3 angle valve job tech question

[m_0ney_pit]

It is fine you disagree with the permatex valve lapping compound, it has only been in use for what? 30? 40? 50? or more years.

You are the first, last and only person I heard had an issue with it.
Also, I would not want to hazard a guess how many gallons of the stuff is used yearly.

Does it embed in the seat and valve? Yes it sure does. How else are you going to see the lap line?

Is it going to cause damage to valve and seat, I do not think so, and I have never seen anything to suggest it has.

IMHO, it just turns to microscopic dust particles once the heat from combustion is added and the valve pops on the seat a few times and out the exhaust it goes.

Also the drill method you use is about the worse way to lap a valve, Here again IMHO, due to valve guide clearance, the valve can #### and you can wear one side of the seat more than the other, leaving the seat oval, and not round. Plus you no longer a flat seating surface on the valve, but a concave face on the valve.

I guess it was a bit ambigous the way I worded that. I did not use a drill to lap, I used it to check the valve for bends. I lapped with a suction cup style spinner.

 

[JacksonAuto]

This is true, also you want seats cut, not ground.




http://www.dsmtuners.com/forums/articles-engine-fuel/341636-how-lap-valve.html

I said valve grinder, not seat grinder. The OP was saying he checked the valves for straight using a drill. This needs to be done in a valve grinder with an accurate chuck.

 

[BogusSVO]

I said valve grinder, not seat grinder. The OP was saying he checked the valves for straight using a drill. This needs to be done in a valve grinder with an accurate chuck.

Jam,, I am in full agreement with what you said, about the valve grinder. I was just adding that a stone ground seat is not the best method also.

(I have a 4g head here that just had a VJ done, with a stone seat grinder, and the seats look rough and as wide as Texas)