403 propane

[1984mm]

I am putting a 403 in an utu and want to run it on propane. I want to use the 10a4213 heads. Any idea of what the compression woild be? thanks
 

[bp4455]

should be about 10:1
 

[1948 mm]

Thanks that compression should work fine, I am planning on eliminating the gaskets between the jugs and the block, then milling the jugs down to zero deck the pistons which will raise the compression slightly.
 

[jd plowboy]

i bought a 403 that had not gaskets under the jugs and it was a mess. it leaked oil all over the place. we put the gaskets under it and it still pulls just as good as it did with out them and dont have the leaking mess. my opinion is the little bit of extra compression was not worth leaving the gaskets out but just my opinion.
 

[torch guy]

Use loctite #'s 515 or 518 flange sealant. No leaks.
 

[mEl]

Excellent advice!! Years ago Case deleted gaskets on most joints including the bell split and all casting splits on their large ag tractors. Paper gaskets would deteriorate, slip out and cause leaks requiring splits. Loctite 515 was substituted for paper gaskets and completely eliminated problems.

My performance engines use a copper wire as a compression seal and red RTV for water and oil control , no other gasket at all and I could not be happier. Specialty gaskets of dubious quality and fit are a thing of the past. I have been using this system for going on 10 yrs. A major plus for performance is dropping the head another .080 thou. Chemical sealing is the answer in lots of applications.

mEl