I have a (almost) stock AS21, 1600DP that pulls well and has good compression, but is showing 20 thou play in the crankshaft, when measured at the pulley.
Written on the sump plate is "rebuilt '87" so I guess that the engine overhaul is overdue.
My question is, when should I replace the case? If I find that the bearings are first or second oversize already, then is it time to replace the case? I know that the dealers offer bearings up to four times oversize, but is it worth it? A new AS41 case is expensive, but (just about) within my budget.
Is it worth replacing anything else when I pull the engine? Pistons & Cylinders? Crank? Camshaft?
I would`nt replace a case that was usable. If it is line bored and fitted with new bearings you`ll get good service from it again for perhaps another 100,000 miles. The more stuff you replace naturally the better but it is not a neccessity to replace it all. Your budget will dictate what to do. Chances are a thrust cut will solve your endplay problems and the crank be fine for reuse. You`ll need new main and rod bearings for sure. New cam bearings as well.
A good manual will provide wear limits to make these decisions. There are min and max specs for everything in the engine so no guessing is required. Check or have them checked.
Your cam can be miked to decide if it is going to be with you for awhile. But a cam is a cheap and easy way to boost power output. Lifters can be miked to determine if its going to be keeps or scrap pile.
Moving outside the shortblock you first come to the pistons and cylinders. Again they can be miked to determine wear factor. This is another of those cheaper ways to improve power, replace badly worn (or in the case of P&Cs warped and scored) liner kits.
Heads are usually rebuildt with the addition of new exhaust valves(intakes are ground).
Thats about it. A good machinist and a good manual are about you need to get this job done. Good luck. bob Ingman
If the person that rebuilt it reused the old shims, the engine could have had more endplay than the spec. when rebuilt.
are you sure your pully is perfect too, I have seen some that were slightly bent to the tune of a few thousandths, thats why I like to measure at the flywheel or off the pulley nut
AS 21 is one of the better cases. It just needs pulled apart and checked out to see if it is usable. For a stock engine you should do fine re-using it if it specs out ok. Often they need align bored, sometimes cam-bored, thrust cut. Is this play end-play or wobble? Stock parts will do you well in my opinion. When I rebuild I often replace the case, but a good used one will get you 100,000 miles many times. I also replace all bearings, put in new P&C, rebuilt or new heads, new cam and lifters, re-surface flywheel, new starter bushing, new fuel line, check heat riser and clear out, new muffler, re-conditioned rods,
have crank checked out, rebuild or replace carburetor, SS p/r tubes. Use good seals. The seals kits are mostly useless. I use good silicone or good German oil cooler seals, pushrod tube seals, oil pump to engine, oh yeah new oil pump.
I also full flow mine, but I've driven 100,000 fine on one that wasn't full flowed. Might be I have more dollars than sense rebuilding a VW, but I don't have many dollars, and I like driving them more than pulling them out over and over although you'd never believe it if you saw me lately.
John
The case has clean heat risers, a new oil pump with oil filter fittings, and small additional sump about 1.5" deep. I also have a carb rebuild kit, so that is taken care of too. All the fuel lines are new.
Before I go much further I will pull the engine and check the endplay on the flywheel, I do know that there is no up/down movement on the flywheel as I did check that the last time that the engine was out.
I need to replace the main seal and gland nut, so I'll check the shims in there too, how would I know if there is an incorrect number of shims? or if the shims were not changed?
usually there are three shims, there is a wear spot where it rides on the bearing, I have pulled engines and found the center shim with wear on it along with the one that rides on the bearing,
I think VW used three because of the sizes available,
good luck
I had my last engine put together with a used case, and had it remachined - the result in my case was a thrust journal that would NOT keep endplay, and it was recut twice to try to solve it. This is not to say that used cases don't work, but I'm putting together a 2332 this time and do not feel like worrying about this again. The ONLY thing really wrong with my 2007cc is the damn case, and I've a feeling that this particular one has problems that have warranted having to cut it and cut it again. 6000 miles is all I got on it before that lovely afternoon when I went to adjust the valves and in turning the crank noticed its tendency once again to move in and out visibly. Not quite 0.020, but close and too close for me.
So this time I use a NEW case, no history, carefully checked over by RIMCO, and done correctly. Peace of mind for me, especially with a bigger engine that I want to last.
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[This message has been edited by mharney (edited 06-18-2002).]
