LT1 Optispark change out

[zgeezer]

My neighbor took delivery on a GMPP LT4 crate engine. Its distributer is rear mounted- just like any other gen I csb. The crate engine d/n mount fi, using an intake manifold and carb. My question is whether anyone has any information about dumping the optispark and converting to the rear cam drive distributer and using fi. Perhaps running LT1 fi hardware and re-wiring tpi ecu or after market. As optispark is widely believed to die from natural causes every 75,000 miles or so I'd like to avoid it if possible. Any ideas?

[Guest Anonymous]

Problem with optisparks is moisture usually from leaking water pump. Newer optisparks had a vacume line attached to the botton of the optispark to suck out the moisture. GM has a PN to up grade cars to newer optispark with vacume line. I've got a 93 lt-1 and just replaced the optispark after 5 years of service, had the car apart anyway. Good luck Mark

[Mike C]

Mark is right on the Optispark problems. If you still want to do this, check out LT1intake.com if shows how to add a distributor so the intake can be used on a conventional coolant flow SBC, but should work on the LT1. I bought a carb intake for my LT1 until I can scrounge the $ for the DFI. One of the beauties of the LT1 for a Datsun swap is that with no distributor through the intake manifold, it is not required to modify the hood latch.

[Pop N Wood]

I am interested in an LT1 for my Z but would like to avoid the opticrap (oops, brand-bashing censor alert) optispark problems.

 

Electromotive makes their coil pack set up specifically for optispark. Says it uses the stock trigger wheel and nothing else. Is anyone using this set up and how well does it work? Does it interface with the computer properly or is the ignition control all in the Electromitive box?

[BLKMGK]

Lol, trigger wheel is one of the problems! It's an honest to gosh optical sensor which means moisture fogs it and crap dirties it. I actually took one apart - it looks like a distributor cap with an optical wheel under it. How itlasted us 100K miles is a mystery to me to be honest. When it goes you'll know it! Check out the Holley ignition for this car - it uses a flying magnet I think. $$$ tho'

[Guest Anonymous]

How about some sort of triggered off the front dampener or something? (Doesn't like MSD have crank mounted triggers?)

 

Regards,

 

Lone

[80LS1T]

Hey Mark, where can you get that upgraded Optispark from? I have a 93 LT1 engine also and it has about 90K on it I want to replace the optispark before I put it in the car. Also how much is this upgraded Optispark unit?

 

Thanks ,

 

Guy

[Guest JAMIE T]

Check out www.camaroz28.com the opti solution is a VERY long going process. I just put a new opti on my '94 Z28 6spd, (among other things ) It's actually not that hard to replace the opti, especially when the motor is in an early Zcar. The distributer Mark is suggesting I think is the '95+ version. It's vented to HELP prevent moisture build-up inside the Opti. It DOES NOT FIX THE PROBLEM. Those cars suffer from the same problems as the earlier LT1's do. The best way to care for your optispark is to NOT steam clean the engine, don't drive through deep puddles(to splash water on your engine), replace the water pump with an electric drive type from CSI or Mezeire, and keep an eye on your coolant hoses(thats how mine failed). I had a heater hose leak and spray coolant all over my Opti. While I had the water pump off, I put the CSI electric drive in the factory pump casing. It flows 40gpm, and doesn't get above the half mark while idling in traffic. Plus it comes with a plug that covers the weep hole in the bottom of the pump housing(another cause for opti failure).

 

The problem with the Electromotive Opti eliminator is that it doesnt have a cam position senser to tell the factory ECU when to fire the injectors. So, sometimes it hits and most times it doesn't. Thats why Electromotive doesn't offer it anymore. But, they will be glad to sell you a TEC3 stand alone system to replace the whole shooting match.

 

One marine company has used LT1's in there boats for a number of years. ECU, and opti is replaced with a Cadillac Northstar ECU and coil packs. I've not done much research on the subject. I did do a search online one time with "marine" and "LT1" as my search and got a couple of good hits.

[silicone boy]

Actually, I would give the Electromotive Direct Fire Unit a look. It uses a crank triggered sensor and obviates the need for a distributor. Yes, you can get it packaged with the TEC3 system (I have one ready to install) or separately.