Need some advice.

Russ/40

Russ/40

Well-known member
When I fired up my rebuild, it ran well, but could not get a roll out of the idle. I ran it several times, for a total of probably 30 minutes. After awhile, it started making one heck of a clack noise, and missed in sync with the sound. I pulled the plugs, and it was running very rich, as the plugs were very black with carbon. I had the carb checked, and fixed a few things that were making it run rich. Put the repaired carb, which ran perfect on a friends car, back on mine. Mine ran lousy. I've come to the conclusion that the rich condition somehow gunked up the valves with carbon and the valves were sticking. I pulled the manifolds off today and shot some Kroil on the valve stems through the ports. I'll let them soak a day or so and turn the motor over occasionally. I also pulled the valve cover. This was a few hours after I had run it the last time. I was surprised to find the oil level in the valve chamber was still higher than the drain holes for the mains. Is this normal? How long should it take to drain? Also, the top half of the valve chamber was dry. It does not look like the oil was getting to the valve stems. What actually lubricates the valve guides? In the V8's, it's a fog of oil that lubricates the valves. Shouldn't the entire valve chamber be wet with oil? I'm peplexed as to if I have a problem. Is it that it just needs to run longer and at higher RPM's. My plan was to free up the valves real well and put it back together and see what happens. Am I on the right track, or does it sound like I have a problem I'm missing?
 
I would use gas with NO ethanol. Ethanol helps to stick valves with it's short shelf life. How old is the gas in your tank? If you put the engine together, did you make sure the oil passages are clear all the way to the crank journals? ( no babbit blocking the end)?
 
My tank is a gallon can with fresh California gas. All passages were spotless. Again, how do the valves get lubed? Seems like no oil is getting up there into the guides.
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Three separate Q's here: 1, Do you actually have a valve stick problem? 2, is it normal for the oil in the chamber to remain above the holes for the mains? 3, How are the valve guides lubed? #1 can only really be determined running with a vacuum gauge, looking for a bouncing needle. The likelyhood of all valves or cylinders having a problem is slim unless the rebuilder really screwed up. #2, If you have new, tight clearances, the holes may not drain for days. If you fish a small brass wire, like a 1/16 brazing rod, down the holes are they open and do you feel a flat bottom (the crank)? #3 Tom W answered that, splash and vapor. Running slow and cold for an extended time does not help.

Is the cam properly indexed to the crank? Cam gears have been known to have their "0" points mis-marked by a full tooth, or installed off by a tooth. A retarded cam would produce the idle and fouling problems you mentioned.
 
OK, I'm feeling OK about the oil circulation. The pump is working well, the drain holes are clear, and yes the tolerances are tight on the mains. The engine ran for a considerable time before the valve sticking indications. It was so bad it would stall it out. It wasn't running well enough to use a vacuum gauge. I probably ran it too slow for too long, trying to get it to idle properly before I had the carb gone through for jet flow. I spent some time in the valve chest today checking lash adjustments since everything is open. When I was turning the crank, I heard a few valves snap shut. It happened so fast I could not tell which one, or ones, it was. Clearly they are sticking. I used the new stainless valves with the one piece guides. Anyone else have this problem with this setup.
 
Bummer! If you remove the valve retainer locks and springs you can try to lift and close each valve by hand. Follow the 'rule of nines' and you won't have to crank too much to get each valve located over the heel of the cam.

You should be able to easily move them up/ down and spin them with your fingers at both ends of the travel if things are OK. Too tight, you may have to pull the head, check for valve guide burrs (VERY easy to do pushing in a new valve with a sharp or burred split lock groove. Number/ mark the valves if you remove them!!! Polish the valve stems and guides with crocus or 2000 paper if crud is the problem. There should be at least .0015" guide clearance on the intakes, .0025 on the exhaust. If not, hone the guides in place to get the correct clearances.

Put moly lube on the valve stems if you pull and reassemble them. I like foaming motorcycle moly chain lube in an aerosol can, with a plastic straw, for new valves, cams, and lifters. Best assembly lube I know, even though it's not marketed as such. Its a mix of synth oil with a stick and hang additive plus fine black molybdenum disulfide powder, a superior solid lube that works even if bone dry.
 
just for giggles , run some marvel mystery oil in the gas . ive had good luck with it cleaning the motor inside . ................... steve
 
I'll second Steve's suggestion of using some Marvel Mystery Oil in the gas. As an even quicker test, pour a little MMO down inside each cylinder. I had a stuicky valve, and that trick got in unstuck pretty quickly. Smokes up the neighborhood for a few minutes, but it might work. Then, add a little MMO to the gas until the engine is not quite so tight.
 
