Fast Fred's Secrets of the OMC MOD50's Thread #1

[Bill Gohr]

Back to the OMCs, to make them cooler other than ditching thermostats if present what other cooling tricks can be used to specifically cool them down and keep them that way? Any old Deflector Alky Merc tricks of any use?

As far as cooling on the 56 cu in blocks, we had many variations to the cooling system on those engines, if you look at the bridge port engines you'll see we changed it at least 6 times between 86' and 93', and after we came out with the 94' oval port engine the cooling system was corrected as well as the piston fit was tightened up.

If you have a bridgeport engine, look at where the water by passes at the bottom and on some of them you can plug that all up and get some more direct flow, some you'll see an angle drilled hole up the bottom headed toward the exhaust side of #2 that was to cure a hot spot next to 2, if you plug that you'll stick it, if you have that block. You'll see other ones with 1/8" pipe plugs to plug some cross drilling we tried, some helped, non corrected the issue til 94'.

When I was at OMC I baby sat this thing through all these changes.