flywheel adaption

Ralphh85 · Post by **Ralphh85** » Tue Apr 15, 2008 9:29 am

im using a different flywheel to what was origanly on the engine, therefore the PCD is different on it to what needs to be to fit the crank, the ways of doing it seem to be...

make adaptor, which i have seen in other peoples builds, basically bolts on with oneset of bolts, and then has threads goign in to it and the flywheel bolts to it.

re drill between the existing bolts ont he flywheel.

since holes are only 1-2mm out i could re drill them so the bolts will fit through, after all they are only clearence holes and it centers on the inside not the bolts.

make new flywheel, not exactly rocket science, but would be bit of a pain in the arse. could use ali tho.

the flywheel center hole is 0.07mm smaller in radious and will almost go on to the crank anyway, would fit with tiny bit of work.

any ideas on what would/wouldnt work?

Ralph

kiwicar · Post by **kiwicar** » Tue Apr 15, 2008 10:10 am

If you have the facilities to do it I would make a new one, it will be right and the best solution because you will have made it yourself and made it for the job. However it is actually quite involved as even in alli it will still need a steel clutch face and a steel ring gear oh and you will have to ballance it when you are done, not impossable but you need access to the right kit.
Best of luck
Mike

ChrisJC · Post by **ChrisJC** » Tue Apr 15, 2008 10:16 am

I think I'd try to make an adaptor. You could also use the adaptor to make up any length issues with the gearbox input shaft.

Chris.

Ralphh85 · Post by **Ralphh85** » Tue Apr 15, 2008 10:19 am

true ind in that case i would make the lot from steel,

i would just waterjet cut the profile from 20mm plate and then have it lathed to the correct thickness,

it would be much easyer to re drill the holes in the current one as i wouldnt have to worry about clutch fitting, ring gear or havign a bespoke flywheel which would have to be compleatly remade if anythign breaks.

i guess a better thign to ask is do you think it would work if i just re drilled the bolt holes?

Ralph

Ralphh85 · Post by **Ralphh85** » Tue Apr 15, 2008 10:29 am

ChrisJC wrote:I think I'd try to make an adaptor. You could also use the adaptor to make up any length issues with the gearbox input shaft.

Chris.

trouble with the adaptor is the center bore is basically the same, if the flywheel center was 5mm bigger in radious it would be great as the adapter could ahve its own locating center.

the advantage of re drilling is i could just put a 4-6mm spacer behind the flywheel to correct it, which is about right.

Ralph

Spag · Post by **Spag** » Tue Apr 15, 2008 11:14 am

As a trial, redrill the holes in the fly.

The (bodged) - er I mean redrilled Princess flywheel fitted on the V8 crank with just a suitably thick spacer to put the clutch in the right place for the g.box.

Worked fine without exploding, but would ultimately recommend a custom fly after you know it all works

Ralphh85 · Post by **Ralphh85** » Tue Apr 15, 2008 11:42 am

Spag wrote:As a trial, redrill the holes in the fly.

The (bodged) - er I mean redrilled Princess flywheel fitted on the V8 crank with just a suitably thick spacer to put the clutch in the right place for the g.box.

Worked fine without exploding, but would ultimately recommend a custom fly after you know it all works

thats kinda like exactly what i wanted to hear,

how acurate do you thinkt he re drilled holes neet to be? i can "drill" them on the waterjet cutter pretty easy, but will only be +/- 0.3mm as its only as acurate as i can place the flywheel on the machine.

surely as long as they clear the bolts and theres still plenty for the botl head to go down on to it should work ok?

yes i will probly plan making a new one at some point but be nice to see it work and idealy get few miles out of it, as i plan on taking it appart again and putting in a better engine in 6-12 months after convertion.

cheers
Ralph

kiwicar · Post by **kiwicar** » Tue Apr 15, 2008 12:01 pm

If you are going to re drill the existing one, do it on a piller drill, stick a piece of scrap stock in the chuck that is a close fit in the existing holes, use this to hold it centered on the hole whilst you clamp the flywheel down, then stick the right sized drill in the chuck and away you go. the water jet is just making life complicated

.
Mike

Ralphh85 · Post by **Ralphh85** » Wed Apr 16, 2008 9:15 pm

kiwicar wrote:the water jet is just making life complicated .
Mike

well after hearing that i just had to!!!

first i cut the inside hole (which i didnt need to cut from the flywheel) and the 6 sourounding holes from a sheet of cheap ali.

then lined the flywheel up over the holes so it was in the right place, this way can place it within few tenths of mm, and fire!

just thought this one stopped the water quite well...

can just about see it cutting....

also cut a spacer to go behind it, which needed slight attention with a file as the holes where very very close fit, and it almost fits, 2 bolts went through perfect rest went throught he flywheel but where jamming as going through the spacer so very very slight fetle needed!

ChrisJC · Post by **ChrisJC** » Thu Apr 17, 2008 7:12 am

Looks good so far!

Chris.