1965 Corsa clone, but a sweeeeeet one

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66corsaguy
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by 66corsaguy » Mon Oct 02, 2017 1:28 pm

Gregory_Miller wrote:Vacuumed it out and replaced the dome light with an LED style. Looks as bright and will run much cooler. Has to installed correctly or no light. I touched it to the terminals in both directions just to see if it had steering diodes to make it polarity indifferent.
I tried to do LED and nothing was working. I thought crappy lights. Are you saying there's a trick to it?


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azdave
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by azdave » Tue Oct 03, 2017 11:31 am

66corsaguy wrote:
Mon Oct 02, 2017 1:28 pm
I tried to do LED and nothing was working. I thought crappy lights. Are you saying there's a trick to it?
Cheap LED PNP bulbs are polarity sensitive (like putting AA batteries backwards into your remote control doesn't work either). If you install a LED bulb and it doesn't work try to plug it in the other orientation.

Better quality PNP LED bulbs have a diode bridge circuit hidden inside that makes them work no matter how you plug them in.
Dave W. located in Gilbert, AZ
66 Corsa 140 4-speed w/factory A/C
66 Corsa 140 4-speed w/factory A/C
66 Corsa 140 4-speed
65 Corsa 140 4-speed
66 Corsa 455 Toro V8
65 Monza 455 Toro V8
65 Monza 4DR 140 PG w/factory A/C
65 Monza 4DR EJ20T w/5-speed

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Gregory_Miller
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by Gregory_Miller » Wed Nov 01, 2017 6:49 pm

I was still having issues with bucking and missing even after all this work after some more driving. Last night I pulled all the plugs and it seemed that the plugs looked like they were running a bit lean, I replaced the 51 main jets with 52s. Checked for fuel leaks with the electric fuel pump while engine off, no leaks.
Tonight, Marty Scarr came over and took a fresh look at my car. Honestly, while I can do a lot, I have never been a "tuner". Results were quite promising as I had way too much base timing set, a left-over from a failing coil. He dialed it back to 16 degrees, and it was significantly better. His suggestions going forward was to back the timing to 14 degrees, add a bit to both idle screws and explore ways to limit the total travel of my vacuum advance a bit.

Happy happy joy joy joy! A HUGE thank you to Marty Scarr for taking the time to come over and help me get past chasing my tail. Might drive it to work tomorrow.

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Gregory_Miller
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by Gregory_Miller » Tue Nov 07, 2017 12:54 pm

So, after further diagnosis, it appears my car is happiest with right about stock timing at the low end, but base timing + mechanical advance + 24 degrees of vacuum advance is TOO MUCH at cruise. So, my plan is to limit the vacuum advance by somewhere between 6 and 12 degrees so all in advance is about 50 degrees instead of 60 as it is now. Idea from both Rex J and Marty S.

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thewolfe
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by thewolfe » Tue Nov 07, 2017 1:40 pm

That's a lot of vacuum advance! I thought the vaccum cans only advanced around 10 degrees.
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Gregory_Miller
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by Gregory_Miller » Tue Nov 07, 2017 2:37 pm

I have been told the "217" can has 24 degrees total advance. It could be less, I will research. I will limit it a bit and see what happens. EDIT: 217 appears to have 11 degrees total advance, not 24. So, I think I'll try limiting it to about 6 degrees and see how it feels.

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Gregory_Miller
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by Gregory_Miller » Tue Nov 07, 2017 4:56 pm

Further info shows that 11 distributor degrees = 22 crankshaft degrees, so along with the 16 degrees of static + 18 of mechanical and 22 of vacuum advance gives me a 56 degree total advance at cruise. Limiting the vacuum advance by 6 distributor degrees will limit timing by 12 at cruise. That's what I will start with.

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Gregory_Miller
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by Gregory_Miller » Thu Nov 09, 2017 4:01 pm

Advanced the timing a touch, but need to buy a better timing light then the weak HF one I have, so figure I'm at about 16 degrees BTDC as 14 was a big doggy off the line. 16 or so is better, but with a timing light I might take it to 18 and see what happens there. I also added a 1/8" drill bit into the vacuum advance slot to limit it's travel a small amount. At this point with the about 16 degrees base timing it seems I need a bit more drill bit to eliminate the surging at the 35 MPH range than the 1/8. If I end up advancing the base timing a bit more of course I'll need an even bigger drill bit. Right now it limits very little, and with a timing light I'll have a much better idea how much I limit it by sucking on the tube and watching the timing mark move as it's pulled in. I'm so much closer than I've been in some time now to just being able to enjoy driving the car.

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Gregory_Miller
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by Gregory_Miller » Thu Nov 09, 2017 7:16 pm

I put a slightly larger drill bit in the advance can I'll see how it reacts to it.. and now, thanks again to Marty Scarr! He suggested that I lubricate the fittings for the balance tube as I have replaced the rubber hoses with compression fittings. This will allow me to tighten them a bit more, he told me, as they do leak a little if not fully compressed. So, I loosened the 2 nuts on the balance tube and set it aside. Lubricating these ferrules was impossible with the Q-tip idea I had as the nut doesn't retract far enough to expose the ferrule. I sprayed a bit of silicone lube on them. Then I tackled the carb base tube side. The passenger side came off without issue, and I set it aside. The driver's side spun on the tube. It also didn't want to come off after I loosened the nut. I finally got it off and lo and behold... no ferrule. *blush emoticon* I had replaced the driver's side tube into the head as the existing one was pretty beat up. I used the coupler with the nut on one end to drive the new tube in, but I guess I left out the ferrule when I reattached everything. D'oH! Well, there is a ferrule now and the vacuum leak there that I couldn't hear is definitely sealed now. I'm going to drive it to work tomorrow and see what the changes I made tonight do. Left base timing alone, but a slightly larger drill bit to limit the vacuum advance an unknown amount but I would estimate about 5 distributor degrees or 10 crank degrees at cruise with high vacuum.
I also adjusted the fast idle tang so I have a bit more throttle opening while on the fast idle cams.

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azdave
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Re: 1965 Corsa clone, but a sweeeeeet one

Unread post by azdave » Fri Nov 17, 2017 1:46 pm

Gregory_Miller wrote:
Thu Nov 09, 2017 7:16 pm
...I finally got it off and lo and behold... no ferrule.
Sometimes we are our own worst enemy. Glad you found the vacuum leak. Hope it improves the performance.
Dave W. located in Gilbert, AZ
66 Corsa 140 4-speed w/factory A/C
66 Corsa 140 4-speed w/factory A/C
66 Corsa 140 4-speed
65 Corsa 140 4-speed
66 Corsa 455 Toro V8
65 Monza 455 Toro V8
65 Monza 4DR 140 PG w/factory A/C
65 Monza 4DR EJ20T w/5-speed

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