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I am chasing a tapping tappet after the oil warms up. – looks like a leaking check valve in the 3rd tappet block. Now that the engine is mounted in the car does anyone have any clever tricks for getting the tappet block out of the engine without dropping all the tappets out of the block in the process?
When I reassembled the engine it was on its side in an engine stand so a bit easier to keep things from falling out the bottom of the block.
Thanks, Jim
Hi jim. if you rotate the engine while watching the lifters, there is one camshaft position where none of the lifters are on a high spot of any of the 4 cam lobes. When in this position the lifter block is easier to remove, since there is less valve spring pressure on any lifters, and there is more room between a valve and it’s cam lobe..
I have used a solvent, like gasoline, or brake-clean to wash the exposed upper part of the lifters, dried them off, then used two heavy-duty rubber bands wrapped around a pair of dry lifters to ‘bind’ them together. Another method would be to put a wrap or two of electrical tape around each clean, dry lifter. I have not tried it, but a good zip-tie pulled very tight also might hole a pair under enough tension to keep them from falling out.
Just wiping then washing the engine oil off the lifters and lifter body will make them much easier to handle.
Removing the intake and exhaust manifolds will help a great deal.. especially for the third lifter block..
Greg Long
Jim: First a quick and dirty. I have a 1935 845. I had a slight noise in one lifter. I added a can of STP to the oil and the noise went away. STP should be added with the engine warm and running. Otherwise, it tends to lay in the bottom of the crankcase and not mix with the engine oil.
If you remove the lift block, take care not to mix the lifter parts. If needed, a new ball bearing can be used to replace the original. Sandy Olson has the gasket for the lifter block to the engine.
Thanks, I got the lifter block out. I am trying to get the engine and drivetrain working well before doing the bodywork, so I am hoping to get it quiet before resorting to STP or thick oil. I don’t have any fenders or hood on the car so it is easy to see and get to them now. I tried something else that worked okay. After getting the lifter block loose and tilted out from under the valve stems and still resting at an angle on the cam I pulled each tappet out of its cam follower bore, keeping each one in its own marked bag to keep from getting them mixed up. I screwed short bolts and washers into a short piece of rubber fuel line that created a bit of a taper fit and I jammed them into each cam follower bore. That had enough tension to keep the bolt and washer attached to the cam followers preventing them from dropping out of the block as I pulled it out of the engine.
When the engine was running there was a lot more oil coming out of #11 and 12, and much less out of #9. Now that they are out I did a quick test to see if 11 or 12 seemed to be obviously leaking more than 9 using the bubble test described by the factory in the PASB’s. Nothing very definitive. I had already done a lot of cleaning and bubble testing when I assembled the engine a year and a half ago and had lapped the seat and replaced the check balls on a couple. Will do more diagnosis next weekend.
Jim
When I rebuilt my V-12 I removed and cleaned all of the tappet assemblies including removing the crossbar that holds the check ball in place, so that I could clean the seats. When I finished the engine I had one tappet the would start ticking once the oil warmed up. I isolated the cylinder and took out that block. After checking all four tappets I found one where the crossbar had rotated and allowed a greater clearance between the check ball and the crossbar. I reset the bar and put it back together and the tick was gone. Eleven years later it’s still gone.
Hope this helps.
Bill
I’m not sure how to reset the cross bar – on mine I think the only option to reduce clearance is bending it in after reinstalling or putting in a larger diameter cross bar. My crossbar is just a tiny diameter pin. Actually, now I recall that when I ended up building a new seat for one of my tappets (not the current suspects) I came up with an alternative way to retain the check ball and adjust the clearance. I guess I blanked that bad experience out of my mind!
Meanwhile I am cogitating to understand what I am hearing vs what I am seeing. Listening with a stethoscope the tapping is clearest on the block near the valve seats – implying the noise comes from the valve hitting the seat at a higher velocity. This implies it is coming from the lifter leaking down while it is pushing the valve up and the valve is hitting the seat harder because it is ahead of the deceleration part of the cam. The tapping clearly goes away increasing RPM above ~1000.
Without thinking about it, I originally expected the noise to be more easily detectable on the tappet blocks with the idea the noise is from having valve lash and it is coming from the cam hitting the tappet or the tappet hitting the valve stem as in a mechanical tappet with lash.
Has anyone noted with a stethoscope whether their tapping seemed to be closer to the valve seat or closer to the the tappets? I haven’t really thought it through but it might be relevant to diagnosing whether a tappet’s problem is from a leaking check valve, too much bore clearance, or too much clearance between the cross bar and the ball.
I am thinking about an alternative test for leakdown, and will probably end up replacing the balls and lapping the seats. I will check the clearance between checkballs and crossbars as well. Not keen to press those tiny crossbars out!
Thanks, Jim