Re: 80’s/90’s 50hp opinions?

[DAN ANDERSON]

It depends on the engine or even the year model of the engine. In this case (1988 E50BELCCS). I had to go look at the block to remember what type cooling system it had for sure. You can always go look for the parts of the cooling system to tell. This engine has a thermostat, but also a poppet valve with a blowoff spring. When water pressure from the water pump gets high enough (RPMs, throttle) them the poppet valve blows off allowing more water through the block. I think that is what Pappy was referring to by revving the engine to warm it up. The motor would actually warm up quicker at idle while the thermostat was closed (assuming it is working). Once it opens or you cause the blowoff poppet to open the motor will receive maximum water flow. Now it will be generating maximum heat at WOT, but no where else.
Most older OMC engines (not classics or antiques) used blowoff type cooling systems. I believe OMC referred to it as thermostat and pressure controlled cooling. That changed in 1985 somewhat with a different strategy. Different subject for a different time.
Just reading about Dynautic design the other night on 1959 OMC engines. I had no idea what that made up word was. Looked it up and that was the "Marketing" buzz word for first thermostatically controlled cooling. Big deal at the time about better idling, less spark plug fouling, etc.

Dan in TN