Flywheel too light?

(Ian) #1

I have a E-type, lightweight flywheel , its made of steel , its around the 15lb mark , would this be too light for a 3.4 MK2 , street use ?

(john) #2

i think you will like it ian, i’ve used a cut down sedan version for 30 years on 3.8L. mine is 17 lb. seems just as smoooth and a little more snap.

(LLoyd (just a rithmetician)) #3

The flywheel on the PrtyKty has been lightened some. The only thing I’ve noticed (before the EDIS) is that it didn’t idle as smoothly as I had liked. Of course… some of that was attributed to the "worst distributor curve in the world “vacuum retard” distributor.

(owneroftheXJR15tooling) #4

Too light by a way. Idle will be rough and the initial acceleration will be problematic, extra clutch slip might be needed to prevent stalling!

(john) #5

my mistake on conversion. actual weight was 10 kg = app 22 lb + i am using the heavier spring pressure plate.

(Ian) #6

This light weight wheel come with a spring pressure plate , that and the plate comes in at 22lb so all in it would be around the 37lb mark , I will have to make my mind up soon , as I plan on doing the engine swap over the winter , all being well !

(Paul Wigton) #7

I believe it will be OK: MAAAYBE a bit rougher idle, but not appreciable.

(Robert and Darlene Stevenson) #8

You’re right as I’ve been running a Fidanza 12# aluminum flywheel in my 64 for that last 15-20 years and I really didn’t notice much if any difference in the idle. I had a little concern with a 3.07 axle and a synchro gearbox about starting at hill side traffic lights which was a needless worry.
Plymouth, Mi.

(Ian) #9

Think I am going to go with the light flywheel , less weight hanging off the back of the crank , has got to be a good thing , are the clutches interchangeable , if they are what one is best , spring or Diaphragm ?

(Paul Wigton) #10

They are not, and, IMHO, the diaphragm clutch has a lighter feel.

(Terry Sturgeon) #11

I’ve got one of Fidanza’s flywheels with a 9.5" diaphragm clutch from AP in my 4.2l coupe with a 3:31 diff and notice no difference in smoothness, or take off from a stop (or for that matter acceleration via seat of the pants feel). Bear in mind that the 4.2l flywheel weighed in excess of 40 pounds. I’ve always understood that the 10" and 9.5" are interchangeable if your flywheel is drilled for it, as some are. No idea if one is better than the other - I doubt it but Jaguar did change to diaphragm, as have virtually all, if not all, modern cars.

(Ian) #12

The big difference would be in the weight I guess !

(Phil.Dobson) #13

I have a 20lb flywheel and diaphragm clutch in my xk 150 …love it!

(Keith. P. series two roadster,,,UK) #14

The spring clutch has a three lever contact area with the release bearing,these are held in play by a special nut and washer, and I think peened to keep from loosening, however, a missed gear once made one of these nuts come off, leaving me with a release bearing touching only two levers and no lift at all…based on the premise that if it happened to me it could happen to anyone, fit the diaphragm…

(Paul Wigton) #15

Unless I was forced to, Id never use a finger release plate over a diaphragm.