No, that would be more expensive than just buying billet aluminum flat bar. You can buy the 2 pieces of aluminum material for less than $200.

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There's no such thing as too much cam....only not enough engine!

OK. Just stabbing in the dark. So the cost is all in the labor, tools, and designing, then.

What is really needed is a better slant six head made of aluminum or cast iron. But I have doubts that a cast iron head would be any cheaper to make than one of aluminum.

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-MattMan
LEANED & MEAN

A 2 piece head is much simpler to make than a 1 piece head. A 1 piece head requires a minimum of a 4 axis milling machine, a 5 axis is preferred, because you simply can't machine some of the features in all 4 or 5 axis' simultaneously. A split head reveals these more complex features and makes them easier to machine with less expensive machines. Using a manual milling machine to make a 2 piece head is also easier with basic fixture making and a DRO, and well within the abilities on many more people, and less expensive. But there are going to be some elements of the head that can only be made with the help of a CNC, even if its only a simple 3 axis machine.

So getting back to your question, the more time and effort you put into the front end with tooling and fixturing, design details and design software you have to create the head in the first place will go a long way in having a nice upgraded cylinder head.

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There's no such thing as too much cam....only not enough engine!

How much improvement can a bolt on head actually make?

I'm thinking that you would have to do what the Aussie's did and make a Hemi head that will bolt on our blocks. The dome shaped combustion chambers will allow for bigger valves and moving the exhaust runners to the passenger side will allow for larger ports.

This would require many custom parts and would get expensive fast.

Turbo slants would love the Hemi heads though.

How much improvement can you make at a price point that would sell?

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1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

The Aussie Hemi head isn't a Hemi, its a conventional wedge style head just like the slants, but it does have better ports. It was only called a "Hemi 6" for marketing purposes.

The main problem with a new head of any kind is very little market compared to the cost to develop one. It will cost the equivalent of near $65,000 to design and make the casting patterns, make or create the tooling and fixtures needed to machine raw castings, making any mods to the first few prototypes to improve and streamline the design even more, just to get a few castings in hand.

Then from that point, you'll need to place an order with a foundry to cast 20-30 heads at around $450 per head, plus shipping, and then have your labor in machining them and buying the parts like guides, valve seats, valves and valvetrain parts to be able to get them to the place where you can begin the valve jobs and completing them. Selling the heads once completed will only pay you back for getting them cast and machining them, it will be a long time before they will start paying you back for the initial $65,000 you started out spending and investing. A newly designed head can be a great improvement, and on other inlines that are already out there, they have increased the output by as much as 125 HP over the best OEM ported head in N/A comparison. Boosted and other forms of forced induction even more.

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There's no such thing as too much cam....only not enough engine!

Ahhh, I see. That is a big investment that will unlikely return. But who knows, enough performance increase and it might sell.

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1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

Yes, high cost, high risk investment with a slow to no return in sight for many years. Even just selling the completed 30 heads only pays you back for casting them and machining them with maybe a couple of grand profit to throw towards the $65,000 initial cost. So $2K-$3K for every 30 heads you sell will take a long time to payoff. After the first 30 sold, it may be a year before number 31 sells....but you still had to invest in another 30 more castings and the related components to sit on them. Who has that kind of money for the risk? I think making billet "one off" heads would be more cost effective. At least you will make money starting with the first head.

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There's no such thing as too much cam....only not enough engine!

What about 3d printing a mould to cast an aluminum head? Feasible? Realistic?

If you have a 3D printer large enough to print a whole cylinder head profile, then yes it is feasible. My 3D printer printed a workable side draft Weber intake for a Cheby inline 6, but is too small to do most of the cylinder head patterns. You can do the ports and maybe the chambers. You also still need some good 3D modeling software like Solidworks or Inventor to create your model to 3D print. You also will have to add the shrink allowance and draft angles to all the necessary features to get the correct size patterns to actually use your 3D printed parts as a pattern or core to make your casting come out right also.

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There's no such thing as too much cam....only not enough engine!

"The main problem with a new head of any kind is very little market compared to the cost to develop one."

This has been what I told been discussed here many many times, and this thinking is often repeated. But What I don't understand, there were literally millions of slants produced, all the other mopar engines have been addressed and near their ultimate performance levels, the Slant not so much, and the big question to me, How can say for AMC motors as an example a market exist for aftermarket alum heads, which can't be anywhere near the production numbers of a slant?

And those millions of engines are where? The cars rusted out and were turned into Kia's Toyota's, Nissan''s, et al. And the remaining ones are being replaced with v8s.

It is cheap HP to drop a 440 into an a-body. It is not cheap to hot rod a \6.

There are a lot of Jeepers still in the AMC market.

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1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

The Australians build alloy heads for almost anything and don't do a Slant. What does that tell you?

In all seriousness, for the cost of an alloy head you are way better off to do a turbo/efi conversion and make some good horsepower.

The one little point a lot of people seem to miss, the biggest benefit of an alloy head is that it is easier to repair when you break it.

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Official Cookie and Mater Tormentor.

Yep, CHI,AFR and Scott Cook over here all do multiple versions of Cleveland heads. There is also a new block being produced for these engines. The Hemi six head was a "never again" project according to CHI. That being said they did revise the casting a while back.

The market for hard core Hemi six guys is small,the market for a Slant six head would be far smaller. Seriously,how many guys are going to shell the 2500 or so for a slant head for a massive 200 plus HP? Guys that want big six Mopar power will either run a Hemi,a turbo Slant and you will still be embarrassed by a junkyard Ford Barra six. That's where the money is in six cylinder engines over here. For the cost of an alloy head for your slant you can have a turbo Barra that will make massive power.