today when i was installing the crank in the engine it will spin freely until the main with the rear seal is torqued down, then it becomes very difficult to turn.

This is a 455 and the seal is the rope version

Thanks

today when i was installing the crank in the engine it will spin freely until the main with the rear seal is torqued down, then it becomes very difficult to turn.

This is a 455 and the seal is the rope version

Thanks

Was this rear main cap original to this engine? If not, it will have to be machined with the replaacement caps in place. Otherwise the bearings may be oversized more than the crank was turne. You have to accurately measure the crank with a micrometer. If everything adds up, it is most likely a bearing or dirt problem.

it is original to the engine, but the engine does turn freeley without the seal in place.

and the bearing clearence checked out ok

Check to make sure you are using the correct size rope seal, The one for a 400 is bigger than for the 455. I once used the 400 seal in a 455 and ended up cracking the block when I torqued the rear cap down.

Toss that rope seal in the trash and get a BOP, and forget about it!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Elohssa:
Check to make sure you are using the correct size rope seal, The one for a 400 is bigger than for the 455. I once used the 400 seal in a 455 and ended up cracking the block when I torqued the rear cap down. </div></BLOCKQUOTE>

thanks i previously read the oppisite, that would explain it however this one was never so tight that the block would crack

Sounds normal to me. I've never found a way to pre-shape a rope seal so that it doesn't have a lot of initial drag. In the engine I'm building now, I temporarily tightened the rear cap with a ring of .005" brass shim stock between the crank and the seal. After removing the brass and reassembling, it still takes about 10 Ft.Lb. to turn the crank. But this is no different from my prior experience, and it's always worked out fine.

I don't like the new rope seals, don't compress as good as the old asbestos ones did. I used to use a wood hammer handle and vasoline to preshape/form the seal. If you did not form the seal it will be tight, and probably leak. Swap to the BOP seal if you can. -Jim

I had the same deal when I rebuilt my 400, by the time all the rods and pistons were installed the crank was turning over pretty good with no oil leaking for 6 years. I did use a large socket to pre form the seal. Dave K.

Haven't used a rope sael in quite a while.
Yes, I agree. The newer rope seals are really flimsly, hard to cut and feels like a cooked piece of spagetti. LOL.

Without the sauce. http://forums.performanceyears.com/g.../icon_wink.gif

To answer the question, it should take a significant amount of effort to turn the crank once the seal is installed.
That said, I too, recommend the BOP seal. I'm not sure I agree with the negative comments on the "new material" ropes. We installed MANY for years, without issue. Had one (1) fail. Had a coupl eof the Caddy seals fail, too. The Viton (BOP) seal is the modern solution to an age-old problem.