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 01-31-2017, 03:34 PM   #1
oldredford
Senior Member
 
Join Date: May 2010
Location: Moncks Corner, SC
Posts: 398
Default Insert bearings

The last 2 Model A engines that I had inserted the rear main bearing failed due to lack of lubrication. The bearing spun cutting the oil flow. The insert shell actually welded onto the crank journal. A big mess. Has this happened to you? The first engine the bearing failed at 1000 miles and the second engine the bearing failed after 10 minutes of running in the garage. I believe inserts are not designed with a gravity flow oil system. Why is it the center main and forward main not effected? Now the first engine has been repaired with new inserts and this engine is running fine for the past 2 thousand miles. The second engine is being repaired, so I will have to wait the outcome.

Last edited by oldredford; 02-02-2017 at 05:09 AM.
oldredford is offline   Reply With Quote
Old 01-31-2017, 03:41 PM   #2
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,515
Default Re: Insert bearings

Quote:
Originally Posted by oldredford View Post
Has this happened to you?
Not to me, but yes I have seen/heard this.
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 01-31-2017, 04:02 PM   #3
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,278
Default Re: Insert bearings

Yes, it has happened to me. The correction to this is that additional oil clearance needs to be achieved.

You say the bearing spun and cut the oil flow...I disagree. The bearing to shaft clearance was likely too little and it was the lack of oil that heated up the surfaces to the point of rubbing and melted the bearing material to the crankshaft The spinning of the insert in the block housing bore was the last thing that occurred as the engine locked up.

The manufacturer of the bearings I use stated .00175" as the correct clearance for the main bearings. That clearance did not work well for me when he switched the final surface of his insert shells from Babbitt to bearing grade aluminum. I find that the aluminum lined rear main insert should have .002" to .0022" to be reliable, (means no lock-up) and leak free. The front and center mains can finish at .00175" and not be an issue with running tight. JMO: The best clearance for all three journals is .002".

I have a Sunnen precision honing machine with the proper sized mandrels to hone the aluminum insert bearing shells for the proper clearance. The Sunnen rep. advised me as to the correct stones and hone oil to use for the aluminum. I built a fixture to clamp and hold the bearing shells at the same tension (crush) they are installed from two rear main caps. The final fitting of the mains requires about 10-30 minutes depending on how many need to be adjusted but the precise clearance is worth the time.

The description you give about the insert shells welding themselves to the crankshaft is a very real occurrence. The inserts, I use with an aluminum bearing surface, are prone to this happening if there is inadequate clearance. I discovered the lock up issue when breaking the engines in on a dyno at full operating loads and high rpm after an extended session of operation.

How to save your crankshaft if this happens: I discovered that the aluminum bearing material can be removed from the crankshaft journal by careful use of muriatic acid. Be careful when using this stuff, it is nasty. Goggles, gloves and a well ventilated area (best outside and stand upwind of the acid bath). Carefully knock the shell from the journal by using a chisel at a low angle on the seams. They will pop off. Next, submerge the end of the crank in muriatic acid for 5 minutes, remove and scrub with a bronze wire brush. Repeat until it is all removed and rinse well with water. Do not leave the end of the crank submerged for an extended period of time or it will ruin the surface of the journal (believe me...don't ask!) Some may suggest you neutralize the acid with baking soda, I did not bit washing it with a slurry of baking soda and water would do so.
After all the aluminum is removed, polish the journal and you are ready to fit the new bearing.

I am sorry for your trouble...it is frustrating. Inserts have been a good product for me when they are installed with the correct oil clearance. I have over 150 of them operating very well with insert bearings.

