(800) 853-2651
SHOP NOW

Engine rebuild dilemma

G

Golden Retrievers

New User
Rebuilding 49 8N. In assembly phase. Should crankshaft turn after installing pistons and rings without fly wheel on? New valves and guides are in. Pistons sleeves were honed and within tolerance. The main bearings were plasti gauged within tolerance. connecting rod bearing were plasti gauged and within tolerance.
 
(quoted from post at 15:48:26 08/15/20) Rebuilding 49 8N. In assembly phase. Should crankshaft turn after installing pistons and rings without fly wheel on? New valves and guides are in. Pistons sleeves were honed and within tolerance. The main bearings were plasti gauged within tolerance. connecting rod bearing were plasti gauged and within tolerance.
Click to expand...
bsolutely........but rope type seals can make them really tight & need some torque to rotate.
 
(quoted from post at 20:48:26 08/15/20) Rebuilding 49 8N. In assembly phase. Should crankshaft turn after installing pistons and rings without fly wheel on? New valves and guides are in. Pistons sleeves were honed and within tolerance. The main bearings were plasti gauged within tolerance. connecting rod bearing were plasti gauged and within tolerance.
Click to expand...

Used assembly lube. using cheater bar and still wont turn Going to try standard bearings. Had 10 over which it measured as.
 
How easily did the crank turn after you torqued the main bearing caps down, but before you hooked the rods to the crank? It should have turned readily in the
bearings (assuming the camshaft wasnt in as well). There is a lot of drag on those rings against the freshly honed cylinder walls so you might not be able to turn
it by trying to push down on a crank throw, but you should be able to turn it with moderate pressure on a socket and ratchet on the front pulley nut.
 
(quoted from post at 17:30:40 08/15/20)
(quoted from post at 20:48:26 08/15/20) Rebuilding 49 8N. In assembly phase. Should crankshaft turn after installing pistons and rings without fly wheel on? New valves and guides are in. Pistons sleeves were honed and within tolerance. The main bearings were plasti gauged within tolerance. connecting rod bearing were plasti gauged and within tolerance.
Click to expand...

Used assembly lube. using cheater bar and still wont turn Going to try standard bearings. Had 10 over which it measured as.
Click to expand...
10 over???"
 


One little point in your procedure is to test turn it at stages during assembly. ie. after mains, after rear main seal, after each rod. So that you find out early on and can ID any problem spots.
 
(quoted from post at 08:06:08 08/16/20)

One little point in your procedure is to test turn it at stages during assembly. ie. after mains, after rear main seal, after each rod. So that you find out early on and can ID any problem spots.
Click to expand...
Shirley" everybody does that, right?
 
Why would you try original size bearings if the crank is turned .010 under and you plasti gauged them and had the correct clearances? Remove the rod caps and see if it turns then. It will be stiff because of the rope seal. Then, one by one replace the rods caps and make sure you don't have a cap installed 180 degrees off. After each one try turning the crank. It will get more stiff with each rod being attached. There is a fair amount of drag with new rings and sleeves. I've had them where I could hardly turn it over with a breaker bar. If all your bearing clearances are good, you should be good to go. If you install standard size bearings on a .010 under crank, it will affect your oil pressure and, may damage the bearings and crank because of too much clearance
 
If you replaced main cap/oil pump mount. need to have it line bored.
make sure main caps are installed in correct location and direction.
 

If a cap is replaced on an expensive motor you get it line bored. There were no caps replaced on this one. Ad it is only an 8N.
 

Any luck ?
I too am assembling my 49 8n engine , I found that the rope seal does grab the crank pretty good even with assembly lube.
So I've gotten to putting a dab of lube on the crank journal before and after each test turn when torquing the bearings.
Using one piece rubber seal on the front , best of luck :)
 
I wish posters would always get back, to the forum, as to what they found out to be the problem in cases like this. one way or the other.

So, many people try to help with, no way to know, if there time and effort resulted in a solution to the problem. Just my pet peeve. Sorry for the rant.
 
(quoted from post at 13:44:08 09/10/20) I wish posters would always get back, to the forum, as to what they found out to be the problem in cases like this. one way or the other.

So, many people try to help with, no way to know, if there time and effort resulted in a solution to the problem. Just my pet peeve. Sorry for the rant.
Click to expand...

No problem 32vicky, somebody makes this same post once a month. Your turn came up.
 
You must log in or register to reply here.

Similar threads

L
Engine Rebuild Questions 172cid Sleeveless
2
Replies
28
Views
860
TheOldHokie
TheOldHokie
E
NAA Engine Rebuild
Replies
9
Views
302
Ebenezer
E
D
ford 850 rebuild
Replies
12
Views
338
used red MN
U
R
Engine seal question for 52 8N
Replies
7
Views
772
showcrop
showcrop
R
Kohler 301S ,Don''t get screwe
Replies
2
Views
622
Riderrider
R
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top