Flywheel dilemma

[Robin Robbins]

So here’s whats happening. My engine is a 1956 normal that i’ve never run (its on a stand). Ive gone through it to the extent of pulling the heads and cleaning up the valves and pistons and all that. Did not crack the case. Put it all back together, and was at the point of checking to see if all the nuts and bolts were tight and maybe putting some oil in it when I put new points in and and as Im getting ready to gap them I discover the engine wont turn (as in with a wrench). The last thing I did was put a new flywheel and clutch on (new stuff all the way through), checked the play (all good) and torqued to about 375-rechecked play, no change.
So the only thing I can think of, since it turned (with the expected resistance) prior, that its something to do with the flywheel.
Much moaning and complaining as I knew I’d have to get another flywheel nut and gasket but I pulled the clutch and flywheel off.
Engine turns fine. Next step, clean it up and try putting it back together and try again. Same result. When torqued beyond a certain point it locks up. Tried the old flywheel and nut, same result. Can anybody tell what Im missing here?

[Phil Planck]

Flywheel wont turn, but moves back and forth with correct endplay when fully torqued?

[Robin Robbins]

thats it. Tried turning it from front and back.

[Vic Skirmants]

If the flywheel still moves front and back when checking endplay, that should rule out a seizing #1 main bearing. Unless the "endplay" is actually the bearing moving in the case, but not permitting rotation because of the locating dowel pin?

[Robin Robbins]

The flywheel wont rotate when its torqued down-I tried to turn it from the front and back and it wouldnt move (Using a wrench). I checked endplay before I torqued it down (with the old flywheel nut) and after (with the new one)and got the same reading on the digital indicator.

[Robin Robbins]

When the flywheel isnt on, the engine turns with the normal resistance from the pistons.

[Vic Skirmants]

Who supplied the flywheel? But you did say the old flywheel did the same.
Hm.

[Robin Robbins]

Ive had it for awhile but I think I got it from PartsKlassic. And, yup, I thought of that and did try the old one.

[Wes Bender]

That's a strange one...... Don't think that I'm questioning your abilities, but are you remembering to remove the flywheel lock on the engine stand after torquing the nut?

[Robin Robbins]

No problem with questioning my abilities, given that Ive done sufficiently similar things in the past. I try to think of them as learning experiences but for some reason they still feel like sand in the machine. So, yes, I did remember to take the lock off. If it turns out to be something simple that Ive just overlooked,even better. Any thoughts or ideas here are appreciated as Im still stumped./Regards/Robin

[Wes Bender]

Buy yourself a Scat flywheel nut. You can reuse them. Leonard has them at Shasta Designs. Gotta replace the soft iron seal each time though.

If nothing else has been done to the crankshaft except the removal and re-installation of the flywheel/clutch, I'm leaning towards Vic's thought about a "clamped" #1 main bearing moving, but won't rotate due to the pin. I would pull the seal and try to turn it without the spacer. You may have a spacer that is too thick. Unfortunately, if Vic is correct, you get to split the case and replace the #1 main bearing......if I'm not missing something here.

[Robin Robbins]

Well, I pulled the heads/carburetors/fuel pump/shroud etc but as noted, didnt crack the case. Given that trying the old flywheel gave the same lock up, it may be the main bearing. Thats a fairly disheartening thought. I will try pulling the seal and spacer anyway, as its no big deal to replace the seal and if it goes the other way it wont matter. I'll look into the Scat flywheel nut too, since I have to order another one anyway. Any body has any other ideas as to what it might be, do let me know. /Robin

[Robin Robbins]

Checked my notes-I got the clutch and flywheel from SierraMadre, though I dont think that is particularly significant. That said, Im going to get out my dial indicator and see if I can find any flex (front to back) in the crankshaft. As noted, Im fairly unhappy about this but I realize its in the realm of first world problems.

[Vic Skirmants]

I use the gland nuts from Stoddard. Perfectly adequate for re-use.

[Harlan Halsey]

+1
It will be interesting to hear the cause when you finally find it. I assume that you are using the Porsche flywheel shim rather than the VW set, and that you measure the .005" end float with a dial indicator between the flywheel and the case. A light tap with a mallet should move the crank back and forth consistently, and the flywheel should turn by hand and only with the distributer installed. (I set the end play before installing the pistons.)
Were it my engine, I would have completely disassembled it, cleaned, measured, magnafluxed, reconditioned, and balanced it. Then if such a thing happened, It would be a more easily solved mystery. (Like the time I didn't line the dowel pin hole with the dowel pin, or turned the engine backwards before installing the distributer.)