455 pont. in 79TA Ross Pistons, eagle rods,steel crank,6x heads, extensively worked,roller rockers. Car builds coolant pressure immediately on starting. 18lb cap slowed it down but freeze plugs started leaking.Car never runs over 170deg. Tried removing thermostat. Made no difference. May be non related but I blew headgasket yesterday. Compression only, no coolant out of header. Any ideas?

455 pont. in 79TA Ross Pistons, eagle rods,steel crank,6x heads, extensively worked,roller rockers. Car builds coolant pressure immediately on starting. 18lb cap slowed it down but freeze plugs started leaking.Car never runs over 170deg. Tried removing thermostat. Made no difference. May be non related but I blew headgasket yesterday. Compression only, no coolant out of header. Any ideas?

your pumpin pressure into the cooling system via the head gasket or a crack in a head. Best thing to do is block checker from your nearest NAPA store (it a cylindrical bottle with a nipple on it. You fill it full of blue fluid and and suck cooling system air thru it. If it turns yellow you have hydrocarbons in your cooling system. That indicates a leak. Been there many times with smaller aliminum head engines!!

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gtvoll@neo.lrun.com

Greg,
Thanks for the response. If that was the case, wouldn't I lose coolant? The coolant level is staying normal. I just had to go through the engine for the second time due to crankshaft problems. I had heads and block checked each time and had the same problems both times. I have blocked off the heater core outlet at the water pump as it is a race only car. Could the water pump be putting out too much pressure by volume.
I just blew the drivers side headgasket yesterday. It was #7 at the back of the head. Seems to be just compression as there was no coolant loss, but I'm a converted Mopar man and don't understand the flow in a 455 block that well.

if the head has a small crack in it it'll only leak cold and may not use enough water to be noticed right away. also see other post. mike