PDA

View Full Version : 289 crankshaft & pulley/damper questions



Thomas63R2
11-19-2006, 11:08 PM
Today, as I was changing out my bent crankshaft power steering drive pulley, I noticed a few things that I am not sure if they are as they should be. The car is a '63 R2 Avanti with the original engine. Well, most of it - one of the cylinder heads is from a '56. Its obviously had some work done on it, but the stampings and numbers on the block are the same as on the factory build sheet.

Here is what I am not sure of:
1) Is it normal for the end of the crankshaft snout to be ~ .700" in from the front end of the dampner?
2) The large (1-7/16" head hex size) center bolt has a 2" shank, with 1.25" of that threaded. Of that 1.25" threaded portion only ~ .550 is threaded into the end of the crankshaft. Is that the way it is supposed to be?
3) I'm wondering if the crankshaft is maybe an earlier year short snout version.
4) Does the Avanti dampner have an unused pulley groove cast into it? This one does have a pulley groove cast into the outer ring of the dampner. There is no way this pulley groove can be used for anything on this car - so what applications did use this groove?
5) The back side of this dampner hub has at least .500" of unused machined seal surface. This is to say that I can clearly see the part of the hub that has the spiral groove to keep oil going back towards the inside of the front crankshaft hub seal. Is it possible that this dampner and crankshaft are both for an earlier engine and that the last builder "cheated" a little by simply not mounting the dampner all the way onto the crankshaft so that the rest of the pulleys would line up?
6) Underneath the large center crankshaft hub bolt there was a mangled plate that appears might have had locking tabs for the center bolt. This plate had two outside bolt holes for the smaller pulley bolts (six of those bolts) to go through and keep this plate from rotating. Am I right about needing locking tabs for the large center bolt?

I'm going to get a new center crank bolt, this one is pretty chewed up. Apparently at least one of the previous mechanics did not have a 1-7/16" socket, so he used the field fix of using a chisel to drive off, and then using a chisel again to reinstall and tighten the center bolt. Also, the .550" of the threads being used on the center bolt appear distressed - as if the center bolt was used to press the dampner onto the crankshaft.

Thomas

New Stude guy! Long time hot rodder
'63 Avanti R2 4 speed with interesting plans

JDP
11-19-2006, 11:24 PM
Here is what I am not sure of:
1) Is it normal for the end of the crankshaft snout to be ~ .700" in from the front end of the dampner?

No it is not.

2) The large (1-7/16" head hex size) center bolt has a 2" shank, with 1.25" of that threaded. Of that 1.25" threaded portion only ~ .550 is threaded into the end of the crankshaft. Is that the way it is supposed to be?

I'd need to check the parts book for the correct length.

3) I'm wondering if the crankshaft is maybe an earlier year short snout version.

Sounds like it.

4) Does the Avanti dampner have an unused pulley groove cast into it?

No, but the Lark/hawk damper does.

This one does have a pulley groove cast into the outer ring of the dampner. There is no way this pulley groove can be used for anything on this car - so what applications did use this groove?

See above. Lark/Hawk fan

5) The back side of this dampner hub has at least .500" of unused machined seal surface. This is to say that I can clearly see the part of the hub that has the spiral groove to keep oil going back towards the inside of the front crankshaft hub seal. Is it possible that this dampner and crankshaft are both for an earlier engine and that the last builder "cheated" a little by simply not mounting the dampner all the way onto the crankshaft so that the rest of the pulleys would line up?

Might be a short snout crank, you should not see the sprial grooves.

6) Underneath the large center crankshaft hub bolt there was a mangled plate that appears might have had locking tabs for the center bolt. This plate had two outside bolt holes for the smaller pulley bolts (six of those bolts) to go through and keep this plate from rotating. Am I right about needing locking tabs for the large center bolt?

The center part of the plate should fold over the bolt head.

http://stude.com/sig.jpg
JDP
Arnold Md.
Studebaker On The Net
http://stude.com
My Ebay Items
http://www.stude.com/EBAY/

64 Daytona HT
63 R2 4 speed GT Hawk
63 Avanti R1/AC
63 Lark 2 dr.
62 Lark 2 door
60 Hawk
52 Starlight
52 Starliner
51 Commander

Thomas63R2
11-19-2006, 11:24 PM
JDP, yes, the engine is stamped RS 2087, and that same number is listed on the invoice to the dealer and the production line order for this car. The car came with a huge pile of documentation, including the original window sticker. I do realize none of that documentation says anything about cheater repairs done by shops who know that most owners have no good way to verify the work done. Like in this case I am a few owners removed from when the engine work likely was done. Que sera, sera. I bought the car decently so some things like this will not put me off.

I'll fix it (build the motor my way) when I have collected a few more high performance parts and my new heads are done.

