I'm using your video and I'm trying to do a basic timing adjustment on a 1946 CJ2A project that I recently got running. In this particular build, the previous owner purchased and installed an electric ignition system - ref: www.kaiserwillys.com/downloads/923068.pdf . I've wired the system as described in the instructions, but when I try and get an RPM reading, the electronic meter is all over the place 800 -1800. I was wondering if you have any advice or if there is a different method to check the rpm on this setup. For background, I'm using a 12v coil with an internal resistor.
Post by Scoutpilot on Dec 28, 2017 15:08:47 GMT -5
Have you tried attaching the positive gauge lead to the negative terminal of the coil? There is no external connection on the electronic dizzy. Are you running a generator or an alternator? Electronic dizzy’s are very finicky about their voltage. It has to be just right all of the time.
I'm running an alternator, and I did try and connect the positive gauge lead to the negative terminal on the coil. Reading is still fluctuating so fast that I cannot get an accurate rpm read. I'm hooking the common ground if that's correct. I also did an ohm check on the coil at rest just to make sure it's in spec and it looks good.
Yes, I'm using a digital meter, but I have an old Sears Tach / Dwell meter that belonged to my dad that I could try. It has measurements for both 6 Cyl and 8 Cyl. My guess is I should read the 8 and divide by 2?
As reference, my other '46 is nearly the same except the coil is 6V with and external resistor and the distributor is normal with points. The digital meter works fine on that setup.
Post by Mashie Niblick on Dec 28, 2017 18:08:42 GMT -5
I’m pretty sure it’s the opposite- multiply it by 2 to get your rpm readings.
I went this this a few months ago with the same tools. My digital meter jumped everywhere, but the old fashioned tach meter worked like a charm. If I remember, it was reading around 400 RPMs and I multiplied it by 2.
The guys around here were beating there heads on the walls with me. They were closer to 15 RPMs. It was a good beat.
That makes sense to double the rpms and I'm glad based on the readings I'm getting on the analog meter. The analog meter is steady at about 500 rpms. I have the vacuum at 16 - pretty good for 5,500 ft of altitude (Aurora,CO). Now I just need to adjust the idle down a bit.
Post by Scoutpilot on Dec 28, 2017 20:20:25 GMT -5
You want 650-700 actual Idle RPM. Idling below that is not good for the motor. Bo is correct. Use the 8 cylinder scale and double all readings for RPM and Dwell. You’re looking for RPM numbers like 325 to 350 and Dwell of 21, +/-1/2º which when doubled is 42º, +/-1º.
Well, I thought I was making progress... but I seem to be stuck on getting the dwell setting correct to begin. I'm using the analog gauge now - Sears 244.2198 - and I have the red wire hooked to the negative side of the coil and the black wire hooked to ground. With that setup I get a reading of 12 on the 8 Cyl scale which doubled would be 24. The distributor is advanced all the way. RPMs are about 700. Any ideas what I'm doing wrong?
Yes, I'm at 15.75-16lbs now on vacuum and I think that is pretty good since I'm at 5,500 ft altitude. I believe you subtract 1 lb per 1,000 ft? I am getting a little bounce in the vacuum and also the rpms. In other words, the engine is not purring but there sounds like it may be missing a bit. All new plugs & wires. I have a compression tester coming in the mail tomorrow so I will check to see what the compression is on each cylinder. All the cylinders seem to be firing as I can pull the wires off at the distributor when it's running and hear a difference in the motor running for each wire pulled - motor struggles a bit for each. Gap is good on each plug too.
It seems to run better at higher rpms on the road.