thepest
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| posted on 6/6/12 at 06:34 AM |
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Main & big end bearings - when to replace?
As per the subject, any guides to this?
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britishtrident
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| posted on 6/6/12 at 07:02 AM |
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Because they are generously sized and get a copious oil supply it is very rare for mains to show much wear unless there has been a major
lubrication problem.
Big end bearings are another matter generally on older types of engines at anything over 50,00 miles the big ends will show signs of wear. Visual
examination of bearing and journal for wear and scoring , check the journal for ovality with a micrometer or digital calliper, check the bearing
clearance by measuring the crush on a short length of soft electronic solder.
Really best to treat big ends as a service item if you have the bottom end stripped and the big ends have been in for a while change the big ends.
[Edited on 6/6/12 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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thepest
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| posted on 6/6/12 at 07:08 AM |
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Was thinking the same and ordering me a set of new big end and mains:
Anyone used this supplier? AutobulbsUK
Selling Vandervell VP2 bearings
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clairetoo
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| posted on 6/6/12 at 09:30 AM |
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The problem (I found) with thise heavy duty shells is that they are so tough they dont wear - but the crank does , so rather than just replace the
shells in the future , you will need a re-grind while the shells will be fine .
I was told only to use those on a steel crank .
Its cuz I is blond , innit
Claire xx
Will weld for food......
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cliftyhanger
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| posted on 6/6/12 at 10:31 AM |
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I always understood VP2 to be the VEY best bearings, the holy grail.
However, they did change a few years ago, when vandervell were taken over. But for my old cars, I would pay serious cash for a set of old
VP2's. They were lead/copper and not tin/ali that most seem to be. However, because they are higher quality, I think they are often labelled
heavy duty? Certainly the King (brand) lead/copper bearings I had to satisfied with were labelled heavy duty. But the tin/ali ones are a harder
material.
But of course, if the engine is apart, it is wise to replace the big ends if there is any sign of wear.
[Edited on 6/6/12 by cliftyhanger]
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Mr Whippy
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| posted on 6/6/12 at 10:59 AM |
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I'd replace them a) if the engine was already stripped down as you might aswell do it then than later b) if the oil pressure was very poor and
didn't reach the factory pressure ranges c) if there was clunking going on when you took you foot off the throttle d) if there was lots of white
metal in the oil during oil changes
The main bearings are usually quite cheap if a slight ball ache to get the right clearences but really a straightforward task and way better to do
early than wait till the crank needs reground
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britishtrident
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| posted on 6/6/12 at 12:03 PM |
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Big ends + a new oil pump will pay off a more than big ends + mains.
The wear in an oil pump can be difficult to measure but it makes a big difference to the oil flow rate particularly important when cold.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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thepest
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| posted on 6/6/12 at 12:11 PM |
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Found me a set locally of New old stock Vandervell VP2 mains, ordered a set of Vandervell VP2 big end (NOS).
Re the oil pump, hmm pressures were always top noch IE 60psi (limited by the pump) when warmed up pressures were at 45psi idleing at 900rpm, pressure
rising with increase in revs. Is there any way to check flow rate?
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Mr Whippy
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| posted on 7/6/12 at 11:19 AM |
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quote:
Originally posted by thepest
Found me a set locally of New old stock Vandervell VP2 mains, ordered a set of Vandervell VP2 big end (NOS).
Re the oil pump, hmm pressures were always top noch IE 60psi (limited by the pump) when warmed up pressures were at 45psi idleing at 900rpm, pressure
rising with increase in revs. Is there any way to check flow rate?
The flow rate is not measured and would be difficult to measure without a test setup. If the engine is in bits do make sure you flush all the oil
passages as they do get restricted with varnish over time. I use flushing oil during oil changes to reduce this, does make a huge difference to the
cleanliness of the metal surfaces inside
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