Franken Kart

Master Hack

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My sanity has been called into question in the newbie thread for some of the things I did to this poor thing. So to remove any possible doubt, I will try to explain how to convert a Mopar HEI ignition to work on a Honda GX390.
The Franken Monster:
IMG_2788.jpegIMG_2786.jpeg

The ignition:
IMG_2854.jpegIMG_2850.jpeg
As you can see my projects get off the rails somewhere between start and finish. I collect a lot of stuff (wife calls it hoarding) and when I see something I can use without spending a bunch of money I use it. Yeah, I spend all day making a part I could go buy for $10. I prefer to make everything. I did not want a bolt together kit.
So with that in mind this thing took a year of work 25 hours/week average.
On to the ignition:
I had a mopar distributer and thought it would be nice to put this on the honda for some centrifugal advance. The stock honda ignition is static timing. Reliability was another factor.
So I figured out how to put a Mopar distributer on the end of the crank.
IMG_2854.jpegIMG_2855.jpeg

OK so its going to fire 8 times every revolution of the crank! that won't work! So file 7 lobes off of the reluctor! Now it fires at the top of the compression stroke and at the top of the exhaust stroke (so what) The tricky part was modifying the distributer to run off of the crank without grinding stuff up. Again this is all stuff I have sitting on a shelf. Cost - 8 hours and $0. The problem is it's ugly and adds another 6 inches to width.
After that setting the timing is pretty straight forward. A timing light is a must.(remember those?) Once the timing is set near TDC then tune it by ear and right foot.
The wiring is the easy part mopar wiring diagrams are all over the net. I added a 30mm carburetor and the thing runs pretty sweet.

I'll get into details if anyone is interested, just ask.

Disclaimer:
This project is not for the faint of heart. You need a lathe and a mill and courage. Screw up and a GOOD replacement distributer is $150 or more. Chinese knockoffs can be had for $50 or so.
 

Denny

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All of that brilliant machine work and you had to use a worm style hose clamp? Lol, I’m just kidding. That is slick. The only real question I have is how did you deal with the distributor cap and coil wire? I have owned, or worked on my share of mopars. My last one was a 70 air grabber, b5 blue, white stripped and interior 440 4 bbl GTX.
 

Denny

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We hardly called your sanity into question, how could we? We all have the same sickness. How would we know if your insane? :lolgoku:
 

Master Hack

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Ahhh, the clamp! That is not just a hose and a clamp, but a distributer drive retaining device. Now the ugly details. The distributer main shaft was replaced with a socket heat cap screw 5 inches long. The distributer drive on the crankshaft is also a SHCS. The actual drive is a piece of an hex key (allen wrench) cut to length. The rubber hose and clamp was put there in case things go wrong and the hex key decides to depart. I would never find the 3/4 inch piece of allen wrench. 3 hours of hard running and nothing came apart, so it was probably un necessary. yes I have spares just in case.
As for the distributer cap, I just cut the top off of the cap and glued a piece of acrylic on there. The 8 wires and coil wire are not needed, there is only one cylinder to fire. The only reason that was done was to make the thing a little shorter.
So the wires from the pickup in the distributer go to the orange box on the firewall and the wire from the orange box goes to the coil. The system fires on the compression stroke and the exhaust stroke. Does any of that make sense?
As for the sanity thing, The wife tells me at least once daily "you're crazy". so it must be.

IMG_2854.jpeg

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Yeah, I know! The rear shocks/springs are going to be replaced with coil overs ASAP.
 
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Denny

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The only thing I see wrong with the rear shocks and springs is the springs should be more outboard. I should have known better on the coil of course with one cylinder it is going to need to only fire one time. (Yes I know it is a lost spark system) But with no rotor or distributor how does the centrifugal advance work? Or are you just using vacuum advance. Been 20 years since I’ve been in a Chrysler distributor.
 

Master Hack

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The springs are too stiff to be outboard any further. The spring rate was calculated for where they are now, but the shock looses too much travel there. It works like a lever, move the fulcrum point and the effort to move the wheel changes. Think wheelbarrow. I need softer springs then l can make coilovers as in the front.
The centrifugal advance moves the plate that the pickup is attached to as the weights swing out.
That advances the spark, by changing the point where the reluctor and pickup meet.
Pretty simple when ya got one in your hand and can see the relationship between the two.
 

Master Hack

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only old guys know what a distributer is. Show one to a youngster and wait for that blank look! A few days go I had a young guy ask why my car had 3 pedals.
 
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