Is there a definite answer to the “Optispark orientation” debate?
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Is there a definite answer to the “Optispark orientation” debate? I’m installing a new timing set at the same time installing a new opti in my ‘92 LT1. After identifying the contacts inside an old dist cap (and verifying that firing order is like all sbc’s) the keyed spline-drive is at 6:00 when the timing sprockets are dot-to-dot. I don’t have the opti out of the car yet, so going from memory, I believe the spline-drive is oriented the same on both sides. That puts the rotor at/or near #6 cylinder contact.
I know it can only be installed in one position, and yes, it should never be forced, and must mount flush to the front cover. Those issues are a given.
Has anybody done the research and solved this orientation question?
thx,
ed
I know it can only be installed in one position, and yes, it should never be forced, and must mount flush to the front cover. Those issues are a given.
Has anybody done the research and solved this orientation question?
thx,
ed
Thread Starter
Teching In
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From my perspective, not being an experienced engine builder, what I’ve been reading is the “solution”. Just install it correctly and it will be fine. Am I the only person that wonders how can the distributor function correctly when it doesn’t start with the rotor at #1 tdc? I did read somewhere that both #1and #6 are at tdc at the same time. That may be what I’m having a hard time wrapping my head around. So please forgive my ignorance, and I appreciate the input
Thanks
Ed
Thanks
Ed
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TECH Regular
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From: Houston Texas
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From: Houston Texas
#1 at TDC, crank sprocket dot is 12 o'clock, cam is 6 o'clock, opti is 3 o'clock. I literally just got done doing it, and this is according to Alldata or whatever my buddy's shop uses, and also correlates with everything online. LT1/LT4 are identical, Camaro, Firebirds, Corvette, brougham, caprice, doesnt matter, all the same. But they are different than SBCs only in everything is keyed so theres really no room for error unless youre using sledge hammers to seat ****.
On the opti, i dont dont why they have the other 2 notches that are similar to the key. This is where people **** up, but youve stated everything right in OP.
So, stop being worried and get in there and bust some knuckles. Run into issues, come back.
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Courtesy of Shbox:
For which optispark? Why should it matter since for both styles it goes on one way?
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Did not know they were different like that. Ill shut my mouth for now. I learned something new today, awesome. Its early, can relax into stupidity for rest of the day.
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From: Little Rock, AR
You don't have to know anything about #1, #6, dot up or down or anything else as long as the key from the opti is put in the timing gear slot (which can be in any position you want). No mystery. No debate.
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LT1 with the keyed opti, not spline opti. When putting everything at TDC without timing set on, opti key/pin should be at 3 o'clock? Not really talking about opti itself, but rather making sure cam is TDC in relation to crank.
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If you have any doubt about where the pin and dots are as they rotate, look at the link:
http://shbox.com/1/cam_timing_ani.gif
You just have to struggle bus trial and error until it slips in the hole. The key is a huge PITA to line up, it could take hours it could take minutes. You just have to line it up, there’s no “wrong” way unless you don’t get it in the hole. I had a buddy somehow manage to jam his in without being in the slot and it wouldn’t run, but it should slide easily. If you force it in, it won’t be in right.