Another 28 chev OHV conversion question.

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Model T Ford Forum: Forum 2013: Another 28 chev OHV conversion question.
Top of pagePrevious messageNext messageBottom of page Link to this message  By kep on Thursday, July 18, 2013 - 02:52 am:

My engine has severe wear and some cracks around the ports/valves and gets water in the oil. As i have a talent for ruining things and making a bad situation worse i came up with the following idea. The easier way to fix this looks like mending enough cracks to keep the water in and install a RAJO/frontenac cyln'head?
So i read in past posts about how someone who used to post on here had used a 1928 chevy head but cannot find any pictures of the adapter plate, looks like if i tried to use the existing stud holes in 1 side of the head by filing them oval the valves would be in the wrong place but if i move the valves to optimal placement i would have to use some kind of machine screw looking thing with a very small shoulder that does all the clamping of the plate to the block and have a stud placed right next to it, not very strong and looks rangi.
This link reveals little as it is broken http://www.gen3antiqueauto.com/PoorMansRajo.html
Not sure what this says, http://www.jernthunderbolt.com/Model%20T.html Does it say the adapter plate can be bought for $170usd or was that only for the valve kit?

And if i made my own should i use gaskets or copper crush rings? (The crush ring idea looks like they would leak water from some of the rangi stud/bolt places) And some of the model T head bolts go exactly where the water ports in the chevy head are so i would have to get creative with the drilling for the water. Maybe have galleries drilled by a gun smith. Or put enclosed pushrod tubes in the intake ports and funnel water in through those too but that would be stupid with bad pushrod geometry.

Has any current posters on here done this?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Thursday, July 18, 2013 - 10:31 am:

A note on the valve galleries, they need to be about half full of oil. Chevy valve have a problem with sticking if not enough oil is present. The 170 is the price of the new valve and seat kit. They may have two kits as the 27 and earlier heads used smaller valves, about the same size as Ford.
Type "jern thunderbolt" into the key wood search you will get lots of hits.
You only use the existing stud hole in the block to mount the adapter plate, the head bolts for the Chevy are in different locations.
Some of the water passages between the Chevy head and Ford block are offset from one side to the other in the adapter plate.
Look to spend 1500 to 2000 for the setup.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John P. Steele, Montana on Thursday, July 18, 2013 - 11:19 am:

Kep you are looking at about $1100. US for the kit. I have three chev heads but still have not done a conversion. A few years back I talked to Neal about ordering but I never followed through. I have heard good things about them. Neal is a really nice guy. I would just spend a few bucks and call and talk with him.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Willie K Cordes on Thursday, July 18, 2013 - 11:40 am:

I have not personally used a chevy head, but one of my sons has. That adapter plate is thick and the chevy head is bolted to the plate after the plate is bolted to the T block. A T head gasket is used below the plate and a chevy head gasket is used on top to fit the chevy bolt pattern. The chevy head bolts only screw into the plate, not into the T block. My son is using the engine on a TT truck and it moves down the road quite well for a TT truck. (50 plus MPH)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Thursday, July 18, 2013 - 11:49 am:

Unless your engine's bottom end is real good, Kep, I'd opt for a replacement block instead. OHV can give you higher rpm and higher compression. You likely wouldn't use higher rpm. Does the Chevy head give higher CR?

Some people convert to Chevy heads. My T engines are converted to Chevy crank and rods.

Mate a Chevy engine into a T with planetary, and you have the best of both worlds...


Top of pagePrevious messageNext messageBottom of page Link to this message  By John W. Oder - Houston, Texas on Thursday, July 18, 2013 - 01:26 pm:

Have the whole works from Neal Jern - unused, with steel 7:1 plate and everything else he sells. Can be bought reasonable. (more reasonable than the $1900 it cost me) If interested shoot me a private message

(will go DO Fronty instead)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Thursday, July 18, 2013 - 01:37 pm:

Use a model A engine and have a lot more power!!Have run and owned both A's and the 176 cuin chevy.Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jerry VanOoteghem on Thursday, July 18, 2013 - 01:42 pm:

Kep,

You're putting a $50 saddle on a $5 horse.

No matter what kind of engine you want to build, start with a good foundation, (i.e. block), or you're wasting your time and money on the rest.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Craig Anderson, central Wisconsin on Thursday, July 18, 2013 - 02:20 pm:

^ That.......kinda like getting a knee replacement when your ankles are shot.......


Top of pagePrevious messageNext messageBottom of page Link to this message  By Noel D. Chicoine, MD, Pierre, SD on Friday, July 19, 2013 - 09:52 am:

I thought the dirt trackers in the day paid the big bucks for the overhead valve heads and simply swapped them onto another block (which was cheap) when it blew.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les VonNordheim on Friday, July 19, 2013 - 11:43 am:

With minimum modifications, the 28 chev. block will mount and bolt on a 4 dip T pan. Adapt the chev. crank flange to fit a T flywheel, use a 26/27 hogs head and you have it all. A small adapter allows the two upper hogs head mounting holes to be bolted to existing holes in the chev. block. The chev. engine has oil pressure to the mains, uses a dist. and water pump. Use ford 292 pistons which will up the compression. Now you will have a real cheater. I have seen and rode in a 12 T that had this set up...it was smooth, strong and low buck.

