Loss of power when too hot normal?

[SSTKO81]

Just got my boat back yesterday from having a new cylinder head put on. Took it out for a test run and everything was great for the first 10 minutes. Then there was a hiss noise and suddenly the temp started climbing. -I slowed down and turned back but by the time I got to the cove I was over 210 degrees and losing RPM despite not touching the throttle.
Well turns out my drive belt snapped and I lost my water pump. I'm sorely hoping that my loss in power, RPMs, and idle were all due in part to high engine temp and no more. Please tell me I didn't damage my brand new head...
I checked the oil and it seemed a little thin but not milky not burned smelling.
Worst part was it was making the Same lawnmower-type noise that led me to replace the head in the first place.

 

[perna00]

Re: Loss if power when too hot normal?

Re: Loss if power when too hot normal?

A compression test will tell you if the heat warped the head and have to get it remilled again. If the test comes out within spec, you just missed due to the heat being too high and causing detonation/preignition.

 

[SSTKO81]

Re: Loss of power when too hot normal?

A compression test will tell you if the heat warped the head and have to get it remilled again. If the test comes out within spec, you just missed due to the heat being too high and causing detonation/preignition.

So you're telling me there's a chance! Yes! I'll put the gauges on it today and see what I see. I sincerely hope that head and the gaskets are ok. BTW. Boat label reads to use SAE 30 oil, but the mechanic said 25w-40 would help keep my pressure up at low rpm. Thoughts?

 

[SSTKO81]

Re: Loss of power when too hot normal?

Didn't break out the compression gauges today. Put on the muffs and ran up to 2000 rpm for about 15 min with no over heating or weird noises. I think we we're ok