[Healeys] Lightened Flywheels

[Bob Spidell]

Listers,

I know this one has been discussed--well, beat to death--but it looks 
like I'll have to pull my BJ8's gearbox/OD to replace a leaky front 
seal, so I'm thinking of installing a lightened flywheel while I'm at 
it. My main reason for considering it is to stop some pretty significant 
run-on ('dieseling,' which I get on my BN2 as well). I'm not totally 
comfortable with dropping the clutch in gear to stop it, and any 
performance improvements would be a plus. It just so happens I just 
caught an episode of 'Engine Masters' on MotorTrend TV, where they 
seriously reduced the rotating mass of an engine--an SBC, which is what 
they mostly do--and got some interesting results: more HP and torque, as 
measured on a topnotch dyno. The gains were shown primarily on 
acceleration which, intuitively I suppose, were greater when RPM was 
raised at 300RPM/minute vs. 600. Any constant speed increases weren't 
addressed as far as I could tell.

The late, great Gary Andersen, who raced, said the main benefit was 
faster spin-up for rev-matching downshifts; anyone noted any other 
significant benefits? The 'Dyno Master' on EM said he'd seen timing 
chain failures with lightened flywheels; my main concern for both my 
Healeys has been reliability, with minimal maintenance required, but if 
it stops/minimizes the run-on I'd be happy. Anyone know how far you can 
go lightening without adverse effects?

TIA,
Bob