PM me if you need more info or help.
Good Day!

www.durableperformance.net

Last edited by Dave in MN; 02-03-2017 at 09:33 AM.
Dave in MN is offline   Reply With Quote
Old 01-31-2017, 06:56 PM   #4
jm29henry
Senior Member
 
jm29henry's Avatar
 
Join Date: Sep 2010
Location: michigan
Posts: 1,057
Default Re: Insert bearings

My engine has around 2000 miles on it at how many miles did you have your failure do I need to worry is,there Anything I could do,to,prevent it
jm29henry is offline   Reply With Quote
Old 01-31-2017, 07:12 PM   #5
George Miller
Senior Member
 
George Miller's Avatar
 
Join Date: May 2010
Location: NC
Posts: 2,975
Default Re: Insert bearings

One problem is it is a long ways for the oil to get to the back of the bearing with out pressure oiling. The way I fix the problem is a oil groove in the upper bearing.
George Miller is offline   Reply With Quote
Old 01-31-2017, 08:58 PM   #6
KMeredith87
Senior Member
 
KMeredith87's Avatar
 
Join Date: Mar 2013
Location: San Antonio
Posts: 172
Default Re: Insert bearings

Sponsored Links (Register now to hide all advertisements)
I had it happen to me. Granted not sure if it was really due to lack oil in my case...had a blown head gasket and also the crank pulley broke on me so the water pump wasn't turning. I got lucky somehow and was able to turn the crank and swap the inserts and all was well...that was a few thousand miles ago...hate to hear it happened to you but I am building another engine now and will be doing inserts again...
KMeredith87 is offline   Reply With Quote
Old 01-31-2017, 09:12 PM   #7
Art Newland
Senior Member
 
Art Newland's Avatar
 
Join Date: Mar 2016
Location: Lynden, WA
Posts: 1,514
Default Re: Insert bearings

Dang... I hate to hear this, was thinking going this direction on a rebuild. I wonder how wide spread a problem this is?
Art Newland is offline   Reply With Quote
Old 01-31-2017, 10:01 PM   #8
James Rogers
Senior Member
 
James Rogers's Avatar
 
Join Date: May 2010
Location: Asheville,NC
Posts: 3,101
Default Re: Insert bearings

This is the exact reason I quit doing inserts. Like most modern "improvements", these engines are not designed to work with them. Babbitt only.
James Rogers is offline   Reply With Quote
Old 01-31-2017, 10:34 PM   #9
Bruce Adams
Senior Member
 
Bruce Adams's Avatar
 
Join Date: May 2010
Location: Northport, NY
Posts: 1,595
Default Re: Insert bearings

I have enjoyed my Inserted Bearing Engine from Antique Engine Rebuilders in Skokie, IL for about five years and 10,000 trouble free miles. I would say many others share my experiences with Inserts.
Bruce Adams is offline   Reply With Quote
Old 01-31-2017, 10:46 PM   #10
CarlG
Senior Member
 
CarlG's Avatar
 
Join Date: Nov 2010
Location: Anchorage, Alaska
Posts: 8,591
Default Re: Insert bearings

I have close to 2,000 miles on my inserted engin. No complaints.
__________________
Alaskan A's
Antique Auto Mushers of Alaska
Model A Ford Club of America
Model A Restorers Club
Antique Automobile Club of America
Mullins Owner's Club
CarlG is offline   Reply With Quote
Old 01-31-2017, 10:58 PM   #11
CT Jack
Senior Member
 
CT Jack's Avatar
 
Join Date: May 2010
Location: Hebron, CT
Posts: 209
Default Re: Insert bearings

I have to ask Dave from MN a question. Is it possible the machinist preparing the block for the inserts didn't install the proper dimensions for a good fit for the OD of the inserts?Taking this possibility into consideration along with a tight bearing fit initially and also maybe the engine wasn't dynamically balanced properly could have all contributed to the failure. If this did happen it had nothing to do with the inserts.
CT Jack is offline   Reply With Quote
Old 02-01-2017, 01:54 AM   #12
Dodge
Senior Member
 
Join Date: Nov 2011
Posts: 1,280
Default Re: Insert bearings

Dave in MN,
I have seen this problem with modern engines also that have aluminum bearings in them, they don't seem to be a forgiving as the old type clevitte 77 bearings.
The problem is mostly on the rods. It must be from some sort of temporary lack of oil.
I haven't inserted any motors yet but will take your advise when I do.
Dodge is offline   Reply With Quote
Old 02-01-2017, 05:58 AM   #13
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,515
Default Re: Insert bearings

