134 vs 172 head


I'm taking apart my 172, and am going to modify it some for tractor pulling.

I have cc d the 172 head, now know deck height, rod specifications, position in the bore, crank to cam clearance, and most of the other information required to begin a thought out design to increase cubic inches and raise compression.

My question is how much smaller is the combustion chamber, intake/exhaust runner and valves on a 134 head as compared to a 172 head?

Thanks in advance
If you want more in3's, use 192 pistons. Should be able to over bore to reach that size. May want to sono check the walls first....

What is the bore size of a 192 (4.125)?

Do I bore out the 3.90 sleeves or remove them and run against the block wall.

What is the OD of the sleeve ?


This topic has been covered before, and if I remember right, the 172 doens't have enough cylinder wall thickness to go to the bore for a 192 piston, even if you pull the sleeves and run on the block wall. There is a "super power overbore" rebuild kit for doing this, though. Available from the parts section of this site. Gives you more cubes, but not 192.
A quick check of my parts manual indicates that the 172 and 134 engines used the same size valves, except for the diesels. I can't say about runner length, but would assume htey're about the same. Main difference I know of is the smaller combustion chamber on the 134 head (which might mean slightly longer runners on the 134's).
No sleeve, bore in block. As Fordfarmer said, it may be too thin. Sonic check the walls first and see if it can be done.


Thanks for the responses, I guess I'll just pull a sleeve and see where I'm at.

I'll go to Ripee's in Farmington Mo. and see if he will let me cc a 134 head, or I'll just buy a core and start from there.

I was just looking to get the information for the math for increased compression, but apparently no one has it

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