One white valve

[Robliepse]

Did you check that the exhaust valve is sealing good? Pour some low viscousity fluid like solvent or alcohol, or brake cleaner in the exhaust port and see if it leaks past the valve seat.

fillled both sides of the valve with alcohol and both sides held it for over 5 min with no leaks

 

[RonnieLongball]

the water jacket appears to be casting flash in that picture. But obviously no way to tell from the picture. I agree with you that your best bet in this situation would be to reassemble and test. Had many radiators come in the shop that would hold 15psi cold, but as soon as they had heat in them wouldn’t hold pressure. I wouldn’t rule that out in the head either.

 

[PlymouthMakesIt]

Is that a head made before or after 1974, when they switched to unleaded gas? The old heads don't have hardened seats as they depended on the lead in the gas to cushion and protect them. If you have an old head and are burning unleaded pump gas you could have cracked the valve seat.

 

[CHGRSE74]

I just quickly read this series of posts…I dident see any mention of magna fluxing the components. Find a reputable machine shop. If there is a crack you will know immediately if not sooner. It is definitely antifreeze that is burning. Did you smell the exh, you will know the smell of burning coolant.

 

[Robliepse]

thanks for all the insights and advice.
~ The valves and valve seats were updated when the engine was rebuilt during the build, I also tested the valves with some alcohol, The "white valve" held the alcohol for several hours with no leakage.
~ I plan to upgrade to some different heads once I determine the real issue (if possible).
~ I'm 100% confident that the car wouldn't start smoking until the cooling started to pressurize and it would get worst under load.
~ Already talking to the machine shop that did the original work on the block and heads. Trying to avoid pulling and disassembling the short block if possible. They want me to bring them the head so they can rule that out before we go to the next step.
~ The car wasn't raced or abused and it has less than a mile of use after it started smoking.
~ Question, which I think I know the answer, do I need to use a new head gasket and head bolts for the initial cooling pressure test or can I use copper spray on my original suspect gasket? Not planning to start the car,

Thanks again for all the advice and insights

 

[Robliepse]

I just quickly read this series of posts…I dident see any mention of magna fluxing the components. Find a reputable machine shop. If there is a crack you will know immediately if not sooner. It is definitely antifreeze that is burning. Did you smell the exh, you will know the smell of burning coolant.

I did a dye chem test (Cantesco) on the head and cylinder and didn't see anything

 

[khryslerkid]

Possible bad head gasket. Check the block and head with a good straight edge. Probably it's good just being machined recently. Use a good quality gasket. Torque it properly then loosen and Torque again. You'll get a little more out of it the second time around.

Good luck!

Did you check the valve guide and bowl area on the white valve? Is the valve white on the backside also?

 

[Robliepse]

dropped head off at michine shop to be tested

 

[Robliepse]

Possible bad head gasket. Check the block and head with a good straight edge. Probably it's good just being machined recently. Use a good quality gasket. Torque it properly then loosen and Torque again. You'll get a little more out of it the second time around.

Good luck!

Did you check the valve guide and bowl area on the white valve? Is the valve white on the backside also?

white on both sides

 

[khryslerkid]

white on both sides

Is the valve stem seal still there? Might look at the other exhaust valves to see if they were used. Some only use them on the intake.

Just saw you took it to the machine shop