GOAL:
The goal of this project is to develop a crank angle sensor setup for use with MegaSquirt EFI conversions or other engine management systems. The setup needed to be clean and well integrated while still being easy to install. A DIYautotune hall sensor and Euro Single groove pulley were selected to design the setup around. Both are required for the installation and are affordable to purchase new. The damper is availbile for multiple resellers including Motorsport Auto, there is a sandard and SFI spec availible. If there is sufficient interest in the kit then I may be able to supply the damper with trigger wheel installed.
This project started as a customer request for a custom setup for his build, I thought the kit could be good to offer to the Datsun community and decided to develop it as a new product, I worked together with the original customer and well be having them made in higher quantities offset the costs.
CAD DESIGN:
Using a spare L28 short block, measurements were taking of the mounting locations, timing cover, pulley, and sensor. These measurements were transferred to CAD and the design process started. I went through a couple ideas before sketching two of them in 3D.
Version 1: LHS Mount
Version 2: RHS Mount at original timing marker location
Version two was selected for the final design. I liked how it was tucked away and would provide a clean installation. The smaller euro pulley also requires a 240z timing marker which many people may not have. By working in an adjustable indicator on the mount this is taken care of. The indicator is designed to line up at TDC when centered but can be adjusted to match your engine perfectly. The decision was also made to keep the sensor mount and trigger wheel fixed without adjustment. The setup is designed specifically for the L-Series and pulley combination and should align correctly when installed, adjustment to the sensor position in relation to the missing tooth can be made in the software to dial it in exactly, accounting for small variances between installations. For this kit, which is designed around the single groove pulley, there is no provision for A/C. However in the future, if there is interest, a new kit may be designed using the same layout and matched to a 2 groove pulley
A 36-1 wheel design is used with the sensor position 60 degrees behind the missing tooth. The wheel is designed to bolt to to the back of the pulley, requiring (3) 8-32 holes to be marked and tapped into the center hub. The trigger wheel needs to be aligned concentrically to the damper and at the correct angle. To achieve this the trigger wheel comes with a center hub and spokes which is later removed after alignment is complete. The wheel slips over the pulley snout centering it axially on the pulley. A small plastic tool, which is 3D printed, is then used to align the pulley in relation to the crankshaft groove. The mounting holes in the pulley are originally cut to 0.125" allowing for easy pilot hole drilling into the pulley. Once the pilot holes are drilled the pulley can be removed, the pulley holes drilled out o 0.165" and the center web cut away leaving only the outer ring. The pilot holes in the pulley can then be final drilled and tapped to 8-32. This sounds somewhat complicated but is very easy and straight forward.
If you desire a different sensor offset in relation to the missing tooth the process works exactly the same except you will need to position the rotation of the trigger wheel without the use of the alignment tool. The sensor is located 46 degrees from the vertical plane of the crankshaft. We can provide templates or even a new alignment tool for a small cost if you are looking to do a different angle.
With a crank trigger and electronic ignition setup the distributor is of course removed from the car leaving an open hole in the timing cover. To tie the kit together and give it a finished look a distributor cover was drawn which utiliizes an O-Ring for sealing.
MOCK UP:
After finalizing the design mock up components were made by 3D printing them from PLA. The fitment went well with just a few minor changes made to the design and alignment of the sensor. Printing components prior to machining is a great way to verify a design without the expense of having on-off parts machined, changes can be made quickly and then reprinted for testing again.
FINAL PROCUREMENT:
The finished components came out looking great and I am happy with the fit and finish. I am excited to get a few of these on cars and recieve some feedback. The kits are now avaiible for purchase through the webstore, with the initial run of (8) offered at a discount for 'beta testing'.
Trigger Wheel Installation Video:
(Orientation for 36-1 ONLY, always consult your engine management user manual before mounting trigger wheel, if you need increased accuracy or a specific position you will need to mark sensor location on your engine and make a template for the exact orientation, contact via email if you have questions please)
Kit Details:
Crank Angle Sensor Mount: 6061-T651 Billet Aluminum, Black Annodized
Distributor Block Off: 6061-T651 Billet Aluminum, Black Annodized
Timing marker: 304 Stainless Steel, Laser Cut
36-1 Trigger Wheel: 1018CR Steel, Laser Cut
Hardware: All hardware required for installation, Stainless Steel
The kit is offered on-sale now for 190USD plus shipping, when the first batch is sold the price will return to normal, 225USD. To complete the installation a sensor and pulley are required: