Main Bearing Specs
- Thread starter B.Rad
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The FAG bearings I got from Norvil last December were made in India. But they are FAG X-life bearings and the quality looks good.
The C3 I bought from CBC Bearings last week is also an Indian - made FAG X-life.
Yikes. I'm starting to wish I'd left the mains as they were. They were ok, they just weren't E - rated type.
Martin
The C3 I bought from CBC Bearings last week is also an Indian - made FAG X-life.
Yikes. I'm starting to wish I'd left the mains as they were. They were ok, they just weren't E - rated type.
Martin
ML said:
Sorry, but this is BS. Several renowed bearing manufactures have facilities in India (and China and ....) which produce these bearings to their very high quality standards just like all their other facilities do. Simply avoid un-qc'ed noname bearings regardless of their stated country of origin.
Tim
Tintin said:
I'm inclined to agree with this. I noted that the FAG bearings I bought came from India when I received them, but it did not worry me. They look like quality parts.
What irks me more is the hassle over the issue with the fit, which has cost me money and time.
As a point of interest, I am reading Derek Magrath's book "Norton The Complete Story" (again), and a particular paragraph caught my eye this time.
It deals with the problems that arose when they moved production from Birmingham to AMC's premises at Woolwich in 1963, and reads in part:
"There were problems, for example, when the clearances of the Dominator main bearings were altered resulting in premature bearing failures."
Deja vu all over again, but I wonder which way they were altered?
Please bear with me, I'm trying to get this photo posting thing right
Martin
Tintin said:
I understand what you are saying, however i did not say avoid FAG brand bearings. Unless they were made in Portugal and fitted to your gearbox layshaft of course....
Given the counterfeit copy issue that is massive in the automotive market, primarily from Asian sources I would always prefer to buy brand name bearings from a non-India or China origin. And the reason is I run an ISO17025 automotive test lab and we see a lot of sub-standard parts with dubious manufacturing credentials.
An update on my tight bearing saga:
Last things first, the C3 bearing is now on the drive side and the tightness problem resolved.
While the cases were apart again I took a closer look at the mating faces which needed some more fettling ( they had been broken and welded up). I'm a bit more fussy now than I was 30 years ago.
Made good use of engineer's blue and JB Weld.
Some observations and measurements made along the way:
Standard inner race as fitted to drive side shaft....1.5935" dia. This is the problem one.
Standard inner race as fitted to timing side shaft....1.5930" dia.
I didn't measure the above races before fitting them to the crank.
C3 inner race before fitting....1.5925" dia.
C3 inner race after fitting......1.5925" dia. Note, this was after removing some scratches from the shaft with a fine oil stone ( I did frequent micrometer checks while doing this).
The heated race fitted fairly easily onto the shaft, whereas I had to drive the standard race on before I did this fettling.
With hindsight, I may not have had this trouble if I had attended to the scratched shaft in the first place. It did need doing because it's the surface the oil seal rubs on. Live and learn!
Cheers
Martin
Last things first, the C3 bearing is now on the drive side and the tightness problem resolved.
While the cases were apart again I took a closer look at the mating faces which needed some more fettling ( they had been broken and welded up). I'm a bit more fussy now than I was 30 years ago.
Made good use of engineer's blue and JB Weld.
Some observations and measurements made along the way:
Standard inner race as fitted to drive side shaft....1.5935" dia. This is the problem one.
Standard inner race as fitted to timing side shaft....1.5930" dia.
I didn't measure the above races before fitting them to the crank.
C3 inner race before fitting....1.5925" dia.
C3 inner race after fitting......1.5925" dia. Note, this was after removing some scratches from the shaft with a fine oil stone ( I did frequent micrometer checks while doing this).
The heated race fitted fairly easily onto the shaft, whereas I had to drive the standard race on before I did this fettling.
With hindsight, I may not have had this trouble if I had attended to the scratched shaft in the first place. It did need doing because it's the surface the oil seal rubs on. Live and learn!
Cheers
Martin
PS
There WAS end play in the crank, it was measurable after the C3 bearing went into the crankcase. It was 0.016". I had been expecting 0.012"
After the fettling and fitting the C3 inner race, I had 0.018". That was with the same stack of crankshaft shims as previously used.
I reduced it to 0.008" by fitting an Old Britts shim behind the timing side bearing. Interestingly, my old Haynes manual shows just that shimming method, but I was getting my parts from Norvil and they only seem to have the crankshaft shims.
