Lister 12/2 rebuild - crank out

[Samo]

Hey folks,
So I think I've finally reached the halfway point in the rebuild of my Bookham (that's where i got it from) Lister 12/2. Took a long time to remove the crankshaft. I took 38AC's advice and took a fine file to it, filed and filed until the bearings slipped over it. More pockmarks than a teenager - I'll try post some pictures when I get a moment.

The white metal on the bearings is in pretty poor shape around the bearing joins  and a fair bit is missing, maybe the engine ran for some time on very poor/little oil before it seized - there's also a bit scoring. However that said the crank bearing surfaces are good and the center bearing diameter is 2.496 by my calipers. Outside bearings are also reading exactly the same. Took 3 readings across each surface and all are consistent and flat. 

Seeing the wear is within limits, I am thinking of going stock bearing sizes, unless someone wants to convince me otherwise? Not done this before so advice appreciated.

cheers,
Samo

[38ac]

I dont have specs for the twins but I suspect that they are similar to the singles for wear. Standard practice in the UK was bearing bores are "to size" and clearances are machined to the shafts,(which by the way is backwards of most American manufactures standard practices).  What that means is a 2" shaft will ride in 2.000 I.D.  bearings and the shaft will be ground for proper running clearance in a 2.00" hole. Your 2.496 shaft then would have .004" clearance in a 2.500 center bearing. About .001" over ideal but not outside of the specs, polish it up and run her,,,

[Samo]

Thanks, that's the approach I'll take 

[Samo]

Not sure if I can link from my google photo's but I'll give it a shot. Here's some pics of the rebuild state....

Crank after filing down the high spots:
https://photos.app.goo.gl/qfB57a3Gmk9UXVg13

Cylinders & Heads

Before:
https://photos.app.goo.gl/62g12zfDx1rRqU2n1

After:
https://photos.app.goo.gl/QuB4CrbSgB0HrC6A2

[broncodriver99]

Nicely done. What did you use for the cleanup? The heads look great.

[carlb23]

looks great now all you have to do is put it back together and enjoy.

[38ac]

Looking excellent!  There is a 10/2 languishing in my storage building that needs same treatment!!

[Samo]

Thanks, I wish I could say I did the clean up of the heads, but the local engine rebuild shop did that when I got the new valves seated. They did a very good job too.

I'll continue to take my time with the parts still to finish up, but I'm certainly getting keen to hear her running again!

[LowGear]

Wow!  May we all have some projects looking that good in our lives.  The "before" looks like something off the Titanic.

[Samo]

https://photos.app.goo.gl/rRQK9BMvR1di8GXa2

Thanks Casey, maybe it came from the titanic... the bore was full of water when I got it !

[Samo]

Me again

I have been cleaning up the head studs, and some are a bit pitted... question: how much pitting before I should replace them? Gut feeling is it's stuffed but I thought I'd ask first...

Here's an image of one:  https://photos.app.goo.gl/gGStIl8fqARC5aov1

Four of the eight are like this, these came from the wet side, others similar but not quite as bad.

[listard-jp2]

/\ My instinct would be to fit them and see what happens, pitting of those studs is very common (I have seen and reused far worse without incident).

Unless you have access to 3/4" Whitworth form screw cutting and gauging equipment, your only other option is to use Indian sourced parts.

However this is not without its problems, because Indian studs are usually under size when measured on the effective diameter of the thread (using the 3 wire method).

In your situation this matters because when you screw the undersize stud into the crankcase it will 'cock over' to one side when it bottoms out, making installation of the cylinder block and cylinder head a PITA

Further more if you measure the effective diameter (using the 3 wire method) you will notice that the crankcase end of the original Lister stud is noticeably bigger when compared to the nut end, this was done deliberately by Listers to reduce the problem as described above, obviously a finer point of the original design which was not recognised or understood by the Rajkot crew

[Samo]

Thanks for the advice, I'd rather not use Indian parts so that's what I will do.