Boss rebuild over heating

4Lowie · 06-22-2009

Hi all, I thought I had all my issuses sorted with my Boss rebuild but no.....Fixed the vacuum leak and it runs sweet, only thing now that I can take it for a decent run I've found it gets hot! You can watch the temp guage move with the thermostat opening but the temp keeps climbing. 100c + after 10km's. Could I have the wrong rotation water pump? We've got the right head gaskets, can't think of anything else it could be, idea's......

Thanks

joef21 · 06-23-2009

If you replaced the head gaskets (not intake manifold), I hope you made sure to installed them correctly. There is a hole in one end of the head gasket that must be toward the back. If not installed correctly this will cause the engine to overheat.

4Lowie · 06-23-2009

Final assembly was done by a very experinced engine builder who know his stuff, thats why we're scratching our heads looking for answers...

steve sturgin · 06-23-2009

Can you double check on the supplier of the water pump to see if it a reverse rotation ? This could be a problem if you are spinning it the wrong way ....

Do you have a spring in the lower radiator hose to stop it colapsing?

I had a new and faulty t'stat in mine that was giving overheating issues.

Over boring these motors can lead to overheating issues also.

Steve

nickgt350 · 06-23-2009

do you have the right distributor i have seen the wrong distributor cause an engine to get hot.

joef21 · 06-24-2009

I had a similar problem with a 69. It turned out that the thermostat broke and would not open. On another car I had,
someone had installed the thermostat backward causing the car to overheat. It would be worth your while to check the thermostat.

andrewmp6 · 06-24-2009

Are you using the stock radiator or something aftermarket?What type of fan you have and does it have a shroud on it.

4Lowie · 06-24-2009

Thanks guys. I've got a new 3 row radiator with shourd,new hoses and thermostat. My engine guy also suspects the dizzy and has sent it off to be checked and mapped to more suit the motor. I'll take the thermstat out and run the water pump and see if the water flows out the top ok.

mustang656man · 06-24-2009

all you have to do to check if thermostat is opening is start your engine with radiator cap off and watch for themostat to open, youll know when the coollant starts moving,flowing fast. from a cold start it should happen in 5 minutes or less with car idleing. wes

andrewmp6 · 06-25-2009

Make sure you have a 6 or 7 blade fan on it and water wetter is cheap and works great.If you don't have a overflow tank get one of those too.

steve sturgin · 06-25-2009

Another thought,

If the water pump is reverse rotation and you are spinning it the wrong way you should be able to see this with the cap off when the t'stat opens(as suggested by mustang656man) . Rather than flowing toward the drivers side i guess it would be heading in the other direction.

Steve

4Lowie · 06-28-2009

Well the thermostat is good, the pump is running the right way so.... I'm waiting on the dizzy comin back from form a rebuild and remap of the advance curve. Could it be just too lean? It's a new street avenger, how close is should the jetting be out of the box?

4Lowie · 06-28-2009

Well the thermostat is good, the pump is running the right way so.... I'm waiting on the dizzy comin back from form a rebuild and remap of the advance curve. Could it be just too lean? It's a new street avenger, how close is should the jetting be out of the box?