Tachs and Magnetos

[RobtheManx]

Hi everyone , I'm planning to run my 2180 in my street car , the motor uses a Mag .

Was wondering if anyone on here has had experience with Magneto Tachs . I have one of the Joe Hunt signal convertor boxes to wire the Tach when I used the engine in Ned Bug , but I never did get it to work , despite following the wiring diagram .

Has anyone used an old Sun Tach which run off a sender unit ? 

Also wondering if there is any kind of magnetic pickup which can be run off the pulley to feed the tach ?

Thanks , Rob

[vwhelmot]

I'm going to run a mag too and already have the hunt converter box but I have a nos 80mm speedwell tach. Me thinks I might have a few issues with my set up and I'm prepared to finish the car without a tach altogether.

[RobtheManx]

Yeah I've got a feeling I'll end up not running a tach too .

[vwhelmot]

I think I will be keeping it simple, no additional gauges whatsoever. They are so last decade anyway! Lol

[Pas]

I don't know about the Sun tach but I know Auto meter made a mag specific tach, model# 5620. It is discontinued now I believe, so I have been looking for a NOS or used one for a while now with no luck so far. If you hear of one for sale and don't want it yourself give me a shout 

I have a NOS Porsche 912 tach fitted at the moment and will try and get it working with a Joe Hunt converter box, but I'm not holding out much hope as I have been told by several people they are tricky to get working at all and if they do work may not give an accurate reading!

[Rocket Ron]

Hi Rob

I ran a auto meter signal conversion box and an autometer pro control with it and this seemed to work quite well and did give a steady tach.

Also tried the two step that the guy in America makes but with mixed results.

Magneto tachs do come up quite a lot on evil Bay and are usually cheap to as there is not much call for them.

Regards Ron

[jick]

Hi Rob

I ran a auto meter signal conversion box and an autometer pro control with it and this seemed to work quite well and did give a steady tach.

Hey Rob...... I have the same set up as Ron in my 59,

It'll come as no news when I say it's untested/Un-run as yet, but I had the wiring done by a couple of fantastic chaps who were well used to all the various Autometer/ Magneto components etc etc  they only do vintage /rally /race type stuff from the early 1900's through to 1970's Formula 1 cars...they loved doing my VW, said it made an an interesting change from Pre-war Lagondas!
They're based in Tenbury Wells..... Shoot me a PM and I'll pass on their details if it helps..

Jick.

[RobtheManx]

I don't know about the Sun tach but I know Auto meter made a mag specific tach, model# 5620. It is discontinued now I believe, so I have been looking for a NOS or used one for a while now with no luck so far. If you hear of one for sale and don't want it yourself give me a shout 

I have a NOS Porsche 912 tach fitted at the moment and will try and get it working with a Joe Hunt converter box, but I'm not holding out much hope as I have been told by several people they are tricky to get working at all and if they do work may not give an accurate reading!

I actually have an old Autometer Magneto Tach in my stash , but wasn't sure if it will suit my car . Wanted to use an old Stewart Warner greenline . If I don't use the Auto meter I will sell it to you Pas .

[RobtheManx]

I think I will be keeping it simple, no additional gauges whatsoever. They are so last decade anyway! Lol

So no oil pressure or temp either ? I was thinking about hiding them in the glove box , save cutting the dash .

[nicolas]

I think I will be keeping it simple, no additional gauges whatsoever. They are so last decade anyway! Lol

So no oil pressure or temp either ? I was thinking about hiding them in the glove box , save cutting the dash .

you don't need that either,  that way you have all the space to put a boost gage later on with the next engine 

[vwhelmot]

It used to have oil temp and pressure but to be honest, they are not going back in. I trust my engine builder.

[Pas]

[/quote]

I actually have an old Autometer Magneto Tach in my stash , but wasn't sure if it will suit my car . Wanted to use an old Stewart Warner greenline . If I don't use the Auto meter I will sell it to you Pas .
[/quote]

Thanks Rob.

[Lee.C]

I am pretty sure I started a thread similar to this a while back..... I am sure some one will find it and post a link 

I have since spoken with Ian @ WPS and he is working on a PROPER electronic convertor for mags, I haven't heard from him in a while so maybe he has some developments....

You could always go for a "Mechanical Drive" unit...

[modnrod]

I've never used a magneto, so I had to do a bit of "G@@gling" to find out what the problems may have been.
After reading this.......
http://www.donzig.com/tachometers.html
........I thought, "Yep, OK".
I'm an electronics tech, so apart from using a readily available kit for a sine-wave-to-pulse converter to drive a standard modern tacho, I thought an easier and simpler way would be to just use a tacho designed for a diesel, which are run off the vehicles alternator.
https://www.google.com.au/search?q=alternator+tach&biw=1920&bih=910&tbm=isch&tbo=u&source=univ&sa=X&ei=afwPVfWyJqW1mAWaxIHYBg&ved=0CGkQsAQ

I rekn one of them will do the job. Hope it helps.

[Lee.C]

Hmm interesting....

[WPS]

There's a few options here....

I've been working with a company to modify any tach you like to work with magnetos with mixed results but I think we're getting there now.....I hope to be able to offer this service once we have an accurate/reliable set up.

The converters suffer from EMF interference from the mag so sheilding the wire can help but usually they're twitchy and annoying!

Rob: I have a SW greenline tach with the appropriate Sun tach converter (very rare in 4cyl mag spec) which I'm gonna be wiring up in my '52 once I have the motor finished/started  so I'll let you know how it goes.

I also run a cable drive Jones tach from my Mallory mag in the Fiat....that works great and is period correct but again hard to find....and I rarely have time to look at it anyway but it's nice to have......reminds me of the start sequence in 'LeMans' 







 

[RobtheManx]

Hi Ian, thanks for that will be interesting to see how it goes with the Sun convertor . I'll run some extra wires through the car and leave it at that for now .

I believe the Lancaster Pilot and I will be coming to see you in April finally with his engine .

Cheers , Rob