View Full Version : Head work on 455 advice

73 Cent
04-04-2012, 12:58 AM
i recently was taking the oil pan off cuz i found a bad leak when i was doing the intake manifold gasket and the timing cover gasket. i recently bought this car with supposedly only 84k miles (story is it sat for 12 years) and when i got everything back together there was a huge milkshake in the oil pan. just straight frappachino.
so to cut to the chase i took them off and had them pressure tested and shaved. ive never done heads before so i was wondereing if anyone had any advice?
im having a mechanic do it for me. he says he is going to grind the valves with a screwdriver and an attachment just cuz he might as well while the heads are off. not if they need it or anything, but just to do it cuz they are off. is this a good idea?
i was also wondereing if there is any special way i should treat my car when its all done. thanks

04-04-2012, 08:44 AM
In my opinion it is always good to freshen up the valves and the seats when the heads are off
They will close better on a larger surface than when they are worn in
And it is a fairly easy job to do when the heads are off
But not with a screw driver you need some grinding and polishing compound and a stick with a suction cup attached to it
Put some polishing past on the valve and grind it against the valve seat with the suction cup wile rotating the stick between your hands
Clean everything up and put it back together
Also install new valve stem seals on the intake valves
You might want to consider new valve springs as well it is not nessesary but they are fourty years old so it can hurt either

After the engine is back together just check the water and oil frequently but that is all you need to do there is no engine breaking in needed

hope this advice helps

73 Cent
04-09-2012, 01:52 AM
check the water in the radiator you mean? or check to make sure there is no water in the oil? thanks for the advice btw

07-08-2012, 02:32 AM
When you use a suction cup and grinding compound to seat the valves it is actually called lapping. Grinding refers to the actual grinding using stones on a valve grinding machine.

Lapping wont hurt anything because it only removes a very small amount of material but if you ever decide to do a real grinding to recut the surfaces of the seats and valves the person doing it must be careful to measure and set each stem highth so that a set or pushrods will fit correctly. Over grinding the seats is a common error performed by some excellent chevy mechanics on a buick head and new seats are needed in most cases. Buick heads are different in the way they are prepared and assembled so whatever you do it is best to have a Buick engine mechanic perform the valve work on your Buick heads. I also believe Olds and Pontiac heads are very similar.

Luck! BL