Can I put a harmonic balancer from any '55-'67 Y block on my stock '54 Merc 256, and would it make much of an improvement?? Thanks : Bruce

A later balancer will not clear the 54 steady rest if still using it. I found this out when I replaced my 239 with a 312. I am assuming the 54 Ford and the Merc were the same. I had to get a later steady rest.

If I remember correctly, the 54's did not use a balancer (actually a dampner I think) . They started with the 55's so I am not even sure you can fit one. I hope someone else will tell you.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

The '54 Mercury did not use a front engine steady rest as Ford did. I have a 1961 292 Y-Block in my '54 Mercury and I used the '54 Mercury 256 crankshaft pulley with the bolt on power steering pulley. All of the belts lined up and the earlier pulley fit fine on the later engine. Alan S. Freeman

Hate to nit pick but it's a harmonic damper, not a harmonic balancer. But beyond that, Ford didn't think the harmonics on the 239/256 engines were destructive enough to mandate a harmonic damper and simply used a solid hub at the front. While a damper installed on the front of the 256 engine would likely not show up as any kind of significant performance gain, I suspect overall bearing life would improve slightly over the long haul (100K+ miles). Starting with the 272 engines, Ford started used harmonic dampers instead of solid hubs on the passenger car engines. Dyno testing shows that the stock harmonic dampers (1955-1964 vintage) are barely adequate on the stock engines and any upgrades in performance dictates a more substantial damper design. Especially where compression ratios are increased over the factory supplied levels.

But in answer to your question, Yes, you can put a later damper on your 54 Merc engine. While you wouldn't feel a seat of the pants improvement, the engine would still favor having it versus the solid hub that was used.

Lorena, Texas (South of Waco)

I want a vibration damper (as FoMoCo denoted it:Whistling that is stock looking, or at least vintage looking, but is effective for high compression, boost, nitrous, but moderate RPM, such as max 6500 RPM. Which are available? Which are best? Are there good compromises between vintage looking and damping?

Which vibration dampers are just "bolt in" on a Y-block?

As I understand the stock vibration damper is limited, but why? Design, rubber, aged rubber?
Some rebuilt stock dampers use silicon rubber, how are these?


Ted, is it easy to measure the vibration/harmonics on a dyno (or elsewhere)?


FoMoCo increased the belt size from 3/8" to 1/2" in 1955 (to increase the belt life), but decreased it later again (to earn money?:w00t. Is there any problems running a 3/8" belt on a 1/2" pulley or mixed 1/2" and 3/8" pulleys?


Most vibration dampers have narrow grooves, is it OK to run a 7/16" belt on both 1/2" and 3/8" pulleys?

1955 Mercury