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Discussion Starter #1
Long story short, I bought this gtv and not really sure what I have or what was done 馃様. I have taken a project over from the second to last PO. The motor was rebuilt over 8 years ago and has never been run. It has C&B cams on it along with some very large sway bars RSR maybe? . Anyhow the ring gear was pretty chewed up so I pulled out the flywheel and am replacing it with an aluminum flywheel. Without tearing the motor apart or anything like that. Should I bring the new aluminum flywheel and clutch to be balanced or should I bring the new flywheel clutch and old flywheel to be balanced with the the new flywheel 180degrees offset to the old flywheel? It's the original 2l motor, but as I have stated I have no idea if it was balanced or anything after the rebuild. It looks like the PO was planning on racing it, terrible paint work, but solid body with new rockers etc.

Any advice would be great. Do I need to put the motor at TDC when putting that new flywheel on?

Help please
 

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Hi

I'm not hugely informed on 4 cylinder motors but here goes.

You seem to be under the impression that the four cylinder flywheel, has an offset balance or is part of the balancing weight for the crankshaft. This is not the case, like most four cylinder engines the flywheel balance is independent of the engine. You can change the weight of the flywheel without effecting the balance of the engine.

If you want and if you can find somebody who can do this, you can have your flywheel, clutch disc and pressure plate balanced, but most people just bolt a new disc and pressure plate to their old flywheel and call it done.

Hope this helps
Bye
 

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For absolute perfection, balance everything. However, I suggest Alfa components are good enough that one can plug and play with assembly. I recently used my Tilton Aluminum flywheel with a different crankshaft and new pressure plate and didn't re-balance anything. The car is a '76 Spider used only for autocross and time trials and runs very well up to my rev limiter set at 7500 RPM.

And, be sure you use the correct ring gear and pin it to the flywheel. I bought my Tilton flywheel back in the last century and they convinced me to send them the ring gear so they could attach it correctly ("Send us your ring gear. If you install it your self, it makes a terrible noise when it comes loose")

Assuming you don't use a crank fire ignition with sensors on the flywheel, there is no need to install it with the engine at TDC. Just clean the bolt threads, use locktite, and torque to spec.
 

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Discussion Starter #4
The aluminum flywheel I purchased already has balancing drill marks in it to get the weight even. It is a used unit that was resurfaced. I was unsure if ALFA 4cyl were balanced to the flywheel ie all rotating mass or not. Thank you

The fact that a new steel clutch surface was installed, does that change anything?
 

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I don't think so. I have replaced the surfaces twice on my Aluminum flywheel, and never gave a thought that this disturbed the balance.

...The fact that a new steel clutch surface was installed, does that change anything?
 
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