Overheating at start up

"Hey guys whats going on. I ha

"Hey guys whats going on. I have a 1970 FWC 318 with the sherwood double pump set up. As soon as the engine warms up she starts to overheat. I used a laser temp to verify this. I have great water flow coming out of the exhaust so I eliminated the raw water pump and system. I changed the impellers in the double pump,had the heads checked and serviced, replaced the head gasket, cleaned out the cooling ports, no thermostat at the moment, primed the double pump, heat exchanger is pretty new, ran fresh water through out the whole system to make sure there was no blockage, you name it I pretty much tried it. I did take one hose off that runs from the bottom of the double pump into the thermostat housing and had nothing coming out. Also would anyone have a diagram on the FWC system with the double pump sherwood? Engine starts up fine, runs great, idles in gear at 700 rpms so I'm assuming the timing is set properly. Any ideas would be much appreciated. I even had another marine mechanic look at it and he was dumb founded.
Thanks!!!"

You might have an air lock tha

You might have an air lock that's preventing the pump from sucking in water to circulate through the engine. I've heard of that happening before with that weird double pump deal.

If I did I'd rip it out and replace it with the conventional deal. Seriously.

Jeff

"Hey Jeff,

Believe it or n

"Hey Jeff,

Believe it or not I even primed all the hoses till it back flushed into the exchanger. I taught about changing or retrofitting that double pump setup but I was looking online for some kind of diagram or set up. Do you have a diagram I could use? This engine is driving me crazy. Thank God the other one runs good with no problems.

John"

"Smart move to get away from t

"Smart move to get away from that old set up. Much cheaper in the long run.

Jeff


"

Hmmm.... I did want to keep th

Hmmm.... I did want to keep them FWC instead of going raw for the complete systm. Salt water out here is a killer lol.......

"Okay. Try this:

Jeff<[img

"Okay. Try this:

Jeff"

LOL Thanks Jeff I'll give

LOL Thanks Jeff I'll give that a shot and I'll let you know how it works out!

John

"So am I straight on this Jeff

"So am I straight on this Jeff??
The exhaust manifolds don't get any water circulation, until the thermostats open,

and out of the manifolds , is the high piont of the risers. (if so equipped)?

Fred 156-M"

"That's about it. There&#

"That's about it. There's always some flow with the t-stat closed, however.

Jeff"