Flywheel bolts

[chris.richard]

6 months after getting my engine, and I still haven't got hold of a set of bolts !:( I got one set, but the thread was wrong. Is there anything special about flywheel bolts? Would the highest quality (e.g. 12.9) high-tensile bolts do? It's not the place to risk a sheared bolt.

[mogul_x]

Chris,

I can't speak with any authority on the Alfa flywheel bolts, but I did change the flywheel on my Toyota MR2 a couple of years ago. The Toyota used what appeared to be very high grade socket head cap screws. I couldn't see any differences between them and a standard cap screw, but that doesn't mean that the Italians didn't do something different.

[chris.richard]

The "wrong thread" set I've got - (M12 x 1.5 as fitted pre '91, instead of M12 x 1.25) have the following on their head - R120, and V * 0, where * is either a back-to-front 5 or F. These aren't the 8.8, R or S markings I'm familiar with - any ideas?

[rutthenut]

Sorry, I don't have any detail on these, although I do seem to recall that the bolts appear to have a very fine thread.

If you contact Adie Hawkins at A.H. Motorsport, I should think he would be able to help. As would most other Alfa engine builders.

Once you've got the right bolts, you'd best check that you have the correct length too.

The standard Alfa build includes an additional spacer/washer that sits on the flywheel. I can't think of the best explanation, but this a flat item about three inches outside diameter, two inches inside, with holes for each of the flywheel bolts. If you don't use this, the bolts may well bottom out into the end of the crankshaft - which will definitely lead to a loose flywheel if not corrected.

I guess you'll have a diagram of that somewhere already, but I thought it was worth mentioning at this point.

[chris.richard]

Thanks, John - I've got one of those.

[kens]

The Alfa V6 uses different lenth and pitch on the flywheel bolts based upon automatic or manual transmission. So, if the engine is converted from automatic for use with a manual transmission, then switch bolt size.

Regards,
Ken Stevenson
Dallas, Texas