the continuing saga of overheating

[tomoad]

my 88 2.4 200 is still overheating,new water pump, new thermostats, new poppit valve, the thing sitting in the water idleing, temp gauge is pointing 3/4 on the hot side, when i nail the throttle temp gauge buries on the hot and water psi gauge wraps around back to 0, gauge is a 30 psi mercury unit ''new'', probably around 45 to 50 pound of water psi when i hit the throttle, you think there is a blockage somewhere or poppit valve not opening. for thermo's i put quarters in with a 3/8 hole's drilled, if i put the regular thermostat's in, just sitting idling the temp gauge is buried on the hot mark in no time. this sob has got me baffled..

[Prof. O/B]

Tomoad, has this engine be rebuilt recently or has there been any replacement of of the exhaust cavity flange gasket or base plate (exhaust plate) gaskets? Can you take a reading with a digital pyrometer with a "beaded" probe or a thermometer to tell if your water temp is hot? These gauges we use aren't really top-notch gauges to start with. Having said that, there are two distinct points that seem to confirm one another; first the temp is high as well as is the water pressure. This would indicate there is blockage and or the water is not circulating through the block properly. These blocks always did run a little on the hot side, and the one you have may or may not be equipped with a hot water return that came from the poppet valve. They re-introduced hot water back into the block via a passage way that lead from the poppet valve back into the incoming cold water through a hole in the block. If you remove the poppet valve plate, you can see the hole I mentioned that allows the hot water to move back into the incoming cold water. If that is the case, some size bolt or pipe plug, don't remember exactly which size, can be tapped and placed into that hole.

It could be a wrong exhaust plate gasket or also one of our infamous dirt-dobber friends may have sealed-up one of the water ports that allows the water to exit out of the exhaust plate, I smell a blockage........................Prof. O/B

[sosmerc]

I agree, there has to be a blockage. It sound like water is not getting past the poppet.
Where are you taking your water pressure measurement?

[sosmerc]

Try removing the poppet assembly completely and then running it for just a minute....you should have a large amount of water flowing out the hole that the poppet valve seats on and your water pressure should be extremely low if even measurable at idle.
A mismatch of poppet valve designs and covers will screw things up.

[us1]

Originally posted by sosmerc
Try removing the poppet assembly completely and then running it for just a minute....you should have a large amount of water flowing out the hole that the poppet valve seats on and your water pressure should be extremely low if even measurable at idle.
A mismatch of poppet valve designs and covers will screw things up.

There you have it.

[tomoad]

the motor hasn't been rebuilt, i took the poppit off after posting this and found i did not screw the screw all the way into the poppit also found the gasket the poppit slides into was not in the slots correctly,i guess that was my blockage ''hopefully'', i plan on going back to the lake tommorrow and we will see, i also today bought me an engine hoist, so later i can pull the pwr head and remove the can and drill the exhast if i can find me a long ass 1/2'' drill bit.. seems the more i tinker the more i tear up, but thats how you learn i guess...

[tomoad]

sosmerc, the water measurement is being taken at the top of the block, behind the flywheel, at the voltage regulator

[tomoad]

it was the poppit, ran ok today, when i got back home this evening i went ahead and pulled the pwr head, removed the can and drilled the exhaust, also put my upper solid motor mounts in, i didn;t find no blockages, but did find the plastic piece that helps you align the water pump on the lu to the waterpipe , melted, and it slided up the water pipe to just under the adapter plate on the mid section.. i cant get this thing to turn the rrrrrrr's i want everything is new except for pistons and rings, i will do a leak down test tommorrow, will releiving exhaust give me any more rpm;s???