Harmonic Balancer for a Model A

B

barry022

Member
Engine rebuilders would have you believe if you ran an engine without a harmonic balancer the engine would self-destruct. Would adding a harmonic balancer extend engine life and reduce some of the vibrations inherent in a Model A engine? If so, why hasn't anyone developed one for the Model A?
 
There's a guy in New Zealand who makes one that replaces the front pulley. I sent him an email just late last week and still awaiting a reply. Reports about it here on the forum have been excellent. I'm sure one of the NZ Barners will chime in with more info.
 
That's an interesting question, and while I know next to nothing about Model A engine design I would be willing to bet some provision was made toward that end, if not strictly a harmonic balancer or dampener. The problem is well known, the problem is a crankshaft in general will reach a point of resonance at a certain RPM and tend to crack or even break. Maybe the A wasn't prone to this but that's usually not the way to bet.
 
barry022 said:
Engine rebuilders would have you believe if you ran an engine without a harmonic balancer the engine would self-destruct. Would adding a harmonic balancer extend engine life and reduce some of the vibrations inherent in a Model A engine? If so, why hasn't anyone developed one for the Model A?
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Balancers have been used /adapted by many Model A/B owners and racers in the past.
I have a Winfield balancer made for Model A/B engine cranks, by Ed Winfield, decades ago. These guys knew the value of a balancer and used them.
I also have a newly made(year or two ago) crank balancer on the B engine that runs in my '30 roadster. Newer cars all run crank balancers and the model a is not a balanced engine at all, like modern engines. Proof of effectiveness !
 
After doing more research it appears the the negative outcome of not having a harmonic balancer is a broken crankshaft, but unless the engine was being raced I have not heard of Model a crankshafts failing in the course of normal driving. Supposedly modern car engines would suffer damage in due time if a harmonic balancer is not used.

Considering crankshaft failures do not appear to be an issue with Model A engines, what is gained if a harmonic balancer is installed?
 
Stock Model As are a VERY Old design & must be driven with utmost care & consideration!!! Like, DON'T RACE, your OLD HORSE.
Bill Careful
 
I've got a Winfield reproduction that I used for several years that I will sell for $100 plus shipping. I'll even throw in the big socket used to tighten the pulley nut. I left it off after my most recent motor rebuild (due to unrelated thrust bearing failure).

They're kind of controversial, like every other Model A modification--especially the flywheel mounted ones installed by Ron Kelly. It seems like the whole rest of the world believes that they should be mounted at the front of the crank. In my experience, they do not significantly reduce vibrations perceived by the passengers. Rather, they alledgely reduce torsional vibrational harmonics perceived by the crank along its axis. They do seem to be more crucial in high-rpm and perhaps hard acceleration/deceleration situations.

More info should be available by searching the archives of this site. There's even controversy about whether they're correctly called dampeners or balancers. Some people claim that unless they are custom designed for a particular motor, they risk doing more harm than good--except for the viscous fluid based models.
 
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They have been produced, and used for years, mostly on modified engines. You probably won't feel any difference but they do save wear on the crank and bearings, and reduce the probably of breakage. The A has natural vibration points, at about 900, 1200 and 2300 RPM, mostly heard but not felt. Some engines are worse than others. If they weren't of value modern cars would not have them, because they are an expense for the manufacturer. Also A's are not driven in a stressful manner. They belong on the front of the crank.
 
That sure is some expensive horsepower..and it costs a bucket full more chasing protection for the big investment you make..I can see some upgrades yielding a nice bang for the buck,but its crazy to pay 100 bucks per horsepower unit with the end result 150 horsepower..and if you use it your apt to break it,tossing all that money away..
 
Stock engines do not need them.
Anything above stock needs one.
The ideal situation would be to have the damper and the clutch/flywheel weigh the same.
It is possible to come close to that.
 

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This subject has been covered at length before and I can only reiterate that after the crankshaft in my motor (which suffered periods of vibration) was found to be cracked, despite crack testing and careful balancing before installation, the fitting of a Murray Horn dampener pulley transformed the motor and the pleasure of driving.
I should add that the motor is seriously modified to the so-called fast touring specification.
It is a simple installation compared with the flywheel unit which looks complex and must be more complicated to install?
These dampers are made by Murray Horn in Levin N.Z. His Company is Engine Restorations Ltd. His email is horn@xtra.co.nz
Murray says this is the best way to contact him.
The dampers are a straight fit to replace the standard Model A pulley. An added benefit is a shallow reverse scroll in the rope seal area to help contain oil."
I should add that Christmas in New Zealand is mid summer and many businesses close down for anything from a week to six weeks, the length of the school holidays, so responses at this time of the year can be delayed.
 
wensum,
Thanks for the update on when businesses reopen in NZ. Over here, pretty much everyone was back at work by last Monday (15th). I sent an email to Murray and expected to wait for a reply.
If only I had known I'd want one of his dampers. I was in Levin just a few months ago.:rolleyes:
 
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