Opti on a SBC

Any one have any information on adapting an optispark to a sbc? Seems if you used the correct cam and timing set the mount could be fabricated. Could an LT1 front cover be adatped for the seal/mount. A remote mount electric water pump would likely solve the next obvious problem.

I really don't even want to end there. I want to use the entire ECM to run the sbc.

I understand the intake adaptation so that's no problem, even though I'd likely be interested in a conventional intake with a throttle body of my choice. Seems like a MAP sensor and the rest could be added.

There also seems to be concern about opti reliability. Is that with high RPM applications? I don't seem to have any problems with mine even spraying 200 with it all stock, at 121K miles. I'd be happy to pay the $300 bucks for a new one at this point.

What about the guy who took the internals out and put them into a HEI? I never did find the post of the pics. Is this possible?

Any body have thoughts or information on the swap?

adapting an optispark to a sbc

:no: Why the hell would you wanna do that?

I knew that was comming, just didn't think It'd be the first post, several reasons.

Aftermarket fuel injection systems with comparable features to the stock ECM are expensive.

Once it's done one could use it on any smallblock including but not limited to aftermarket blocks: motown, world, aluminum....Additionally, big block applications would naturally follow depending on opti arrangement.

LT1/LT4s were not produced long enough to provide a reliable and steady core supply for years to come, CID is also limited.

Additionally, when I first started this old school vs new school hot rodding, I thought the whole ECM stunk. Now, after learning and programming the ECM, even as limited as the stock ECM may be, there is just to much opportunity to let it just pass by, it's worthy of pursuit.

I would start w/ the LT1 timing cover and adapt it to the SBC. I believe the LT1 timing cover is taller to accomodate the water pump drive shaft / seal. I'd just seal that up and put it on the old school SBC (provided it would fit). Concerning the cam, I think it would be a drop in deal if using one specifically for an LT1. If using stock roller lifters, you'll need to make sure your block can accommodate(sp?) the lifter hold down piece.

As far as I know, it's the high rpm that kills the opti spark. We killed two w/ in days on my friend's car. There are mods you can do to make them live (or so I've heard), but I'd just as soon get rid of it.

Good luck. It sounds like a fun project and a cost effective method of adding FI to your car.

Later,


Steve.

Does the front cover lower portion fit? I think you're right on the front cover height. That's why the balancer is also spaced way out? May have to run a LT1 balancer/hub for clearance?

One could use aftermarket hydraulic roller lifters. A little expensive, but nice to have a hydraulic roller.

I'm a nitrous user, so there is no need for the high rpm and breaking the opti.

Hopefully, we'll get some opinions on the opti internals in the HEI. That'd make this a sweet deal, leaving the front cover stuff alone.

I think the lower portion is the same and will work. The opti location forces the LT1 balancer out. If you had a remote water pump (as you stated), the opti wouldn't be that bad of a deal to change. It's the water pump removal and coolant evacuation that makes that job a total pain.

Later,


Steve.

I believe its actually the high voltage running through/around the opti that hurts them, but people freak out way too much over optis. If you think about them in respect to traditional distributors. An opti on a bone stock LT1 would run for 100k+ if there were no other problems, IMO the only reason they get a bad rep is how hard they are to replace compared to a distributor. If you really want something better than pick up MSD's DIS system. But for cam timing its hard to beat the opti, optical sensors are THE best form of crank/cam sensing if it wasnt for theyre fragility, considering most sense 360* of revolution in 1* increments instead of an 18 or 24X signal from a VRS or Hall sensor.

Ideally, a perfect system to me would be a completely sealed up opti, signalling an aftermarket DIS setup, which is what I think the LTCC is.

another idea is to convert the Gen3/4's EFI system to an SBC....

this is the deal

You HAVE to run a GM block(Bowtie or one of the stock roller blocks) because they are the ONLY ones that use the cam retainer plate. Other waise no way to hold the cam in place. the opti is not strong enough.

I will convert any front cover to do this for $125.

The water pump can be any of many after market setups. Once I get mine finished I will probably sell them also. They will be a bolt in for reverse cooling to use on a Forth gen f/y/b-body. they will use a Mezier or CSV(CSI) electric pump.

