3.2 Carrera fuel injection on an SC 3.0
 

I have tried searching, and it is difficult due to the numbers in my search needs, lol....

But just like the title says, I want to put 3.2 injection onto an SC 3.0 to go into the 68 I am building. Is this a popular swap? I'm wanting fuel injection, and this seems like the cheapest and easiest way to go.

Does this exist? Is it possible? If not, why not. If so, is it awesome?

I'm sure you will get many replies - but a few things to think about if you are going with the full DME setup:
you will need the flywheel that can trigger the DME sensors. You will need to modify your transmission to accept the speed/reference sensors. I'm not even sure if a 3.0 case has the mounting bosses for this sensor bracket so this may put you out of the running for an easy swap right there. '68 probably has a 901 type transmission, so not sure if a flywheel upgrade is possible either.

The only other consideration would be the intake port size and making a smooth transition from the 3.2 intake runners/plastic gasket to the 3.0 intake ports.

Good luck either way.
Bill

I'm doing 915 trans from the same SC car as well. I never thought about the flywheel needed. I'm sure that can be sourced. Looks like the only hiccup might be the speed/reference sensors... I have seen before that someone makes an adapter that goes from the 3.0 intake bore to 3.2, but now I can't find that. I can't be the only person that has wanted to do this.

If not this simple injection system, then what is the next best plug and play setup to go with?

It is annoying that there is no simple injection system for air cooled 911s. I bet there are two dozen or more fuel injection systems on the market for the small block 350 in my El Camino. Of course the number of SBC Chevy engines built in one moth is likely more than all the air cooled 911 engines ever made and the SBC has been around from 1954 to 2003 and still made in aftermarket for less money than a set of heads for a 911.

Glen -- haven't a number of folks put together EFI conversion kits using Megasquirt, etc. for CIS engines/systems? See, e.g. https://www.bitzracing.com/products/Partial_EFI_KIT/

these types of solutions might be a lot easier to implement (and tune) than a motronic conversion.

If you check out the turbo forum there are several threads on converting CIS injection cars to EFI using megasquirt.

You could use the 3.2 intake but fire the injectors and time the spark using a Microsquirt V3. Should even be able to trigger it with the SC distributor. I know that leads to dozens more questions but it would be more adaptable down the road if you could scrounge up some ITB's. Or a turbo....

Hi Carwash,
I installed a 3.2 manifold on a 3.0 SC. The 3.2 heads are shorter on the intake length and have longer studs. The 3.2 system uses plastic spacers between the head and manifold. I did not use the spacers as I would have had to replace all the intake studs. Instead I did a little porting of the CIS injector pocket in the head to better fit the 3.2 injector. I used the SC intake pivot and attached that to the 3.2 throttle body. I might have had to tweek that part, cant remember. I first did this in the 80's and used a 280ZX stock fuel injection system triggered from CD box (ECU was fuel only) with the 3.2 Injectors. I replaced the 280ZX system with a programable system designed for GM TPI cars that had fuel and ignition control. I locked out the advance on the SC distributor and feed the distributor directly to the ECU. ECU fired a MSD CD ignition. This system is still running today in a friends SC. I eventually changed back to CIS to fit in Stock club race class. I dynoed this engine many times with both CIS and 3.2 manifold. 3.2 manifold was good for 20+ HP and made more peak torque as well. CIS made more torque from 3-4K. I think you could adapt the complete Motronic system but it will be some work. You would need to use the flywheel from a early 3.2 that ran the 915 transmission. You would also have to notch said transmission and fab a mount for trigger sensor. Alternatively you could move the trigger wheel to the front pully. Injectors are batch fired so not timed. You would need to keep your SC distributor but not use it for spark signal. The 3.2 distributor is dumb (no ignition trigger) and rotates the opposite direction. You would need to change the ignition trigger from the distributor to output from Motronic ECU. I do not know if the output from ECU can trigger stock 6 pin CD box so might need MSD or go with standard coil like 3.2 Carrera with a ignition modules triggered from ECU. I used the stock CIS fuel pump so no change there. Might have to change tach as I am not sure if tach output from Motronic ECU will work with SC tach. You might need a custom chip to make everything work correctly on smaller engine. Hope this helps.

john

john

Jesus.... this seems like way more work than I want to get into.

I suppose anything is possible but first you'll need to get your head examined when you realize how costly it would be to convert a CIS engine in parts and machining.

Awesome? You might be greatly disappointed when you realize how much low end torque you will sacrifice as the Carrera DME is notorious for falling flat off the line.

By the way, it would never smog anyway!


Cheers,

Joe
87 Carrera

I have a 3.2 intake on a 1980 3.0 SC. If it's a 78/79 SC then you have a little easier path - buy the phenolic spacers from Turbokraft to make the transition from the 40 mm runners to the 38 mm ports. The spacers allow room for the injector squirt path.

You can use the the 3.2 fuel rails and run ALL new rubber lines with ethanol rated lines ie. Gates barricade. Use Microsquirt or Megasquirt 2 to drive the injection. Entirely doable but it is work. Many here have Megasquirt start up files that can help you out.

I looked into this for my SC engine, I already had a 3.2 manifold on the shelf. The lack of flywheel sensors was the biggest issue. Apparently some of the very late SC engines have provisions for the sensors, but mine didn't. Clewitt sells an EFI kit that uses the 3.2 manifold and uses a crank sensor, but it costs about $3k.

Well what’s the most affordable decent bolt on plug and play injection system ?

Was going to suggest something from Rasant https://rasantproducts.com/collections/motec-m84-ecu-packages

They used to do a full efi kit with sensors etc but looks like they have revamped the website.

Probably best to contact Al Kosmal at https://www.x-faktory.com/
He distributes the RHD itb kits from Aus and can point you in the right direction for sure.

Bitz Racing.

https://www.bitzracing.com/

Carwash,

Rasant used to have a really useful manual on their website that explained in detail the conversion of an SC to EFI using the stock CIS inlet manifold. It had parts listings and guidence of tuning etc. Really well done.

Unfortunately they have replaced it with this one which isn't as SC specific but still might be useful to you:

https://cdn.shopify.com/s/files/1/0506/5677/2250/files/Rasant_Products_Engine_Management_Installation_ITB _v5.pdf?v=1605753519

Maybe someone here may have a copy of the original version they could share or maybe Andrew at Rasant would email you a copy if you ask nicely.

Actually the Bitz Racing manual that Jamie linked above for converting an SC to EFI is just as good as the disappeared Rasant one.

Wow, that x-factory kit is sexy as hell... $4750 doesn't seem terrible for a complete plug and play ITB setup right?

Al (x-factory) does a great job.

Most probably the way I will go.