has anyone over thought of mounting an optispark to a conventional distributor shaft to use an obd1 or 2 lt1 pcm on an older SB or BB for true SFI?

 

Not a bad idea if you could make it fit... cheap EFI.

 

its quite large so that may make clearance issues, but true SFI for older motors costs hella $$$ with custom crank/cam triggers and such. or.. someone could just modify a 95+ opto cover and cut the waterpump section off and make a sealing surface like the older style timing chain cover? and just use the pump drive gear like our LT1s.

 

The Opti-Spark was moved to the front of the cam so the cam-to-distributor gearing clearance would not add to "scatter."

Since the high-res pulse of the Opti-Spark is supposed to have 1 crankshaft degree of accuracy, I wonder how it will be affected by the extra gear clearance. However, I would think a worn timing set would also affect it. But, a worn timing set and cam-to-distributor gear clearance would be even more.

Tom Piper

 

I believe the problem you would have would be getting the rotor of the opti lined up with the correct cylinder. Since the opti bolts into place and is driven by the cam its put in a certain position.

 

all that would be needed is an indication to line up #1 tdc. I'm not sure where the dowel or key is in relation to the rotor.. I never payed much attention to that but that would be a small hurdle. it is possible that a small amount of "slack" could be taken out by manually clocking the distributor.. even if there was a small amount of scatter, I think the gains of a fully programmable fairly inexpensiveSFI to an older motor would outweigh the loss in precision of a degree or two of timing.