Electric tach fubar

[88v8]

So the second electric tach is fubar.

Needle jumps around, then when I go over 2000 it jumps to max and stays there.

I recall the same happened to the tach in my previous vehicle. The common factor is that it had a Lumenition Optronic (optical) electronic ignition, and the tach was hooked to the coil. I wonder if there is a problem with the spark plugs affecting the ignition - no other sign of that - or upsetting the tach.

Should I change to resistor plugs, or perhaps just on the left bank where the ignition and coil are located, or is it just one of those things...

Ivor

[BlownMGB-V8]

Have you considered using Theo Smit's tach movement driver circuit?

Jim

[Moderator]

Should I change to resistor plugs, or perhaps just on the left bank where the ignition and coil are located, or is it just one of those things...

Yes, I'd try resistor plugs.  And I'd recommend using the exact same model spark plug for each cylinder.

[88v8]

Thankyou.

Theo Smit I guess is here.
No haven't encountered that... electrikery...  likely beyond my pay grade.

I bought a Faria tach now, then realised I need to find a way to podmount it as no one makes a 110mm pod for a 4" tach, sigh...

V8

[Spitfire 350]

I made a spacer ring out of a thin piece of plywood and covered it with black felt to mount my tach and speedo in the large stock mounting holes.

[DiDueColpi]

I usually just gut the old gauge and mount the new one inside it.

[88v8]

Eight new resistor plugs BPR5ES. On a drive today, only 15 miles but still... the tach was OK.
So maybe it was interference with the ignition module.
In which case I have a spare 4" tach :{

I found that NGK are now offering solid-top plugs, meaning the little wotsits don't unscrew. This is good, unless one is running a vintage, as I have several times found a misfire due to the wotsits undoing themselves, and had to affix them with threadlock.
Not all progress is bad.

[MGBV8]

When installing new spark plugs, I always put a wrench on them & tighten the top nice & snug with pliers.  Never had one loosen up.    They sometimes are loose out of the box.

The solid top version of the BPR5ES is part # NGK4006.

[DiDueColpi]

A little late to the party, but here I am ready to limbo!
Here are some shots of my 66 Elan S2 with a GPS speedo and a Digital tach.
I wanted them to appear mostly original. So pointers and housings were swapped over.
No more concerns about gear ratios or tire sizes and the tach recognises a pertronics ignition!
Looks original and actually works.
Live like you mean it
Fred

[Moderator]

that's VERY nice!

[DiDueColpi]

Thanks Curtis, a lot of effort went into them.
If you want to see more, I just listed the Elan on BAT.
Looking to free up some travel cash.
Wish I had some pics of my Jensen Interceptor dash. That one was over the top.
I'll post some of my TGB dash when I get home. Its not too shab either.

[Moderator]

You forgot to post a link, so I'll fix that for you here: https://bringatrailer.com/listing/1966-lotus-elan-s2-10/

What a spectacular example!  But you certainly didn't leave much for a tinkerer like me to mess with. I'm curious:  What changes would you make to it now if you were planning to keep it forever and drive it yourself frequently? (So, to be clear... if you didn't care about resale value.)

Best of luck with the auction!

[88v8]

Some smart topiary you have there.

My tach remains erratic. Most days OK, some days not.
In addition, the mileometer on the Speedhut GPS speedo has gone awol. Occasionally I can see it and it still seems to be recording, but the readout is mostly illegible.
Lifetime guarantee, but I have to go into the birds nest behind the dash to get it out, then send it to the US and the shipping rates now are insane.

Yes, very nice car. The travel money will enable you to look at lots more cars. You could even come to next year's Goodwood Revival.

[DiDueColpi]

Hi Ivor, the gardening is the handywork of the lovelyLynne.
And yes to Goodwood. Been wanting to get there for quite some time.
Do you have a suggestion about the best time to go?

[DiDueColpi]

Ivor. You probably have an EMI problem. (Electro magnetic interference)
The easiest way to find out is to get the cheapest transistor radio that you can find. (they still make them?)
Tune it off station on the AM band, and start the car up. Turn things like the wipers or the heater rmotor etc on and off.
If you can hear them on the radio you've got a problem. Rev the engine, if you hear an engine speed static then you have an ignition issue, if you hear a whine that rises and falls with the engine then its probably an alternator/generator problem.
It's a genuine old,oldschool trick but I've used it a ton on late model stuff with "unfixable" problems.
Live like you mean it.
Fred

[DiDueColpi]

So, Curtis.
If I was to keep the Elan it would get wider and lower, it would have a proper cage tied to the backbone frame. Mostly to stiffen it up. Partly because I build them and I like to show off.
I have an old original set of BBS honeycomb 16 x 10 forged 3 piece rims that would mate to the car somehow. An orphaned Alfa Busso, twin turbo 3.2 V6 and its 5 speed rear transaxle are hidding in the corner of the shop looking for some new love. Also a bunch of the Alfa magnesium supension would migrate across the floor. The pop up headlights would become faired in in the original position.
Other than that I would leave it alone.
Or, all of that stuff will find its way into a 58 Citroen trucket thats sitting in the Bunker unloved.

[DiDueColpi]

I removed the post, was having a poor me moment.
Cheers
Fred

[Moderator]

The auction ended, and it appears the buyer got a helluva good deal. I hope you consider the results satisfactory, and that the transfer is hassle free.


16x10 wheels under an Elan!  Ha!!!

I really love a well-designed and well-crafted cage. Getting one inside such a tiny car will be a magic trick. Getting one inside, through, and around the fiberglass will surely make it much trickier!  It's tricks that make hot-rodding interesting. I looked at Alfa Spider rear suspension parts with great envy at one point. They'd suit an Elan for sure. Won't match up to your wheels. (I failed to find a gear ratio that worked for my little project.) But wouldn't Busso anything be an impossible fit inside Elan? It's a crazy thought exercise.

The two modest personal must-haves I come back to are (a) headrests, and (b) fuel injection. Your cage addresses the first, and your Busso engine the second. The Lotus-Ford engine would be neat-o enough for me, except I've been daydreaming a bit about what a custom EFI solution for it might look like.

The Elan does really need bigger/wider tires.

[MGBV8]

My dad would certainly appreciate the Elan's door openings with extra room to get one's feet in & out.

[DiDueColpi]

I Was hoping to do better, but I'm OK with it.
There is definitely a Canadian penalty when selling in the US.
It's border envy I think.
The suspension that I have is from a Milano, front and rear. So rear transaxle and clutch, front engine.
Everything will fit if the height is great enough that I drop the car from!
Fuel injection for the Lotus twin cam, for me, would consist of gutted webers with four of the short style injectors hidden inside.
The ecu would be Megasquirt. or an SDS unit.
Those skinny little tires on the Elan hang on exceedingly well. The car weighs nothing. And the balance is spot on. It really is a thrill to drive!
Cheers
Fred

[Moderator]

I'll bet!  I'd love to drive one.  

Closest I've gotten is sitting in this one:  http://www.britishracecar.com/AlanTosler-Lotus-26R.htm  

(I had lotsa articles in-process when I ran out of gas on BritishRacecar. I wish I'd written text to go with these photos.)

[DiDueColpi]

That car would be a lotta fun for sure!