Motor hot to touch

Ran my cyl chrysler today, had been sitting for about a month since last taken out. I have only ran about 10 gallons through it since the overhaul. Anyway, it runs fine and pumps water like a dream but when I touched the cylinder head it was too hot to keep my hand on it. It has NEVER been too hot to touch. The block itself would be hot and the exhaust plate but not the head. But now the head is too hot to touch. I grounded the overheat buzzer and it sounds so I guess its not overheating but remember it failed me when it blew out any way. Any ideas on why it would run hotter now???

Re: Motor hot to touch

Just took the t-stat out and put it pot of water, it opens, ran engine real quick without t-stat to see if water comes out of head, it does but there is some exhaust smoke. Put t-stat back in and ran, water coming out of midleg is SCALDING hot and head it still too hot to touch. My guess its running bordeline before overheating because ive used it twice with no problems. Im baffled. I pretty much did the rebuild by the book with 100% new gaskets and silicone where it called for. And going by my oe manual I can eliminate, the pump because of great flow and clogs. Here are some other causes: exhaust cover gasket leaking, cylinder mounting gasket improperly installed, head gasket leaking, cylinder mounting gasket leaking. How do I narrow it down or am I going to have to take the f-ing power head off again? pardon my french.

Re: Motor hot to touch

Healy, when you say it was "never too hot to the touch", was that before or after your rebuild? When you say "water was coming out of the head", do you mean it was coming out of the head where the t/stat housing is located? Have you checked the impeller? Also, are you running it in a tank or at the lake? My engine runs a little warmer in the tank.

Re: Motor hot to touch

I know for sure before the rebuild it was cool, dont remember after so i have no baseline to see if its a new problem. I even thought it ran too cool but I think I read on here chryslers and Forces run cool. I know it is NOT a flow issue. It pumps like Niagra Falls. I ran it for a few secs WITHOUT the t-stat and housing to see if it was pumping up that high and it is but should you see exhaust (slight) coming out of there too? It is not clogged.its a stumper, I can touch maby 4-5 sec tops before not being able to handle the heat and like I said the water coming out of the midleg is scalding hot. Help Please!!! I will get a temp gun in a few days and update. Thanks

Re: Motor hot to touch

You need to get an IR gun on the head - it sounds as though the tstat is working correctly and keeping the head at the correct temperature at around 140F - check for hotspots on the head though with the IR gun.

The exhaust gas and the coolant should only mix in the exhaust so I wouldn't expect to see gas in there EXCEPT (and I'm no expert) that I have installed a temp gauge and pee tube on mine with clear plastic tube and I can watch gas bubbles in the cooling water coming down the pee tube - so either we both have a similar problem or it's normal

Have you run it on the water yet?

Re: Motor hot to touch

Yeah I had it on the water twice with no problems. Thats why I was so alarmed when I found out it is running that hot. Lets say it is at 140, is that too hot to touch? My book says a bad base gasket can get exhaust in cooling sys so I'd hate to have to take the powerhead off again.

Re: Motor hot to touch

Just a guess, but I would suspect that the reason it's running hotter after the rebuild is due to the fact all the cylinders are now operating the way they should. 140? is not too hot for the motor. One thing that you want to double check is timing.

Re: Motor hot to touch

Healey, what model and year is the motor? My Chrysler is always a 2-5 sec to hot to touch after the t-stat opens up, it has also been rebuilt. I have luke warm water out of my exhaust though. Is there any chance you have the exhaust cover gaskets in the wrong order?

Re: Motor hot to touch

Healy, just a thought, try running the motor with a heavier oil mix. See if that cools it down any. Maybe, and I'm reaching here, it could have something to do with "breaking in the motor". It sounds like everything is working correctly. Good water flow etc...

Re: Motor hot to touch

I'm already running double oil for breaking, a fellow boat owner also said basically the same thing about being "tight" due to the rebuild mabye theres more friction. I just bought a ir thermometer and will post temps in a few.

Re: Motor hot to touch

Checked temp with the ir thermometer and the top of the head reads 130 with the lower reading 140.... SORRY. 140 feels a hell of a lot hotter than it sounds. I guess my guard is still up after the rebuild. Thanks for the replys again, didn't mean to waste any bodys time.