Quote:
Originally Posted by CT Jack View Post
I have to ask Dave from MN a question. Is it possible the machinist preparing the block for the inserts didn't install the proper dimensions for a good fit for the OD of the inserts?Taking this possibility into consideration along with a tight bearing fit initially and also maybe the engine wasn't dynamically balanced properly could have all contributed to the failure. If this did happen it had nothing to do with the inserts.
I'm not Mr. Gerold, but you are very correct in that the OD tolerance is only 0.00025" either way, ...which takes a good machinist with good equipment to be able to repeat that 3 times per block. Not all engine rebuilders have the skill and/or equipment to pull that off. Babbitt is much more forgiving.
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Old 02-01-2017, 07:41 AM   #14
Jon
Senior Member
 
Jon's Avatar
 
Join Date: May 2010
Location: Kalamazoo, MI USA
Posts: 166
Default Re: Insert bearings

So my take from this is if the inserts need to be fit by machining then the advantage of having inserts so they can be changed out quickly just got thrown out the window.
__________________
John - Kalamazoo, MI
Jon is offline   Reply With Quote
Old 02-01-2017, 09:23 AM   #15
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,515
Default Re: Insert bearings

Quote:
Originally Posted by Jon View Post
So my take from this is if the inserts need to be fit by machining then the advantage of having inserts so they can be changed out quickly just got thrown out the window.
That has always been a sales pitch used by the ones who were promoting inserts, but generally what I have seen is the crank journal pin is worn/scratched when the inserts are worn-out where the crankshaft really needs to be machined again. Where this has the potential to be troublesome is the inserts only come in nominal sizes (Std., 0,010", 0.020", 0.030", 0.040") so if the crankshaft journal pin is worn 0.0025", the crankshaft would need to be removed and machined to the next undersize, whereas a babbitted bearing can have the crankshaft machined to 0.003" undersize and the new babbitt machined to fit the journal pin diameter. Another way to say this using the above scenario is, you potentially have the ability to machine the crankshaft 3 times with babbitt vs. 1 time with the inserts. (.003" x 3 = 0.009" vs 0.010" with the inserts)
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Old 02-01-2017, 11:22 AM   #16
1929
Senior Member
 
Join Date: Jan 2015
Location: New York
Posts: 902
Default Re: Insert bearings

I have inserts, no problem.
1929 is offline   Reply With Quote
Old 02-01-2017, 11:33 AM   #17
Fullraceflathead
Senior Member
 
Fullraceflathead's Avatar
 
Join Date: May 2012
Location: Chillicothe, Missouri
Posts: 944
Default Re: Insert bearings

If the Bearing Crush is machined correctly you will not have a problem.
This is the Key and requires a Sharp Machinist.
Any Bearing will eventually fail if it doesn't have adequate oiling.
__________________
"If I asked people what they wanted they would have said faster horses."
-Henry Ford

"Primitive technology is not a design flaw"


1928 Ford Model A Roadster Pickup
1930 Gordon Smith Air Compressor
1941 Willy's Pickup
1960 Thunderbird-For Sale
1964 Buick Riviera 2x4 425
1965 Pontiac GTO, 455 Super Duty
2004 Dodge Ram SRT-10, V-10 Viper
1977 Charger Jet Boat,460 Ford,Jacuzzi Jet
Front Engine Nostalgia Dragster,Supercharged 296 "Fullrace Flathead" Ford
Engine Build up on DVD ask
Fullraceflathead is offline   Reply With Quote
Old 02-01-2017, 11:53 AM   #18
Dave in MN
Senior Member
 
Dave in MN's Avatar
 
Join Date: May 2010
Location: Jordan, MN
Posts: 1,278
Default Re: Insert bearings

Quote:
Originally Posted by CT Jack View Post
I have to ask Dave from MN a question. Is it possible the machinist preparing the block for the inserts didn't install the proper dimensions for a good fit for the OD of the inserts?Taking this possibility into consideration along with a tight bearing fit initially and also maybe the engine wasn't dynamically balanced properly could have all contributed to the failure. If this did happen it had nothing to do with the inserts.
All the factors you mention could contribute to a failure.
The main point I was trying to make is that the clearances for insert bearings are a narrow range and very much less forgiving than Babbitt bearings.

