I am not say it will be the exactly the same, but it is not very much change. The links Slowbird posted show the same thing as what I am describing. The assumption that Aluminum heads always gives you the ability to run more compression on pump gas is not very accurate, there is more to it than just the head material. chamber designs, quench, port CSA, port volumes, velocities, velocities in relation to piston speeds, flow at different lifts, I/E ratios, valve angles, runner lengths. The thermal loss due to the head’s material is relatively small. It is still a factor, but not what it is built up to be.

This was worth talking about in this thread string, since the 1.5 compression theory is one of the things that has been used to drive aluminum head sales across all brands, preventing cheaper alternatives with iron head offerings. I am not bashing aluminum heads here, just pointing out the iron heads could be very capable competitors.

[Dragncar]

I would like to see a test with more variables . Different compressions and octane fuels with the same exact ports and chambers, iron vs aluminum.
It would be nice if a direct iron-aluminum Pontiac head swap was available. But none exist. Relying on Chebby sux.
I mean, 9-1 CR iron headed Pontiacs on 91 octane gas makes a fantastic street engine. Would it be just as great with the same exact head, same gas and CR in aluminum ?
It might, just would like to see it.
In all my years racing a low compression iron headed 455 everyone of the 454s with iron heads who ran like times in A bodies, had 11.5-12.1 compression and ran race gas.
I was quicker than some of them too.

[misterp266]

Could an E head or Kauffman head be poured in cast iron instead of aluminum? Same mold? Wouldn’t that be an easy place to start or am I missing something?

[Jay S]

Originally Posted by Dragncar

I would like to see a test with more variables . Different compressions and octane fuels with the same exact ports and chambers, iron vs aluminum.
It would be nice if a direct iron-aluminum Pontiac head swap was available. But none exist. Relying on Chebby sux.
I mean, 9-1 CR iron headed Pontiacs on 91 octane gas makes a fantastic street engine. Would it be just as great with the same exact head, same gas and CR in aluminum ?
It might, just would like to see it.
In all my years racing a low compression iron headed 455 everyone of the 454s with iron heads who ran like times in A bodies, had 11.5-12.1 compression and ran race gas.
I was quicker than some of them too.

It would be fun to see that with everything the same, including the 30* intake valves.

Lots of Iron to aluminum examples out there…2000 LQ4 6.0 liter LS had 9.4 SCR and iron heads, 315 HP, the 2001 LQ4 6.0 liter LS had 9.4 SCR and aluminum heads (slightly better flowing with a little bigger port volumes) 320HP.

Indy 440-1 Mopar big block heads flow 380+ out of the box, they were first released in Iron, not aluminum. They were not made on any kind of large scale, they were not cheap either. Not what Pontiac guys are asking for, but every bit as insane. We don’t need 900HP mud truck heads for our Pontiacs. These Pontiac heads do not necessarily need to be cheap depending on what the use is, but it would loose a lot of the target market.

[1965gp]

I think this is a great idea but Im looking at it from a completely different viewpoint. I don’t know that we are the target group- here are my thoughts:

A 455 or 428 build today is a $1500 core to get started and will either end up with correct heads, performance factory heads or aluminum heads. This build is not the Target customer.

Now- we are seeing a significant increase in 350 and base 400 builds (even 301’s in some cases!). I think if you had a factory style head that would bolt up to a 350 and 400 along with a performer rpm intake you are in the game. D ports so the customer can use their existing exhaust.

Bonus if you pair a budget crank to stroke like used to build a Chevy 383. I’m not an engine builder so someone smarter than me needs to figure this out.

We need LS/LT power out of a Pontiac 350 to keep people from swapping.

Guy has a 75 Ventura with a 350 in it and wants more power. Right now building the 350 is not even an option.

But, if for $1000 they could get heads, $300 for a cam, $300 for an intake and $900 for fuel injection you are in the game. For $2500 you get to keep the classic look, match LS power (which is now dated) and not have to deal with the changes needed for an LS swap (mounts, oil pan, new headers, etc).

