Port engine overheating on a 427 that has been converted from FWC to RWC
New (rebuilt) circ pump.
Pulled t-stat, tested, working fine
Pulled PRV's...good shape and working
The engine will cool if I restrict the water flow coming out of the back of the oil cooler to the PRV's with a vice grips. If I remove the vice grips, no water comes out the top of the t-stat housing and the temp rises.
Good water flow out the top of the PRV's at idle.
The impeller was supposedly replaced 1 year ago, but that was only 25-30 hours on the engine, however I am thinking there might not be enough flow although it looks like the same amount of water through the exhaust on both engines.
From the photo documentation, it looks like you need to pull the pump off the engine to get to the impeller, correct? If so, I doubt the marina changed both impellers last year for a 1 hour labor charge!!
If it's not the impeller, do I have clogged exhaust manifolds?