VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 1940 Harmonic Balancer

What years of passenger cars used the same harmonic balancer as a 1940? Will a harmonic balancer from a 1950 216 work on a 1940 216? Why or why not? Thank you.

The Chevrolet parts book says 1937 to 1940 all.

The 1940 was 2 3/4" with thru hub, 6 5/32" diameter.
The 1941 and up was 3" thru hub and 6 1/32" diameter.
For what its worth.

You also need to verify that your engine is a 1940 216 before looking for another balancer. Check the serial number on your block to do that. According to the Chev's of the 40's parts catalog the serial number should be between 2697268-3665902 or B105462 - B221935. The block casting number is 839132.

What is wrong with your balancer?
Thanks, Mike

P.S. Gene is the Harmonic Balancer bananced as part of an engine rebuild? Is it balanced on the crank or separately? If a prong for hand starting is broken off should the balancer be replaced? I have been collecting balancers that I assume are reusable. You don't see them for sale on ebay or through our part distributors???

I would have a used 40 harmonic balancer for sale if that helps.

dtm

Thank you all. ChevGene and Toolman, I sent you PMs.

How can you tell if a Harmonic Balancer is aged (rubber is deteriorated) or damaged beyond usefulness?

Thanks, Mike

First the harmonic Balancer does not balance the engine....but could be out of balance. The balancer should be balanced with other rotating parts. If an ear is broken off of the crank attachment it would have little affect on the rotating balance as it is so close to the center of the rotating mass, especially if the car is never driven over 60 MPH.
The harmonic balancer dampens out the power impulses transfered to the crankshaft to reduce "twisting" of the crankshaft.

The first year to used the soft rubber rings rather than the pin and flat spring version was the 1939. (for replacemet parts the 1939 version was sold for use on 1937-1938 engines).
Yes, due to heat and oil and old age I am sure the rubber loses some of the intended qualities. I, my self, would not be concerned for several reasons and have never heard of it causing a problem

Where it can cause a problem is on a car that the timing mark is on the rim of the balancer and the outter rim and shaft on the center hub making it impossible to set the timing with a timing light. I don't recall this happening on a Chevrolet V8 but it is common on a Corvair. The is a place that "rebuilds" Corvair balancers to cure this problem. I am not sure if fresh rubber ccan be installed in our old 6 Cyl balancers.
That being said not all Corvsirs had a balancer, some just had a pulley. This was true also for some small block V8 Chevrolet engines in the early '60's.

The pre-war Plymouth engines had a balancer only on the Deluxe models....so go figure.

Thanks Gene for your insightful explanation. As always you are an amazing gentleman and an inspiration to us all. Hope winter is treating you well.

Best wishes always, Mike

Chev Gene: How about the thru hub on the 1940 Harmonic Balancer is really 1.75 = 1 3/4" and not 2.750 = 2 3/4 inch diameter? I just measured my 1940 engine.

dtm

I am giving the numbers in the parts book and to be honest I am not sure what/where they were measuring.