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Discussion Starter #1
Hello all,

As I am a young buck and have never done anything to a car other than keep it running, naturally I will come across things that I dont know of as I proceed with my resto. I have a 1977 Nova Rally and I was planning on switching out the guages for some white Auto Meters. As I began researching, I found that there were electrical and mechanical guages. What exactly is the difference? Is one better than the other? Which kind do I need for my application? Any help would be appreciated greatly!

Thanks,

Doug the Noob :)
 

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Electrical gauges run off a sensor, and mechanical gauges directly sense the pressure, temp, etc. Look at the back LH side of engine next to distributor (V8), if there is a sending unit with a wire plugged to it, you have electrical oil gauge and odds are your temp sensor is also electrical. On the other hand, a mechanical oil gauge will have either a small plastic or copper line that runs from the block to the gauge and the water temp will have a sensor unit with coiled wire running to the gauge.

I'm not sure that one is better than the other. Note however, that because a mechanical oil gauge feeds oil pressure directly to the gauge, you run the risk of a leak both at the block and at the gauge if you don't connect them properly. I ruined a brand new radio before I got my connections right. The mechanical water sensors are fine, but the coil running to the gauge needs to be kept away from any heat source such as headers, manifold, etc. The other thing is that you'll have to drill new holes in the firewall to feed the tube for the mechanical gauges, and that will leave you with a few extra wires in your harness that you will no longer need. And you will also have to do some wire splicing for the gauge lights if you are totally converting the gauges as I did with my 76.

Hope this helps!
 

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Discussion Starter #4
StoveBolt said:
Do you have the rally cluster now? tach etc?.. if so why would you want to change (just my opinion)
What I have in the car now is the stock setup as far as I know. I do not have a tach. It has four of the same sized circles outlined in white. The far left one has red warning lights for brake, oil, and gen. The middle two are the speedo and the gas gauge. The far right one is where a clock would be, but no clock is present. I am planning on changing the interior over to black from the original Firethorn Red. With the black interior and the new steering wheel that will be coming shortly (mine is sticky from the years of hot sun) a white set of auto meters would look much better in my opinion. Thanks for the question!
Later,
Douglas:D
 

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Discussion Starter #5
jade76 said:
Electrical gauges run off a sensor, and mechanical gauges directly sense the pressure, temp, etc. Look at the back LH side of engine next to distributor (V8), if there is a sending unit with a wire plugged to it, you have electrical oil gauge and odds are your temp sensor is also electrical. On the other hand, a mechanical oil gauge will have either a small plastic or copper line that runs from the block to the gauge and the water temp will have a sensor unit with coiled wire running to the gauge.

I'm not sure that one is better than the other. Note however, that because a mechanical oil gauge feeds oil pressure directly to the gauge, you run the risk of a leak both at the block and at the gauge if you don't connect them properly. I ruined a brand new radio before I got my connections right. The mechanical water sensors are fine, but the coil running to the gauge needs to be kept away from any heat source such as headers, manifold, etc. The other thing is that you'll have to drill new holes in the firewall to feed the tube for the mechanical gauges, and that will leave you with a few extra wires in your harness that you will no longer need. And you will also have to do some wire splicing for the gauge lights if you are totally converting the gauges as I did with my 76.

Hope this helps!
Thank you for your reply! Looks like I will be leaning towards the electrical guages. Not that it matters at this very moment, the interior is pretty much last on my list. Gettin that tranny in there and maybe even a new 350 are the main concerns right now. BTW, is this Tony from gen4novas? I wasn't sure if it was or not. If so I'm Doug, I bought the clutch kit from you for my trans conversion. Well thanks for the input! It was really helpful.
Later,
Douglas
 

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Hi Douglas,

Welcome to the site. Nice story & photos on cardomain. Good luck with the manual trans conversion and getting the front bumper fixed.

Best of luck. Keep the 4th gens alive. (Maybe someday we'll see real repro parts!)

Jay
 

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SB-

You beat me to it. Was just about to post the same auction. It would go well with Doug's car since it's got a V8 tach.

I think there was a link on this site or in Nova Times where someone did the splices to make the rally cluster work. If he's lucky enough, maybe find a boneyard rally with the correct wiring harness.

Jay
 

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Hi Doug,

Didn't realize it was you at first.

Wish I would've known you were swapping out your interior, we could have made a trade on that. I have a set of black interior that I'm looking to go back original with the firethorn red for my 78 Rally 4spd that I haven't started yet. It needs a few patches before I can do anything else to it (Trunk pan, quarters, floor boards, partial cowl panel), but I want to restore it original.

Also, on my 76, I have both factory electrical gauges and I added a couple mechanical. I know on my 76, the factory electrical gauges just serve as warning sensors, so I added a mechanical oil pressure and water temp so I can more accurately monitor them rather than relying on the warning light to come on when something goes wrong. I'll have some new pics in a couple days.

Can't wait to see some results on your project. Let me know if you need any help setting the clutch up.
 
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