Factory HEMI Head!

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Killer6 said:
No, the best idea is building an improved aluminum slanty head from scratch, and again there is no consensus on what it should be. If You design a cross-flow type head, the
market will be tiny, and it would be foolish not to go 4-valve at that point. Or, more practical, design an improved version that will accept std. manifolding, flow better, have
an improved chamber, and of course weigh a good 30+ pounds less. I am working on ideas that would permit flexibility between stock apps & very hi output projects, but
ideas are a long, long way from reality. Time,$$$,R&D,& collaboration are all needed for anything to get close to happening. Lately I haven't haven't had much of any of these!
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A cross flow head would not be too difficult to package if it incorporated a raised, upward angled exhaust port on the right side, and was packaged with a fenderwell header.
 
whitepunkonnitro said:
A cross flow head would not be too difficult to package if it incorporated a raised, upward angled exhaust port on the right side, and was packaged with a fenderwell header.
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Actually, I favor the reverse, the exh. where it is and a high port intake w/a profiled plenum above the inner fender...no cutting....no sparkplugs to access. The problem is how
many slanty fans are going to pop&drop the coin for all the dramatic changes that go along with this....answer,....not nearly enough.
 
Killer6 said:
Actually, I favor the reverse, the exh. where it is and a high port intake w/a profiled plenum above the inner fender...no cutting....no sparkplugs to access. The problem is how
many slanty fans are going to pop&drop the coin for all the dramatic changes that go along with this....answer,....not nearly enough.
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The reason I would keep the intake on the left side, is that very high RPM Hemi's benefit from a long, curved runner. The curve helps pile the mixture to one side, and creates a swirl effect in the otherwise dead parts of the chamber. All that room could make for some very interesting intake combinations
 
69_340_GTS said:
Thank you. It still doesn't look right, because they don't appear to line up with the inboard ends of the rocker arms in the bottom picture. I guess it's because the bottom photo was taken on a weird angle.
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The picture does not show the obvious angle at which the pushrod holes had to be drilled. Once you put that into perspective, it's easy to understand how they can align.
 
69_340_GTS said:
Thank you. It still doesn't look right, because they don't appear to line up with the inboard ends of the rocker arms in the bottom picture. I guess it's because the bottom photo was taken on a weird angle.
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Rr-read My post, You have to look towards the upper part of the head in the lower photo, the exh. holes look like they open into pockets just inside the headbolt holes,
the intakes are obscured by the upper rockershaft. The pushrods have a high amount of angularity, and the tappet cups are probably only an inch or so below the deck.
 
whitepunkonnitro said:
The reason I would keep the intake on the left side, is that very high RPM Hemi's benefit from a long, curved runner. The curve helps pile the mixture to one side, and creates a swirl effect in the otherwise dead parts of the chamber. All that room could make for some very interesting intake combinations
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I've measured room for a realistic 13" runner + plenum in my '64 GT, more room in a '67 & up body, how long You think You'd want runners for 8K?
 
whitepunkonnitro said:
The reason I would keep the intake on the left side, is that very high RPM Hemi's benefit from a long, curved runner. The curve helps pile the mixture to one side, and creates a swirl effect in the otherwise dead parts of the chamber. All that room could make for some very interesting intake combinations
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Exhaust on left. Intake on right. Intake manifold runners fold over head and end up on left.............
 
whitepunkonnitro said:
Fine if port injection is part of the plan
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I wouldn't do this conversion any other way, which is why it's not going to happen, You might have maybe 20-30 people in the entire country that might have the coin
and the desire to go the distance with it.

If ever a Mopar mill needed a dramatic improvement in head flow, it is the RB eng.
Remember the Newman marketed Covalt 32valve heads? Almost nobody bought
them, yet they could make an easy 800HP w/a fully streetable cam, $10K for the
entire kit. Intake,pushrods, valve covers, fully assembled w/rockers,the works. Yet
crickets, even with guys dropping 60K on mountain motors, they failed to sell.
I read somewhere that Covalt would refuse to even talk about it out of disgust.
 
