To torque, or not to torque

ICOM 756 · #1 01-31-2021, 03:56 AM

I rebuilt a k301. I did the 30 backed off then retorqued to 24 fp on the Connecting Rod. Well I messed up and motor had some grit in it, and was getting to much metal in oil. So I pulled it apart, and hope I fixed it with a good hot soap bath.

anyways...
Being the rod was torque to 30 already, do I need to retorque to 30 then 24, or just to 24fp ??

Bryan S · #2 01-31-2021, 04:13 AM

Quote:

I rebuilt a k301. I did the 30 backed off then retorqued to 24 fp on the Connecting Rod. Well I messed up and motor had some grit in it, and was getting to much metal in oil. So I pulled it apart, and hope I fixed it with a good hot soap bath.

anyways...
Being the rod was torque to 30 already, do I need to retorque to 30 then 24, or just to 24fp ??

The reason for the torque to x then back off the nut, then re-torque to x is for when you put a new rod/s in an engine, and one would hope, that new bolts were used as well but... people are cheap, and some are in a really big hurry.

It's done to help eliminate rod bolt stretch.
If your bolt was new, and you did it the first time, you do not need to do it again. HTH

finsruskw · #3 01-31-2021, 08:51 AM

Any new rods I have bought that were in rebuild kits already have the new correct bolts for that application.

ol'George · #4 01-31-2021, 09:58 AM

Always, always,.....
wash a rebored block with hot soapy water to get the fine honing particles out of the engine, paying special attention to the cylinder bore.
I wash a block first with gas to get any remaining contamination out, blow with airhose then the hotsoap water, followed again with a the air hose to dry the block. Small instant rust is of no concern to the bore,after drying. if not going to assemble, soon, do coat the cyl wall with oil and cover with plastic to prevent contamination. If you are getting contamination in the crankcase, do a through cleaning and inspect the cylinder/crankshaft for damage, from it Clean the piston and ring groove area.
Assembly of an engine cannot be too clean.

ICOM 756 · #5 01-31-2021, 01:53 PM

Quote:

Originally Posted by ol'George

Always, always,.....
wash a rebored block with hot soapy water to get the fine honing particles out of the engine, paying special attention to the cylinder bore.
I wash a block first with gas to get any remaining contamination out, blow with airhose then the hotsoap water, followed again with a the air hose to dry the block. Small instant rust is of no concern to the bore,after drying. if not going to assemble, soon, do coat the cyl wall with oil and cover with plastic to prevent contamination. If you are getting contamination in the crankcase, do a through cleaning and inspect the cylinder/crankshaft for damage, from it Clean the piston and ring groove area.
Assembly of an engine cannot be too clean.

ya know i thought i had it clean. but nope lol brake clean and new rags dont work lol ...
it got on the crank side of rod. grrrrr but i was watchin oil and maybe 3 hours total on it.. 2 oil changes. i feel i have the rod back.
the piston has the scuf marks 90degrees off the wrist pin sides. only 2 spots. cam lifters seem untouched thank god lol

i called the shop up. he said same with hot soapy water lol think i would have known this .. grrr

i used 1000 grit on the rod . very little bit.

pix below nail doesnt catch anything in cycl not touched it yet... rod is cleaned up but this is what i looked like grrrr
i did have the rod hole towards the cam for the oil.. lol

IMG_2601.jpg
IMG_2682 smaller.jpg
IMG_2681.jpg

ol'George · #6 01-31-2021, 05:23 PM

Yes that is debris scuffing.
Actually after a gas bath, I hit them with the garden hose, then the air hose, then visually see if I missed something then the hot soapy water bath.
and the air hose again.
Check the crankcase breather as well as the valve spring area.
Every crack and cranny has to he clean.
Good news is, I don't see and real damage to be of concern.

ICOM 756 · #7 01-31-2021, 01:44 PM

Quote:

Originally Posted by Bryan S

The reason for the torque to x then back off the nut, then re-torque to x is for when you put a new rod/s in an engine, and one would hope, that new bolts were used as well but... people are cheap, and some are in a really big hurry.

It's done to help eliminate rod bolt stretch.
If your bolt was new, and you did it the first time, you do not need to do it again. HTH

Yep, that's what I was thinking. It's the pre-stretch. Yes, was new rod and bolts from Isave.