Engine: What are the differences between R1 and R2 Avanti harmonic balancers?

[PackardV8]

I probably knew this at one time, but having two R2s in for rebuild, I notice their harmonic balancers are stamped "SC" on the inside face. Being they're from R2s, one could posit this refers to "Supercharged." However, I don't have an R1 on the shelf at present, so can't compare. Differences between R1 and R2s, anyone?

I notice SI only lists one part number, 1554247, for all Avanti Jet Thrust engines, but they're out of stock.

FWIW, it currently costs the same dollars to have a balancer rebuilt by Damper Doctor as to buy a new one from SI. However, a prediction is if/when SI gets new stock, their price will most likely go up.

jack vines

[Dwight FitzSimons]

The Avanti parts catalog lists only one part number, 1554247 for "all." I may have an NOS one, if I can find it.
--Dwight

[PackardV8]

The Avanti parts catalog lists only one part number, 1554247 for "all." I may have an NOS one, if I can find it.
--Dwight

Thanks, Dwight. Sometimes logic is just a guess. "SC" could as easily be Studebaker Corporation.

jack vines

[2R2]

The only difference that I am aware of is the damper for a JT Hawk or Lark is different than one for an Avanti.

[Dwight FitzSimons]

The only difference that I am aware of is the damper for a JT Hawk or Lark is different than one for an Avanti.

AFAIK, the only difference between the damper for an R1/R2-powered Lark or Hawk (JT engine) and an Avanti (R engine) is a fan belt groove cut into the damper. I have a couple of those engines (in cars).
--Dwight

[R2Andrea]

Per the engineering drawings, the only difference between the JT/JTS and R/RS dampers is the belt drive groove. SC is the maker's mark for Schwitzer Cummins.

[studediesel]

Interesting discussion.
The pictures below show a 1558279 dampener for a JT or JTS. The hub in the center has 1554247 cast into it, the same part # for the R1,R2 dampener. It also has SC cast into it and the outer ring has SC stamped into it. The outer ring has 127193 stamped in to it. I think that is the ring #. Most likely different on the R1,R2 dampener.