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Killer6 said:
I wouldn't do this conversion any other way, which is why it's not going to happen, You might have maybe 20-30 people in the entire country that might have the coin
and the desire to go the distance with it.
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Dont underestimate the number of people in this world who will drop big bucks just to be the center of attention when they pop their hoods.
 
Killer6 said:
Maybe so, but read My edit above...........................
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I see the edit.
Those heads are about as desirable as tits on a bull.
The B/RB is covered by Hemi heads. I'm sure his heads were things of beauty, but the market for something like that would be less than tiny.
Aside from the obvious bling appeal of a Hemi Slant, there is a very real flaw in the engines that this could turn around.
Because of the long stroke, long rod and small piston area, the Slant is doomed to always be a slug down low.
They don't wake up until around 3 grand, when the speed of the journal swinging past that dead TDC zone better matches the pressure wave.
Then, just as they wake up, they flat run out of cylinder head. This is why getting any reasonable return in terms of performance on a N/A Slant is so dismal.
Now, with a high capacity cross flow head, the concept of Slant performance can be completely rewritten.
Imagine a 9 or 10,000 RPM 170 or hybrid 198 Low Deck in a sub 3000 pound car with a clutch. You are talking world class modern performance out of a basic engine that can be had for scrap prices anywhere in the country.
There are probably close to a million of them still out in the wild.
This idea can have some serious legs
 
whitepunkonnitro said:
No, the Aussie "Hemi" is a regular inline wedge.
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That's not true. The combustion chamber is not a full hemisphere in shape and size, it is more like a shallow bowl, and the valves are angled to match that shape. Because it is not a cross flow head, it dispenses with the need for complex valve train componentry. They are a great engine, they produce close to one horsepower per cubic inch in factory form, easy to build and extract big horsepower. I've built dozens of these over the years, the ultimate straight six!
 
whitepunkonnitro said:
I see the edit.
Those heads are about as desirable as tits on a bull.
The B/RB is covered by Hemi heads. I'm sure his heads were things of beauty, but the market for something like that would be less than tiny.
Aside from the obvious bling appeal of a Hemi Slant, there is a very real flaw in the engines that this could turn around.
Because of the long stroke, long rod and small piston area, the Slant is doomed to always be a slug down low.
They don't wake up until around 3 grand, when the speed of the journal swinging past that dead TDC zone better matches the pressure wave.
Then, just as they wake up, they flat run out of cylinder head. This is why getting any reasonable return in terms of performance on a N/A Slant is so dismal.
Now, with a high capacity cross flow head, the concept of Slant performance can be completely rewritten.
Imagine a 9 or 10,000 RPM 170 or hybrid 198 Low Deck in a sub 3000 pound car with a clutch. You are talking world class modern performance out of a basic engine that can be had for scrap prices anywhere in the country.
There are probably close to a million of them still out in the wild.
This idea can have some serious legs
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That is very true what you are saying, and I would love to see this. Hate to rain on your party but with the engine being a SLANT, doesn't leave much room on the right hand side (whoops! nearly said driver's side, I'm in Australia) for a manifold.
 
I'd start with...
3D CAD
Billet Aluminum (not enough volume for castings)
5 axis CNC
DOHC
Modern chambers NOT necessarily Hemi
3.62 or shorter Stroke
Zero deck
Belt Drive cams
Off the shelf rockers
Crank trigger
Dry intake EFI
External oil pump
 