The cost comparison is interesting:
Norvil shims.... A$4.80
Shipping from England....A$4.50
Old Britts shims....A$18.40
Shipping from USA....A$16.20
In both cases the actual packet of parts was similar size and weight to a Christmas card, but for some reason the Old Britts packet was then put into a larger envelope. Maybe USPS requirement?
Cheers
Martin
There WAS end play in the crank, it was measurable after the C3 bearing went into the crankcase. It was 0.016". I had been expecting 0.012"
After the fettling and fitting the C3 inner race, I had 0.018". That was with the same stack of crankshaft shims as previously used.
I reduced it to 0.008" by fitting an Old Britts shim behind the timing side bearing. Interestingly, my old Haynes manual shows just that shimming method, but I was getting my parts from Norvil and they only seem to have the crankshaft shims.
The cost comparison is interesting:
Norvil shims.... A$4.80
Shipping from England....A$4.50
Old Britts shims....A$18.40
Shipping from USA....A$16.20
In both cases the actual packet of parts was similar size and weight to a Christmas card, but for some reason the Old Britts packet was then put into a larger envelope. Maybe USPS requirement?
Cheers
Martin
If you use an old but Ok condition inner race from a discarded 'superblend' and grind the internal diameter out a little, it will slip on and off the crank with ease and once you have the end float that you are satisfied with, you can then press on the correct inner race. Bearings are made to such fine tolerances that It will almost always give you the right clearance.
Shims in the crankcase behind the bearing outer require the bearing and case to be repeatedly heated up to remove the bearing outer to facilitate fitting or removal of the shims.
Shims in the crankcase behind the bearing outer require the bearing and case to be repeatedly heated up to remove the bearing outer to facilitate fitting or removal of the shims.
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B.Rad said:
I'm not the expert but: If you read the application note from a/any bearing manufacturer you will see the bearings are NOT meant to be mounted in an aluminum housing....therefore the C'3 clearance is called for. The extra clearance disappears due to the extra shrink fit in an aluminum housing (has nothing to do with the crank)...You will note the comment of "nipping up" with a nominal clearance bearing.
Not sure what all the mystery iz..........to me...the bearing clearance mystery issue is less baffleling than why people don't "get it". :?:
the physics and math are there....slaps you in the face
flame suit on :mrgreen:
dynodave said:
I'm farther from being an expert than you are, but I'm in the process of building my engine so I'm sharing my experience with the forum. What you say is entirely true, and Jim Comstock also mentioned it, yet the nominal clearance bearing fitted just fine on the timing side. And it's winter in Oz so the crush should be at maximum. The micrometer measurements showed the difference to be the swollen inner race, which was perhaps my fault.
I suppose there are many variables at play in a 40 year old engine that an experienced engine builder (which I'm not) would be prepared for, eg wear in the case from a bearing that has spun.
"Do it yourself" is fraught with danger, but at least we get to know our machines.
Cheers
Martin
Here's another twist in the CN vs C3 story:
After doing a trial assembly with a C3 in the drive side and leaving the CN in the timing side, and getting a good result, I removed the CN bearing and re-fitted it with a small dab of loctite 641 to insure against spinning, as there was some evidence that a bearing had spun in the past.
When assembled, the TIMING side was too tight. The only change made here was the addition of loctite.
As I wanted to stay with the loctite metod, I changed to C3 for the timing side as well.
After doing a trial assembly with a C3 in the drive side and leaving the CN in the timing side, and getting a good result, I removed the CN bearing and re-fitted it with a small dab of loctite 641 to insure against spinning, as there was some evidence that a bearing had spun in the past.
When assembled, the TIMING side was too tight. The only change made here was the addition of loctite.
As I wanted to stay with the loctite metod, I changed to C3 for the timing side as well.
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My experience of using loctite in an aluminium housing to stop spinning is that it does not work, it will lose grip within 1000 miles. My guess is that the loctite's bond is lost when it meets the movement caused by the steel bearing and aluminium's differential rate of expansion each time the engine heat cycles.
kommando said:
Which Loctite? There is a gazillion different formulas and some work better than the others. This stuff is usually very sensitive to oil contamination unless this is adressed specifially. Degreasing bearings and crankcases to sufficient levels is rather difficult. I use 603 for this purpose, let's see how it works.
Tim
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