Balance shafts
#16
Rennlist Member
You can get the crank bolt off by lodging a socket/breaker bar into position and hitting the starter. But you will need the flywheel lock to get it back on.
#18
Drifting
Good description on what you are doing. Just another question, is this an engine short block that you personally witness running or was this engine short block purchased to be rebuilt by you? What year is the short block?
The following users liked this post:
Tiger03447 (03-26-2021)
#19
Drifting
I think you just got really lucky. The balance shaft covers are matched to the block and not interchangeable even between the upper and lower positions on the same block.
#20
Addict
Rennlist Member
Rennlist Member
I did some searching about fitting bearings just to see if anyone else has done this. I found this post by Redlineman
"I have never had the problems you are having, unless you consider installing non-matching covers (lower in this case) to a previously shaft-deleted engine a related exercise. This is something I have done successfully.
I did it by hand fitting the bearings to the shaft. Install and torque to spec. Turn shaft, remove and inspect the bearing for wear points. Hand sand the back of the bearing at the "tight spot", LIGHTLY brush the bearing surface with 00 steel wool to clear the wear marks, reinstall to spec and repeat until it turned freely. It has worked well for over 2 years since in a race engine."
Last edited by Charlie; 03-26-2021 at 09:14 PM.
#21
Rennlist Member
Why would the covers be matched to the block? Are they the only thing that controls the end-float or something?
#22
Drifting
The upper and lower crankcase sections as well as the balance shaft cover are machined as a unit and must always be fitted as a unit. Observe correct identification marking
https://rennlist.com/forums/944-turb...t-housing.html
#23
Rennlist Member
I think I've mixed up the terminology. By "cover" you guys seem to be referring to 1/2 the housing for the balance shaft, right? (The other half being the block itself.)
I was envisioning something like the "lid" for the camshaft (ie: a circular cover that covers just the end of the balance shaft). But there doesn't seem to be one of those at all.
If so, yes it certainly makes sense as the bearing races would have been align bored.
I was envisioning something like the "lid" for the camshaft (ie: a circular cover that covers just the end of the balance shaft). But there doesn't seem to be one of those at all.
If so, yes it certainly makes sense as the bearing races would have been align bored.
Last edited by jeyjey; 03-26-2021 at 08:48 PM.
#24
Rennlist Member
In theory, the covers with the seperate caps could be swapped, as any mismatch at the front where the o-ring sits could be dealt with with a bit of sealant. The other unitized design could be swapped only if align boring was done, which would likely be pretty expensive. That's certainly not practical now, but one day when these cars reach a certain level of rarity it might be...which is why I cringe when people treat these cars and their parts as a disposable commodity.
The following 2 users liked this post by tempest411:
jeyjey (03-27-2021),
Tiger03447 (03-26-2021)
#25
Rennlist Member
Thread Starter
Dear T&T: This was a non-running engine in a car I got for almost nothing..It had been sitting in a field for about 10 years. It was a derelict, but as a "restorer" type person, I just couldn't let this car, much less a PORSCHE just disappear into the mud and turn into a total rust ball ready for the scrapper.
The BS covers came off the engine, and I presume they were original. I checked the number on the upper shaft cover and it was a (1). Upon further recollection, it seems that we had some difficulty with the rear bearing/shaft/seal combination upon the rebuild a few years back. I was able to get the crank pulley and the cam belt cog off the front shaft today. Therefore, I was able to remove the rear cover. I will soon get into the "meat" of the problem. But alas, I have to remove the intake manifold and associated bits before I can get to the upper cover. When I pulled the upper cover nose off yesterday, (about 1/4") it spun quite freely. I hope after this hiccup? the shafts will spin as freely as this nose portion did. I think while it is still on the lift, I will tackle the lower cover first, since it is the more "bound up" of the two, and easier? to access.
The BS covers came off the engine, and I presume they were original. I checked the number on the upper shaft cover and it was a (1). Upon further recollection, it seems that we had some difficulty with the rear bearing/shaft/seal combination upon the rebuild a few years back. I was able to get the crank pulley and the cam belt cog off the front shaft today. Therefore, I was able to remove the rear cover. I will soon get into the "meat" of the problem. But alas, I have to remove the intake manifold and associated bits before I can get to the upper cover. When I pulled the upper cover nose off yesterday, (about 1/4") it spun quite freely. I hope after this hiccup? the shafts will spin as freely as this nose portion did. I think while it is still on the lift, I will tackle the lower cover first, since it is the more "bound up" of the two, and easier? to access.
Last edited by Tiger03447; 03-26-2021 at 11:21 PM. Reason: additional info
#26
Drifting
Hi Tiger03447
is there a Teflon washer on the outboard balance shaft end between the shaft and the housing? Was the balance shaft housing torqued with the snout fully inserted but bolts not tight? For the end cap o ring seal, there are the same id diameter for early engines and 2 different id's for late engines. PET provides # to distinguish early and late blocks?
is there a Teflon washer on the outboard balance shaft end between the shaft and the housing? Was the balance shaft housing torqued with the snout fully inserted but bolts not tight? For the end cap o ring seal, there are the same id diameter for early engines and 2 different id's for late engines. PET provides # to distinguish early and late blocks?
#27
Rennlist Member
Thread Starter
Dear T&T: Yep, all the housing covers were torqued to spec, and the "ghost" washer was there as well. Perhaps I missed the correct number in the PET, since I was primarily looking at the WSM during the re-assembly. I do know the A & B type seals and their direction was followed with intense scrutiny. Good to know about the different end seals...I'll have to double check on all of that along with the engine number. I do know that the engine in the car, when found, had the original engine in it. (83). Thanks for your info and replies.
#28
Rennlist Member
"ghost" washer was there
I've never heard it called that but oh so appropriate. It is very hard to see, being clear mylar. I wonder how many engines get assembled with 2 or more stacked together?
I've never heard it called that but oh so appropriate. It is very hard to see, being clear mylar. I wonder how many engines get assembled with 2 or more stacked together?
#30
Drifting
Make sure you have everything assembled in the correct order. Check this thread.
https://rennlist.com/forums/924-931-...orqued-on.html
https://rennlist.com/forums/924-931-...orqued-on.html
Compare your BS front snout with bushing as removed with 1st photo in posting. In the photo, the bushing is installed in reverse orientation causing the flange of the bushing to contact and compress the oil seal when the pulley is torqued.
Last edited by T&T Racing; 03-27-2021 at 10:58 AM.