Does anybody have a line on a good 289 long snout crankshaft?

I'm guessing that I can continue to use this Lark dampner because there does not appear to be any issues with it otherwise. Even though I can see the machined hub surface on the backside it seems to hold the oil back okay.

If anyone here is good with straightening out a bent crankshaft power steering drive pulley I will GIVE my old pulley to a good home. At least I know this pulley is correct for an Avanti as it matched the new pulley I found.

Thomas

New Stude guy! Long time hot rodder
'63 Avanti R2 4 speed with interesting plans

JDP
11-19-2006, 11:25 PM
BTW, did you check the engine number to make sure it starts with "RS" ?

http://stude.com/sig.jpg
JDP
Arnold Md.
Studebaker On The Net
http://stude.com
My Ebay Items
http://www.stude.com/EBAY/

64 Daytona HT
63 R2 4 speed GT Hawk
63 Avanti R1/AC
63 Lark 2 dr.
62 Lark 2 door
60 Hawk
52 Starlight
52 Starliner
51 Commander

Thomas63R2
11-22-2006, 03:31 AM
After more consideration here's my thoughts on my crank and damper issue:
1) The locking plate underneath the center crankshaft bolt on my engine was flattened and doing nothing to prevent movement of the center bolt.
2) Adding up the dimensions it now seems obvious that the crankshaft bolt had been slowly backing out. Since a chisel was previously used to tighten the center bolt there was unlikely not enough torque on the bolt. The reason why I could see ~ .500" of the backside machined hub surface and see the crankshaft snout ~ .700" in from the front of the damper is simply that my damper and pulleys had been sliding forward as the center bolt backed out. Since there is maybe a .200" register off the center of the crankshaft pulleys I can see where having the crank snout just slightly in from the damper face is probably the way it should be.
3) I had only eyeballed the pulley alignment off the crankshaft pulleys vs. their respective driven accessories, I'm pretty sure that really measuring it would have immediately shown me it was off.

Now I am wondering what kind of bearing damage could have happened - because I'm sure the crankshaft bearing thrust surface is all screwed up from not having the damper hub seated. At least I believe that having a properly seated damper is important for the crankshaft thrust on the Stude engine.

Live and learn, I'm just another in the line of Studebaker owners suffering the effects of bad or misinformed past mechanics not completely understanding Studebaker engines.

Thomas

gordr
11-22-2006, 03:50 AM
quote:Originally posted by Thomas63R2

After more consideration here's my thoughts on my crank and damper issue:
1) The locking plate underneath the center crankshaft bolt on my engine was flattened and doing nothing to prevent movement of the center bolt.
2) Adding up the dimensions it now seems obvious that the crankshaft bolt had been slowly backing out. Since a chisel was previously used to tighten the center bolt there was unlikely not enough torque on the bolt. The reason why I could see ~ .500" of the backside machined hub surface and see the crankshaft snout ~ .700" in from the front of the damper is simply that my damper and pulleys had been sliding forward as the center bolt backed out. Since there is maybe a .200" register off the center of the crankshaft pulleys I can see where having the crank snout just slightly in from the damper face is probably the way it should be.
3) I had only eyeballed the pulley alignment off the crankshaft pulleys vs. their respective driven accessories, I'm pretty sure that really measuring it would have immediately shown me it was off.

Now I am wondering what kind of bearing damage could have happened - because I'm sure the crankshaft bearing thrust surface is all screwed up from not having the damper hub seated. At least I believe that having a properly seated damper is important for the crankshaft thrust on the Stude engine.

Live and learn, I'm just another in the line of Studebaker owners suffering the effects of bad or misinformed past mechanics not completely understanding Studebaker engines.

Thomas


Thomas, I concur with your assessment. You probably have a long-snout crank, and the damper has been walking. You should be able to grab the damper and move the crank back and forth a LOT, (.002 - .006 is the spec.), unless you are really lucky and the timing gear on the crank has stayed put.

See if you can get hold of a pusher tool as called for in the shop manual for installing the crank gear and balancer. Hopefully the thread in the end of the crank isn't stripped. If it IS stripped, I think the thread is 11/16 x 20 N.F. Northern Tool may have a tap, if needed.

If the crank endplay hasn't hammered out the thrust bearings, you may be able to push the balancer back on, and install a new bolt and lockplate. I'd sure give it a try.

Gord Richmond, within Weasel range of the Alberta Badlands

Thomas63R2
11-22-2006, 08:25 PM
Gord, thanks for giving me some hope of miracle luck with the crankshaft timing gear maybe holding it all together. I'll check the endplay this weekend. I haven't really driven the car a lot since I bought it in April, and most of the time I've kept the engine below 3,500 rpms. We'll see how it turns out.

Thomas