Corvair Forum

I just noticed a potential problem where the bolt attaches the harmonic balancer to my Corsa engine crank. See below:
. The bolt is torqued to 50 Ft Lbs (I double checked) but as you can see there is a gap between the bolt head and the washer underneath it. The washer is loose. I know these washers are convex but when I installed it it still had some bend to it (maybe not enough). There is a .020 gap between the bolt head and the washer. I can get a new washer but the gap seems like a lot of space for the washer to fill in. Or I can just get another washer to put on top of the stock washer to make sure it compresses. Any thoughts on this one ???

Thanks -

Alec

Alec,
It's been a while, but as i remember there were several different lengths of this bolt in use. I don't know why, but it's possible that the bolt you have is too long and has bottomed in the crankshaft. As you know it should be tight against that washer.
Bob Helt

Item #44 shown below. Is it possible you might have picked up a substitute bolt in your car's past that could be the crankshaft pulley bolt that was intended for the A/C and SMOG engine? You might pull the bolt and measure its length, and then contact Clark's Corvair Parts or The Corvair Ranch in Gettysburg, PA http://www.corvairranch.com/ or California Corvair Parts to find out. Also, is it possible that the original thick washer (Item #45) was replaced with a standard flat washer that might be too thin and allowing the bolt to bottom-out?

https://ssl.corvair.com/user-cgi/catalo ... IN&page=12


Part number C6106: BOLT-PULLEY TO CRANKSHAFT GR8

Weight: 0 lbs 4 oz
Catalog Pages(s): 12(44),182
Price: $ 2.40

Part number C1770R: BOLT-A/C & SMOG CRANK PULLEY

Weight: 0 lbs 4 oz
Catalog Pages(s): 12(44),182
Price: $ 2.65

Part number C1135: WASHER-CRANK PULLEY

Weight: 0 lbs 4 oz
Catalog Pages(s): 12(45),182
Price: $ 1.00

The above photo shows the stock washer and bolt that hold the balancer on a Corvair. The bolt is a grade five 1/2″ -20. The washer is a very special part made by GM. It is made of heat treated steel, and it has a very slight concave surface on the side that touches the balancer. When it is tightened, this washer goes flat, and spring loads the bolt tight. This is why in its stock form on the car, it doesn’t have a lock washer nor Loctite applied to it. The “bevel” washer is doing the locking task. On cars, this system works flawlessly.

https://flycorvair.net/2012/01/12/balan ... tallation/


http://californiacorvairparts.com/index ... er=product


Used original engine crankshaft pulley bolt washer for 1960-69 Corvair engines including turbos and 140's.

CRANK BOLT
http://californiacorvairparts.com/index ... er=product

Used original engine crankshaft pulley bolt for 1960-69 Corvair engines including turbos and 140's
Approx length is 1.5 in.

Ahh, THANKS Bob and Brad. I didn't realize there were different lengths of crank pulley bolts. The bolt that is there is the one that was in the engine when I bought the car. The washer that's there is correct - unless there were different thickness washers as well. I'll pull the bolt and use calipers to measure the bolt hole depth and the bolt thread length (including the washer thickness) and see how they measure up. I'll report back when I get that done.

Alec

OK, I've pull the bolt off and done some measurements.

The pulley bolt shaft length is 2". The washer is 5/16" thick. It has a slight convex side to it so I think it is the correct washer but my washer doesn't have the recessed lip in it as shown in Brads picture. The bolt + washer will want to thread 1 11/16" into the crankshaft hole. The crankshaft hole is 2" deep, but is only threaded for about 1 5/8". So the bolt will run out of threads before it contacts the washer. As Bob and Brad surmised, the bolt is too long, especially if, as Brad suggests, the stock bolt should only be 1.5" long. I'll have to get a new bolt...

Thanks again guys for the quick replies. One more problem bites the dust.

Alec