Engine tapping after valve job :(

[wormy-28]

Ok, senario, I found #3 and #5 cylinders head gasket blown. So, I disassembe and sent the heads to local machine shop for inspection. They call and tell me my exhaust valve seat has sunk in the head and new valve seats will need to be installed , exhaust only. Sure, I'm no machinist. I get the heads back, milled .03" also. Now, I take a good look at these and visually you can tell the intake valve stems are definitaly taller than the exhaust valve stems. Also noting in the combustion area the exhaust valves sit above the intakes,, where as before they looked level,flat. Finally got this sucker running tonight to find a serious lack of power and after 30 minutes runtime the engine is tapping with a throttle snap.
I did upgrade to the 100 pound kirban springs and upgraded to a ta49 at this time.

 

[BadAssGN]

Sounds like you used the wrong machinist...

first of all, it's not advisable to replace valve seats in a turbo application, for the price of a stock head you could get a good used or rebuilt set fairly cheap. I've seen this before, I personally got boned by a machinist who didn't realize the valves had to be the same height. then like most shops wouldn't fix it or give me back my funds.

My opinion, Take the car to the machinist, let him hear the noise and ask him what he plans to do about it.

You should get another set of heads, and don't press in new seats...

Sorry to hear about your troubles....

 

[Jerryl]

Ok, senario, I found #3 and #5 cylinders head gasket blown. So, I disassembe and sent the heads to local machine shop for inspection. They call and tell me my exhaust valve seat has sunk in the head and new valve seats will need to be installed , exhaust only. Sure, I'm no machinist. I get the heads back, milled .03" also. Now, I take a good look at these and visually you can tell the intake valve stems are definitaly taller than the exhaust valve stems. Also noting in the combustion area the exhaust valves sit above the intakes,, where as before they looked level,flat. Finally got this sucker running tonight to find a serious lack of power and after 30 minutes runtime the engine is tapping with a throttle snap.
I did upgrade to the 100 pound kirban springs and upgraded to a ta49 at this time.

Did you verify the preload of the valves during assembly?
With a 0.030" mill (Maybe you implied 0.003"), that will definately mess with lifter pre-load.

Combine that with the exhaust valves not set to the correct "install height", you could have way too much spring pressure, and/or broke a spring from coil binding. Worst case, the pressure is too high and you will ruin the cam ............

Quit running the car ........ You may be asking for trouble! :frown:
Pull the heads back off and get them done right.

 

[PaCemkr86]

Did you verify the preload of the valves during assembly?
With a 0.030" mill (Maybe you implied 0.003"), that will definately mess with lifter pre-load.

Combine that with the exhaust valves not set to the correct "install height", you could have way too much spring pressure, and/or broke a spring from coil binding. Worst case, the pressure is too high and you will ruin the cam ............

Quit running the car ........ You may be asking for trouble! :frown:
Pull the heads back off and get them done right.

i totally agree, coil bind will also cause the pushrod to bottem out the lifter causing the oil to pump out of it , thus causing the lifter tapping = flat cam etc....

 

[wormy-28]

tap. tap.

Thanks for the good info, I do believe tomorrow I will take the car to the machinist. He is a stubborn old bird. The heads will only milled 3 thousands of an inch. I think I wrote that incorrectly...oh well. My Powermaster took a dive during my road test last night too!!! Maybe time for conversion