kont5u

Hi there. I have struggled with my rebuilt S2 engines balance shafts for the last two weekends I've had to work on the car. After torquing the lower shaft housing correctly I noticed that it didn't spin freely by hand. I took it apart and noticed by feeling with my finger that the two halves of the bearing journal are not even but there is a small gap that causes the shaft to bind when torqued. I changed the housing over to the other side to test if it would help. And it did. Both shafts now spin pretty nicely by hand. When disassembling the engine, I didn't check which side the housings were take from. I had learned from 944 8 valve WSM that on the early engines, with separate bearing bridges the bridges are marked with 1 and 2. 1 meaning it's the lower balance shaft journal and two meaning it's the upper (intake side) journal. I applied this principle while assembling my bs housings as I guessed that the numbers have the same purpose and after seeing images of other engine builds they always seem to have number 2 on the upper bs. In my case it seems that number 1 works better on the turbo side.

Could it be that the stamping on the housing were somehow mixed up at the factory, or could the locating pin for the housing on the block be somehow displaced and force the bs housing to dislocate itself? Number 2 housing works very well on intake side as well. So there's basically problems with the number 1 housing only. I have new bearings for both balance shafts, that should not be a problem.

I've already drilled and tapped for turbo feed on the number 2 housing because I was very certain that it would be mounted on intake side. I'm considering putting number 1 housing on exhaust side and number 2 on exhaust side as they seem to turn easiest that way and I have figured out that they could do less harm while rotating quite easily even if being on the wrong side, than being assembled on their original locations and eating the bearings while binding. It's just frustrating to have to drill and tap the other housing also.

Any thoughts much appreciated.

JustinL

If you've got the wrong housing on the block, you'll never get the shaft to turn once it's torqued down. They're definitely matched. It seems unlikely that you could get one housing to randomly be perfectly matched to another, but then to hit that lottery twice on the same engine seems crazy. Also if they were perfectly matched, then it wouldn't matter which one you used as neither would bind. Based on that, I'll bet you tapped the wrong one and just need to plug that one and tap the other. If you can still turn everything by hand once it's torqued up, I'd say you got it right. I've been down this path and done and redone balance shaft housings more times than I'd care to admit. Are there any other clues on the housings you can use like dirt patterns or scratches?

kont5u

Thanks Justin for your input. I’ve checked the numbers on the block and the housings. They are matching, so no problems there. It’s still confusing that the number 2 housing works for both positions. I have another block where the other housing is from another block, still works. It’s the early housing with separate bridges though.

Thom

The 4 digit stamping on each balance shaft housing, which is the same as on the girdle, should face upwards, and this cannot be confused.
Which configuration works correctly?

kont5u

This would mean that I've tried to fit the housings on wrong sides. I hope you are right Thom, thanks! I think I'll just get the other housing drilled and threaded also and plug the other one so maybe I can continue with my engine. I've also heard some opinions about taking the oil feed to turbo from somewhere else than bs housing due to the #2 connecting rod oil feed suffering from original turbo feed from bs housing. Is that something to consider? And if yes, then where should the oil feed for turbo be routed from?