Wasn't long ago that e-bay had a seller selling billit optis for $250.00 or best offer. It has a bolt for advancing just under where the wires are for the harness. I offered $195.00 and got it. Didn't know what I was getting and left it on a shelf for a couple of months. Today I decided to open it up to see what I got. It has a stockish looking cap, yellow. When I opened it up it had a red rotor. Going further I found a washer on the reluctor wheel that said MSD so I am assuming it's a MSD billit unit. Are these good units? Only time will tell.

 

Do a "search"..... the MSD Opti gets discussed frequently. Many people have had problems with the MSD units, although over the years they seem to have solved a lot of the problems. They still suffer from the rotor screws falling out, etc.

General consensus is that a factory GM part is preferred. About the same price from thepartsladi on ebay.

The MSD has a red cap. Sounds like you may have a unit made out of parts from various manufacturers. There's no "reluctor wheel" in an Opti.... do you mean the optical wheel?

 

yes I did mean the optical wheel. When I put it back together I used blue locktite on the rotor screws.

 

I also shoped on e_bay for an opti. I saw info on all-ignition.com & checked their site. Decided to purchase their Hi_Po Opti-2 unit. 300 dollar. When I received, no instructions, so, I used MSD opti info found online. I dissected it and found it to be a copy of the MSD (? the optical encoder). I am running it now w/ no problems...yet. I also adjusted for max spark retard and use a variable MSD adj timing control due to a FI app. The quality looks to be good relative to the stock GM unit and the Summit brand. I've had many opti failures over time from 1997, and, have modded the opti many times from singular parts. B.

 

A couple years ago, AllIgnition admitted scamming people be selling "brand x" parts and labeling them "OEM GM parts". The parts failed prematurely. Then they came up with relabled parts, with catchy new names. I doubt they changed anything. I would avoid them on principle. How long/how many miles have you been running it?

Why would you retard your timing with the Opti? Timing is meant to be adjusted in the PCM, even with an FI setup. The adjustable timing on the distributor is useful if you want to advance or retard your cam.

 

After taking the opti apart and putting it back to gether I noticed that when i sucked on one of the vacume lines with my finger over the other, I was still pulling a lot of air. I traced this back to where the rubber plug with wires goes through the billit housing and the bolt for the adjustable advance. Silicone around that plug and all external screws and teflon tape on the advance bolt took care of those air leaks and now it's air tight.
Bottom line is that if installed as shipped I am sure it would have failed during the first rain.

Injuneer " The MSD has a red cap. Sounds like you may have a unit made out of parts from various manufacturers" Yes this is what it appears to be unless it's an MSD with an oem cap. I don't know if MSD marks it's billit housing.

The cap looks to be oem and the enternals are MSD. The rotor has phillips screws but allen screws would be better. I do like the fact that the opti plugs into the harness instead of the other way around.

 

For $200 dollars less the msd I decided to go for it since the Summit std opti failed @ 1 year. I've been thru many opti distributors. Various failures, and, I have made many of my own mods which most others are not in approval (I have had some experimental failures also - like BHO?).

The std adjustment on the all-ign.com dist was far more advanced (mid position) than a (non-adj) stock opti. I run 34* spark adv @ MAP->100kpa (12~14psi max) PCM.

I run a large IC and sometimes Mehanol_h2o spray on those hot days, but use Evans NPG cooling media which helps prevent detonation. I backed off the dist time adj screw to the max retard position and used my msd manual adj spark adv unit. PCM controls all the spark advance on the road for my app. The CMotion cam is set @ 114* Intake CL. I have about 200 miles on the all-ign.com dist. And, these are hard abusive miles. I have gone thru 3-gm opti's, 1_detec opti (very overrated a money waste), 1-Summit opti (no return allowed). Failures... 3_rotors, 2_dirt fowl, 2_encoders. I am getting more encoder failures now. I solved the rotor and dirt problem with an external c_case VAC pump. I've started shoping for DFI Gen_7 now. B.

 

So from what you are saying, it appears the AllIgnition timing adjustment suffers from the same problem as the MSD timing adjustment - there is no way to know where its set, or whether its correctly indexed to the cam.

Now you've got a setup that adjusts the timing using three different systems at once - the PCM, the screw on the distributor and a **** on the MSD timing adjuster. Sounds complicated.

What do you feel you will be gaining with the DFI Gen 7? What will you use for a cam position sensor, if not the Opti?

 

I think, not complex @ all. The PCM flash is a constant. The Opti timing adj is set and does not change. The variable timing unit has been calbrated with a scan tool and locked. So far, I like the MSD manual timing adj unit with the MSD 6a and the 8202 coil. Easy timing adj w/o the PCM flash.
The DFI Gen 7 would require a dual sync distributor. I would modify for fit of the dual_sync unit and eliminate the opti spark (cut the cowl and possible machine a special piece). I did mods for the VAC pump mod on the LT1 since there were none for an ATI FI app. Likely use the Victor Jr EFI manifold as some of the web site members have done. Sorry... Correction, cam timing is @ 104* @ tdc #1 cyl.
Just throwing my experience out there (one Engineer to another). B.