Small block Hemi heads

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Gryzynx

Gryzynx

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This cold weather must be freezing up my mental capacity. I got to thinking about some small block hemi heads which were being developed a few years back by a company called Rod and Custom Machine. Only saw pictures and a Google search turns up plenty of mention, yet their website seems to be in forbidden territory and all the references are at least 5 years old.

Also found some info about a company called Arao Engineering who claims to have a 32V hemi head for Ford and Chebbie small blocks. Seems to be some very negative experience in dealing with this company, but their website appears to be current.

Maybe the whole point of this is old news and we do have the new hemi to keep us satisfied, but the idea of making an aftermarket aluminum head of hemi design for small blocks does seem to be feasable. Has anybody actually seen one of these hemi conversions? Does anyone know what happened to the companies mentioned?
 
IIRC i think cantefield(sp?) tried to make some smallblock SOHC hemi heads. I know Stage V Engineering made RB hemi conversion heads. FYI, the 5.7/6.1 isn't a hemi.
 
I remember reading about them. Seems they didn't flow all that well for what they cost. More looks than anything. Don't know what happened to the company. Maybe they went out of business.
 
One of the parts vendors had them in a catalog a couple years back. Mopars by Crane I think. They sure would look cool, but W-5's would flow more and cost less.
 
I remember seeing something about that a long time ago.

Seems like they were based on early gen 1 hemi heads, I think one of the early blocks has a head bolt pattern that was close to an LA block.

I think they were really expensive. You had to buy a complete kit, including intake.

I though I saw an advertisement in the Mopar Collector Guide.
 
A-BOMB360 said:
IIRC i think cantefield(sp?) tried to make some smallblock SOHC hemi heads. I know Stage V Engineering made RB hemi conversion heads. FYI, the 5.7/6.1 isn't a hemi.
Click to expand...

The 5.7/6.1 is more of a Hemi than any other 16-valve V8 that's been made for the past 30 years or so... it's just got dual plugs per chamber and squish pads added in ("bathtub" chamber). It's actually much better than a "true" Hemi and just about the most efficient way to make a two-valve combustion chamber.

Screw SB Hemi heads anyway. Technology and research has come far enough to where you can make pretty much just as much power with a wedge as a Hemi (at least as far as old-school V8s go). If you wanted to spend the time and money to adapt Hemi heads to an LA block you might as well just drop in a 5.7 or 6.1 and get lighter weight, better fuel efficiency and a lot more potential for big power (along with infinitely better parts availability and aftermarket support).
 
that hemi head kit was in mopar collectors guide a few years back....I looked it up right when it came out just out of curiousity..... cost between 7 and 8 grand just for the kit....really expensive. Might as well build a REAL 426 hemi if your going to spend that much just on heads.
 
Gryzynx said:
This cold weather must be freezing up my mental capacity. I got to thinking about some small block hemi heads which were being developed a few years back by a company called Rod and Custom Machine. Only saw pictures and a Google search turns up plenty of mention, yet their website seems to be in forbidden territory and all the references are at least 5 years old.

Also found some info about a company called Arao Engineering who claims to have a 32V hemi head for Ford and Chebbie small blocks. Seems to be some very negative experience in dealing with this company, but their website appears to be current.

Maybe the whole point of this is old news and we do have the new hemi to keep us satisfied, but the idea of making an aftermarket aluminum head of hemi design for small blocks does seem to be feasable. Has anybody actually seen one of these hemi conversions? Does anyone know what happened to the companies mentioned?
Click to expand...
I am building an old Desoto hemi and the head bolt pattern does seem to have a lot in common with the 318s. Wilcap did make 11 sets of the Desoto aluminum heads based on the old 291s. I think they all ended up on salt flat cars. Bill
 
DionR said:
Found an archived website, looks like the real website is dead.

Rod and Custom Machine SB Hemi Heads
Click to expand...



The intake flow numbers are low......244cfm that take vary little to do with a little time and a die grinder, with a stock set of stock LA heads.........and the exhausted flows more then the intake???????????? something is vary wrong there.

Still, it's to bad, that they never made it into production...........................
 
Cudafever said:
The intake flow numbers are low......244cfm that take vary little to do with a little time and a die grinder, with a stock set of stock LA heads.........and the exhausted flows more then the intake???????????? something is vary wrong there.

Still, it's to bad, that they never made it into production...........................
Click to expand...

I don't know the flow numbers on these old Desoto heads but they did look a little backward. I ported the intakes until they needed tubed and then used smaller valves on the exhaust. Since the motor will be turboed I'm not too worried about intake flow. Just a little street rod that will never see the drag strip. Mostly local car shows. Lets not tell Gene Adams about the poor performance of the Desoto heads. He was only able to go just over 200 MPH in the quarter on 305 cubes unblown. But then it is all about exhaust flow when running nitro. You don't need alot of intake port when dumping in liquid nitro. You do need alot of exhaust flow to get the burned mixture out, hence-that's why the Chryslers dominate the fuel classes. Bill
 
EARLYHEMIBILL said:
I don't know the flow numbers on these old Desoto heads but they did look a little backward. I ported the intakes until they needed tubed and then used smaller valves on the exhaust. Since the motor will be turboed I'm not too worried about intake flow. Just a little street rod that will never see the drag strip. Mostly local car shows. Lets not tell Gene Adams about the poor performance of the Desoto heads. He was only able to go just over 200 MPH in the quarter on 305 cubes unblown. But then it is all about exhaust flow when running nitro. You don't need alot of intake port when dumping in liquid nitro. You do need alot of exhaust flow to get the burned mixture out, hence-that's why the Chryslers dominate the fuel classes. Bill
Click to expand...

OK i can understand that, with the nitro and all, but click on the link above. them flow #s were for a LA head the was made in hemi design. meant for gas............
The intake flow should have been flowing 260-310 to have been any thing close to the price tag!

As i said before, still sad that they didn't make it into full production.
 
I always figured those heads were meant more for the street rodder crowd and we have some serious performance choices available in wedge heads, but I noticed the new hemi shares bore spacing and a 4 bolt per cylinder pattern with the LA engine. Along with the same stroke as a 360 and similar bolt patterns on the bellhousing, is it possible the new hemi heads might mount to the LA and Magnum blocks? Don't have a set handy or I might give it a try. Still a long way from a running engine and there are a lot of improvements in the new hemi like those 4 bolt mains, but this might be a way to ease the pain of a new hemi swap into an A body. That, or I'm still having turkey induced hallucinations!
 
Cudafever said:
The intake flow numbers are low......244cfm that take vary little to do with a little time and a die grinder, with a stock set of stock LA heads.........and the exhausted flows more then the intake???????????? something is vary wrong there.

Still, it's to bad, that they never made it into production...........................
Click to expand...

I thought the same thing when I looked at the flow numbers. The exhaust doesn't need to flow more than the intake. In fact it shouldn't from everything I've read. I have the feeling these heads were designed more with looks in mind than performance. Maybe that's why they never sold good.
 
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