In the middle of a partial engine rebuild and was out with the wife when it hit me. How will the white lithium grease I am using as assembly lube tolerate the heat on the exhaust valve stems? If it burns and turns to carbon, it will be trouble.
I wonder if I should remove it from the exhaust valves and just use some heavy oil on those stems?
We've never used anything other than motor oil during assembly. Everyone has there own ideas on all this stuff but I figure if the engine is going to run in it, than it's good enough for start up. Keep in mind everytime you store it for the winter your not going to pull the head and take out the valves and pre-lube them before starting up at the next driving season. Key to happiness is don't over think your project.
If not for my Dad and his logic I would still be working on my wheels, I tend to over do it too. Dad said "Hell it's a Model T not a Packard" put it together and drive it...!
Good point Steve. Hard to beat motor oil.
The worst thing you can do is use the white Lithium Assemply Grease on anything. There is a better than 50 percent chance you are going to STICK at least one Valve Open.
When ever I put on a seminar the first thing I cover is three things I try to get the class to remember. Educators will tell you that a class only remebers three new things at each seminar. The first thing I put up on the black board is DON'T EVER USE WHITE LITHIUM ASSEMBLY GREASE. White lithium ASSEMBLY grease can turn as hard as a rock and stick a lot of moving parts such as BEARINGS. The heat on the valves will harden the lithium even faster than other parts.
If that was my motor I would pull the plugs and turn the motor over by hand and as each valve is wide open spray the stem with WD 40 to wash as much lithium of as possible. Then I would use a good grade of light weight motor oil to cover the stems.
As soon as you can I would start up you motor and run in for very short periods of and on.
Our Nascar engine builder always used STP as an assembly lube. On my own engines, I just use clean oil.
I've used STP or the Lucas equivalent (recently) on assembling engines since the 70's. With a splash type oil lubrication engine, your asking for disaster when using white lube or any other type of "grease". The white lube plugs the oil holes and won't allow oil to enter the mains, rods, or anything else.
I forgot to add... Use motor oil on valves, lifters and cylinders.
I have been in the shop all morning (since 0300) and had not buttoned up the engine at the time I had the above thought. No worries, as I removed the lithium from the valvestems (it remains a bit on the cam lobes) and used 10w-40 as the final assembly lube.
Have been able to do many of those little chores you always want to get done but haven't due to the trouble of it all. Now the whole thing is apart, so I am taking advantage.
The new valves fit the reamed guides so much better. I can't believe all the oil crud that built up on the valves and in the intake ports of the block.
Will post pictures soon.
Good move Eric, remember if it's still apart where you can access it brake parts cleaner in the spray can will De-solve the grease also you may want shoot the lifters with it wipe it clean with a shop rag and then go back with motor oil 50 wt. works good.
Good luck on the build, sometimes what we think helps with an assembly process actually winds up hurting in the long run, Royal Purple makes a good grade assembly lube also, but I would stick to motor oil if it were me.... it's more cost effective and you still get great end results.
Here are some images of the old valves and gunked up intake ports.
Here they are after a good cleaning.
And almost ready to button up...
How do the intake valves get so much stuff on them?
These were what were in my Coop...... YIKES.......
Kep, loose valve guides and vacuum from the suction created on the intake stroke will cause oil and other things to be drawn in though the guides and collect on the valves. During the decelleration mode, the vacuum is greatly increased due to the throttle plate being closed but the pistons are still trying to draw in air. The deposits "coke" on the valves over time due to the engine heat.
Does it precipitate all over the intake as well? i was worried there was something really wrong with my car when i saw that gunk in there.
Some will deposite in the combustion chamber also but part gets burned up.
The intake valve and chamber just keep collecting the oil mist that turns into hard black "coke". Those valves were very loose (like a spinning plate balanced on a stick). That build up was starting to restrict intake flow I imagine.
Now the new ones are a perfect fit so this issue should be a thing of the past.