Crank Pulley Rubber Worn Out?
Turbo Mini Forums

Hi All,

Another question as I move forward with my project:

I'm hoping to use an old crank pulley with the extra counterweight and machine it for a Megajolt setup but amd worried about what looks like dry rot on the rubber in it. I'm not sure what this rubber does or if it would be an issue? Maybe it can be repaired?

I think you need a new one...

http://minispares.com/product/Classic/Engi...k%20to%20search

Pedro Silva

http://miniciados.blogspot.pt/

Try cutting a bit of the rubber and see if the cracking continues inside, if not then it's ok to use.
Cheers John

Roger that, thanks for the replies. I think I'd rather not risk it coming free.

Is the damper important or could a standard pulley work fine? I'm going to be balancing crank, flywheel, con-rods and pistons which should hopefully help remove a need for much damping

you also need balancing the pulley

Pedro Silva

http://miniciados.blogspot.pt/

you also need balancing the pulley

Pedro Silva

http://miniciados.blogspot.pt/

Roger that on the balancing, that definitely makes sense.

Does anyone have drawings or dimensions for the pulley if I were to make one on my own? I don't know that anyone has done that before but I'd be into giving it a shot.

The idea of the rubber (?) bonded pulley is that it damps out harmonic vibrations on the crankshaft.(it is sometimes referred to as a harmonic balancer)

The 1275 is a long stroke engine and needs something like this, or very accurate balancing of the entire crank, clutch, flywheel etc if it is going to be used hard.I,m not sure that you could make a bonded pulley yourself, but I may be doubting your ability !

Most roadgoing 1275 engines survive pretty well on the standard "harmonic"pulley

That makes sense, I should note that this is for a 998 engine which, I believe, were fitted with the lighter stamped version or the harmonic style depending on the year. I'm not sure if the harmonic balancer is needed for these.

I'm not sure that I could handle the bonding myself but I was looking to take a go at something like the MED trigger wheel. I guess the question will be if I need the harmonic balancer.

and you cant balance the damper

Yes i moved to the darkside

Instagram @jdm_brett

Brett, why not?

Pedro Silva

http://miniciados.blogspot.pt/

If its a 998 then most didn't have dampers. I would say you will be fine without one. Just fit a trigger wheel in addition to the pulley.

Fit a new one

Jawd

Or you can try Selby trigger wheel...

Pedro Silva

http://miniciados.blogspot.pt/

Still curious to hear about why the damper can't be balance but that Selby trigger wheel looks awesome. I wonder if I can get a verto option?

Hes quite active on here
https://www.facebook.com/SelbyRaceEngines

Of course you can and must balance the damper. However, when it's as fucked as the pictured one, it might need it again.
If you're serious about your engine, you bin that!

I thought that the damper should be balanced. Definitely binning the one I have, now I'm just considering my other options.

I emailed Selby regardign the flywheel trigger wheel and it is non-verto only at the moment. I've got some thoughts for a verto option that I think I might start another thread about.

As I look to sourcing these, I'm wondering if a Midget/Sprite would fit. They look awfully similar and are much more available and cheaper here in the states.
Does anyone have any experience fitting these?

So I ended up not taking any gambles and getting the new damper.
I'm going to machine it for a trigger wheel. Does anyone know the missing tooth location in reference to the keyway?