Rope gasket question??

[Lynn Patrick]

1951 8N. I am in the process of rebuilding the engine as it smoked really badly. Have installed the 2 rope crankshaft seals in the block & now can't tighten the main bearing caps at all before I can't turn the crankshaft even by prying with a big screwdriver on the flywheel. What's the trick here? Any help is appreciated!
Thanks,
Lynn

 

[Dean]

Are the rope seals in the proper locations and properly trimmed?

Do not torque the main caps until you are certain to avoid block and crankshaft damage.

Dean

 

[Lynn Patrick]

I think they are. They look like they are. Is there a good way to make sure?

 

[TheOldHokie]

(quoted from post at 16:01:00 09/16/14) 1951 8N. I am in the process of rebuilding the engine as it smoked really badly. Have installed the 2 rope crankshaft seals in the block & now can't tighten the main bearing caps at all before I can't turn the crankshaft even by prying with a big screwdriver on the flywheel. What's the trick here? Any help is appreciated!
Thanks,
Lynn

Verify the problem is the seals. Can you tighten the caps and turn the crank without the rope seals in place?

TOH

 

[Lynn Patrick]

Yes

 

[Plane Bart]

I used a large socket and tapped on it with a hammer to get
mine seated trimmed the edges with a new razor blade I also
have heard some say to add a dab of gray per a text to the
ends where we cut them.

 

[NOXJohn]

Rope seals need to be soaked in oil several hours
before installation. Once installed I coat with
engine lube. If you have not soaked them they
should be removed, soaked and reinstalled.

 

[Hobo,NC]

I install them DRY and coat the sealing surface with lube... I am unsure WHY the seal provided for a N is so much different than anything else I have ever worked on... I believe you could soak them till ell freezes over and they still will be hard... I have been into several N's that I think have never been into the original seal is a standard limp rope seal and nuttin like the ones provided in a gasket set we see today. Fel-pro offers a limp rope seal but I think its a gamble to use it because its to small...

I have installed it both ways it made no difference if its locking up the crank its installed wrong soaking it in oil will make no difference... My money is on he did not trim the ends close enuff are set the seal as been noted...

 

[Lynn Patrick]

Thanks all. I soaked the seals for several days before installing them, but (as Hobo said) they did not soften at all. I'm going to pull the crank today to see what the problem is. Will report findings when I know more.
Thanks again.

 

[Lynn Patrick]

I just pulled the crank & checked the seals. The rear looked like it could be seated more so I took a large socket as Plane Bart suggested & tapped them both in solid, then put the crank back in & put on the flywheel. I still cannot turn the engine if the main caps are snugged up at all. I have not torqued anything or even tightened the caps too tight.

 

[Lynn Patrick]

As Pogo once said, "We have seen the enemy and he is us." I found the problem, and it is me (with help from the parts supplier)
I went back & re-read all the responses & realized I had answered TOH without really reading his question, so I decided to try his suggestion. I pulled the mains again, cleaned them up & checked them before pulling the crank. They are .020 overs in a box marked standard. It's my fault for only checking the box label, but somebody messed up at the most reliable 8N's parts house!
Guess I reorder some parts!
Thanks for the help.
Lynn

 

[Hobo,NC]

Always test fit with out the seals All I do is install the bearing shells in the block lay the crank in with out the caps and make sure it rotates free...

 

[Tall T]

Wrong shells were my first guess yesterday and I should have posted. Same thing happened to me in 1976 with my first rebuild. It was a 235 Chev (1953) with a wick seal. The block was in my huge kitchen and a younger friend who was taking a machine shop course in school was helping me but everything was so rushed with his girlfriend waiting impatiently outside, that i was as nervous as all get out.

So anyway, we put the newly turned crank in, he torques down a couple of mains and the shaft won't turn. Freaking out, I says, "It's OK Julienne, I'll figure it out and do it myself."

So on to the ferry and off to the Vancouver library I go, to study the 1953 shop manuals which fortunately for me started off with:
"This manual was written not only for the seasoned mechanic, but for the man of little experience." Bingo!

I keep forgetting and would have to look it up (again) but when "rolling" the seal into the groove one rolls either towards the center or from the center outwards. It is important especially when you don't have a seal installer.
I left 1/16" higher than the block face but narrowed/shaped that part a little to make sure that no wick interfered with the cap to block faces (right or wrong). I cut the wick flush with the cap mating face. I think that the machinist who turned the crank told me that.

No soaking but I coated it liberally with Lubriplate before installation.

Cheers,
Terry

P.S.

Looked up "rolling the seal in" for you, from an original 48 to 51 shop manual.

[b:0aaaeb74e3]Note:[/b:0aaaeb74e3] When rolling the seal (using a round rod) start at one end and roll it to the center of the groove. Then starting at the other end, again roll toward the center.

[b:0aaaeb74e3]Note:[/b:0aaaeb74e3]
To prevent possibility of pulling seal out of groove a round block of wood the same diam as the crankshaft may be used to hold packing firmly in place while the ends are being cut off.

The book says to cut the seal flush with the cap but doesn't mention how to cut the block side.

FORGOT TO MENTION:
The reason my shaft wouldn't turn was because unbeknownst to all my incorrect advisors, my main bearing caps had to be shimmed with brass shim stock. Lengthy process with plastigage but the operation was a success. .0017 on the mains.

 

[showcrop]

Are you using plastigauge?