Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 07-27-2017, 04:39 PM   #1
jetrod
Member
 
Join Date: May 2010
Location: Central NC
Posts: 68
Default crankshaft misaligned--follow -up

In June I posted this inquiry;While chasing down a drive train noise I have found the crankshaft is not centered by about .015 in the horizontal. Dial indicating the recess in the flywheel housing reflects this and dial indicating the dowels that locate the flywheel housing also reflects this. So my transmission and motor (crankshaft) are offset by .015. Is this the source of my drive train noise? I have ruled out the differential and the transmission is recently rebuilt. Will the misalignment eventually effect the transmission? Thanks in advance, Jerry.. Now the results are in!!! I installed a new engine with the crankshaft in the proper place and BEHOLD the drive line noise is gone. SO WHAT DID I LEARN? As it turned out the the old engine that was rebuilt by an established rebuilder and was .025 of center (not .015) and none of my mechanic friends had ever even checked that dimension or knew of anyone who checked that dimension before reassembly, I wasn't alone in not looking for this with a new short block. SO WHAT SHOULD YOU LEARN? When getting ready to assemble a rebuilt engine make sure the builder has checked and warranted that the crank is in the right place. It Will save a lot of aggravation. (The builder who will remain nameless is making good on the error.) Jerry
jetrod is offline   Reply With Quote
Old 07-27-2017, 05:28 PM   #2
Brian T
Senior Member
 
Brian T's Avatar
 
Join Date: May 2010
Location: San Diego,Ca
Posts: 1,377
Default Re: crankshaft misaligned--follow -up

I learned something many years ago, always read the small print on a machine shops invoice, it states that the assembler is responsible for finding any errors with the machining, if you are capable of assembling an engine you must have some mechanical ability.
__________________
Nothing can be made foolproof, ---- fools are ingenious bastards.
Brian T is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 07-27-2017, 05:46 PM   #3
Synchro909
Senior Member
 
Synchro909's Avatar
 
Join Date: Jun 2014
Location: Melbourne, Australia
Posts: 7,496
Default Re: crankshaft misaligned--follow -up

At least the builder is making good. You could have ended up in deep doo doo!
__________________
I'm part of the only ever generation with an analogue childhood and a digital adulthood.
Synchro909 is offline   Reply With Quote
Old 07-27-2017, 06:34 PM   #4
harleytoprock
Senior Member
 
Join Date: Aug 2014
Posts: 438
Default Re: crankshaft misaligned--follow -up

Did this happen because the main babbits were not line bored accurately?
harleytoprock is offline   Reply With Quote
Old 07-27-2017, 08:10 PM   #5
jetrod
Member
 
Join Date: May 2010
Location: Central NC
Posts: 68
Default Re: crankshaft misaligned--follow -up

Definitly
jetrod is offline   Reply With Quote
Old 07-27-2017, 10:55 PM   #6
Bob Johnson
Senior Member
 
Bob Johnson's Avatar
 
Join Date: May 2010
Location: California
Posts: 977
Default Confused

Sponsored Links (Register now to hide all advertisements)
When you checked the flywheel did it "wobble" ? If the babbits were not line bored correctly then the flywheel would still turn without a wobble. However it would not be centered with respect of the housing. If the main journals were ground off center then there would be a wobble.

Bob
Bob Johnson is offline   Reply With Quote
Old 07-28-2017, 09:32 AM   #7
100IH
Senior Member
 
Join Date: Dec 2011
Location: SW Idaho
Posts: 970
Default Re: crankshaft misaligned--follow -up

One more thing to check on the work that has been done, for the shops doing the work and for the customer. Obviously, more in the shops realm of responsibility. Good out come in the end, thank you for posting.
100IH is offline   Reply With Quote
Old 07-28-2017, 10:08 AM   #8
Bob Bidonde
Senior Member
 
Bob Bidonde's Avatar
 
Join Date: May 2010
Location: Long Island, NY
Posts: 3,463
Default Re: crankshaft misaligned--follow -up

Having had a bad experience which ruined a newly rebuilt engine because of the rebuilder's negligence, I have disassembled professionally rebuilt engines since. Not once have I found an engine that was 100% right in my opinion.

Some things I have found on several engines:
> Oil holes in connecting rods and main bearings under-size due to babbitt entering the holes;
> Oil drain pipe inserted in the rear main bearing too far;
> Plug material left in the rear main bearing oil drain passage;
> Valves out of adjustment;
> Valves guides not concentric with seats in the block;
> Improperly cut valve seats;
> Main bearing clearances too tight;
> Excessive oil leakage through studs of rear main bearing;
> Undersized cotter pins in connecting rod caps. These pins move when splashing through oil and eventually break-off into the crankcase;
> Improperly installed oil pan gasket;
> No assembly lube on camshaft and plunger;
> Dry rope seals at front of crankshaft;
> Oil pump tied up with clothesline. The rope disintegrated, clogged the oil pump screen and starved the bearings.
__________________
Bob Bidonde

Last edited by Bob Bidonde; 07-28-2017 at 10:21 AM.
Bob Bidonde is offline   Reply With Quote
Old 07-28-2017, 11:43 AM   #9
Kurt in NJ
Senior Member
 
Kurt in NJ's Avatar
 
Join Date: May 2010
Location: on the Littlefield
Posts: 6,156
Default Re: crankshaft misaligned--follow -up

When I took my 3000 mile after rebuilt engine down for adjusting bearings the rear main was crumbled ----2 other local people had engines done at the same shop--- but not installed, the first one we took apart the Babbitt looked ok, but the wadding was still in the oil holes, the second engine the Babbitt had no oil grooves or hole drilled to the oil pipe

This is when I decided how much worse could I do on my own
Kurt in NJ is offline   Reply With Quote
Old 07-28-2017, 12:28 PM   #10
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,975
Default Re: crankshaft misaligned--follow -up

Along with all those problems, some use there boring equipment with a bend in the boring bar. So when they mount there center boring support there mains will not be in line. problem is many people do not under stand what happens when you do things in a certain way. The only way to rebuild a engine is the right way. there are no short cuts. A lot of engine builders are not real machinest.
George Miller is offline   Reply With Quote
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 03:44 AM.