1968 Coronet 500 Project

[JimKueneman]

Jim it sat for more like 15,lol. 2 jobs and then retirement hit so now have the time. Actually been on the road last summer&this year.Now getting a repaint.

Hopefully it is not in Paint Jail.... Now I see the interest in my thread

 

[oldbee]

Hopefully it is not in Paint Jail.... Now I see the interest in my thread

It’s only been a week lol. I’m original owner so I at least know what’s been changed/modified. Jeff

 

[threewood]

Do you take your car to the Midnight at the Oasis show?

No, never been. My 62 was in the parade for about 4 minutes last year. They lined the cars up out front of our station and down the street. I happen to be leaving work and pulled right into the parade traffic. Until some uptight chevy owner started blasting his horn for me me to get out. Flew him the "#1" sign and peeled out

 

[JimKueneman]

It’s only been a week lol. I’m original owner so I at least know what’s been changed/modified. Jeff

That is cool

 

[JimKueneman]

Yea you can buy these but what I wanted was not really available so I am designing my own that will fit in my stock 318 distributor and have full support for adding a custom advance curve. Keeps me out of trouble....

PIC24 so it can do floating point math in 2 clock cycles. It will be the most advanced/configurable ignitor available.... Will anyone else want one?

 

[JimKueneman]

Getting my blanking on.... Bit more testing and I’ll throw in the Pertronix III and blank out the double pulse! It needs a bit longer blanking at low RPM too there are a few jitter there that I think it catching a trigger on the back edge of the firing pulse now and again.

 

[JimKueneman]

Good day at Lawley Chevrolet Show in Sierra Vista Az today! Scared the mustang, he left early!

 

[oldbee]

Heard about a mint ‘55 Chebby 6/cyl in Phoenix in garage since 59 or so with a crk’d/warped head(?). Been in the woman’s garage ever since, she’s 70 and won’t sell. I guess these “old things” are still out there with no one the wiser!

 

[JimKueneman]

Took her to work the other morning after a winter storm. Cold morning that I got to use the rear window defogger! The twilight of the morning and ice mist made for some cool photos.

 

[JimKueneman]

Finally have the Pertronix III working with the FiTech. I have not really noticed any performance difference other than maybe during WOT it does not stutter... maybe. I think the reason in the old days electronic ignition helped overcome short comings of carb tuning. With EFI and high pressure the fuel is completely atomized and the high voltage spark does not help as much. What it should help with is you can run leaner fuel mixture to help get better MPG.....

 

[oldbee]

So how did that antiquated defogger work?!! Jeff

 

[JimKueneman]

So how did that antiquated defogger work?!! Jeff

Ha Ha, almost useless!

 

[JimKueneman]

Ok I am assuming that was you Jeff?

Whoever it was.......

 

[Billccm]

My neighbor's El Camino with crate 350 and FiTech, running stock GM HEI shows the AFR bouncing quite a bit. Swing is 13.6 to 15.6 almost constantly. Is yours more stable?

 

[JimKueneman]

My neighbor's El Camino with crate 350 and FiTech, running stock GM HEI shows the AFR bouncing quite a bit. Swing is 13.6 to 15.6 almost constantly. Is yours more stable?

Something is wrong. Exhaust or vacuum leak.

 

[JimKueneman]

Will he drive it to Sonoita?

 

[JimKueneman]

Experiment time. I have not been able to find the caps that go on the screws for the fender headlight splash shields. A Coronet Facebook group guy sent me one original so I made a model (first time) and have 4 coming from Shapeways (3D printed) in 2 different materials. We will see how they come out!

 

[JimKueneman]

Finally installed the new Legendary Interiors headrest chrome. Best to leave it in the sun to get the vinyl soft then press down. You will be able to find a few spots that the glue is not very strong. Slide a screwdriver through then work your way along pressing the vinyl away from the screw drivers vs pulling the chrome off. Wipe down with Acetone and stick the new ones on. They have double back tape.... not real sticky... may need to glue them with better glue on the ends.

 

[oldbee]

Experiment time. I have not been able to find the caps that go on the screws for the fender headlight splash shields. A Coronet Facebook group guy sent me one original so I made a model (first time) and have 4 coming from Shapeways (3D printed) in 2 different materials. We will see how they come out!View attachment 555550View attachment 555551View attachment 555552

I thought Classic had them? I do so much browsing I cud be wrong.

 

[JimKueneman]

Lets see how the Pertronix III works. Its dwell is about 6ms at idle.

What is interesting how they handle when it is reved up..... They actually turn the switch on BEFORE the flame is extinguished in the cylinder! This will maximize the current for the next ignition cycle.... interesting.... I would not have tried to do that....

Next I wanted to see the difference between the system with and without the factory inline ballast resistor.

The first one is with the resistor out of the circuit so if you do the math the circuit is trying for 12A peak and the resulting double firing. I am going to guess the integrated circuit that they use limits the current to about 6A-7A based on the devices I have looked at.

I then put the resistor back in and the math says it should max out around 5A-6A so there is not that much lost from the resistor out. You can see the area under the curve of the first firing line is a little lower than the first so about 2/3 the joules to fire the A/F mixture. Still WAY more than the points gave.

The resistor will drastically reduce the stress on the Penrtonix switch and the factory coil. I am going for reliability and not blazing performance. I don't see the difference in performance so the resistor is staying in for now.