KosmicKuda said:
I'd start with...
3D CAD
Billet Aluminum (not enough volume for castings)
5 axis CNC
DOHC
Modern chambers NOT necessarily Hemi
3.62 or shorter Stroke
Zero deck
Belt Drive cams
Off the shelf rockers
Crank trigger
Dry intake EFI
External oil pump
Click to expand...
I will begin by posting this, I am NOT trying to discourage anyone, just make them aware of the facts. Don't expect to have people beating down Your door, You will have to
commit to doing this with the mindset it won't make You a dime, that is all. I have been working out ideas that will accommodate stock manifolding, and provide even an
otherwise stock engine with improvements, & of course the ability to really honk for those who are going for it. Trust Me, I've thought of a 4 valve arrangement, even
using a stock type cam in the head. But this narrows a very small market down to a teensey weensey one, nobody (say eddy/weiand/etc.) is going to make a run of
these. Billet? Been done already, & with that I will leave You w/this link........ Slant Six Forum, :: View topic - Aftermarket Aluminum Cylinder Head?
 
This is beginning to become like the vàrious threads on slantsix.org. OHC head, it's been done, by a factory engineer years ago. It turned up in for sale section a few years ago. A better head, once again already done. Dutra did the blueprints years ago, nobody wants to fund the casting. Even the guy that owns a foundry doesn't want to take the risk. So you are beating a dead horse.

And there is no interchange between the flat head and the slant six so the "hemi" head won't bolt on, if it existed.
 
kesteb said:
This is beginning to become like the vàrious threads on slantsix.org. OHC head, it's been done, by a factory engineer years ago. It turned up in for sale section a few years ago. A better head, once again already done. Dutra did the blueprints years ago, nobody wants to fund the casting. Even the guy that owns a foundry doesn't want to take the risk. So you are beating a dead horse.

And there is no interchange between the flat head and the slant six so the "hemi" head won't bolt on, if it existed.
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I never implied that it would "bolt on". Only that the factory had built one and that the basic architecture was close enough to the Slant that a similar head could be made to work
 
Well , if close enough is what you are looking for. Then why not the head from the Toyota 2JZ-GTE. At least the bore spacing would be a match.
 
kesteb said:
Well , if close enough is what you are looking for. Then why not the head from the Toyota 2JZ-GTE. At least the bore spacing would be a match.
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I don't think Tony is articulating this well enough for You. He is basically stating to duplicate the idea from scratch to suit the slanty block instead, but the basic set-up on this
flathead won't work on a slanty for a couple of reasons;
1) The position of the rocker arms requires the high angularity crossover pushrods, facilitated by what are probably short valve stems w/pushrod cups riding in the original
guides where the valves used to be, and they would be close to the deck. No way to do this on a slant block, and probably put too much side load on the guides, not to
mention the loss of lift from lobe to rocker.
2) There are going to be too many who will want/insist on running a carb(s), so.....(a) pass side intake means side draft only,..or (b) you're hacking out the inner fender for
a slant six and trying to find room for 6 pipes behind Your wheel/tire & steering....:eek: !!!
If one insists on a crossflow design, Hemi or 4 valve(and You know I'm in the latter's camp), the best approach will be the one Covalt designed & engineered, and it's
either side-drafts or SMPFI for You, or just go home.....................................
 
Yep, and until somebody comes up with the $60,000 or so dollars to fund the pattern making and casting. You are beating a dead horse.
 
kesteb said:
Yep, and until somebody comes up with the $60,000 or so dollars to fund the pattern making and casting. You are beating a dead horse.
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True, unless a somebody has the tools, skills, time, & knowledge to execute the design & patterns themselves, then it is a matter of raising enough $$$ up front to get a
commitment to cast a run.......not holding MY breath but........................................
 
3D CAD
Billet Aluminum (not enough volume for castings)
5 axis CNC
DOHC
Modern chambers NOT necessarily Hemi
3.62 or shorter Stroke
Zero deck
Belt Drive cams
Off the shelf rockers
Crank trigger
Dry intake EFI
External oil pump
Click to expand...

…and a pony! No, two ponies! And $50bn in untraceable bills! And a bottomless bucket of really good southern fried chicken! And…

You will have to commit to doing this with the mindset it won't make You a dime
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In fact, it will wind up costing you a very, very, very large mountain of dimes.
 
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