Discussion in 'Early CJ-5 and CJ-6 Tech' started by 65seejayfive, Jun 9, 2019.
Advanced like how far?
I upgraded my points to a Pertronix unit and in the process I read an article by Christian Hazel in 4Wheel and Off-Road and he noted that they advanced the timing from 5 degrees BTDC to 12 degrees BTDC on their Hurricane they were working on. Once I find my TDC mark I’ll finally be able to see where my engine is set and tune it accordingly. All because someone before me swapped out my crank pulley to one with no mark
I run around 10btdc. I also replaced 1 of the advance springs with a slightly softer one for quicker advance. Even with my head shaved and block deck cleaned up , these things don't make any compression. I've never heard any detonation. I burn all my junk gas in this. With tank half full, I've added as much as a gallon of old gas drained out of a motorcycle or atv, that set through winter with no stabilizer. In ww2 they burnt all kind of junk in the original flat head.
I'm having an issue of when I put a load on it, like going up a hill, and I floor it to keep speed, it starts to give and go and struggle. Wondering if I should increase plug gap a little and more advance.
Are you sure it's getting enough gas? If it is bucking or acting up and the timing is correct and plug gap is correct then something else might be wrong.
Play with your advance, leave dist loose enough u can hand turn and test drive, keep advancing a tad at a time and see where it runs best. And also test while climbing that hill, pull choke slightly, to c if more fuel helps? I'm running a spark amp, (msd), with .035-.040 gap. And if your tires are taller than 28-29 in, don't expect much acceleration up grade in 3rd gear.
I had a heck of a time finding mine as well. It turned out there was a buildup of crusty oil and dust on the pulley that I needed to scrape and brush before the notch showed itself. I painted it to make it more visible and it did the trick.
A very common experience. Use a strong light and take your time - the notch can be very small.
Mine look like they were replaced a few years ago so I don’t believe that is my problem, not a bit of grease/oil on them. I keep looking at them thinking I’ll find it but I haven’t yet.
One of the reasons you need to run more advance then the recomended 5° BTDC is the fuel we are using now has a MUCH higher Octane rating then the engines were designed for. Higher Octane = Slower igniting hence the need for more advance on the timing to make up for the difference between 68 Oct and our now 87 Octane. And all of this should be done with a timing light.
Back in the day, a very succesful shop owner and old school mechanic would set the timing perfectly by ear. He would slowly advance the distributor until the motor started pinging/knocking and then back off a tad and lock the distributor down. Back in the 70's before the advent of electronic ignition, most cars/trucks had yearly tune-ups to replace points, plugs, condenser, etc as the plugs and ignition components wouldn't go 50,000 miles plus as they do now with electronic ignition and iridium plugs. These engines are glorified inline lawn mower engine whose design dates from the very early 30's. As long as you get the point/plug gap/dwell correct and the fuel mixture right, then set the timing/distributor to where the engine performs the best for your present engine's condition.
I know that many people used to set timing by ear, guy that lived across the street from me did the same thing. I've also found that setting by ear and using a timing light generally end up with almost the same result.....IF everything else is installed correctly of course.
1) Get an adapter from autoparts store for putting air in the cyl through the sparkplug hole.
2) Put on a short (6") piece of hose that fits tight over the adapter.
3) Put a small water balloon over the end of the hose and secure it tightly with a zip tie.
4) Turn engine by hand until the balloon fills up and stops filling.
You'll clearly see he balloon getting bigger and then smaller as piston starts to drop.
I just put pressure on the fan belt with my hand to tighten it. I use my other hand to then turn the fan and spin the motor that way.
Other plugs out and trans in N of course.
My dad worked 44 yrs for the railroad. He set locomotive timing by ear instead of using the right tools. He showed his apprentice's how to do the same. He's wearing hearing aids now and probably all of his apprentice's too..
Use a vac gauge.
CLOSE Plug gap & advance timing a bit. Try it & let us know
I suggest that you find TDC @ #1 , on compression stroke. Here's how : Remove your six spark plugs & clean & gap them. With your Coil wire off, have someone click - crank the engine , while you have your thumb tight over the # 1 SP hole. When you feel the compression , tell them your good & to stop. Place your ratchet & a 7/8" socket on the crank pulley . Look down # 1 SP hole & turn the crank back & forth a little each way until your at the very top of #1's stroke. TaDaa !...That Is TDC . File a notch on your main pulley , at the zero pointer on your block mounted gauge. Paint that notch White. it will now be there forever. Put your plugs back in , start her, & use your timing light to see where you are. Loosen your distributor hold down screw & move distributor a little & watch your timing go before or after the mark. Set to spec for that engine ( ? ) , Tighten distributor, and see how she runs !. Most likely pretty good.
P.S. I just realized this a late response, but your my pal & this is how it's done on any 4 stroke engine . How have you made out on Setting your timing ?
These are all great ideas! I hate to say it but I haven’t actually tried anything yet. I like the balloon idea, that seems pretty slick. Things are finally starting to slow down a bit so I think I’ll dive into this in the next week or two. Thanks guys
I just watch the #1 intake valve open and close, now you are on the compression stroke. You can take apiece of wire and bend it until you can get it down on top of the piston thru the spark plug hole, now you can turn it over until you find TDC, then back it down about 5*. That should get it running, once it is running, you can test it until it runs right, keep advancing it until it runs crappy, then turn it back until it runs right. Timing is the thing that matters most on these little motors. Good luck
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