Stage 1 headers
Stage 2 fuel injection
Stage 3 intake
Stage 4 cam and heads

All interchangeable with stock parts, all can be done one at a time, will fit 99% of the Pontiac engines on the road and will give most general enthusiasts plenty of power.

That is our competition- that keeps this engine design relevant for the next 15 years.

[mgarblik]

Originally Posted by misterp266

Could an E head or Kauffman head be poured in cast iron instead of aluminum? Same mold? Wouldn’t that be an easy place to start or am I missing something?

Not a foundry expert by any means, but "actual" use of Edelbrock or KRE molds will never happen. While I am not aware of any active attempts to keep an iron head from happening, these two companies see an iron head as a loss of business for them. They have Zero interest in iron and don't manufacture or market any iron cylinder heads for any brand. They feel each pair of aftermarket iron heads is a lost sale of aluminum heads for them. There is some truth to that of course. But their aluminum heads are not legal for many types of racing and many Pontiac people will not use aluminum heads because of the incorrect look and fitment in some cases.

[Schurkey]

Far as I know--and I am not an expert--is that you can interchange Aluminum and Magnesium in the same mold.

Iron required a dedicated mold. There's no pouring iron into a mold intended for Aluminum and getting a decent, usable product out of it.

[Nobuddy]

The shrink factor for sand casting iron is about half that of aluminum so just pouring iron into molds made for aluminum results in an oversized part. My estimate is a bit less than 1/8" oversize over the length of the head.

[tom s]

one big issue is the cost of shipping iron heads!With the limited demand for pontiac stuff compared to ford and chevy I dont think you will find them IF they were to get made be any cheaper than alu.Just my thought.Tom

[mgarblik]

Originally Posted by tom s

one big issue is the cost of shipping iron heads!With the limited demand for pontiac stuff compared to ford and chevy I dont think you will find them IF they were to get made be any cheaper than alu.Just my thought.Tom

That is a good point. They certainly would not be shipped as a pair in 1 box. That would put them into the oversize/weight category. Individually, they would fall under that 70 lb. threshold most shippers use.

[tom s]

The first shipping would be up there also,if from China you can only put 40K lbs in a container,also from Australia so unless you can figure out how to ship something that is light you will be shipping a lot of air.So if you ship on pallets that would be about 280 pair of heads.Everything will add to the cost,machining and handling will be harder.There must be a reason it has not come together bu now?Tom

[hurryinhoosier62]

Originally Posted by slowbird

https://www.motortrend.com/how-to/cc...er-heads-test/

Also season 5 episode 57 of Engine Masters aired in March 2020 test it also

Thanks. I’m never too old to learn new things.

[hurryinhoosier62]

Originally Posted by misterp266

Could an E head or Kauffman head be poured in cast iron instead of aluminum? Same mold? Wouldn’t that be an easy place to start or am I missing something?

No, cast iron melts significantly higher than aluminum. The difference in melting and working temps would destroy a mold designed for casting aluminum

[hurryinhoosier62]

Originally Posted by Schurkey

Far as I know--and I am not an expert--is that you can interchange Aluminum and Magnesium in the same mold.

Iron required a dedicated mold. There's no pouring iron into a mold intended for Aluminum and getting a decent, usable product out of it.

If memory serve me, the melting and working temperatures for cast iron are over 1,500 degrees higher than the melting and working temperatures of aluminum. There is no way a mold designed for aluminum would survive having cast iron poured into it.

[Sirrotica]

Die casting can be used for metals with a lower melt point, such as white metal, aluminum, etc. Die casting is able to have more detail in the molds.

Sand casting is usually used for ferrous castings, as the dies are usually a steel alloy and, will survive casting metals with a lower melting point. Sand castings is likely the easiest, and cheapest way to cast ferrous metals.

[Nobuddy]

They are all sand cast so makes little difference.