906 Flywheel

Does anyone have a 'factory' 906 Flywheel as there seem to be several different weights quoted.

I have seen figures of 3.3kg and 3.5kg quoted.

I would like to know the actual weight of a genuine part.

I am trying to model this type of flywheel and should be able to check weight before machining.

https://imagizer.imageshack.com/v2/xq90/924/b5xfMG.jpg

You could ask these guys, their website claims to have one: http://nwmachineproducts.com/2016/02...-906-flywheel/

andy

Andy,

Thanks,

AASE Sales also have a 'genuine' 906 Flywheel which they say is 7lbs 12.6oz (3.48kg).

Neither the Flywheel shown by NW Machine Products nor the AASE flywheel have the circumferential grooves on the back face and this may account for the variation between 3.3 and 3.5kg.

https://imagizer.imageshack.com/v2/xq90/922/hxAEyk.jpg

Bill

I have this, will try and get it weighed tomorrow, although again it does not have the grooves on the back:

Thanks,

This looks like another variation as the resign that the cover bolts to has not been cut away and the holes for the locating dowels still seem to be present.

Unfortunately I don't know its history (acquired in bulk parts purchase), photos of the pressure plate that it is attached to:

Tim, that looks like the one I have in my '65. Mine does not have the grooves.

John

Thanks John; I had a look back through my records and it was described by the previous owner as "67/68 factory race flywheel and 906 pressure plate" so I think this, allied to it being like the one in your 911 and not having the grooves on the top, would suggest the flywheel is a 911 Sports Purpose part rather then 906.

Tim, as a side note. Mine uses a 356 throw-out bearing, not a 911 one.

John

Here"s some shots of mine. The inside of mine looks like the 906 one.

John

Attachment 496997

Attachment 496998

Here's one with the grooves on the back : http://www.magicsix.de/schwung906e.php

Homologation paper for the 906 states 3.565 kg for the flywheel (8.8 kg with the clutch)

Olivier

Here is what I put together based on specs from a sports purpose flywheel. I have a feeling this is what you would find on a T/R or R originally. Weight is 9.5lbs / 4.2kg. Would give a little more weight than say a 906, better ability to drive on the road or in a rally setting.

Comparing the original flywheel with the machined version you can see the edge chamfered section is machined further and meat taken from the back then grooves added.

Gordon may have more firsthand info from the Rs he worked on.

Thanks, Brad

Here is the R one Brad copied. The holes are a little different drilled on the circumference, production flywheels just had wider spacing.

This might be of some help understanding the 906/911 parts, its from the Sports Purposes outline, p13 (1968).

Thanks for the info, Ernie!

Here is the 906 one I have in my car. I was changing the disc. You can see one holes in the pressure plate. Interesting I have never had a problem with it in the car.

John

Attachment 497495