OMC question for Skools
 

Skools:

Any idea if a set of V6 OMC heads ( casting # 325556 & 325557 ) I purchased off ebay will fit my 1984 235 Evinrude?

I remember you posting a OMC engine specification listing awhile ago but seem to find it now. Did V6 OMC have different bore sizes? and if so, would that be a issue to consider?

Second, Any idea how much you can shave off the head to increase compression. I'm running 95 PSI across all six right now and what Alittle more punch. If I read it right on off another site (zip zoom fly) 10 thousands = approximately 5 -7 PSI increase per cylinder. Any experience how much to shave?

Thanks for any help you can provide

Kamikaze

Re: OMC question for Skools
 

according to parts book it wasn't the correct one. but still may fit. i had a 140 with shaved heads and it had 136 PSI before the shaved heads. after i put a set on that were shaved it jumped the compression to 190 PSI and the stock starter couldn't turn it over. But it run like he!! and made around 175 hp. Heads on it were actually shaved to much these were shaved 1/4 inch lol. You'll have to richen it up to run higher compression. I'd check the piston to head clearance before taking off the stock ones in the spark plug hole. Then mount your new heads and turn it over by hand without plugs and check the piston clearance.

Re: OMC question for Skools
 

Thanks for the info. I appreciate it

Kamikaze

Re: OMC question for Skools
 

those heads fit all yrs 150, 175,& 235 up to 1983 came out with different heads.