259 Main Bearing Clearance

[wdsj]

Just got my 259 from the machine shop.
i am installing .01 oversized bearings

Measured the mains clearance today
all are .002 except the front which is .003
manual spec is .0005 to .0025

opinions?
assembly it or back to the shop[?]

dell

Dell
59 Silver Hawk
62 GT Hawk

[StudeRich]

If you want it to dependably last any length of time and save the crank, you turn the crank to .010 and use that size bearings. [^]
It is .0005 beyond spec.

I wonder how much it varies on that .003 under journal in 8 or 10 places around it? [:0]

Quote: "Just got my 259 from the machine shop.
i am installing .01 oversized bearings"

I think you mean .001 Undersize, those would put it back to only .002 clearance though, so it's up to you, you're right on the edge there! If they are very round, it may work fine.

StudeRich -Studebakers Northwest Ferndale, WA

[wdsj]

you are correct on all points.
but I thought the shop grinds the crank which makes it smaller, then the bearing is thicker (oversize)to maintain clearance.
am I correct but using the wrong terms to describe?

anyway it is out of spec, and after all the work and $$ it should be right
thanks
dell

Dell
59 Silver Hawk
62 GT Hawk

[59r2]

How good is your machine shop? one way to do it ie to cut the caps a little and line hone them . Is your connecting rods loose also , they can cut the caps and hone them to specs,a tricky operation .If they hone too much they will cut thur the bearing wear surface. I just had it done and everthing is perfect.(the reason I had it done was my crank after polishing was alittle undersized ,but nice and clean. It must have been pulled apart for factory servive because it had .0001 oversize bearings installed, which made std bearings out of spec).If yours was just cut it seems it was over polished or over cut . you could cut it again to .02 and hope for the best.

1959 HARDTOP R2 clone
1960 conv
SDC member since 1972

[StudeRich]

Yes you did describe it wrong, they grind the crank making it smaller, but bearings are described in terms of the crank size, so it is now UNDERSIZE!

quote:Originally posted by wdsj

but I thought the shop grinds the crank which makes it smaller, then the bearing is thicker (oversize)to maintain clearance.
am I correct but using the wrong terms to describe?

StudeRich
Studebakers Northwest
Ferndale, WA

[JDP]

Sounds like the .001 bearings will put you in spec. Even without them, you are not far out. Studebaker made the .001 and .002 bearings for just your situation. ( A engine with just a bit of wear)

JDP/Maryland
64 R2 GT (Sid)
spent to date $62,839.60
63 R2 SuperHawk (Caesar)
spent to date $54664,75
63 Daytona HT/4 speed
63 Lark 2 door
57 Wagon

[wdsj]

My engine was not just a bit of wear. Significant scoring.
The bearings I put in are .010 undersized (stamped on the bearing .010 US). Crank was supposed to be ground to match.

Do they make a .011 undersized? I have only seen 10 thousand increments (.010, .020 and .030).
But I am not an expert.

So close and I only measured on spot. not 8 or 9 as noted by StudeRich.

Dell
59 Silver Hawk
62 GT Hawk

[JDP]

If you had the crank turned .010, why is one journal out of spec ?

JDP/Maryland
64 R2 GT (Sid)
spent to date $62,839.60
63 R2 SuperHawk (Caesar)
spent to date $54664,75
63 Daytona HT/4 speed
63 Lark 2 door
57 Wagon

[gordr]

The obvious answer is to pull the crank out, and have it miked. If the #1 journal is in fact ground undersize, then either the machine shop made a mistake, or else that was the largest size to which it would clean up.

Also, check carefully that the bearing cap is seated perfectly in the block, and doesn't have a little bit of debris blocking it.

If the journal checks out OK, it might simply be that the front bearing in your set was made a little oversize, and a different bearing might work.

Gord Richmond, within Weasel range of the Alberta Badlands

[wdsj]

To complete this post, I checked with the shop. The owner showed me the Federal Mogul manual that show bearing clearance as .0006 to .0033
He did not have a Studebaker manual.
In his opinion, it is within specification.

Dell
59 Silver Hawk
62 GT Hawk

[PackardV8]

We've all been bitten on the backside by failure to specify for what we were paying and what were our expectations. The machinist is correct in being within the leeway for a production-house-rebuild. However, if you are building a custom engine, you should always give the machinist a punch list of YOUR max/min clearances. By relying on the shop, you gave him permission to give you production, not custom work tolerances.

thnx, jack vines

PackardV8

[wdsj]

You are sooooo correct.

Dell
59 Silver Hawk
62 GT Hawk