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Discussion Starter #1
Short of trying to find an electronic rev counter with the same size and sweep as the original one, has anyone found a electronic-to-drive conversion kit?

This is for the GT Junior 120mm rev counter with built in oil pressure guage.

Much obliged.
 

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When I converted my Alfa Spider to a twin spark engine I found out that some of the rev counters used in the 1980s Series 3 Spiders (before they went to the single large instrument binnacle) are electronic driven rather than the mechanical drive. They don't have the oil pressure guage but the needle sweep is similar although I don't know if the diminsions of the dial are the same. Maybe a combination of the S3 and your existing rev counter? - don't know if it can be done as I haven't done it but it's a possible line for investigating.
 

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Discussion Starter #3
When I converted my Alfa Spider to a twin spark engine I found out that some of the rev counters used in the 1980s Series 3 Spiders
I found these people in the States:

Cable X...Electronic Speed Signal to Mechanical Speedometer Adapter

But they don't seem to do rev counters.

All I really need to find is a 240 degree sweep 120mm rev counter and then swap the internals.

I am going to try starting with the Original 75 rev counter and see how I get on. Spent a few hours looking at this and not found much else.

Just bought the whole cluster for £30 so not too afraid.

Is there a way of taking out the rev counter without removing the dash?

Thanks.
 

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My GT Junior is Left hand drive (Imported from Italy) not sure if the approach I took would be the same for RHD- I removed the rev counter without taking the dashboard out. I did it by undoing the screws holding the fuse box to under the dashboard and lowering it. This gave me enough room to squeeze my hand up underneath to undo the two thumb nuts the hold the instrument in place and remove the tacho cable. I then pushed the dial through the dash which gave me enough room to dis-connect the electrical connections. I found it best to lie on my back across the front seat with my head under the dash - not comfortable and it was a tight squeeze to get my hands in.

When putting it back in it's useful to have someone else around to ensure that you put the dial back in level as it's hard to judge when your head is underneath the dash trying to tighten the thumb nuts up again!
 

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Discussion Starter #5
My GT Junior is Left hand drive (Imported from Italy)
Same as mine, LHD from Italy. I will take apart the 75 cluster and test it on its own first, then follow your instructions.

If it works I will post the whole job with pictures.

Thanks a lot for the info!
 

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I have a 73 junior, converted to TS. My rev counter also has the built in oil pressure gauge.

I removed the electric unit from a 75 tacho, and put the Jnr face over. Its a massive fiddly ballache to join everything together and to fit in the old cluster bowl. I ended up having to cut chunks of metal out.

Temporarily wired it in and it worked (to my surprise). Anyhow, when i went to fix it in the dash permanantly, i must have shorted something and it stopped working!!

So i now have another 75 unit to try again!!
 

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71 Berlina 74 GTV 17 Giulia Q4
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I put one on just to check and the mechanical one read 300rpm fast.
 

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My little Sun tach is spot on. The mechanical tach was about as accurate as the speedo, which is best for impressing passengers who don't know any better.
 
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