96capricemgr

iTrader: (1)

The MSD cap and rotor kit for the "unvented" opti adds the vent. So "venting" is NOT a valid argument for buying the whole thing. Just something guys use to comfort themselves after that kind of cash outlay.

James Montigny

iTrader: (13)

Is the venting a good enough excuse to swap, or simply a factor to consider if you are already having to replace your cap and rotor for other reasons?

My existing OEM replacement barely has 8K on it and looks great, I don't see any reason to
replace it for the new motor other than to add the venting "feature".
Motor is still outside the car at this point, so if I'm going to do it, now seems
like the time to take care of it.

93Z2871805

iTrader: (5)

So, I assume your gonna use the stock unit with the MSD cap and rotor even on the 383.

James Montigny

iTrader: (13)

That's why I was asking.
My stock unit and semi-new cap/rotor are in good shape.
Unless the venting is a huge deal, I see no reason to change it.
I mean, if the opti dies due to gas buildup, I'm just gonna have to replace it. No huge loss.
Just a little more work to do it later than to do it now with the motor out of the car.

Smokeshow_2006

iTrader: (3)

I had an msd unit, Bought it before I was a member here, before i was informed. after aproximately 10,000 miles, the optical unit fell apart. Not exactly a good investment for 5bills. On a stock, or relativly stock car, the delco opti is perfect, If you're winding the **** out of your car, 6500rpm+, you'd be better off making the investment on one of the "distributorless" systems.

James Montigny

iTrader: (13)

Distributorless would still use the stock optical sensor.
The only advantage I see is moving the high voltage out of the opti.
And if I remember correctly, one of the distributorless vendors stopped making/supporting their products.

But yes, I certainly see your point about the MSD optical sensor you had being a poor design.

93Z2871805

iTrader: (5)

I'm in the process of building a 383 too but even then I see no need to rev the **** out of it, 5700-6000 is about all I need to go. On that note, I have two questions about the rpms: 1) Does a 93 have a rev limiter? If so what's it set at? and 2) What are the max safe revs for a stock bottom end 180,000 mile LT?

BALLSS

My 'current" opinion is diferent from when I bought the MSD unit. it 'should" be better than the OEM delco but my recent experience would not support that.

My 17k mi Delco unit is back in and no high RPM miss.

Shaft play appears to be the problem on the MSD I have. $111 service quoted from MSD

what ever unit you get, go vented

96capricemgr

iTrader: (1)

How many miles did you have on the MSD?

BALLSS

Dwayne;

not many. About 4k mi

rotor came off at 2k mi, reinstalled using lock tite. High RPM miss was present from beginning which was valve spring and aparently opti related. new valve springs solved the 'float" but a intermittant but distincet cut off then go again was going on. assumed it was ignition related so I pulled the MSD. Cap/rotor looked good, no signs of moisture but shaft had way more play than when the unit was new.

car would run fine, just break-up above 5500 "sometimes". Since there is so much play in the shaft I can see the rotor itself move so assume at high RPM's enough play for optical sensor to keep up allignment on the disc.

Since I bought the car new Optis have been a problem, mosytly due to "other" things. Like many my attempt to install what should be a better part in the end did not last.

I think we all agree the "Opti" from a design and build point certainly has flaws and the fact most of us are pushing RPM's beyond 5200 any brand has problems. I have disected both Delco. MSD and Dyna's unit. The later 2 try to address known weaknesses and appear to do a decent job at that but all have the same optical sensor, wheel. Interesting that the MSD bearing vs Delco bushing did not last.

we can make cars go faster...but often at a cost of parts.

BizZzatch350

iTrader: (33)

I have had good luck with AC Delco relacment optis, when I convert to a vented, I'll be using a GM vented unit. Dont see the point in dumping money in to an MSD when so many people have had issues with it.

96capricemgr

iTrader: (1)

With the 190K I have put on my cars the only opti problem ever had was one worn cap and rotor ausing poor running in wet weather and that was not on the fast car that sees high rpms.

In my experiance the "opti poblems" are grossly exagerated on the internet.

TABBED 5.3

iTrader: (1)

what is generally considered the max RPM for an opti?

Fixxer99TA

iTrader: (5)

https://ls1tech.com/forums/lt1-lt4-modifications/930312-just-picked-up-msd-opti-would-you-like-my-opinion.html

Must have missed that one...

3DFORMULA

iTrader: (4)

I tried the MSD early on and it would not rev past 1200rpm out of the box. Installed a used GM opti and it is still fine after lots of runs. My input

ABA383

iTrader: (1)

I still run the stock GM AC Delco Opti with no problems...I have seen more people with issues with MSD over the years so I just dont think its worth it...Like Dwayne said earlier caps and rotors are maintenance items as they wear like any other cap and rotor...replacing them can be such a pain that most will never change them until they have a failure...I run my set up to 6500 rpm and have for 13 years with no problems...I did change out the stock opti for another in 2005 when I switched cams and had the heads re-ported...The genuine AC Delco stuff has worked well for me...

--Alan

93Z2871805

iTrader: (5)

I just changed my ORIGINAL opti. It had 180,095 miles on the clock. When I took it out it came out in 4 pieces, the cap, the base, the rotor, and the drive were all loose. The contacts were rusted and the ball bearing was laying in the cap.

James Montigny

iTrader: (13)

Not bad for a stock opti.
What did you replace it with?

93Z2871805

iTrader: (5)

I almost dread saying that I replaced it with the MSD unit. But, I bought the damn thing before I heard all this bad ****. I assumed (wrong might I ad) that when everyone else was upgrading the ignition they changed the opti over. I looked at another GM one, the Accel unit (that I couldnt find for a spline drive), and the MSD. I know, I know now that I have the feedback from all the much wiser LTX guys I'll know not to do that again if I can just go with an OEM. But I will say it is running a HELLUVA lot better.

93Z2871805

iTrader: (5)

By the way james, do you have a stock bottom end on that 11.8 motor?