Freshly rebuilt cammed engine runs hot

[moocow]

Hey guys,

I just did a top end rebuild and installed a lumpy cam and my heads were worked on while I had them out.
While the engine runs pretty much perfectly, it gets excessively hot and I can't think why.
I flushed the coolant and oil systems. I put anti freeze and anti boil coolant in yet when I turn the car off after a drive it still bubbles over into the overflow and around town the needle creeps up to 3/4.
Any suggestions?

 

[Immortality]

Do you have any details on the cam and what timing are you running in the car?

How old is the radiator cap? If the coolant system is loosing pressure it will boil over easier which is generally due to a faulty radiator cap.

 

[Sabbath']

Whats the age/condition of the thermostat and water pump?

 

[moocow]

It's a stage 2 comp cam, double row timing chain set to standard timing, fairly old radiator cap, brand new high flow thermostat, fairly new water pump.

 

[DevilDRake]

Same thing happened to my car with the exact same mods, radiator cap shat itself then it blew a radiator hose after it lol. After replacing it was all good.

 

[moocow]

A bad radiator cap could cause it to get hot like that?

 

[rossymond]

Yup.

I would throw money at it being the rad cap also.

 

[luckyvt94]

The boiling point of water gets higher under pressure. So if your loosing pressure the water/coolant will boil quicker

 

[moocow]

So I just changed it and I think it might have been that.
Don't I feel smart lol