onevette80

Is it possible to installing dist. 180 out? (93 Vette) Or, is there only the right way given the key ways? Thanks

Alex94TAGT

Nope, there's no way to install the 1993 optispark "180-out", though it is possible to misalign the spline-drive. Just align the flattened teeth, and make sure the optispark fits flush on the timing cover without being coerced. Then you're all set.

The Engineer

I keep hearing of people who have got their Opti miss-keyed (indexed) incorrectly, but I'm not sure how that can happen (I have a 97). If it slips-up easy and fits flat on the timing cover, it should be correct.

Also, you may want to do a quick start/run before installing the water pump and coolant just to make sure everything is OK.

WD

Alex94TAGT

Well, me neither. I've had both types, and there was never any ambiguity in regard to installation.

Though, I've met some people who just have a knack for getting the square peg in the round hole...

onevette80

So there is no way to get it out of time other than putting the timing chain on wrong. dot to dot should be good to go? Thanks guys

Alex94TAGT

Short answer: Again, no. No worries. Just align the splines.

Long answer:

1) The optispark rotates in unison with the camshaft. It's a 1:1 ratio, 360-degrees, which is why you can't get it "180-out" so long as the splined drive is aligned correctly with the flattened tooth. This is not like the cam and crank, in which, it takes two crankshaft rotations to equal one rotation of the camshaft.

2) The timing set does not need to be "dot-to-dot" (#6 TDC) to install the optispark.

Yes, you can screw up the timing by getting the timing chain off by a tooth, but that will make both the camshaft and optispark (spark/fuel/valve timing) out-of-synch with the crankshaft, which is a little different than misaligning the optispark to the camshaft (spark/fuel timing out-of-synch with correct cam/crank position).