3b Crank pulley diameter

[etsola]

Hi there, may be looking to fit a trigger wheel on my 3b.

I don't have access to the car right now, can someone tell me what is the diameter ?

thanks

[andy10v]

About 162-163mm ish (outer diameter of the front V belt pulley)

[etsola]

Alright thanks, more or less 6.5".

About that diameter if I want the trigger wheel at the back and more than that if I put it at the front.

Cheers

[andy10v]

[etsola]

Thanks a bunch

[andy10v]

How are you going to attach the trigger wheel?

[Error404]

Bad idea putting a trigger wheel on the outside of a harmonic damper

[Thuppu]

It would be easy to weld the triggerwheel on the center section. I can make 60-2 tiggerwheel that you can weld on there.

[UrS4boy]

Hi there, may be looking to fit a trigger wheel on my 3b.

Contact Marc S. at EFI express, a NAmerican VEMS dealer. See what he has to offer.

[etsola]

I'm considering to weld it either on the outside or middle section.

Thuppu, how much would that cost?

Also, I have a spare 7a crank pulley, can I use this one and bolt it on my 3B?
I ask because I heard that the crank is balanced with that pulley so if I take a pulley from another engine does it mean I need to balance the crank again with the new pulley?

I see that EFI express machines the outside of the pulley. I might want to do that if I can use the 7a one ( since I'll be able to do it in advance and then install it).

034 seem to have added one on the outside.

Error404, can you develop on that?

Thanks for the replies

Cheers

[Thuppu]

The problem when fitting it on the outer section is that it will vibrate and move some as the dampper rubber is the only thing that holds it. It can cause trouble to the sensor signal.

I could make you one for 30e + shipping.

If you have the engine out, then there is a PnP solution, Lupo OEM 60-2 trigger crank rear plate.

[Error404]

The outside of the harmonic damper is not fixed relative to the crank, it vibrates, so the crank reference is continually moving. Plus the rubber is 20+ years old, so very unlikely it runs true, which may cause trigger errors. Weld to the centre section like Thomas suggests

[etsola]

Ahhh makes more sense now.

No I don't have the engine out... And I have a timing job coming, hence the good timing to put a trigger wheel there

Interesting Thuppu, I Pm'd you.

As for the 7a pulley, can I use it or not ? Is it balanced with the crank from factory ?

i.e. If I get Thuppu's trigger wheel, can I pre-fit it on my 7a pulley and just to the swap when doing the timing belt job ?

Cheers

[Thuppu]

I have been using a AAN damper that is not a pair with the crank and other engine internals. No problems. Of course not many km, maybe 4-5000km driven only, but few track days and limiter at 8krpm.

[etsola]

Good, I'll go get that 7a pulley then