Modern OHV Head

Dusty12682

Dusty12682

Junior Member
I remember about 10 years ago there was a guy who had adapted a modern OHV head to a T block. Has anyone seen what I'm talking about? If so, is there any information and images of the process?

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I recall seeing something along that line, using a more modern head. Even if you find references to it, I don't recall really seeing anything more then it might have been done. If you do a search more then likely you will find information about using a Chevrolet 4 cylinder head from the 20's, not so much about what you might be looking for.
 
redmodelt said:
I recall seeing something along that line, using a more modern head. Even if you find references to it, I don't recall really seeing anything more then it might have been done. If you do a search more then likely you will find information about using a Chevrolet 4 cylinder head from the 20's, not so much about what you might be looking for.
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Do you remember the engine measurements and bore spacing measurements for the T?

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Your looking for a RAJO cylinder head kit, check Chaffin's Garage Corona CA

Hope you have been putting your pennies away, a complete kit is $4,200 and if you go that route go the extra mile and pair that up with a KC Warford transmission.

Personally if you want a modern OHV, buy a 5.0 Mustang.
 
39portlander said:
Your looking for a RAJO cylinder head kit, check Chaffin's Garage Corona CA

Hope you have been putting your pennies away, a complete kit is $4,200 and if you go that route go the extra mile and pair that up with a KC Warford transmission.

Personally if you want a modern OHV, buy a 5.0 Mustang.
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That's nice that they're selling rajo kits, but some people cannot afford the extra cost, and this thread is about the same idea as they did in the 20's and 30's. People being inventive and adding/creating a modern solution to the need for more power/speed. It may not be the purest idea, but neither is a replica head, its more about aesthetics between the two. If you see my build, its built using materials not really available at the time, but the idea is the same as it was in the 1920's, build a fast car out of what would be possibly junk parts. Had they had the materials available then that we have now, they would quite possibly have used those materials, including what is being discussed in this thread. I'm not trying to attack people, simply trying to see what ingenuity people have used to create more power on a budget; the idea is still there, just using modern technology.

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Folks have probably adapted about any ohv head with 4 chambers that has close enough cylinder spacing. It generally always requires a machined adapter plate. The 1921/23 3-port Olds/Chevy heads were the only ones that adapted well back in the day but they would likely be more expensive to purchase and set up than the late reproduction aftermarket stuff.
 
rotorwrench said:
Folks have probably adapted about any ohv head with 4 chambers that has close enough cylinder spacing. It generally always requires a machined adapter plate. The 1921/23 3-port Olds/Chevy heads were the only ones that adapted well back in the day but they would likely be more expensive to purchase and set up than the late reproduction aftermarket stuff.
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Also those engines/heads aren't as plentiful as they once were. I figured there might be people looking to do an OHV, OHC, or even a DOHC but might not know they have the possibility with some tech help that it is possible.

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The 3 port Olds looks good, but reports I have seen, does not add all that much. Most guys doing the Chevrolet overhead conversion use the 2 exhaust port 1928 Chevrolet head. Google "MTFCA; poormans RAJO" or "MTFCA; Chevrolet overhead" Are you building a speedster?

The Chevrolet head is not a bolt on and go conversion it requires an adapter plate between the block and head. Unless you can make your own adapter plate or find one, you might be better off just getting one of the high compression heads. I have shared a lot of info on the Model T Ford Club of America as have others. The project has its rewards, pitfalls and takes time, YOU need to be able to figure stuff out and get it all to work together. While the cost still can come in way under a bare RAJO head, it will still cost a good deal more then a good high compression head. If and when you actually take the plunge and get started on this, there are people that can offer advice out there.

https://www.youtube.com/watch?v=hiVaPQzH9OM
https://www.youtube.com/watch?v=_p40Pd1viO4&t=18s


You might want to ask on the Model T Ford Club of America (you need to sign up but do not have to be a member to post) I think you will find more people there that have done stuff like this then here or HAMB.
 
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I have a 1928 Chevy head and rocker arms I will be selling in the near future if your interested.
 
Dusty12682 said:
Thanks for the advice!

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Don't give up , if it is an 'itch' that you just have to scratch !

The fellow who made the great chev four head to A block, died a number of years ago. His creations are sometimes available at swap meets. I've passed on several at Bakersfield. He made a steel plate which made the job easy ! Having had / owned the 4 cyl chev...I would pass for the minimal gain, IMO. But it is an option, eh.

I cannot think of the members name, right now, but he is/was on the model A side of Fordbarn. He is a VERY smart engineer type A/B builder for self use.

He used a modern V8 head and modified it for use on his model A engines. Made all/everything himself on lathe ! Powerful builds that he raced hill climbs ! Amazing talented guy.

You might want to ask there. If his threads still exist, you will learn a LOT. He was not shy at posting pictures of his work...how to, and answering Qs.

I'm losing memory and cannot think of these two guys names....
 
"Having had / owned the 4 cyl chev...I would pass for the minimal gain, IMO. But it is an option, eh."
Not really true. Comparing the stock Chevrolet engine to a T engine with adapter plate and 28 head installed, not the same. A lot depends on how the adapter is machined. Jerns adapters came in different ratios (both T and A), I wish I had kept a file with the info. With the pop up on the T pistons, flat surface of the Chevrolet head, you can do a lot of things with the 1" thick adapter plate (you can go a little thinner), re designing the combustion space. RAJO's may have about the same squash space and some more (not all were made for the speed set, a number of them were sold as improvement for trucks) unless they have been decked with about the same size valves as the Chevrolet. My compression went from about 50 to 75/80 using the one I made, nothing special, just offset holes 3-3/4" in diameter. For a stock crank that gain was ok. Any more then the bottom end would need attention. The 2ed You-tube video is mine. To add; mine was made so the stock T overhead valve type gasket could be used on one side and stock Chevrolet gasket on the other. The water outlet on block and heads don't line up so there is an adapter to take care of that.
 

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When you choose a head you must be sure to get one that has an exhaust valve at each end of the head otherwise the Ford cam will always be opening the wrong valve on that one end cylinder.
I suppose you could have a new camshaft made with a firing order to suit the head.
I knew a guy that cut the two rear cylinders off a sixties Jaguar head but he never did get two camshafts made to just run four cylinders.
 
I don’t need more power in my T, I need more reliability.
The flat head and block are fine, just get that coat hanger wire out of the basement and get a crankshaft and some decent rods in there.
And put counter weights on the crank so a ton or so can be shaved off the flywheel.
Just the way it was the T preformed well enough. A little higher revs and a stronger flywheel flange would be fine for touring around in the city or the country. With or without a Ruckstell
 
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