1971 Datsun 521 - L18 Single DCOE

Show off your Megajolt installations, vehicles and action shots here!

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fenderstrat536
Posts: 11
Joined: Thu Oct 21, 2010 7:50 am

1971 Datsun 521 - L18 Single DCOE

Post by fenderstrat536 »

After lurking and reading nearly every new post since I had joined I finally finished and installed my Megajolt v4

Quick back story:
This truck came to us after it had been overheated. the PO had the head decked but never resealed the motor, so it was all corroded. Went to the JY and happened to find, in another 521, what we *think* was a crate replacement motor imported from Japan back in the day. So out with the stock L16 and in with the L18 with "high comp" head. Next a 5 speed transmission. The DCOE lacks a port for ported vacuum off the carb making a standard vacuum advance distributor less than ideal to use. And then there was Megajolt...

Now for some pictures:
trigger-wheels.com 36-1 trigger wheel milled to fit the stock pulley, then welded.
Custom mount, that I designed, using a Ford Explorer sensor. At one point I had read they made a stronger signal, this may not be completely true though.
The bracket is meant to be modular, utilizing the back plate then just designing a new holder for different triggers and differing crank pulleys and their lengths.

In these pictures the trigger wheel had not been welded nor is the motor at TDC, it was just a mock-up on a spare motor.

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While the wiring isn't that pretty, it works and will probably be reworked eventually

Although we found out, while rebuilding the carb, that the manifold actually has a bridge between the two runners, we still plumbed in two ports to get a vacuum signal. Used 3/16 push-to-connect tubing and 3/16 -> 1/8 npt swivel 90° fittings


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Started out by just wiring the EDIS module and coil to run on limp-home-mode, it fired up first try, at 3:30am!
This was even after rebuilding the carb, which turned out to be disgusting. This was a thoroughly exciting moment!

Next day wired in the Megajolt, adjusted 2+ degrees globally, since my trigger wheel alignment wasn't nearly perfect,and we were off and running. This is the best the truck has ever run, and now the truck is quite exciting to drive. Now just need to figure out the spots on the map that need adjustment. Let the data logging commence!

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