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Re: Crank gear 180 degrees outconfused smiley
Posted by: Wagon Master ()
Date: November 19, 2018 06:57AM

If the crank gear did indeed spin exactly 180° and locked, you could have moved the distributor 180° and fired it up. Till it broke loose again.😲

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Re: Crank gear 180 degrees outconfused smiley UPDATE
Posted by: woodwalker ()
Date: December 02, 2018 06:17AM

Morning all. Yes, the key was sheared. Starting from the beginning, the motor was very tired, using oil, lifter clatter, etc. The crank was reground, entire assembly balanced including the flywheel and then heat treated. The crank gear was left alone.

On initial start up with the distributor in the recommended position, the motor tried to run but would not catch. I advanced the distributor to the point where I had to raise the coil up so that I could turn the distributor far enough to make it run. It started and ran for 30 minutes and then quit. It would not rev past 2000rpm and would back fire through the carb if I tried to rev it. There was no knocking sounds and being concerned about breaking in the cam [Otto tb20], I let it run. The temp gauge read 400 degrees. A new repro thermistor was installed so I believe the reading to be accurate.

I believe the key started to shear upon start up and then allowed the gear to move to the 180 position after the 30 minute running time. If there is a positive to all this, it allowed me to inspect the internals and I'm happy to say that everything looks great!

The next motor I build will have the gear removed and a hardened key installed as insurance.

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Re: Crank gear 180 degrees outconfused smiley
Posted by: solo2r ()
Date: December 02, 2018 07:43AM

Knowing that the gear has slipped, I would dowel the new gear along with your hardened key.

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Re: Crank gear 180 degrees outconfused smiley
Posted by: 66vairman ()
Date: December 02, 2018 09:34AM

I installed new gears (long story) and used the hardened key on both my rebuilds. So far so good.

Anybody ever have a hardened key fail?

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Re: Crank gear 180 degrees outconfused smiley
Date: December 02, 2018 10:17AM

Long ago,like 43 years, in another place, I bought a dead 65 corsa with a 110 engine. Had would not start issue. Checked all the timing, valve operation, etc, still no run. Finally, determined that the cam lift for a particular cylinder was not in sequence with where the piston was in the cylinder. Only thing left was to check cam/crank gears. Engine showed no signs of having been apart. Can't remember what I saw but end of story the crank gear had spun on the crank. Soooo, it can happen. I never met prior owner so have no idea what driving stunt caused it. I had a new gear and key put on it and the engine ran, must be the one in the 63 van.

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Re: Crank gear 180 degrees outconfused smiley
Posted by: davemotohead ()
Date: December 02, 2018 11:18AM

Bill at Chair City Corvair Center Replaces the Key and gasket on all his Rebuilds as he was bitten with the sheared key 3 times if I recall correctly, Not sure if I would dowel pin the gear as Solo2r suggested, it was a fix for a long time but a lot of the racers have found a dowel pinned gear actually made the gear looser from lack of pressed surface area, most racers are now welding the gear to the crank snout, The Jury is still out on the dowel pinning.





Email me at: Dave Motohead

1960 4dr sedan caveman car
1961 Rampside (Chetside)
1962 Rampside (Barnside)
1962 Short Rampside (Shortside)
1962 Monza 700 Wagon
1963 Monza 900 coup (General Nader)

-----------------------------------
Rust Free Lancaster Ca

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Re: Crank gear 180 degrees outconfused smiley
Posted by: 63turbo ()
Date: December 02, 2018 12:41PM

Doweling the crank is probably a good idea for a crank gear that has never slipped, and probably a bit iffy for gears that have slipped. I think the real
problem is that the replacement gears don't go onto the crank with as much interference as the originals. I doweled my original crank in 2004, and many
moons and much abused miles later, it is still fine.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car



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Re: Crank gear 180 degrees outconfused smiley
Posted by: 66vairman ()
Date: December 03, 2018 01:37PM

davemotohead Wrote:
-------------------------------------------------------
> Bill at Chair City Corvair Center Replaces the Key
> and gasket on all his Rebuilds as he was bitten
> with the sheared key 3 times if I recall
> correctly, Not sure if I would dowel pin the gear
> as Solo2r suggested, it was a fix for a long time
> but a lot of the racers have found a dowel pinned
> gear actually made the gear looser from lack of
> pressed surface area, most racers are now welding
> the gear to the crank snout, The Jury is still out
> on the dowel pinning.

That's interesting Dave. From a force vector perspective - a dowel between the crank and crank gear directs force outward from the crank axis - or could oblong the crank gear and make it loose on the crank.

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Re: Crank gear 180 degrees outconfused smiley
Posted by: Seth Emerson ()
Date: December 05, 2018 09:47AM

People dowel them, weld them and/or setscrew them. We setscrewed one that had sheared during an 8AM practice session at Sears Point on Doug Hargroves racecar. We dropped the motor, left the heads on, split the cases, re-oriented the crank/cam exactly to "close enough" and bolted the motor back together. Poured the same oil back in, pushed him onto the pre-grid at about 1 o'clock. He won the D/Production race. It was filmed by one of the crew in the next pit. Fun Times!

Seth Emerson

Check my new Performance Corvair Web site [www.perfvair.com]

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