WARNING! Getrag flywheel

[CanAm Dave]

Hi All

Not too happy today as balancing had to stop on my new engine. The problem being the flywheel. It is an original factory supplied flywheel for the Getrag transaxle. The problem was that when on the balancer it was showing that it was 40g out of balance. I was there at the time and it was found to be the recess cut in the back of the flywheel to sit over the crank. Even though it was on the dowel it could move some 15thou each way. I have an aftermarket crank but the raised section on the crank measured exactly the same as a standard GM crank. I am now having some machine work carried out on the flywheel so a sleeve with the correct inner diameter can be fitted into it. Costing £130.

The balancing is carried out at 500rpm so at 6500rpm it becomes a lot heavier. At 100mm from the centre a 40g imbalance at 6000rpm would be more than 9 stone.

Maybe the factory could comment on my findings?

Most people fitting the flywheel would be unaware of this problem.

Regards Dave

[BigMack]

I'd talk to Kennedy Engineering about that. They machine those flywheels.
Cheers!
-Mack

[gtr-gaz]

Hi Dave. I had the same problem on my flywheel for the G/50 box. I had to have the flywheel AND front pulley worked on.

It should be the engine builders responsibility to ensure it's balanced. American Speed in this case.

[Chewy]

Thanks for sharing this although I hope it is a one off. I refitted my engine and Getrag gearbox last week and fortunately I did not have this problem. If anything I had the opposite problem that the flywheel was almost a machine press fit. It took a lot of careful encouragement to seat it correctly. It was that tight that I did not want to pull it on with the bolts for fear of threading them. It looks like they need to tighten there machine tolerances.

[steve_d]

Chewy said:

....... It looks like they need to tighten there machine tolerances.

Their tolerances may be tight but the crank manufacturers not so.

Steve

[Chewy]

Good Point

[stig]

steve_d said:

Chewy said: ....... It looks like they need to tighten there machine tolerances. Their tolerances may be tight but the crank manufacturers not so. Steve

Given that I've had to 'ease' both my flywheels with a dremel to get them on the crank, I'm personally a bit surprised that you've had this problem?

I can understand your frustration, but I'd have thought it was worth talking to the factory direct first?

[CanAm Dave]

Glad to hear it's not been so much of an issue for most people. I would of talked to the factory first but I don't want any more delays on getting my engine back. I've been waiting long enough! Good news is I should have the engine back in just over a week. Then I can put the engine together and get the car back on the road. Should be on the road next month. Here's a pic from last weekend. Trying to find space for all the bits.

[stig]

Looking good Dave. That looks mega tight for the rear canopy over the 'charger!

[CanAm Dave]

It sure is tight Stig! I have a special tiny stainless bulge to fit on the rear clip.

[stig]

CanAm Dave said:

It sure is tight Stig! I have a special tiny stainless bulge to fit on the rear clip.

Ah, that would explain it

Shame you couldn't use plexiglass to show it off!

[CanAm Dave]

Now there's an idea! That would be cool.

[stig]

CanAm Dave said:

Now there's an idea! That would be cool.

Certainly cooler than the stainless will be - watch those fingers!

[pb3]

Dave, what intake manifold are you using? And are those carbon fibre rocker covers I see - very nice.

[CanAm Dave]

Hi Phil

It's the Holley Commander MPFI system. You can buy all the components separately, intake manifold and throttle body etc. The throttle body is available in either 1000 or 2000CFM size. I'm fitting the rear clip back on today to see if it will over my new carb hat. Fingers crossed! Yes the covers are carbon Reverie items.

Regards Dave

>> Edited by CanAm Dave on Friday 5th May 11:15