FL Junkie

iTrader: (23)

im lapping my valves and ive got one intake valve that wont seal. ive lapped it 4 times. first 2 times i did it with my thumb, that didnt seem to cut it. poured gas in the intake port, still leaking out. so i tried it twice with a drill. i didnt run the drill very long only a several turns in each direction on low speed. i put gas in it and its still seeping out.
i could put the drill back on it and just turn the **** out of it but i dont want to go too far. am i just not cutting it enough? the valve is straight far as i can tell.

KCS

iTrader: (20)

You need a valve job

FL Junkie

iTrader: (23)

so it will need machine work to get it to seal right?

FL Junkie

iTrader: (23)

its not a huge amount that is leaking out, just a little bit seeping.

KCS

iTrader: (20)

It's seeping at atmospheric pressure, imagine what it will do under the dynamic pressures of an operating engine.

A competent machine shop should be able to cut a VJ for you, but you may want to be more selective if want a good performance VJ.

NVR_SPDS

iTrader: (39)

A good quality VJ from a knowledgable shop isnt super expensive, and can probably gain you a few HP.

excal21

send em to the machine shop... prolly looking at about 500 to disassemble, clean, check clearances, valve job, reassemble.

RonSSNova

iTrader: (3)

If the rest are fine, you would only need to have one seat touched and the valve faced.

Are you blueing the valve and seat prior to lapping?

A blue felt pen works fine. Just paint the seat and valve face with it, then very lightly lap the valve to the seat with fine compound. . You should be able to see what the issue is.

If the blueing is gone all around the valve face, the seat is the issue. If not, the valve is the issue, likely slightly bent.

Ron

machinistone

That's too much for a valve job alone, throw in a surface and you're on track.

We go $350 for the valve job which includes a radius cut on the exhaust seat, and 5 angle intake seat. Surfacing is $120, seals are ~ $20. $500 if it includes a little bit of SSR and bowl work would be a good deal.

Don't try to correct a seat that does not seal with lapping, it will never fix the issue of concentricity or seat erosion which is the root cause. Lapping should only sparingly be used to check seat width position on the valve, it should not be used to try to correct for bad machine work or wear. Get a valve job done.

01ssreda4

iTrader: (96)

Is it cutting a circumference around the valve evenly? You should be able to see a thinner area indicating there is a problem. The grinded area will look fresh, and areas where they aren't touching will look different.