Page 1 of 1

New small end bearings different

Posted: Sun Oct 08, 2017 10:43 am
by BIGMIKE
I'm still in the process of a complete rebuild on my majors engine but not sure about the new small end bearings I have. The old bearings had 3 holes in them with a X machined on the inside of the bearing, the 2 smaller holes lined up with the 2 holes in the conrod but the new bearings just have 1 hole in the centre which obviously now doesn't line up with anything to let the oil in or have the large X to help lubricate the pin?
Just wondering if this ok or worth drilling the 2 small holes through the small end again? All the bearings advertised seem to be like this so assuming my old ones are genuine fordson and all new ones are aftermarket so not made as well?

Re: New small end bearings different

Posted: Fri Oct 13, 2017 9:36 am
by BIGMIKE
Well eventually got silver fox tractor spares to answer the phone and it seems the hole in the new bushes is irrelevant and you have to drill new holes to suit and reamer the bushes to suit the pins

Re: New small end bearings different

Posted: Sun Oct 15, 2017 6:24 pm
by AdrianNPMajor
Hello Mike
Would have come in earlier on this thread, except that I don't have anything more useful to offer than an observation.
I have rebuilt a 1958 Mk2 engine and a 1963 NP Super engine. In both cases the gudgeon pins and small end bearings were unworn. Measured with micrometer and, in the case of the pin, a human finger tip. The case hardening on the pin was untouched by the millions of revolutions, and the new gudgeon pin from the rebuild kit fitted the original small end bearing with no play.
In both cases I fitted new pins in the original bearings.
If there had been any wear, I would have taken the components to the engine workshop that skimmed the head. I doubt any home workshop would be able to reamer the bearings to the necessary tolerances.
Good luck.
Best, Adrian. :thumbs:

Re: New small end bearings different

Posted: Sun Oct 15, 2017 8:00 pm
by BIGMIKE
Thanks Adrian I too had planned to just fit the new pins in the old bearings but when I stripped the first one down I'd found the bearing had been turning in the small end so thought screw it I've come this far I'll replace the lot!

Re: New small end bearings different

Posted: Sun Oct 15, 2017 11:46 pm
by oehrick
AdrianNPMajor wrote: I doubt any home workshop would be able to reamer the bearings to the necessary tolerances.
Best, Adrian. :thumbs:
I'd suggest that if they had a 99 year old Drummond lathe such as mine Adrian
https://web-beta.archive.org/web/201105 ... hoenix.htm
they might well be able to do the job and without the need for that dangerous electricity stuff :wink:

Newer, non 'engine lathes' don't have the advantage of the decent boring table so couldn't do the bores, valve seats or big ends either, I have seen one of these set up to line bore mains but thank heavens for replaceable shells :clap: as it is a pig of a job !

(Confession time, the old girl does sport a variable speed, reversible drive electric motor now, treadle still available for use, however due to a terrible accident is also awaiting a new whitemetal crossfeed nut to be poured, so without cross feed is 'hors de combat', she will be running for her centenary next year and I've a set of steam engine castings seasoning so she can machine a centenary engine as a monument to the durability of old iron)

Re: New small end bearings different

Posted: Mon Oct 16, 2017 12:25 pm
by AdrianNPMajor
Love the Drummond lathe, Rick.
Interesting to see that they were used by REME field companies.
Must be very handy.
Best, Adrian. :thumbs:

Re: New small end bearings different

Posted: Mon Oct 16, 2017 11:43 pm
by oehrick
Sure is Adrian

The only place where I have seen a surviving WW1 travelling workshop is at Duxford, RFC (shoeing the horses used for pulling the stringbags out to take off :wink: :wink: ) They had an engine / dynamo for lighting & welding, lathe drill possibly mill or more often shaper.

Sometimes old tech is ideal for renovating machinery from the period :D

Re: New small end bearings different

Posted: Sat Oct 28, 2017 2:43 pm
by shepp
Just a thought, but if the small end bearing has been turning in the con rod end then your con rod might be scrap - the fit might have been too loose in the first place, but if the bearing has been turning......?