The Stovebolt.com Forums Home | FAQ | Gallery | Tech Tips | Events | Features | Search
Thanksgiving

Much to be
thankful for

YOU!
The Stovebolt Collective

Thankfulness year 'round.
All around!
Searching the Site

Get info about how to search the entire Stovebolt site here. To do a search for just the forums, get those details in the IT Shortbus fourm.
Old Truck Calendars
Months of truck photos!
Nothing like an old truck calendar

Stovebolt Calendars

Check for details!


Who's Online Now
1 members (Bowtie john), 86 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums60
Topics127,654
Posts1,046,323
Members46,391
Most Online1,229
Jan 21st, 2020
Step-by-step instructions for pictures in the forums
Previous Thread
Next Thread
Print Thread
Page 2 of 4 1 2 3 4
Rcnicholl #1398930 Fri Feb 26 2021 12:49 AM
Joined: Dec 2008
Posts: 1,113
5
'Bolter
Plastic gauge it, and see what you have for clearance.


Brian
1955.2 3100 Truck


The older I get the more dangerous I am!!!!!
Rcnicholl #1398945 Fri Feb 26 2021 02:11 AM
Joined: Jun 2011
Posts: 4,650
E
'Bolter
Measure the OD of the crank with a micrometer to compare when you plastigauge it.

Ed


'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires.
'47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle.
'54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed.
'55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
Rcnicholl #1398992 Fri Feb 26 2021 02:25 PM
Joined: Feb 2021
Posts: 12
R
New Guy
Good suggestion. Will see about doing that.

Rcnicholl #1398997 Fri Feb 26 2021 03:08 PM
Joined: Feb 2004
Posts: 25,315
H
Kettle Custodian (pot stirrer)
The post I made last night didn't show up for some reason. Absolutely DO NOT try to shim the rod for a better fit. That is only done on Babbit bearing engines, and no 261 was ever made with Babbit rods. Remove the cap and bearing shells from the tight rod and inspect the crankshaft and bearings for debris, scoring, or other causes of the sudden lockup. I'm going to guess a piece of debris left over from an oil passage has found its way to the rod journal and jammed the works. Measure the diameter of the rod journal with a micrometer, NOT a dial or digital caliper. A properly ground .020" undersize journal should measure 2.2925" +/- less than .001". There should be no scratches or score marks on the crankshaft and no debris imbedded in the bearing shells. I have an idea that the engine builder might have been a little careless about assembling the engine in a clean environment or he did not clean the oil passages properly. Oil clearances are less than the thickness of a strand of hair, and a dirty buildup has wrecked untold numbers of engines. Good luck!
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!"
Abraham Lincoln

Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self.
Ernest Hemingway

WAG MORE- - - - - -BARK LESS!
Rcnicholl #1399009 Fri Feb 26 2021 04:50 PM
Joined: Jan 2013
Posts: 1,685
S
'Bolter
Last year I bought a complete 235 off craigs list claimed it was newly machined and assembled but would not turn had zero miles on it. I got the thing dirt cheap almost free because the owner was done with it and hated looking at it and reminded him of how much money he spent on it. It was bound up more that a 90 year old on morphine. Upon disassembly found that the crank was turned .020 under and they had .030 under bearings in it. Advise to start measuring but first would look at a poor installation on the rope seal.

Steve


1953 Chevrolet 3100
261 cu inch, sm420, 3.55 rear, torque tube still,omaha orange, still 6 volt, RPO green glass, side carrier spare, all done
https://www.youtube.com/watch?v=Bli...n05i04t1aokgm4p04jiwgffwhyyih5xbk0h00410
1964 GMC 1000
305 Big Block V6, sm420, the next cab off restoration
Rcnicholl #1399050 Fri Feb 26 2021 11:03 PM
Joined: Feb 2021
Posts: 12
R
New Guy
Mic'ed the crank at 2.285
Plastigauge was at .0015 at cylinder #6 which was binding

Not sure whether to add a shim to get min. .002 clearance or put it back together and assume it was 5 year old assembly lube that locked it up. That seems to be flushed out by the oil frim spinning the oil pump. So I'm thinking about pulling the individual bearings and cleaning them and checking all the clearances with plastigauge. If it checks out I put it back together and continue to prepare to start it up for the first time.

I welcome any ideas and thoughts?

sstock #1399053 Fri Feb 26 2021 11:19 PM
Joined: Feb 2019
Posts: 2,953
AD Addict
Originally Posted by sstock
Last year I bought a complete 235 off craigs list claimed it was newly machined and assembled.........Advise to start measuring but first would look at a poor installation on the rope seal.

Steve

I agree with Steve. My 235 was newly machined and rebuilt before I bought my truck and the previous owner had nothing but issues. After wrangling this engine for more than a year, I disassembled it and the clearances were all over the place to the point I had to get it totally remachined by a reputable machine shop. There is allot of shops that do shoddy work.

My point being you really should disassemble, clean and check the clearances and other to satisfy yourself that you have a good engine.


Phil
Moderator, The Engine Shop & Interiors

1952 Chevrolet 3100
Project Journals
Stovebolt Gallery Forum

‘59 235 w/hydraulic lifters
“Three on the Tree” & 4:11 torque tube
12v w/ Alternator
Rcnicholl #1399079 Sat Feb 27 2021 02:21 AM
Joined: Feb 2004
Posts: 25,315
H
Kettle Custodian (pot stirrer)
2.285" is not a correct undersize, no matter what the Plastigauge says. Here's a few correct measurements:

STD.- - - - -2.311-2.312
.010" undersize- - - -2,301- - - -2.302
.020" undersize- - - -2.291- - - -2.292
.030" undersize- - - -2.281- - - -2.282

A 20 under bearing will be sloppy loose, and a 30 under will lock it up.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!"
Abraham Lincoln

Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self.
Ernest Hemingway

WAG MORE- - - - - -BARK LESS!
Rcnicholl #1399236 Sun Feb 28 2021 02:42 AM
Joined: Feb 2021
Posts: 12
R
New Guy
The original measurements I made with a digital calliper which wasn't accurate enough. My micrometer doesn't go over 2" so I am borrowing one from a friend and will get back with the real measurement.

Rcnicholl #1399243 Sun Feb 28 2021 03:58 AM
Joined: Dec 2017
Posts: 1,183
D
'Bolter
In your previous post you queried about installing a .002 shim on the rod to gain a little clearance. It’s the second time you mentioned it. Hot rod Lincoln previously advised you that the rods in your motor should never be shimmed. If that wasn’t enough warning, let me warn you a second time, no shims on the rods. Those are precision bearings that require the proper crush, clearance and clamping force to be round, stay in the rod and work as they should. Installing a shim is just an invitation to a rod bearing failure. So scratch that one off your list of possible solutions. Believe me, having that kind of catastrophic failure is no fun at all.

Re measure the journal. If it comes up to specification, clean everything up, then coat the bearing with lubriplate’s white engine assembly lube.

https://www.movingupgaragedoors.com...msclkid=fb5669cc71b710217e8509f76540e0ec

Then see if it turns, by hand, not using the starter. If it does, you are good to go.

Last edited by Dragsix; Sun Feb 28 2021 04:00 AM.

Mike
Page 2 of 4 1 2 3 4

Moderated by  Phak1, Woogeroo 

Link Copied to Clipboard
Home | FAQ | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Powered by UBB.threads™ PHP Forum Software 7.7.5