Lightened flywheel

[cheitane2003]

Dear Sir:
In order to obtain a quicker throttle response I would like to do something with the flywheel.
It is said in your book, page number 100, that the minimun weight for a standar-type clutch is 7,1 Kg.
I would like to know aproximately, which are the zone/s where I can get this without danger for the flywheel live.
I can see part of this question in page number 97,photo number 8/25, but it is only in one face of this element. Is it posible to obtain a plan such photo 8/34 for this purpose?
Thank you very much.
Yours faithfully,

[Guy Croft]

I am not going to advise how to do this from photos. It is too risky.

You need to make an accurate drawing of the cross-section of the flywheel, then work out where you can remove metal to ensure that it is nowhere less than 12mm thick front-back after lightening. Every part must have a generous radius.

If you want to send your dwg to me by e mail I shall check it for you,

GC

[SteveNZ]

If you can, take a look at a 1600 Delta turbo flywheel. These use the same size clutch as a 2L but are much lighter.

[cheitane2003]

Thank you very much for your time and atention to my question,I will paint a plan of this part to know exactly the measures.
Yours faithfully,

[cheitane2003]

Guy

Following the indications in your book, I lightened the flywheel from 8,2 Kg to 5,6 Kg with no less than 12mm thick everywhere.

My question is if I would find any problem installing a standard clutch on it.
I can put several images if you find it interesting.

Thank you very much.

[Guy Croft]

I cannot see a problem - unless the clutch bolt and dowel positions have been changed, I imagine that you still have at least 8mm of thread for the mounting bolts (1 x thread diameter is about the shortest female thread I would use)

Do remember that the lightened fw must now be balanced with the crankshaft and the mounting position marked up, because of course if the balancer does not mark the mounting position it could be mounted 180 degrees out.

GC

[cheitane2003]

Guy:
Thank you very much.
Please,let me know: when you said fw with crank, that means: TOGETHER???
Or can both items be balanced separated?
I cleaned the cross passages in the crank too.
Best regards.

[Guy Croft]

Good!

Balancing method for the in-line 4 cylinder is:

1. Balance fw
2. Balance crank
3. Balance check/adjust as a pair.

The pair must be marked up with a balance witness mark. If you dowel the crank fw pair together - do this before balancing. Likewise crank mods, gallery pugs, oilway relief.

By this means an imbalance of either component be correctly identified and corrected. I normally ignore the front pulley and one can assume (well, except at very high rpm - over 7500 on the 2 liter) that any decent production clutch is OK in balance and can just be bolted on.

(Engines with say, Vee cylinder blocks and those with externally balanced crank (ie: those with balance masses on the fw to compensate for inherent crank imbalance) are done differently)

GC

[cheitane2003]

Guy:
Thank again for your help.
I‚´m looking for new pistons for this Spanish Lancia Beta 1920 ccm motor with the head you can see.
The standar pistons have a 3 mm high domes,can I put higer domes in order to obtein better CR or will it be dangerous?