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Still overheating, please help.....

i have a motor just like that and had a simalar oil pressure problem. mine was a plug in one of the the pressure passages was left out on rebuild and it would not hold very good oil pressure when hot. but i also never got mine that hot before. another thing that i found out about was after a time or two of removing the intake tubes the clamp that holds the tube to the cylinder would get warped where the bolts tighten it down and cause an intake leak you can lay them flat on a counter top and if you see daylight where the tube goes its bent. there simple to fix though. just thought i share some hard learned personal lesson.
 
lycoming specs min oil pressure at 25psi at idle for sv 0 540, max at 100. should be the same for the angle valve. not any help but ?

try running 5 gal of av per tank of pump. it will help.
 
5 gallons of Avgas to a tank of pump gas aint gonna do squat!Quit being cheap and run avgas.
 
No oil pressure at idle and 30 to me says problem. The av gas will help quite a bit. A shroud will help tremondously as well. The other option is to take it to Jr. Either way there is no cheap way to fix the problem. I don't remember from the other post but did this just start or has this always happened? Is it possible it is running to lean some how?? (Lean rich cable issues??) My SV runs at about 35 lbs at idle and about 60 lbs running when hot. My AV used to run at 40 lbs at idle and 70 lbs running when hot
 
Do a compression check and see what kind of cylinder pressure it has! Do all 6 because if you have a dead or weak hole that will also make a motor overheat. If their low you know it's not been hopped up to much and look elsewhere but if it's high say like 250 or higher then you have found something that will make an air-cooled motor overheat!
 
Your problem is no oil pressure. Even at 210 degrees you not overheating and oil press should be better than 25 idling and 75-85 running .
 
I lost pressure in my 4 cyl. once and it turned out to be a piece of trash keeping the oil pressure relief from forming a seal. I will say that when that happened to mine, it happened all at once and not over time. It still might be worth pulling it off & cleaning it out...it only takes a few minutes. Not postive if this image has it in the same location as yours either.

pressure-relief.jpg


Rick
 
Davie GSO480 said:
bearing problems
Click to expand...

I don't know how long you have had the boat but a couple washers might have been a fix to get rid of the boat when it needed bearings. I guess trying Avgas would be a pretty simple trouble shooting step, Best of luck!
 
The washers are added to increase the spring pressure which increases the oil pressure. The maximum is 3 on a short stack and 6 on a tall stack. The one rick shows is adjustable and doesn't use washers. You have some big problems with the engine. Don't run it until you get it tore down and fixed. It doesn't get better. It may have started with a small fix like oil pump gears but it sounds like you have some big problems now. Not impossible to fix but it needs a complete overhaul in my opinion.
 
I hate to say it but it sounds like you have a bearing issues. That is way to much of swing in oil pressure from cold to hot. Sounds good when your motor is cold but dropping off to 0 when it is warmed up is real bad. You can adjust the plunger by running it in a couple of turns. But that probably will only prolong the problem.
 
Jurnigan's, Wally Moore are excellent. I think Super dave is in st.clouds. Also Mike Thurman is great but he is all the down to miami.
 
check the vernier therm for working . It is the thermostat for the oil temp. Also make sure you are going into the bottom of the oil cooler with hot oil & out the top with cold oil. You can trap air in the cooler & it will not work.

Make sure both lines do not go in the bottom of the oil cooler.
 
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