Stack

[Astro]

Maybe the wrong place but it is still a mini. When driving on the trailer this afternoon everything was all right. 200 miles later when driving from the trailer, the Stack tachometer only went back to 4.400rpm. All contacts seems to be all right. When trying to program the number of cylinders there are every time different reactions. Still no idea what to do and it might be better not to race tomorrow.

[dklawson]

I have only handled a Stack tachometer once so I cannot offer suggestions regarding its switch settings. However, if the problem with the Stack will prevent you from finishing a race weekend, consider rushing out to the nearest auto parts store and buying a lesser model to salvage the weekend. If they don't have one with a shift light, go old school and put a strip of white tape at your desired shift point. Most will have an adjustable redline marker. If the budget one does not, put a stip of red tape at your self imposed redline.

All this being said, are you using a multi-spark ignition that might be confusing the Stack?

[Astro]

Thank you, but in the middle of the french jura there is no shop near by. Running a classic car Championship the ignition is also a classic one and it has never been a problem for the stack. I tried to reset several times, controlled the contacts with a multimeter - something went wrong inside. This time we finished and next time we will have a conventional tachometer and an extra shiftlight. When one will fail the other one will still work.

[CooperTune]

They are not cheap and when they go crazy they are gone. I have two and one was sent back for repair and is back in service. The other is in the same box ready to go for repair. The repaired one has been in service for 5 years without issue. I on the other hand have issues trying to get it to do all the things it is designed to do. Steve (CTR)

[Vegard]

I always rev my Mini until there's no more power available..... Why do I need a rev counter??

[rich@minispares.com]

I always rev my Mini until there's no more power available..... Why do I need a rev counter??

that's what valve bounce is for isn't it?


or it is in a 1071......................

[Astro]

That's the problem. It's a 1290 short stroke 8 port. We returned the Stack and mounted an old Jaeger. Better than using my ears.

[Frogeye61]

Maybe I'm a little too old skool, but I've gotten a TR-6 distributor which has a cable tach drive, and a Spitfire mechanical tachometer.

[rich@minispares.com]

as one of my mates is fond of saying


'use the crank'

as he revs his 1293 round to 9400rpm..................

[Astro]

there has been a kit from spares, but not anymore available. Just got the information that the pointer of the Stack has been bended.

[mk1]

All mechanical tacho parts are still available from speedograph. I have one fitted in my 850.

All you have to do is find a head you like.

http://www.speedograph-richfield.com/

[olddad]

"Maybe I'm a little too old skool, but I've gotten a TR-6 distributor which has a cable tach drive, and a Spitfire mechanical tachometer "

Used that setup as well. Not enough electronic parts to malfunction, and parts too cheap and available.

[Astro]

A 6 Zylinder distributor? The spiti tachometer is a bit low. We need one up to 8.5.

[dklawson]

Most of the Triumphs from the 1960s through early 1970s had Delco distributors with a cable take-off for a mechanical tach. I understand there were some Lucas distributors with that tach take-off but I have never seen one up close. I think the take-off gearing for the 6- and 4-cylinder distributors is the same so I am not sure why OldDad would have started with the 6-cylinder distributor. Regardless, you can put the 4-cylinder Delco distributor parts in the 6-cylinder shell to convert it (the stampings on our GT6's 6-cylinder Delco indicate its shell is/was for a 4-cylinder application... so it goes both ways). Regardless, I don't know that I have ever seen a Triumph tach calibrated for more than 7k RPM which is obviously a lot lower than the 8.5k you are looking for.

What I remember about the mechanical Triumph tachs is that they are all calibrated with an odd ratio of 3.55:1. If you find an 8.5k mechanical tach calibrated with that ratio you could connect it to one of the Delco distributors to meet your requirements but... the advance curve of the Delco is probably quite unsuitable for your Mini's race engine. I myself went the other way with our Spitfire and replaced its mechanical tach with a later electronic one. Cables wear out, make noise, and mechanical tachs can become quite inaccurate when they become dirty with age.

[CooperTune]

Would that be bent? Or is that the different same language. I have the dynamo from an early Sprite with tach drive off rear. Could always tell when fan belt was loose. Steve (CTR)