3.4 in a Locost -- what to do?

[geek49203]

I've got lots of bits from a 95 Camaro that I intend on using in a "locost" Lotus 7 clone:

- 3.4 motor, motor harness, PCM
- t5 trans
- steering column (no key tho)
- pedals

I also have a scrap 3.4 motor (I got screwed), the upper end from a 2002 3500 V6 (with wiring harness), and the wiring/ECM from a OBD1 Celebrity Eurosport.

Gosh, something has GOT to work, right?

IN the first stage, I just want to get the motor running with the least amount of hassles. I'm told that if I get the dash wiring, plus the steering column wiring, and the little thing to disable VSS, the OEM OBD1.5 system should fire. Total cost, around $250 or so. Bonus is that I could run the OEM gauges for a while, which would save money (have you priced out aftermarket gauges??)

OR, I'm told, I can use the bits from the Eurosport. Not sure how, but hey, I'd like to learn. And that shouldn't cost anything 'cause I have everything?

I've also seen some conversion wiring harnesses to use OBD1 on the stock OBD1.5 harness, but that was $350 or something.

Anyway, I know only the basics of EFI (ie, I can find the throttle body on a bet), and am willing to learn.

OHHHH... since this will be licensed as a 1957 model car, the emissions stuff isn't a problem.

So what should I be doing, at least in the first stage, just to get the car running?

Thanks!

[Superdave]

I would install that 3.4/T5 as it is, but use the OBD1 engine harness and ECM to run it. The stock 3.1 tune will handle it ok for now. That will get you going.


Later on when you decide you need some more power swap the 3500 top end on to the 3.4 and stick a bigger cam in it. Then you can get deeper into the ECM stuff and have the fun of tuning one of these things.


I'm jealous of your project, it sounds like loads of fun!

[geek49203]

Thank you for your help! I already have plans to delete the p/s, the AC, and reroute that belt accordingly (reverse water pump?). I suspect that the EGR system can go, replacing them with blocking plates at either end, if I follow your suggestion?

I haven't compared the two harnesses, but obviously it would be great if I didn't have to hand craft the wiring to the dash, steering column, etc. Does that OBD1 harness I have, along with the ECM, somehow connect to the rest of the wiring?

Thanks!

[Guest]

I agree with Dave, install the 3.4 as is. I only say this, because this is your first EFI rodeo by the sounds of it.

You can then get the tuning equipment for the OBD1, and learn to tune on the engine as it is, and get comfortable with it. Then when you want more power and swap to the genIII top end, you will already have the basic understanding of what you need to do to get it tuned.

Any pictures? I have a friend that wants to build a Locost 7 after we get his 240Z and 240SX done. I want to persuade him to use a 60 degree V6 in his.

[geek49203]

Well, finally... I have the frame built to the point where it is a roller. I used a scrap 3.4 block and a t5 to do the mockup work, so I was a little nervous that a more fully dressed engine would actually fit into the thing (I moved it to the passenger's side as much as I could). Here are some pics:





I've got to fab up some alternator mount that goes on the lower pass side of the motor, 'cause the stock position is where I want the hood to be. I think I might use a Fiero mount, and from there, figure out if the water pump will turn the right way.

Also in my stack of parts:
- OBD1 wiring and 1227727 ECU from a Celebrity
- Top end from a 2005 GM 3500 out of a Malibu (newly rebuilt heads, intake, water pump housing, etc).
- OBD1.5 ECU out of the Camaro (16184737). I have a vendor who says he will reflash it for $200 so I can get the car running (turn off VAT/VSS, etc). The attraction there is that I could simply get the thing running with the stock harness, allowing me to complete the car.

-

[Guest]

I'd save that $200 for tuning equipment and use the '7730 ECM/harness as is, to get the engine running. The 3.1 FWD bin will be pretty close for getting the 3.4 running. It will just need some tweaking to get perfect. Many people have used stock bin files of similar engines, in similar situations to yours and drove pretty well.

[geek49203]

I guess an update is in order.

1. I got MadTuner to alter the OEM ECU (95 Camaro A/T), turning off stuff and eliminating the speed limit and stuff.

2. I don't have the thing running yet, but the fuel tank (using the pump off of a Corsica!) has been made, and I'm just now buttoning up the motor after a mostly rebuild (heads/intake with an oil pump change).

3. I needed to shorten up the belt 'cause I won't be running the A/C (no roof) or the power steering in this car. And since it's gonna be licensed (hopefully) as a replica of a 1959 Lola, or a 1957 Lotus Seven, a lot of other stuff won't be needed. So I put on a timing cover and water pump from a '89 Camaro,and then relocated the alternator down low on the passenger side. I had to attach the 24x crank sensor to that older timing cover (gotta love JB weld?) but the rest is pretty straight forward. I now use the shortest serpentine belt in the parts store.

Will keep you informed. I did put the 2005 Malibu 3500 bits on the motor while it was apart, and I will put that on as soon as this motor is safely running. BTW anyone got any cam recommendations for a 3.4 hybrid with the 3500 bits?