The one issue with making the head accommodate too many stock type bolt-up pieces is that you get basically an expensive stock head. The racers won't be too enthused about that, and I think you'll find the street guys won't pay that much money for a light stock head.

As far as the chamber goes, here again, finding one that works with high compression and high lift, but will also work for the street type guys will be a challenge. I do agree with Dan though, don't worry about different sizes, just make it so the head can be milled. Remember, an aluminum head dissipated heat too well, and makes the motor think it has less compression than it actually does to start with.

One thing I would like to see at least tried is to put the little comma shaped rise in the intake port floor ala Chevy's swirl port. Not sure if anyone realizes it, but that was one of the things Bob Glidden used in his P/S heads. If he bothered with it there must be something to it.

The big problem is valve size. You are pretty much stuck with what we use now because no matter what you do with the head it will still be bolted onto a 3.5" or less bore in most cases. Get the valve too big and it gets shrouded by the cylinder wall anyway. I see people making big numbers on a flow bench with 1.88 intakes, but they never seem to want to comment on how it runs at the track or on the dyno.

The rocker deal is another kettle of fish. I would love to see stud mounted rockers. However, since Slants oil the top end through the shaft that would put you in spray bar territory. Again, not something everyone would be fond of. There are some rollers available, but here again, most people can get away with stock rockers and be plenty safe.

Realistically, to make this a viable project that will not suck the soul out of your wallet, you will have to pick whether you want to sell a head that does one thing really well or a lot of things poorly. As has been said before, you can get a really good iron head done for less than $1500. You'll also be pretty much tied into taking deposits before you ever cast a head because many of the people crying for aluminum heads don't have 2 nickels to rub together when it comes time to pay.

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Official Cookie and Mater Tormentor.

Okeh, let's copy the head from the Chrysler 2.2T3 engine. That's the one Lotus built for Chrysler. 224 hp and 217 lb·ft of torque in stock form. Four valves per cylinder, 3.445" bore, DOHC. H'm...this'll require some, erm, reëngineering of parts beyond the head!
Why?
Yeah, what he said.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Like I said Dan, that one is a kettle of fish. I personally like stud mounted rockers on a performance engine IF we're doing a clean sheet head. It is merely a personal choice to open up the rocker choices some. With a spray bar oiler it may also be easier to restrict flow to keep more oil in the crank where it is needed more.

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Official Cookie and Mater Tormentor.

Copy the Z06 combustion chambers and ports. It seems to do OK w/mpg & HP. R&D is complete now.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

That'll only work if we're going to put the resultant head on a slant-6 block with a 4.06" bore. No such a block, so we need to keep looking for a combustion chamber in the close range of the size we need. Combustion chambers can't be scaled up or down and keep all their dynamics.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Why can't they be scaled? I disagree. You might lose a little if anything at all but everything is done. Flip the exhast around 180 degrees and call it a day.

BTW, I just drove my dad's viper to Florida. 25mpg avg for 1,300 miles. Not bad for 600hp and an engine 2.27 times larger than a 225. It's possible to have the best of both worlds.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

For a price.

Average cost of a used Dodge Viper in my neck of the woods is $40,000 and up, with most being centered around $50-55k

Average cost of just about any used slant six powered vehicle- $100-$2000.

Remember, even with a low-cost head of $1,500 you are still asking most slant six owners to purchase a part that cost two to three times what their entire car cost. Heck, you can still buy turbocharged k-cars around where I live for $500, and those will beat any slant on the street in performance and MPGs.

It would be interesting if someone could come up with a template or mold which would allow the adding and removing of material to a stock head to change the combustion chamber shape. Reworking the stock iron pieces might be much cheaper and simpler than tooling up for a whole new aluminum head.

Because combustion dynamics change. Hot spots and cold spots and quenchout areas change.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I don't know if an aluminum head is going to happened at one time or another, but I know for sure that I will love to have the chance to buy one, whether if I do or not. I think that it will be a great addition to the Slant Six Performance minded guy ...


On the other hand I think that I can help, at least with pictures of the Argentinean ACTC Slant Six Race Heads (ACTC stands for "Asociación de Corredores de Turismo Carretera" something like "Road Racers Association")

Those heads were a special casting made for the ACTC with heart-shaped combustion chambers, thicker walls and some others goodies for the racers. This are NOT cheap and easy to find and it is impossible to find one that hasn't been already fully race ported, but I think that would be nice for you to have the chance to check one.

A friend of mine is a Dodge racer and has one that I can get my hands on (possible for my new Slant?? ) so give me some time and I will post some detailed pictures of it.

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Martin Zappettini
1974 Dodge Polara RT 318cu.
1965 Valiant III Coronado Slant Six 6-Pack (soon!!)

It's still an internal combustion engine and the dynamics might change (enough for any one to tell?...doubt it). Use the proven design and go....otherwise you will have every cook in the kitchen and a big fat mess.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

Reed, good point. The 2.2 does it and it has a head that is just as crappy as the slant in terms of port flow and design. It even has the intake and exhaust on the same side!!

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

Sure...which is why to use a proven combustion chamber that fits our bore. When you take a big chamber and shrink it by whatever means…you're no longer using a proven chamber.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

It's ten times better than what we have now (which is nothing) and we don't have the $ to pay for the development like the OEMS. It would cut years and costs off of an individual proprietor's development.


I wonder how long the Aussie manifold took to design and get it they way they wanted before it was introduced to the market? After it was introduced, changes have continued.

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11.02 @ 120.56
http://www.youtube.com/watch?v=EAxRmoDgsdY
Chassis dyno
http://www.youtube.com/watch?v=wd6hFGzLJMc

We're quarrelling over whether to replace the nothing we have with a nothing we don't have on an aluminum head that will almost certainly never be built. This argument is silly. Let's stop now.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.