Excessive Starter Shimming?

[brad.arcova]

I'm moving parts from my old SBC to my new SBC and it seems like I need an excessive number of starter shims. Both engines have 14" 168 tooth flywheels and the starter has an offset bolt pattern for a 168 tooth flywheel. The starter worked fine on the old car with 0.100" of shims and had a paper clip's worth of clearance between the vertical portions of the flywheel and starter teeth. Now, with 0.120" of shims I still don't have enough clearance. I can definitely get the right clearance with more shims; maybe to 0.140" or 0.160" but that seems like an excessive amount of shims.

I checked the starter boss on the block and it looks fine. The mating surface on the starter looks fine. The dimensions between all the bolt holes measured with a caliper are the same on the old and new blocks.

The old block casting is 3970010....350...1969-1980...2 or 4 Bolt Main.

The new block casting is 10243880...350...1995-2000...2 or 4 Bolt Main...Vortec truck, Gen.I crate motors and "ZZ4", roller cam, one piece rear seal.

Should I be looking for something else or just go ahead and add more shims?

Brad

 

[grumpyvette]

you didn,t mention the type of starter your using?

some of the mini starters are adjustable, or index-able and that changes the clearances and some have several bolt mount hole options.
not all 168 tooth flex-plates or flywheels are identical in diam.
shimming a starter more than 1/8" seems excessive but its not un-heard of, and if done correctly it won,t hurt anything if thats whats required, but almost every time I run into some similar condition its the result of a mis-match in some component, its likely that the starter designed for the older two piece rear seal block has a different clearance to the flywheel than starters designed for the newer one piece rear seal block,
occasionally you'll find damaged flywheel ring gears,
naturally you'll need to use the correct replacement parts from the original manufacturer in most cases,

http://www.thefind.com/cars/info-flywheel-ring-gear

http://www.tciauto.com/Products/Flywheels/

RING GEARS ARE CHEAPER THAN FLY WHEELS AND IN MOST CASES REPLACEABLE COMPONENTS


(1) Pull trans

(2) Remove flywheel

(3) HEAT WITH A PROPANE TORCH, THEN Tap ring gear off

(4)CLEAN AND INSPECT RING GEAR MOUNT SURFACE AND CLEAN IF REQUIRED, Heat new ring gear with torch, OR by placing in oven, place fly wheel in cardboard box covered with DRY ICE
once both are at correct temp.place flywheel on flat concrete floor

(5) Grab ring gear with pliers and drop onto flywheel, making sure its properly aligned

(6) Install flywheel back onto engine

(7) Bolt trans and flywheel/clutch back to engines drive train

(8) Inspect old starter to make sure bendix gear alignment and clearance is still good

(9) Start engine

 

[brad.arcova]

That's probably it. It's going from a 2-pc seal block to a 1-pc seal block. It's a mini-starter from Pace Performane. The catalogs I'm looking at don't seem to differentiate between 1-pc/2-pc seal blocks.

Is there a spec for the distance from the pinion to the flywheel? I saw your link to
http://www.tiltonracing.com/ins/98-095.pdf
specifying 0.1" - 0.04" but I don't think that applies to my starter does it? Mines A LOT further away than that.

Since it's non-indexable, I'll get some more shims and move it out some more; except for having >1/8" of shims it seems fine.

Brad

http://paceperformance.com/index.asp?PageAction=VIEWPROD&ProdID=251485

http://garage.grumpysperformance.com/index.php?threads/problem-with-starter.1646/#post-12717