Case question for possible location for crank trigger Options

[technicalninja]

What was the original use for the large hole on the flywheel side of the right (passenger) engine case?

Looks like it could have been a good flywheel lock location.

To me it looks like very good spot for a crankshaft position sensor...

What was its original reason for being there?

[technicalninja]

I think you are over estimating the "jitter" that is caused and it is really a non-issue. Look at the OEMs in the 90s before they had all their tooling switched over to make those directly connected sensors.

Nissan, Toyota, Mitsubishi all had their CAS systems (getting their cam and crank positions) running off of the exhaust camshaft (directly connected or through a gear) driven by a rubber timing belt. This adds about all possibilities of error and they worked perfectly fine. The only time they would fail to keep accurate timing is when the motor made gobs of power and the torque would stretch the belt.

As for the phase relationship between the senors there is no need to adjust that ever mechanically. Only if the original design got it wrong, even then you just adjust it with software.

Im all for the do it yourself idea. There are plenty of projects I have made that cost me a lot more than just buying an off the shelf product. But it still doesn't stop me from poking holes in mine or someone elses idea. It all helps in the design process

The cost no object SBC builds all employ small Gilmer belts to reduce jitter that exists with an old-style chain drive. This jitter affected both cam timing and the distributor that was driven by the cam. The belts are a tiny little shock absorber in this application. Jesel is famous for their belt drives.

Torque will not stretch one of these belts very much at all before it breaks them.

Many of the CAS sensors used Mitsubishi sourced optical sensors (including the LT1 in the Chevy world). I like optical sensors; they worked really well.

Mitsubishi stopped making these about a decade ago and now even the MSD billet distributor for LT1 is not worth buying. Only real solution for the LT1 crowd is an upgrade to the LS1 system with COP.

I have moved over to the current OEM style of doing things. Simple mag sensors directly on the item being sensed. The OEMs did this for cost savings first and accuracy second but the acuraccy is world class if the application is correct.

Thanks for your insight. sometimes another's views open up a world of possibilities...