Farmall Cub

Clark Thompson wrote:it wasnt only the dome top pistons that slightly upped the HP it was with the combinations of pistons, cam and carburation. I dont beleive it went to 15 engine HP though.

In the book it does mention cam, carb and governor in cub and cub loboys making the increase, it was only talking about piston changes in this part...

Clark Thompson wrote:I am currently building a hopped up C-60. It is bored .060. Has a new after market head that is somewhat different than any IH head with much less CC's. Plus I had .040 shave off the head to gain another 3 CC's less in each combustion chamber. Im using aluminum flat top pistons with total seal rings.. The intake and exhaust ports are bored and poilished along zeneth carb and the manifold to go with it. Maybe by spring Ill have time to get it fired up.

Please tell us how well this does n please show pics of head combustion chamber n where you got it please... Hope whoever ported n polished the exhaust knows that you DON'T polish intake ports as you need some turbulence to keep the atomized fuel suspended in the air and NOT to fall out of suspension and return as liquid fuel as this is not nearly as combustible. Show pics of manifold and modifications to block (ie porting etc.) (is the manifold ported or a custom one ? unsure the way you mentioned it)

there are a lot of factors in increasing the peformance of the C-60. First of all the camshaft did change as well as the timing on the gear of the cam. one important reason for porting is so the intake and exhaust parts match to the manifold ports.I have seen the ports on the manifold and block to be off as much as 1/4 inch. This will hamper performance alot. On the this engine and the previous one I built I was able to open the ports on the block and manifold from 5/8" to 7/8" all the was to the valve guide. The zeneth carb along with the manifold to go with it atomizes the fule much better than the IH carb plus its venturi is larger as well as the inlet. also with the zeneth there is a adjustable main jet avalible.Getting rid of the cast iron pistons is a no brainer. less weight in pistons = faster rpm and more torque. using total seal rings virtually no compression reduction by blow by.using a electronic ignition is important because when compressions over 130 lb it takes more voltage to ignite the plugs. Last one I build held 155 lbs of compression. I heard that the last C-60 I souped up made 27 HP on a dyno.I cant verify this. I dont have the manifold or head installed yet so I can take some pictures and post them. what is really holding me up on installing the head is im trying to find a head gasket that is 1/4 the thickness of the original. I figure less gasket thickness will increase compression ratieo even more.

Clark, do you happen to know what year the camshaft changed and what part number IH went to?

Not sure of the exact change in cam and gear date. I do know In my 1976 IH cub it has a differnet number on the cam. The gear has a different number too. When I rebuilt the engine I compared that cam to a early cam. the timing mark on the gear was on tooth off from the early gear.I didnt think at the time to record the part numbers on these items. Now I wish i did.The engine im building now Has a cam out of a 184 loboy that had been burnt in a fire. It had domed pistons like my 1976 did.. Before I put the pan on the engine ill try to get the number off the cam. The engine I built about 4 years ago had a custom pulling cam. I sent that origninal cam to dennys carb, they sent it out to somewhere in canada to have it custom ground.I had a file on that engine with all the specifications on that engine but it disappeared with the engine.

Camshaft gear part number 1954: 251 256 R1 (36 T)
Camshaft gear part number 1979 : 251 256 R1 (36 T)

I just checked my book too. It is possible that they are only showing the different cam & gear in the parts books for the numbered series loboys and I dint have one of those.I do know the engine block is different ( externaly ) in the later loboys. I have 2 of those blocks.

ENG-1 covers all C-60 applications and the data is consistent with what I have posted. I check a 1954 TC37; ENG-1 1976; and TC 37 1979 to confirm data.

The 1950 head is just under 33.5 cc. The 1976 head is 30 cc.

Since I found a small crack the head of my 'New International Cub' (77) I set out to find a new one. I didn't assume it was original but the parts manual (TC-37F, last edition) only listed one, 355 691 R2,same number as on the head. So that's what I figured was 'right' for a late Cub. I should pay more attention to the cast codes??

At any rate, I thought I would check the 'spare' 64 and it's got the same part number..... Also a hairline crack in the same spot . I ordered one from what I assume is a 154 and I couldn't read the part number till I took the layers of paint off.... Same number, but I am a bit concerned because the cast number was ground off and the new number stamped on it. The question is.... should I be concerned?


BTW the head is still available from CaseIH, also an aftermarket one sold through their distribution network, $377 and $257.

Larry, the "new" International Cubs used the same head as all of the 154's. Where is that crack?

Dang yawl are letting all my cats out the bag, makes it harder for me to get them good buys on ebay

Bob, I was pretty confused by what you said about the head being 'rare'. The spark plug 'guide' was missing on this one, so I thought possibly the head was off (replaced??) at some point, so it may not have been original (but it was red with no trace of yeller). Not sure what the original gasket was, but there was a Felpro on it. I spotted a bit of coolant when it was running, after it got warm it disappeared. Figured a slight crack that seals itself when it gets hot?? The crack on both the 77 and the 64 are near the head bolt between #3 and #4 plugs.



Boss, don't worry about me giving away secrets.... I don't know any

Rare on Cubs as original from the factory- New International Cub only.

the only time i have seen a head cracked like that is when it was improperly installed or the surfaces of the head and or block were out is wack. A freeze crack would be along the lenght of the top of the head.

Clark, I suppose something not 'flat' could also explain the 'soot' on the red head that I didn't notice until last night. I will try to ensure the block is flat, the only thing I could think of to check the new head for any warp was a piece of granite, looks pretty good. The yellow head is the 'spare' 64, it doesn't look to be cast from the same mold as the red one, but the crack is surely in a very similar spot. Planning on using spray 'copper coat' on the gasket and will double check the service manual for the torque procedure.