|
|
|
|
Joined: Jul 2003
Posts: 52
Active BB Member
|
OP
Active BB Member
Joined: Jul 2003
Posts: 52 |
Putting together my engine. Torque the main bearings and see a hair line crack on one of them. What can be done ?? can it be fixed or just replace it ??
|
|
|
|
|
Joined: Dec 2000
Posts: 3,332
1000 Post Club
|
|
1000 Post Club
Joined: Dec 2000
Posts: 3,332 |
Dear Mr. C;
Are you speaking of the bearing cap or the insert??
JM...
John M., I.I. #3370
"There are no shortcuts to any place worth going". -Anon
|
|
|
|
|
Joined: Jul 2003
Posts: 52
Active BB Member
|
|
OP
Active BB Member
Joined: Jul 2003
Posts: 52 |
The Cap. Is it not true that the caps are machined for the engine. changing caps you have to machine the crankshaft.
|
|
|
|
|
Joined: Dec 2000
Posts: 3,332
1000 Post Club
|
|
1000 Post Club
Joined: Dec 2000
Posts: 3,332 |
Dear Mr. C;
Okay; If you have a cracked cap you should have it 'magna-fluxed' to see if the crack is deep enough to matter. Most can be repaired.
Each crank journal is a different diameter and each cap is machined for/to the block. This is why they can't be interchanged etc. One could "I suppose" turn the center 2 180 by not marking them prior to dissambly on some models.
If you have to repair/replace one it is possible to use shims to make up any differences. It just depends how far off center it is.
Your Machine Shop can advise you further after inspecting your cap. Rarely are they bad enough to worry with.
In the 50s when all we had were the 216s & early 235s to "hop up" this was a concern when running 10-1 in drag engines. The later 55-62 235/261 engines rarely have this problem running stock.
Good luck, John M.....
John M., I.I. #3370
"There are no shortcuts to any place worth going". -Anon
|
|
|
|
|
Joined: Jul 2003
Posts: 52
Active BB Member
|
|
OP
Active BB Member
Joined: Jul 2003
Posts: 52 |
Thanks John will do that. I do have one more
block just in case.
|
|
|
|
|
Joined: Oct 2002
Posts: 125
Contributor
|
|
Contributor
Joined: Oct 2002
Posts: 125 |
If the cap is really cracked then get a cap from the same journal on a scrap block. You then must have your machine shop align bore the bearing bores. What they do is remove a little bit of material from all the cap split lines and rebore all the bearing caps on one setup. This keeps everything straight.
Gael
Gael
37 chevy sedan, 261,t5
57 pickup
58 burb
|
|
|
|
|
Joined: Dec 2000
Posts: 3,332
1000 Post Club
|
|
1000 Post Club
Joined: Dec 2000
Posts: 3,332 |
Dear C;
Gael is right. However; this is a costly & time consuming process which might not be necessary.
Let's try to fix the cap if needed first.
Then we can consider that option.
JM....
John M., I.I. #3370
"There are no shortcuts to any place worth going". -Anon
|
|
|
|
|
Joined: Apr 2000
Posts: 540
Major Contributor
|
|
Major Contributor
Joined: Apr 2000
Posts: 540 |
There was a guy here a year or so ago ago from my area with the same problem.He got a cap from a another block,it fit perfectly,no align boring necessary.May be the case for you also.
I believe the best think you can do with a cracked main cap is toss it away.
70 Triumph 650 cc ECTA current record holder
|
|
|
|
0 members (),
533
guests, and
35
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
|
|
|
