[ozboss302]

Chasing a different perspective on a strange overheating issue I am having. Engine is 302 windsor bottom end, being in oz 2v close chamber heads with cooling hole mods. I also added the small stem holes across the top of the deck. Single plain pro boss manifold. I have drilled the rear of the heads and run hoses forward to the manifold. Engine performs well and seems to do everything right bar the cooling system. Example. drove out to the track saturday night( hot night). When pulled up over flow bottle steaming and bubbling in top hose. Temp gauge is not accurate, we worked out temp was 210f. Cooled it down pretty quickly. missing ruffly 2l water. When cool went and ran one pass. no temp problem. left the fan run between each run no problem. last pass. top hose bubbling but nothing else. drove home temp on 180f. pulled up driveway top hose and tank bubbling for about 5 mins then fine.
Very large 4 core radiator, cast iron water pump lhs inlet, 180f thermostat, good quality coolant and water wetter, 22psi non recovery cap. currently running gilmer drive water pump runs 1 to 1 with crank. when bubbling in top hose engine is overly hot and doesn't feel smoking hot. using thermo gun as temp gauge is inaccurate(late discovery) top hose around 195 bottom hose 160 obviously different materials read differently but engine isn't cooking. Any suggestions on cause or something that I am not seeing? Any suggestions would be appreciated.
Allan

 

[mel88643]

It sounds as if your head gasket is weeping/leaking into your cooling system.

 

[PSIG]

I have drilled the rear of the heads and run hoses forward to the manifold.

Allan - this may be your issue. The Clevor mod ports the coolant out the front of the heads. The coolant at the rear of the heads has passed through the block, but not yet through the heads. Diverting it there bypasses a portion of the coolant around the heads rather than through them.

David

 

[DanH]

Chasing a different perspective on a strange overheating issue I am having. Engine is 302 windsor bottom end, being in oz 2v close chamber heads with cooling hole mods. I also added the small stem holes across the top of the deck. Single plain pro boss manifold. I have drilled the rear of the heads and run hoses forward to the manifold. Engine performs well and seems to do everything right bar the cooling system. Example. drove out to the track saturday night( hot night). When pulled up over flow bottle steaming and bubbling in top hose. Temp gauge is not accurate, we worked out temp was 210f. Cooled it down pretty quickly. missing ruffly 2l water. When cool went and ran one pass. no temp problem. left the fan run between each run no problem. last pass. top hose bubbling but nothing else. drove home temp on 180f. pulled up driveway top hose and tank bubbling for about 5 mins then fine.
Very large 4 core radiator, cast iron water pump lhs inlet, 180f thermostat, good quality coolant and water wetter, 22psi non recovery cap. currently running gilmer drive water pump runs 1 to 1 with crank. when bubbling in top hose engine is overly hot and doesn't feel smoking hot. using thermo gun as temp gauge is inaccurate(late discovery) top hose around 195 bottom hose 160 obviously different materials read differently but engine isn't cooking. Any suggestions on cause or something that I am not seeing? Any suggestions would be appreciated.
Allan

a 180* t/stat and runs at 180*. thats a problem ?

non-recovery cap , get one and change the overflow to a recovery system . you shut the engine of it will heat soak and can boil the coolant .

plus if you over fill the non-recovery system it will spill out every time
. btw rear to front steam lines , not needed

 

[ozboss302]

I will blank the rear steam lines and see what difference that makes. Thanks for the replies.

 

[ozboss302]

Update, removed radiator and found the tops of all the cores blocked. Have split the radiator to clean. Possibly left over from previous engine but i am looking at a filter. Found the brand new stewart warner temp gauge faulty. reads 160f all the time. I have gone back to a 160f thermostat the copper radiator for the time being and left everything else the same. So far appears okay, will test drive later this week.

 

[KULTULZ]

...hmmpf... :tup: