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Crankshaft pulley on a 140HP
Posted by: Colorsarge ()
Date: April 21, 2022 02:04PM

Just how critical is it to run a harmonic balancer on a 140? Just came across one equipped with a steel pulley from a 95 HP.

Frankford, De., eight miles north of Ocean City, Md.
1966 Corsa convt.

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Re: Crankshaft pulley on a 140HP
Posted by: RobertC ()
Date: April 21, 2022 03:00PM

Any idea how many miles were put on the engine with the solid pulley?

Doubt a street engine with a solid pulley would "roll over" and die (crankshaft break) after a 1000 miles. Race engines are exposed to more "forces".

If / how well the engine is balanced may be a slight factor.

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Re: Crankshaft pulley on a 140HP
Posted by: Colorsarge ()
Date: April 21, 2022 05:35PM

Everything with this engine is an unkown factor. Miles on it and any internal work that was done is a guess. Definitely has been apart probably fairly recently judging by appearance only. My thought is that they make high performance aluminum pulleys for the Vairs and people run them, are they ok but the steel ones bad because heavier rotating weight?

Frankford, De., eight miles north of Ocean City, Md.
1966 Corsa convt.

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Re: Crankshaft pulley on a 140HP
Posted by: joelsplace ()
Date: April 21, 2022 05:40PM

Solid aluminum is not ok. Corvairs break cracks with the balancer so not having one is a big risk.

Joel
Northlake, TX
5 Ultravans, 135 Corvairs and counting...

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Re: Crankshaft pulley on a 140HP
Posted by: aircooledairhead ()
Date: April 21, 2022 07:18PM

Chevy could have saved a few bucks per car if it had used the plain steel pulley on 110, 140 and 180’s. I’m guessing the harmonic balancer was a necessity that justified the expense.

The steel pulley is lighter, and for an autocross motor it might work out.
Most engines we come across at this stage are mixtures of parts people had laying around.

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Re: Crankshaft pulley on a 140HP
Posted by: RobertC ()
Date: April 21, 2022 07:19PM

Pros / cons have been discussed in previous threads.

In 1977, Corvair mechanic put a solid (64) pulley on my “new” engine (new crankcase, new crankshaft)- engine completely balanced.

About 200,000 miles so far

My 140 has always had a balancer.

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Re: Crankshaft pulley on a 140HP
Posted by: RobertC ()
Date: April 21, 2022 08:01PM

I should add that the same mechanic rebuilt my 140.

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Re: Crankshaft pulley on a 140HP
Posted by: JimBrandberg ()
Date: April 21, 2022 08:14PM

When harmonic balancers are $140 or more it's not uncommon to find a solid pulley someone has installed along the way. It's better to change to HB soon but I wouldn't be quaking in fear to run it a little.

Jim Brandberg
Isanti, MN
CorvairRepair.com



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Re: Crankshaft pulley on a 140HP
Posted by: dryenko ()
Date: April 22, 2022 12:00PM

I know where you an get a nice new USA made in USA HB....

Bob C aka Dryenko
Dobson, NC 27017

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Re: Crankshaft pulley on a 140HP
Posted by: 63turbo ()
Date: April 22, 2022 07:58PM

Put the harmonic balancer on! There's 2 peaks that the balancer is designed to attenuate, one is at wide open throttle at 1200 rpm, and the other is at wide open throttle between 4400 and 5000 rpm. If somebody has had good results with a solid pulley on a 140, its only because the engine is never run at those rpms and loads. Not because GM wasted money putting on something that wasnt needed.

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

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
Test Start#2 [www.youtube.com]



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