seal valve stem

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speedcostsmoney

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my question 2004 vmax bought brand spanking new, about 70 000 km or about 55 000 miles, just ripped off the heads, striped them when removing the intake valves noticed that the upperside of the valve, ON THE STEM SIDE, there was a build up ( dark black pretty shure an oil build up ) guessing the SEAL FOR THE VALVE STEM was no longer good well i'm guessing here, but is there a reason that they are no good already, by the way exaustside ok:ummm:
 
An alternative explanation is that the motor has been overfilled with oil or there is excessive blow-by and as the crankcase gasses are re-circulated through the ail box then this could be where the build up comes from.

Whatever the cause I'd be inclined to replace the valve stem seals as you now have everything apart.

If you are really bored you could also take the time to remove any steps between the inlet stubs and inlet port.
 
How many of these valves look that way?

The valves have some super hard coating on them, forget the name at the moment, but the coating is black as can be.

If it's a buildup on the backside of intake valves it can be from reversion or rich mixture, it's prolly normal. Mine had buildup on all the valves, intake and exhaust, reflecting what I expected to see.

As routine practice the seals should replaced when the heads come off.

Post a pic....of the heads and valves both side...
 
Intake valve right?

Sean's gonna know lot better than I but my guess is that is more due to carb mixture than bad valve stem seal? Plus reversion from cylinder back into intake tract which is not controllable due to cam grind.

Do you idle it a lot? That can contribute in my humble opinion.

How was your oil consumption?

Bad seals will usually show up as smoky exhaust on initial fire up if it's like other engines I'm more familiar with

I wouldn't worry too much just replace the seals regardless.

Why did you have to pull the motor apart? What happened?

You did take measures to get each valve back in its proper home? Or are you doing full valve job and recutting valve seat and seating area on valve itself?

When I did mine I did a "poor mans" valve job using lapping compound and the valve for that hole and lapping them in.
Those wooden suction cup lapping things don't work worth a shit on our valve faces either.
Turned out to be a complete waste of time, wouldn't stay "stuck"
I used a piece of tubing pushed over the stem chucked into a drill and did it that way, just don't get carried away, there's tons of info out there on how to do it.

Used a wire wheel to remove all the crap off the valve face and backside.

Replaced valve seals but not guides. Mine had 42,000 very hard miles at the time, was down for tranny repair.

I did have the heads resurfaced the minimum needed to get them flat and at 50RA or better.
 
opened up the engine cause of aggressive powershifting second gear was slipping or jumping out of place so while the engine is on the kitchen table, opened up the rest of the engine to see how the engine looked , everything looks good except for the intake valve build up
 
the intake valves on the front head cyl 2 cyl 4 no build up, but cyl 1 and cyl 3 the back head lost of build up, running a ufo exhaust with an X CROSSOVER cyl 1 exaust with cyl 4 and cyl 3 with cyl 2, this exhaust system pulls alot running 2mm main jet for tan color plugs,by the way ride for 185 km with v-boost then fall on reserve, stock 150 km fall on reserve, thinking the rear exhaust pipes are too short. got rear exhaust down pipe similar to stock, a little longer than stock that then connects to front exhaust by means of a loop,then to a 2 inch pipe to a 2 inch exhaust canister straight pipe. correct me if i'm wrong but thinking that there is not enough back pressure in the rear exhaust which creates alot of reversion yes the ufo exhaust is VERY LOUD
 

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