The cheT engine is on display at the Bill Evans Museum in San Diego.

The chev. head has small valves compared to other OHV's but still a good performer.

I don't think Royce would approve.....but still a fun project....just keep the hood down!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Royce in Dallas TX on Friday, July 19, 2013 - 12:15 pm:

My dad did a couple of Chevrolet head installations on T blocks in the 1980's. There is a LOT of labor involved.

Results are nothing special. Looks interesting, runs no better than one of Ralph Zaicjek's heads on an otherwise stock T motor.

Of course once you don't have a Model T engine in your car you don't have a Model T in my opinion.

Dad installed a Model A engine on a T pan and transmission for a guy around 1990. Lots of work splicing half a Model A pan to half a Model T pan. Modified the crank, radiator, custom exhaust, ending up with a real abortion of a car despite all the hard work and craftsmanship. Ruined and seriously devalued a perfectly good Model T Fordor sedan in my opinion. Sometimes you do that if the customer is paying.


Top of pagePrevious messageNext messageBottom of page Link to this message  By kep on Saturday, July 20, 2013 - 06:13 am:

i do have a better block somewhere but i do not want to ruin it. The guy whos house the block is at might help me fit a model A crank inside it but then i would have to change the 'rods and pistons too and the whole thing starts to become of questionable cost/benefit ratio. Stubborn foolishness can be really expensive if i pursue it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Sunday, July 21, 2013 - 04:19 pm:

Royce,

I think that Model A engine conversion ended up on rag tag pickup owned by Buddy Young.

Ted


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Sunday, July 21, 2013 - 05:42 pm:

The chevy 4 was a good engine as seen how many survived their cars to live on in other uses.My only qualm is the fact they only had slightly more power than a stock T engine.At the cost why bother? Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Sunday, July 21, 2013 - 06:26 pm:

It should be cheaper for you to buy a good used short block from Calif, than Chevy head, adapter, etc.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Sunday, July 21, 2013 - 09:07 pm:

The 1928 Chevy 4 cylinder produced 35 horsepower.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ricks - Surf City on Sunday, July 21, 2013 - 09:13 pm:

With taller pistons, it could maybe double that 35.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Gregush Portland Oregon on Monday, July 22, 2013 - 12:57 am:

28 Chev exhaust and intake valves are bigger then the T to start with. What your HP should depend on which adapter plate you use. I am not sure but the rocker might be 1.5 to 1 in 28. 28 (and earlier) heads, the intake ports were somewhat restricted but the restriction is a pressed in sleeve and once taken out gives a good sized opening.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Monday, July 22, 2013 - 08:39 am:

RD,The easy way to get 70 hp from those chevs is cheat with your pencle! The same way they clamed 35 hp,small horses! Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les VonNordheim on Monday, July 22, 2013 - 11:11 am:

The 28 Chev block matches up with the model T pan mounting flange. The original mounting holes in the pan need to be re-drilled.....old holes welded up. The back of the 28 Chev block requires some machine work so the T hogs head seals properly. The back of the Chev block resembles how the T block is shaped.

It would be much less $$$'s adapting a 28 Chev block to a T pan and hogs head compared to the expense of putting the OHV and a stronger crank in.

Yes, it's not totally a T......but how many modifications can one do and still call it a "stock" model T engine. Just adding dippers on the rods....the engine is no longer original.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ted Dumas on Monday, July 22, 2013 - 11:13 am:

One of my best friends has a 28 Chevrolet. Its much more like a Model A and will move on down the road. I don't think the 35 HP is a false claim.

Here's the power curve from the 1928 Parts list:


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les VonNordheim on Monday, July 22, 2013 - 12:44 pm:

I do have 2 1928 Chev 4 cyl. engines that are available if anyone wants to start a project. It interested me in doing the project years ago after riding in a 12 T roadster that had the set up that I described. Was amazed on how smooth and strong the 28 Chev engine performed. With the hood closed everything looked stock T. With the three pedals and pan....there were no tell tail outside giveaways.
Sadly, the owner of the 12 model T removed the Chev engine setup because of all the flack he got from other T owners. That was over 30 yrs. ago. Now the engine sits in in a Museum.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Kenneth W DeLong on Monday, July 22, 2013 - 01:56 pm:

Im sorry to say my info is what i did in the early to late sixtys.Bud.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les VonNordheim on Monday, July 22, 2013 - 02:45 pm:

In addition, the CheT had Ford 292 pistons which stick up 1/4" more than stock. I also have enough new .030 (Old Stock) 292 pistons and rings to build an engine.


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