The cam bearings are Kolbenschmidt and might be standard size. Mains and big ends I have no idea. They all need to be replaced and the only way to know which size is to measure the cam, crank and case. What is the condition of the cam and followers? If you put the followers face to face, they should rock slightly – the face should be convex. Keep the followers in the same position they came from if you intend to reuse them.
On mine the oil pickup tube was incorrectly fitted. Yours could have several causes - oil pump internal clearances, built on warped case, ran low on oil so the pickup sucked air - that was the effect of the bad tube fitting on mine - At higher revs too much of the oil was in circulation for there to be enough left in the sump even when the oil level was ok! I can imagine the same happening to a properly fitted one if the level got low enough. Possibly there is a fault with your pickup tube that allows it to suck air. Warped case - bolt the halves together and torque to correct settings - shine a light in one end and look in the other looking for gaps either side of the bearing saddles. Pickup - you'll just have to check it's not falling apart and the pump end is fitted snugly in the case. Running with low oil level - only you can answer that one. How quickly did the oil light go off when you started it? One thing I forgot to mention before you took the engine out is a test where you stop the engine, switch the ignition back on and see how long it takes for the oil light to come back on. This is a judge of how well it holds pressure. Once you've checked the above possible low oil pressure causes, if it seems ok I wouldn't worry too much.
You can measure the end web and crank journals and big ends with calipers, do some quick sums to see if they’ve been machined/ground. Can in theory measure the centre case web with calipers, but CSP do a handy “template” tool for about £12. That’ll tell you whether the case has been line-bored. Very nifty (also do one for the crank if you’re feeling lazy).
Can someone please confirm using the measurements I've taken , I think I need bearings 0.25 The attached pic shows haynes manual standard and my measurements As you can I've not been able to measure some parts but I think we can work it out with the measurements taken, I hope Thanks in advance
Yes, no need to measure them all, the crank journals will all have been machined the same amount. IIRC you already measured the thrust as std, that's the other important spec for the bearing set.
So just to clarify I'm looking for bearings 0.25 Standard thrust Standard case So big end bearings would also be 0.25 Would I also replace the small end bushes aswell or not Would there be any noticeable gain from upgrading the camshaft to a more"sporty" version, along with the 1641 b&p that I'm fitting Cheers
Measure them. I meant no need to measure every main journal. Likewise the big ends, but do look at at least one. I would stick to the stock cam for a bus. You're only adding a moped's worth of capacity, you won't even notice - new rings will make a far bigger difference or chucking out some camping gear. The stock cam is perfect for a bus. All a "sporty" one will do is move what little power you have up the rev range.
Cheers, the old big ends have 0.25 stamped on them, Where is the best place to source the bearings? As the pump is out shall I just replace it with a schadek one, or are oe ones better if they are in tolerance Thanks again, I have been reading through the tom Wilson book,
Er, if it's in tolerance, why would you replace it? Clearly the OG ones were/are fine on millions of motors. Check the wear inside the lid/behind the cogs on the body. Whatever you do, do not uprate it to a bigger one - all they do is upset the balance of oil going through the cooler i.e. you could end up more or less bypassing the cooler. Same goes for the relief plunger springs - worth checking those and also pump actually are original spec for this reason as a lot of folk do not understand and automatically think bigger is better - in this case it's not, it's a disaster.
That's fine I will measure the pump the pump as per Wilson instruction, Best place to buy the bearings or are they all selling the same ? Thanks for answering soooo many questions
Does look like both the crank and the big end bearings have had a 0.25 grind on them (you'll find out when you fit new bearings ). Does seem like your case hasn't been line bored, which is slightly unusual, but do the "small torch behind the split main bearing" test to see if it needs one. Need to measure the flywheel end case web to see if the case has been thrust-cut. Leave your cam as it is, look on the back of the cam bearing shells for size (likely to be "STD"). Machine 7 will sell you the bearings. You'll likely need to lightly sand down the thrust faces on the end one, as the Silverline bearings out of the box are a press fit onto the camshaft Buy a new oil pump if you feel like it - it's your engine . Most originals are scored to buggery inside by now.
I put the case halves back together today and put a strong torch in the case with the light off in the garage and I saw no light around the split in the case, I also checked the oil pick up and that was stiff and no movement, What assembly grease is best, the Wilson book says moly grease, with a brush and white grease Any thoughts
If I do need a replacement pump(I haven't measured it yet) the schadek ones seem to be heavy duty and 30mm gears I believe zed said to avoid those ones, I would like to order the parts over the weekend
You may have seen this topic before, very informative. https://www.thesamba.com/vw/forum/viewtopic.php?t=513083&highlight=builds
With the crank in new bearings, you'll need to rotate it to check for any binding. I found assembly lube is so sticky, you can't really feel anything. Squidge of engine oil better.
I've ordered all the parts from machine 7 Hopefully in the next week of so it should be rebuilt Thatns for everyone's advise, I will need more shortly, Cheers
