A Jensen SP (440 Six-Pack engine)

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bobclevenger
Posts: 99
Joined: Mon Mar 28, 2011 9:54 am
Location: Reno, Nevada
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A Jensen SP (440 Six-Pack engine)

Post by bobclevenger »

Yes, you read that right, a Jensen SP, in fact a Left-Hand Drive SP of which there were only 13 ever made. This one has a 4-speed manual gearbox (with overdrive 4th gear) which makes it a "One of None" since there were never any SP's built with manual gearboxes. But you want to know about the MegaJolt installation, don't you?
Well, I just "finished" (are these projects ever truly finished?) installing an EDIS ignition system with a MJLJ/E controller with the hard rev limiter. The rev limiter is probably overkill for my use, but it can't hurt.

First thing after acquiring all the parts was to design a bracket for the VR sensor and have it made up. It is shown in the photo below. The material is 1/4" mild steel. The mounting holes are 3/8" diameter and 4" on centers. This matches the lower bolt holes on the timing cover. The overall depth (distance from the timing cover to the front of the mounting plate) is 1".
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Then I had to figure out a way to get a 36-1 trigger wheel on this big lump of iron. I could have had a little machining done and used the Ford wheel on the back side of the crank pulley, but I came up with a different solution to this challenge. I bought a new vibration damper from the nice folks at Summit Racing and had my fabrication shop (Proto-Fab in Sparks, Nevada) cut 36 notches in the circumference. I would remove the necessary tooth to get the correct 36-1 configuration later. This tooth has already been removed in this photo. I could have had them do this on the original factory damper, but I didn't want to have the car down for that long. The photo below shows the VR sensor bracket and the toothed damper both. The notch that is missing from one corner was a mistake, you don't have to do this. Note that after you remove the tooth, the vibration damper will be slightly out of balance. Either add some weight to the side that had the missing tooth (if convenient) or drill out an equivalent amount of metal on the opposite side.
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The photo below shows the parts (before painting) mounted on a spare 440 block. The Yellow line marks the tooth that had the 0° timing mark on it, and in this photo it is aligned with the 0° BTDC mark on the timing tab. The red line marks the position of the VR sensor when the crankshaft is at TDC on #1 cylinder. Oddly enough, these are exactly 5 teeth apart, so the tooth with the yellow mark is the one that gets removed. If you don't want to remove the tooth that has the timing mark on it, you can move the VR sensor one way or the other by one tooth so that the removed tooth gets to be one side or the other of the timing mark tooth. I won't tell you what stupid mistake I made doing this! Do it this way, not the way I did it! I found that 8 thicknesses of Blue Painter's Tape is just about 1mm. so I put 3 pieces of tape on the VR sensor when marking the position for the mounting holes. This gets the sensor plenty close enough to the toothed damper.
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The EDIS-8 module was mounted behind the grille in the area where the old MoPar ignition module and alternator regulator used to be. I just drilled and tapped the sheet metal for the 10-32 mounting screws. This is on the starboard side of the car, just inboard from the headlights.
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This is where the two coil packs need to find a home. Not a whole lot of room here! Note the decapitated distributor. This needs to be here to keep the oil pump drive gear in place. I plan to have Proto-Fab make a dummy distributor stub to do this.
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These next two photos show the mounting points I chose to use for the coil pack bracket. The RED arrows point to the mounting holes.
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The next two photos show the mounting bracket I made from the old Ford bracket and some strap steel. Don't rag on my welding job... it was the first time I ever used a wire welder. And it works!
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These next two show the coil pack bracket in place.
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And below is a shot of the coil packs snug in their new home.
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And finally, a shot of the MegaJolt/E unit in its nice cool glove box.
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Yeah, a bit of a job, and more involved than absolutely necessary, but it fits and everything is solid. I'll take some new photos of the car soon.
...Bob

spandit
Posts: 129
Joined: Wed Dec 22, 2010 10:43 pm
Location: East Sussex, UK

Post by spandit »

Looks great. I'm a little concerned about my install now. I removed my distributor yesterday to mount the coil pack in its place but your comment about the oil pump drive has got me thinking - is this a common arrangement?

bobclevenger
Posts: 99
Joined: Mon Mar 28, 2011 9:54 am
Location: Reno, Nevada
Contact:

Post by bobclevenger »

You got two things to be concerned about on a Big-Block Chrysler engine.

First, if you just pull out the distributor there's nothing the keep oil in and dirt out but a big hole.
Second, even if you put a simple plug in the hole, there is nothing to keep the intermediate shaft down and engaged with the camshaft gear and the oil pump; it can rise and become disengaged. When that happens the oil pump stops pumping and the engine dies soon after. The cheap way to deal with this is to get a junk distributor from a similar engine and just cut the head off of it. A distributor that no longer works can't be much at any wrecking yard (or is that "auto recycling centre" now?).

If you are dealing with a different engine, I plead ignorance.
...Bob

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