hello ppl, ive built many engines before but new to the boxer while ordering my new bearings i noticed on the vwh site that they list barrel spacers and shim kits? i dont mean to sound stupid but what are they for and how to you know which you require? i am going to be fitting 1641cc pistons and barrels with a pair of solex 40 carbs. i have had the case and crank checked and the crank reground (case .5 over and mains .5 under, also the mains at .25 under) is there anything else common on these engines when rebuilding that i am likely to oversee as a new comer? many thanks james
make sure you get a complete victor reinz seal kit - everything else, and I mean everything, is pants by comparison. Get a tub of permatex (stateside tuning sell this) and you are almost guaranteed that it will stay leak free. Don't be tempted to put any silicon sealant etc on any of the case joints etc - use the permatex and you'll be right. When you put your new pushrod tubes in with new seals just use a light smear of engine oil on the pushrod tube seals - again, don't us any sealant etc, let the oil do it for you.
When you fit your new barrels and pistons, tepm bolt up a barrel, spin the engine until it's at the top of it's stoke and the distance between the top of the piston and the top of the barrel is the deck height. For T1 engines you aim for 1.5mm using the barrel shims. Same for T4 engines but you should check it's 1.5mm for these as well. So you won't know if you need any/what thickness until you get part built up.
cheers zed. i better get the barrels and pistons ordered and get measuring. i tried to measure the crank end float today so i can order the correct thrust size for the bearings but im unsure where to be measuring and what the end fload should be. i measured off the end of the crank and got 3mm in total of movement?
Unless you're machining the crank or case, the bearing sizes you need are stamped on the bearings you took out. Icluding the thrust bearing. The end-float is set with 3 shims - there MUST be 3. So you fit two, fit the flywheel and check the endloat, then calculate what thickness the third has to be to get within tolerance. Of course you can add this figure to the other two for total shim thickness, then make it up with what you have to hand.
the crank has been reground to 0.5 and the case has previously been line bored to 0.5. i take it the trust bearing is the crank end bearing. i fitted the crank today and measured the end float in the crank shaft using the old bearings and measured with the flywheel on and got a total movement of 0.84mm. it looked alot more than that though!
That sounds about right with no shims from memory. The shims are all around 0.3mm - 0.24. 0.26, 0.28, 0.30, 0.32, 0.34. Assume that's with your new bearings?
no new bearings fitted yet as im still not sure what thrust size i need to order when ordering the bearings. i dont remember any shims falling out when i removed the crank but it didnt have any endfloat before
would i be right in thinking that the size for the trust bearing would be the width of the bearing on the internal diameter?
The thickness of the thrust face on the bearing next to the flywheel. If the case has been cut, they go up in whole mm's - again should be indicated on old bearing.
managed to get a few measurements today as been off work lately with a back injury. thrust bearing case width trust bearing, flywheel side opposite side and this is the only shim that i removed from the engine behind flywheel does this help shed any light on the size of trust i need to order?