When line boring the Model A block for inserts, we find that the impurities in the cast iron are very abrasive to the tooling. Another complication to the process is that the front, center and some of the rear caps are steel. This requires tooling that will work well with both materials. We have found that if you are not using a tool that can stand up to the rigors of these materials, the bit will wear and the resulting bore is significantly tapered. Always tight near the end of the cuts. We also note spots in the cast iron and caps that are hard and deflect the boring bar slightly. These small areas create hot spots in the bearing fit due to reduced clearances as the insert is distorted over these "bumps". We have found the most durable tooling is manufactured by: Micro 100 Tool Corporation The tooling we use: M100 series AL-6 Bit. (5/16") C5 Grade. The tooling is available in sizing to fit most boring bars.

When starting to assemble an engine, the first thing I do is carefully measure the line boring of the block. I have cylindrical ring gauges that are equal to the maximum block housing bore suggested by the bearing manufacturer. This gauge allows me to quickly calibrate my bore gauge and accurately measure the housing bores. I often find that a bore may be slightly cone shaped due to bit/tooling wear on the last pass of the line boring machine. I also detect the occasional small spot that deflected the boring bar. I have Sunnen portable hones set up for "A" and "B" line bores and I adjust/straighten the bores to the upper limit with very coarse stones. This honing step along with specifying a mid-range journal sizing on the crankshaft results in good bearing fit with little final honing of the insert shells necessary. Even with this extra work and tight grinding spec, about 50% of the assemblies require a light honing of the rear main inserts. I usually open them up about .0003" and they are perfect.

When assembling, if one is tight, I could ask the crank grinder to take a few tenths off the journal diameters but that takes time and running. I purchased a Sunnen precision honing machine and built a fixture that holds the inserts, with proper crush, to be able to adjust the final clearances. With the honing machine in my shop, the process takes just under 10 minutes per journal to complete the fitting. It is usually only the rear main that needs this adjustment.

I have not had a bearing failure since I increased the clearance to .002" from .00175" on the rear main. As I stated earlier, I set the clearance between .002" and .0022" for the rear main. If the front and center Plastigage out to .00175", I do not adjust them.

Side note: Inserts, when installed correctly, offer excellent service. I have over 90,000 miles on my inserted engine in my Phaeton. I have never had the pan off the engine since assembling it! I do not "baby" this engine and it has always made it home.

Summary:
JMO: If you are not able to complete this final adjustment to the clearances, you are probably better off using Babbitt instead of inserts.
Good Day Guys!

www.durableperformance.net

Last edited by Dave in MN; 02-03-2017 at 09:43 AM.
Dave in MN is offline   Reply With Quote
Old 02-01-2017, 12:02 PM   #19
modelAtony
Senior Member
 
modelAtony's Avatar
 
Join Date: May 2010
Location: lafayette,la
Posts: 459
Default Re: Insert bearings

I HAVE OVER 70,000 MILES ON MY PETE'S AUTOMOTIVE engine and I haven't been driving this car for about 2 years now, working on interior and paint. I have never had one problem. Averaged about 1500 miles per month after retiring only run about 1,000 per month. My oil system is bone stock. Speeds on interstate 63-65 mph , when I get a whild hair I have run it up to 96 mph only for about 3 miles. see my info for more. Have fun modelAtony tony white Lafayette, LA
modelAtony is offline   Reply With Quote
Old 02-01-2017, 12:05 PM   #20
1929
Senior Member
 
Join Date: Jan 2015
Location: New York
Posts: 902
Default Re: Insert bearings

Quote:
Originally Posted by modelAtony View Post
I HAVE OVER 70,000 MILES ON MY PETE'S AUTOMOTIVE engine and I haven't been driving this car for about 2 years now, working on interior and paint. I have never had one problem. Averaged about 1500 miles per month after retiring only run about 1,000 per month. My oil system is bone stock. Speeds on interstate 63-65 mph , when I get a whild hair I have run it up to 96 mph only for about 3 miles. see my info for more. Have fun modelAtony tony white Lafayette, LA
Are you using a fuel pump at that high speed?
1929 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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 09:14 PM.