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Discussion Starter · #1 · (Edited)
well here is the issue, although i have searched for a answer i cant seem to find a solution. so the deal is that my b20a5 will burn a bit of oil under first start up after it has been sitting for a couple hours. or if it has been idling for about 5 minutes at 750rpms then you take off. it will go away after going through 1st and 2nd for the first time. i assume that my valve seals are as tight as a krispy cream around a pencil. so my exhaust ports are loading up with oil and then being burnt and blown into my fart can. so i was feeling like replacing the valve seals. so first do you guys feel like it would help my issue at all or am i just opening up a new can of worms. my real question being about the cam bearings, so without replacing the cams or machining my old ones. do i keep the existing bearings and reinstall them in their current place? as they are already matched.
 

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I don't think your hurting anything by doing valve seals. They are not terribly expensive and you can adjust your valves and inspect your plugs at the same time.

Our engines don't really have cam bearings like you find in other engines. They have cam caps which are marked I1, I2, I3 etc and E1, E2, E3 etc. for Intake and Exhaust. The cam caps and head surface are the bearing surface for the cam and can be polished if needed but be careful not to remove too much material otherwise you have to machine the bottom of the cap and have it line bored and clearanced. Honestly if they look good I would leave them alone.
 

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The cams are lubricated by an oil journal. There are no bearings.
If your valve stem seals are shot you will usually see a puff of smoke out the back after idle. If that's the case it would be a pretty sure bet the engine is getting old and looking for a freshen up anyway. Valve stem seals are usually a head off job.
 

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Discussion Starter · #5 ·
its been a while since i have adjusted my valves(owned it 5 years prolly adjusted them 3 times) but i dont remember how deep the springs sit in the head, do they sit too deep to get a compressor on them to undo the retainers? maybe i should pray for warmer weather and run heavy oil. or just buy a 5th gen with low miles.
 

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its been a while since i have adjusted my valves(owned it 5 years prolly adjusted them 3 times) but i dont remember how deep the springs sit in the head, do they sit too deep to get a compressor on them to undo the retainers? maybe i should pray for warmer weather and run heavy oil. or just buy a 5th gen with low miles.
I would get one the kind of compressors that you hit with a hammer and the keepers get cuaght by the magnet. You can also use the same tool to install them. Works good on our engines and I think Lisle makes it.

You can use the rope or compressed air to hold the valves up.
 

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80 PSI should be fine

I always put the piston for the cylinder up to TDC just in case there is a leak or other loss of pressure for whatever reason the valve cannot fall all the way down into the cylinder, because if the valve falls in the cylinder your most likely pulling the head. Not Good.
 

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Discussion Starter · #12 ·
so I think ill try it!!!! am I looking at about 5 hours? im ordering that Lisle tool. what kind of lube would you recommend on the seals during installation?
 

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dont use shop air to hold the valves up.

take out the spark plug, put the piston at BDC or just after on the compression stroke. thread in a few feet of GOOD rope, something that wont fray or break. leave about 5 feet of rope outside of the head. SLOWLY rotate the motor towards TDC. when you feel the motor naturally stop because the rope is now touching the top of the combustion chamber, stop. the valves will now be held in place. note, they may drop millimeters but not enough that it will be a problem.
 
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