OK Tach question...

[Shealey]

I have a 59 Bugeye. I need an electric tach as I am no longer running the 948 cc engine.

Is the later Sprite electric tach the same size diameter?

If not does anyone have a late Sprite tach they want to part with? I'll make one out of mine and a later electric tach.

 

[drooartz]

The later tachs are smaller in diameter, though I believe it is possible to fit the electronic guts into a Bugeye gauge case. You can always run the original generator if you want to, it will work on all the A-series motors.

 

[Trevor Jessie]

The sweep on the donor tach is important. I think the MKII Sprite tach sweep is a little different. But... there is an "autometer" brand (I think) tach that has almost an identical sweep to the MKI tach.

 

[bugimike]

Drew is correct. You can take apart the two tachs and switch the guts. I have found you can do the same with the speedo too, but the odometer "window" has to be trimmed out due to more numbers on the new unit than on the old style!

 

[Shealey]

Ok, Anyone have a late tach they want to part with?

 

[bugimike]

As a matter of fact, I do!! I have two, one is complete and I woulld like to keep since it is intact. The other lacks the chrome ring and glass (which you would not need anyway!) PM me and we can make arrangements to get it to you!

 

[Shealey]

PM sent. Thanks sounds like exactly what I need.

 

[Trevor Jessie]

OK, maybe I'm all wet. If you want to retain the bugeye tach face, but use the mechanism from a later, how would you make the rpm's line up. Doesn't a Bugeye go to 6,000 and the later to 7,000 (in a shorter sweep)?

You guys are going to make me go to the basement and dig through boxes... aren't you?

 

[jlaird]

Some place on the web is instructions for doing this.

 

[Trevor Jessie]

in the knowledge base
/bcforum/images/%%GRAEMLIN_URL%%/wink.gif

 

[Trevor Jessie]

https://www.britishcarforum.com/lore/attachment.php?id=12

 

[drooartz]

Wonder if Doug Lawson (dklawson) here will chime in on this one. He's done a lot of fiddling with gauges.

I don't remember if the gauge sweeps are different. All I've got is the Bugeye gauges, so nothing to compare to.

 

[jlaird]

Ha, beat me to it.

 

[drooartz]

Look here:

https://www.britishcarforum.com/bcforum/ubbthreads.php?ubb=showflat&Number=152595

Also,

https://www.britishcarforum.com/lore/article.php?id=063

I knew this stuff was here somewhere!

 

[bugimike]

Very comprehensive "how-to" in the Knowledge section!!

 

[dklawson]

I can't add any to this discussion. I've seen very few Bugeye instruments so I don't know about the tach's range or sweep. I hope the PDF proves helpful though.

 

[Billm]

It is probably covered in the link above but-- the positive ground tachs (up thru '66 or '67?) are the same size as the bugeye (face diameter). The negative ground ones are the small ones.
Bill

 

[Shealey]

I just sped read though the how-to article and realized the RVC tach conversion will not work with electronic ignition. I'm just going to purchase an aftermarket tach designed for usae with electronic ignition and use the guts in my early tach.

Thanks all!

 

[Trevor Jessie]

I think maybe it was a VDO that had a cheap 6000 rpm tach with about 270 degrees of sweep.

 

[ncbugeye]

You don't have to switch to electronic tach. ncbugeye has a 1275 and still runs the mechanical rev-counter. You just have to keep the dynamo from the 948, that's all.