Valves running dry or to tight?

New Engine...Ouch! I understand your concern....shakes a guy up a bit when a fresh motor starts making noise.
I agree with MikeK. It sounds like you may have some tight clearances. I also use the one piece guides and often need to hone them after driving them into the block to remove burrs/deformation at the driven ends. The other conditions in your engine sound normal for the way you ran it for the first period. I would suggest the next time you start the engine, "goose" the throttle ocassionally to create some "oil fog" in the engine. It is the only way you will get oil to the valves. Just do not hold the high rpm steady, quick pulses to around 1600 rpms. A low speed idle..like you would try to obtain when setting the idle on a carb would not be creating this "oil fog" I use Clevite bearing lube on my valves when assembling. (Available at most NAPA stores) It works good if you can not obtain MikeK's suggested product. (foaming motorcycle moly chain lube in an aerosol can) I have to check this product out...I've never seen it!

BTW: With a fresh engine, don't expect to be able to properly set the idle on a carb until you have at least a couple hours of run time. I usually set up a customers carb after 3 or more hours...actually after I am satisfied with the compression test results. (IMO consistant compression between the cylinders is an indication of the state of break-in)
May I also suggest: When you start driving your car, don't lug the engine. Shift down on the long hills and when turning a corner. Fresh rings like their oil and IMO lugging the engine may force the oil out of the ring assembly leaving the cylinders dry.

From what I can see in your post with the photo, it looks like you have a good looking restoration well on its way. Keep going...
Good Day!
Dave in MN
www.durableperformance.net
 
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Thanks for the responses guys, I'm going to need a lot of encouragement here, as I'm getting pretty frustrated. I put everything back together today, (before your posts). I soaked the guides real well and oiled them up before putting it back together. When I ran it I had the rpm's up and goosed it occasionally. Part of the time it ran great, part of the time horrible. Loud clacking noises that bring a chill at times. When it ran well, I could accelerate it well. When it ran bad, the throttle did nothing. Should I tear into it and start over? Should I run it to beat the band? I'm lost
 
"loud clacking noise" means something is wrong and I woudn't run it and do more damage. Bite the bullet and tear it down to see what's wrong. Better now than on the road.
 
Who did the rebuild? Were there ANY modifications to the block or oil system? Clean fresh oil will drain down the walls of the valve chamber when warm but should should certainly leave a film as well as a few droplets around the tappets.
 
Marco, the rebuild was done over thirty years ago before I purchased the basket case. The babbit work was done, and apparently well. It fits well anyway. I checked the mains and rods, and they were right on spec at .0015" When I inspected the rebuild, I found the valve train to be poorly done. The tappets were worn out and the valve lash was anywhere fro.002 to .030". The valves were too thin, but the seat work was very good. I purchased the double nut tappets, and the stainless valves, one piece guides and springs from Snyders.
Only modification to the motor, just the valve train.
 
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Another way the valve guides are lubricated is by the suction created when decelerating. Part of the break in procedure should be to accelerate to 45 or so and then take your foot off the gas and decelerate. The acceleration puts combustion pressure on the rings, and the deceleration sucks oil mist up through the valve guides.
 
Not that I recommend you do it, but the dealership that rebuilt my 8N tractor motor drilled a horizontal hole midway up the tappet boss to direct oil to each tappet. I have never had a problem with that motor, but it does not get used that hard. I would agree that the fog in the motor should lubricate the valves and tappets and you should not have to do anything special.
 
Well it has been a few days since I posted with this problem, and my depression is easing, as I acknowledge to myself it is not going to just go away, and I'm going to have to pull the motor and tear into it. Before I get to that which may be awhile from now, let me ask another question. I am not clear as to how the lubrication system works in the "A". From what I can see, the oil pump pumps oil into the front reservoir, and should overflow into the middle and rear reservoirs. The external tube returns excess oil to the pan. From what I remember, there is a large opening toward the rear of the cam gear into the front chamber. The bottom of this opening seems too low to allow oil to overflow into the middle and rear chambers. I have my chassis on stands, and the front of the engine is a little lower than the rear. What is the attitude of the motor in a properly wheeled chassis? Level? I do have ail in all three chambers when I pull the side cover. How high is the proper oil level in the running car?
 
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