Valve Guide Lube / Pulled the head off to adjust valves, opinion plz of photos 2nd day

[sgkent]

Am in the process of doing a lite overhaul on a Briggs Engine, a 190cc L-Head. That will include cleaning the combustion area and checking valve lash. The Briggs book goes into using Led-Plate #93963 on the stems if I take the valves out, which is probably occasionally available on Ebay but most places show it as discontinued since it has lead powder in it. Is there any reason I cannot just use the red Assembly lube (Ultra Slick) on it? I have some moly paste that I can mix with it if critical, although moly is a two edged sword. When the molecules are flat, it is really slippery, but when the molecules stand up on end, it is an abrasive. I've always just used engine oil on valve guides but generally try to follow factory procedures.

Led-Plate


Ultra Slick

 

[ILENGINE]

Motor oil is fine. What do you think lubes the valve stems when running after the assembly lube or Briggs valve stem lube has been washed away by the motor oil.

 

[sgkent]

I have never used anything but oil or assembly lube like Ultra Slick. It is very similar to the Torco assembly lube that cam makers supply. Just following along with what the manufacturer says to use. Supposedly the led-plate will last longer than assembly lube or oil. Considering how much valve guides on these engines wear, it probably doesn't last all that long either.

 

[slomo]

Agree with the others, normal sump fill oil.

Besides that ancient tub of magic has probably had all the solvents and oils dry up and turn into some other goo like stuff. I'd toss it in the can. Stuff doesn't last forever.

 

[sgkent]

Thank you.

 

[ILENGINE]

Agree with the others, normal sump fill oil.

Besides that ancient tub of magic has probably had all the solvents and oils dry up and turn into some other goo like stuff. I'd toss it in the can. Stuff doesn't last forever.

I have been using on my can of valve guide lube for 28 years. still looks just as good as new.

 

[sgkent]

There is a place online that sells parts for gun enthusiasts who sells a small tin of Armite LP-250 for about $6. It is the same as the Led-Plate. https://www.shootersconnectionstore.com/Browse-by-Manufacturer/JP-Rifles/Armite-LP-250-Sear-Grease I had considered ordering some if it was essential to proper installation and wear. As I said, I usually just use a mix of Assembly Lube and synthetic motor oil.

 

[sgkent]

I pulled the head off. Pictures don't do justice. The cylinder is normal except on the exhaust side where there is discoloration and extremely light scoring from the carbon. Cross hatch is all gone. It feels rougher to my finger nails but not scratches and not gouges. The exhaust valve is almost white. I rocked the valves with them against the lifter all the way up. The intake is tight, the exhaust has a little movement but not that bad. I'll check it again when the valves are cleaned and lapped. Clearly it has been burning oil on the valve side - you can see the carbon build up - but reality is it has 450 - 600 hours on it. Not sure it is worth splitting the case and taking it down further. I have a new set of std rings if I want to use them. Haven't measured the cylinder yet with a bore gauge to see how much wear is there. A slight ridge at the top but I have seen car engines far worse get rebuilt with a light honing to even out and crosshatch, and last another 100,000 miles. Have to think about it. One of those things that it works now so other than cleaning the carbon and freshening it, taking it futher apart might result in one of those gee, wish I had left it alone moments, in for a penny, in for a pound. $5 turns into another $100 etc..

One thing puzzles me though. The piston is clean over much of it. That can be caused by oil washing past the rings, but this engine does not burn oil other than maybe a puff once in awhile when it starts for 5 seconds. The head has carbon all over it so not sure why the piston doesn't too. All the engines I ever worked on, carbon is usually across the entire piston. What do you think?

 

[slomo]

Never been de-carboned. All in the engine manual. I keep preaching about it.

See in the bore where the piston is cleaner? Not as much bore scratching. Now look where all the carbon is at on top of the piston. Bore is tore up. There's your dinner......

 

[sgkent]

yes. My fault.

Cleaned heads. Cleaned grime off carefully in parts washer, and heads in glass bead machine. Still have to wash it and blow it out to make sure all bead residue gone, then check it with a straight edge. It was 60F this morning and 75F - 80F with a breeze all day until about 4pm when the breeze died and the temp jumped to about 95F and no breeze here in the Sacramento Valley. It was too hot to wash it and finish the job. I'll do it in the morning.