Thiese two parts and a oil pump drive shaft from MSD will get you running with a stock PCM and the Intake of your choice ;) I am going one step further and using a Crank trigger Distributor instead of a oil pump drive ;)

Good luck and let me know if you want your cover converted

I've done a similar set-up, as mentioned in another post in this section.

I used a late-model caprice Gen2 SBC, because of it's striking similarity to a Gen3 block. I use an LT1 cam, and a converted cover as well. The sensor and a modified base plate are intact, but nothing else from the opti was used. For induction, I use a converted intake from LT1intake.

Works great, saved me thousands of dollars, and gets me the same numbers that an LT1 will.

Will the dist off a 99 Chevy Full size van work? They have a cam sensor in the cap, but it only has one notch in the wheel.

May be a stupid question but out of curiosity, Is this so one can use a SBC engine using EFI while running a factory PCM?

I agree, the opti seems fine for what I do, jonaddis84.

oneflyn95z28, I forgot all about the roller cam button, thanks for the heads up. I might also call to see if a cam manufacturer will put the LT1 cam end treatment onto a hydraulic flat tappet cam. I don't see why they wouldn't. Then one can chuck the roller lifters, cam button, and roller compatable block.

Can one space out a water pump to straddle the opti? Would plates with 90 degree fittings installed and a remote pump work?

Are there other available distributors that will work?

Are there better EFI systems to work with?

I agree, the opti seems fine for what I do, jonaddis84.

oneflyn95z28, I forgot all about the roller cam button, thanks for the heads up. I might also call to see if a cam manufacturer will put the LT1 cam end treatment onto a hydraulic flat tappet cam. I don't see why they wouldn't. Then one can chuck the roller lifters, cam button, and roller compatable block.

Yes, you can call any cam manufacturer and have them do this grind. It's a little more money, but no big deal.

Can one space out a water pump to straddle the opti? Would plates with 90 degree fittings installed and a remote pump work?

Yes, you'd have to have them machined, might have some problems with the gasketing; but hey, this is new territory.

Are there other available distributors that will work?

Are there better EFI systems to work with?

1. Not that I'm aware of.

2. Depends, what is your definition of better? What your doing, and what I did, is alot more trouble than slapping an already proven aftermarket system on. But if you want to pass emissions, use your stock computer, and mystify the hell out of your friends; then you should go this route.

May be a stupid question but out of curiosity, Is this so one can use a SBC engine using EFI while running a factory PCM?

I did my variant of this conversion because of the previous reasons stated in this thread, core availability in the future, more aftermarket parts, THOUSANDS OF DOLLARS cheaper, and many other factors.

bone daddy, thanks bud (cam and pump info). I actually already have plates (for another project) made just need drilled and tapped. Sherwood sells a pump for about $120 bucks that can be used as a water pump. Plenty of other regular pumps are available also.

I agree, i'm not spending thousands of dollars on an aftermarket EFI, plus half the fun is getting there (fabrication and creativity). Buying parts to go fast is just boring.

I would define better as perhaps more compatable with a simpler pulse type distributor like any other electronic ignition. Seems the opti has a low and high resolution pulse, 4 and 180, or something like that.

When you said you use the baseplate and sensor do you mean the 360 holed wheel and sensor, just ditched the housing. What did you use for spark distribution? Looking at the opti page it seems like the sensor and wheel could be put in a distributor.....

When you said you use the baseplate and sensor do you mean the 360 holed wheel and sensor, just ditched the housing. What did you use for spark distribution? Looking at the opti page it seems like the sensor and wheel could be put in a distributor.....


Yup, the high and low resolution sensor are on a machined plate with a machined billet cover. Kind of looks like those covered plates they have when you eat in a hospital room. :p

For spark, I use a system similar to the LTCC. I threaded 8 holes in my valve covers and attached the coils there. I think it looks trick.

I agree that if you were so inclined, you could probably fit both sensors in a distributor. One of the problems is, you'd have to have a "normal" cam ground so that it had the dissy gear, and the LT1 nose. There would be some slack in the system, but you could probably tweak it out with a little tuning. And spark, that's another thing.. you would need to decide how to get spark to the cylinders. If you went the LTCC route, your holes on top of the dissy would be pretty much useless, and the cap just a cover. It would work, but it would look bad, and would have to be moisture sealed.