Endplay Question

[RussellK]

For no other reason than sucumbing to my VW neurosis I did the quick dirty check Saturday. Removed the belt, gave the pulley a tug a twist and slammed it forward. Nothing. Tried again. This time an ever so slight clunk. Tried again. Nothing. Tried again. Nothing. Tried again. A slight clunk. The movement is so slight you can't see it but the clunk indicates movement. Other forensics on this motor? I have absolutely no metal bits in the motor, great oil pressure and great compression. I have no long trips planned for this motor. A couple of 200 milers this summer. I'd rather not pull the motor and check it with the dial indicator until this winter when I have more time. Am I being foolish? Do I have reason for concern?

[dtrumbo]

Can you rig up your dial indicator for use on the fan end? I actually did this on the motor I was rebuilding 'cuz I'm an idiot and didn't realize it's much easier to do the measuring on the flywheel end. Here's what it looked like.

[Gypsie]

Also remember that when you are moving the crank while it is sitting all comfy in it's case and wrapped by the main and rod bearings, you want to try to relieve as much 'friction pressure' as possible. I would try to set the crank to be at tdc so that the rotation will be at the 'turn around'. I feel like this would give the best opportunity for the parts to align and slide back and forth easily. I don't know if this makes sense.

No movement is more indicative of binding than 'no endplay'.

[RussellK]

I'll have to see if I rig up the dial indicator like that. I'm thinking that you're correct Gypsie about that binding. Would a healthy motor have a slight clunk? It's barely perceptible.

[dtrumbo]

When I was building my engine I had a nice clunk. As soon as I installed the main flywheel seal my nice clunk turned into a mushy nothin'. I learned you have to use the dial indicator and ignore your other senses (including common!).

[Bleyseng]

"clunk"? it should be almost nothing as .004-.006 is small movement.

[dtrumbo]

It was almost nothing but clunk is the only word I think of to describe it. The dial indicator told me it was right. The 'clunk' all but completely disappeared once the seal was installed.

[hambone]

Should be little to no "clunk". Clunk usually means too much endplay i.e. tired old engine.

[RussellK]

I hate describing symtoms by sound as it all but gets lost in everyone's translation and makes me crazy in the same way car talk on NPR does. This is not a clunk as in the sound of your forehead hitting the table but more a little uh from the back of your chest so quiet even your best girlfriend can barely hear it with her head resting on your chest. Helpful clarification?

[Kubelwagen]

Sorry I swooned a little at "best girlfriend...chest" what were you saying?

[Gypsie]

One mans clunk and all that...

The dub has gotten into your brain and must be sated... Hook up your dial indicator. It will give you an exact measurement. Use that to guide your senses for future reference.

light perceptible movement (with some perceptible movement) is likely a good snug fit. No perceptible movement may be too tight, but the dial will settle it.

The binding possibilities of 4 main, 4 rod and 4 wrist pin bearings sliding around eliminates any quantitative 'clunk' readings with the engine in place.

[Oregon72]

On my engine I remember "clunking" the thing back and forth 50 times to make sure I was getting it right. If I ever build another engine, it will come with much less OCD, I hope.

Gypsie is correct.

[Amskeptic]

On my engine I remember "clunking" the thing back and forth 50 times to make sure I was getting it right. If I ever build another engine, it will come with much less OCD, I hope.

Gypsie is correct.

With solid lifter engines, people have the valve clearance movement to compare to the endplay. At .006" a crankshaft does get clunky, and is too much.
A light click tick movement is good. The new shims + seal + oring, softens things to where a dial indicator is a necessity, again we have a logic gate:
IF no click > THEN test. (may be good . . . may be tight)
IF click > THEN no test necessary
IF clunk > THEN no test but number would be nice. (definitely not tight, but may be loose)