valve stem seal installation

i always just put a bit of assembly lube at the bottom of the seal and push it in place using my finger [he said bottom,lube and finger all in the sentence, thats bad]!!!!!!!

ok I see the new clips on the new seals. reassembly is going to be fun, everything is clean.

I am going to lap the valves first

please don't lap the valves all it does is widen out the valve seat and make the contact area wider.

yep

timebomb33 wrote:

please don't lap the valves all it does is widen out the valve seat and make the contact area wider.

Amen. With today's seat cutting and valve facing techniques, isn't old fashion valve grinding compound obsolete, along with the handle-fitted suction cups?

within a couple minutes of warming up that little bit of surfacing is lost due to expansion anyway,i can understand it maybe after a fresh valve job just to make it perfect.but by itself i see no benefit.

Hadn't heard the problems with valve lapping before. So if someone wants to freshen up their head, aside from taking measurements, is replacing the valve seals and general cleaning the only thing a DIY'er can do without going to a machine shop and getting the seats re-cut?

its just my personal opinion/experiance for whats its worth

Hear's a thread from another forum with some interesting commentary regarding valve lapping.

Valve Lapping

Patton, that page is interesting reading but I'm afraid to say it does nothing to change my understanding of the pro's and cons of lapping...its still clear as mud.
Thing is this, new oem valves,guides,springs.
The bits for this baby cost more arms than I've got so I can't risk a mistake like this.
So with so many opinions what to do?
I aint tossing no coin.

what type of equipment were the seats cut with,that would be a big help so we can answer you better

With regard to lapping (grinding),

PLUMMEN wrote:

within a couple minutes of warming up that little bit of surfacing is lost due to expansion anyway,i can understand it maybe after a fresh valve job just to make it perfect.but by itself i see no benefit.

This seems consistent with the FSM (at least from 1973 through 1979) because the FSM does include lapping (first using coarse, then fine grinding compound) after the valve faces and seats have been freshly cut to specs "to properly match the surfaces."

I find nothing in the FSM to suggest that lapping would be appropriate thereafter under any other circumstances (such as additional lapping later on whenever it might be convenient).

As known, the width of the mating surface between valve and seat is critical to the balance of proper sealing and heat transfer.

I believe timebomb's excellent advice is directed against random additional future lapping likely to widen the mating surfaces beyond specs.

My lesson learned -- lap only incident to fresh cutting.

Good Luck!