OK, I know there are a lot of threads concerning this. I have read them all and tried to apply them to my situation. The engines I have are 1981 FWC 318's with log style exhaust manifolds. I have rebuilt the raw water pumps, and they seem to be pumping fine. I have removed the thermostats completely. Even at idle, my engines will get up to 185, 190, and I have uneven raw water flow through the risers. (the inboard side of both motors only has about 1/3 the flow of the outboard side). I am going to try to track down why this is, but I don't believe it is all of the cooling issue since if you did add up both flows (from the exhaust exits), all that flow is going through the heat exchanger, and it should certainly be enough to scrub the heat from an idling motor.
A few of the other threads have mentioned air lock on the coolant side. I will say that when I run the motors with the coolant caps off, there is not a lot of turbulence going on. I would think with no thermostats, I should see some movement immediately. The circulating water pump should be moving coolant all over the place. I did have the exchangers looked at and cleaned, so I would believe they are not the issue. I have read in some of the other posts that the "bypass" line that leads from below the coolant tank(in the intake manifold) to the circulating pump can short circuit the coolant flow through the block. Has anyone had success with blocking off or restricting this hose? I realize there is much to say on the topic.
Thanks,
Dave
A few of the other threads have mentioned air lock on the coolant side. I will say that when I run the motors with the coolant caps off, there is not a lot of turbulence going on. I would think with no thermostats, I should see some movement immediately. The circulating water pump should be moving coolant all over the place. I did have the exchangers looked at and cleaned, so I would believe they are not the issue. I have read in some of the other posts that the "bypass" line that leads from below the coolant tank(in the intake manifold) to the circulating pump can short circuit the coolant flow through the block. Has anyone had success with blocking off or restricting this hose? I realize there is much to say on the topic.
Thanks,
Dave