3.2 US Franken-CIS to 3.2 Euro EFI build

[Nux]

Gents

I've thrown myself into a new and hopefully fun engine build. Not my engine, but I'm doing the planning and the wrenching. Dropped the engine this weekend, and I started to dig in right away.

It's a US spec 3.2 long block, fed by a '78 CIS. Stock exhaust manifold and a nice Dansk sport exhaust. We need to fix some oil leaks on the way, but the owner is really looking for more power and would like to have a shiny new engine, so cleaning and painting is warranted.

Naturally, we needed to get rid of the CIS asap. This is a budget(isch) build and I have some very nice Carrera intake manifolds (mockup):



I also have these babies:



So that's our starting point: New 3.2 Euro pistons and Mahle cylinders. Original 3.2 manifolds. And a MS ECU on the shelf, so we're going EFI.

I would like to use 20/21 cams if I can get the stock ones re-ground. Trying to convince the owner to change the exhaust - we will see.

I could use some advice on the EFI. I believe 30lb injectors should be able to do the job. But looking at the manifold, I think the injector sleeve is very small and not very deep. Any suggestions for a suitable injector?

Also: The engine has none of the original 3.2 sensors and no idle valve. I will add the usual sensors for oil temperature, manifold air temp etc. and we are debating wether to use the Bosch CDI and SC dizzy or go full ignition via MS. Budget is an issue here.

I've done several EFI conversions on 3.0's both with original manifold and ITB's. I haven't used the AAR so far, which hasn't been a problem. Do we need the idle control valve (or AAR) on the 3.2 manifold?

Cheers!

[Peter M]

Nux,

I ended up selecting a set of Bosch 0280 155 931's, which are 28.55lbs/hr at 3 Bar. They are a modern 4 hole "bolt in" upgrade for the original 0280 150 158's (22.8lbs at 3 Bar) and work with the original harness connectors and found them to work well with the standard Motronic setup. (AFR verified on a dyno.)

I also expect the 931's will also have enough headroom for my 3.4 litre conversion with full sequential injection.

[Nux]

Perfect - thanks.

They could be close to 100% duty cycle for your 3.4 build, don't you think?

[dap930]

Nux,

You do not absolutely need an electronic IAC valve, you can set the warm idle with the throttle stop. But, if the car does not have a hand throttle, it make cold starts hard. You could use the CIS AAR for cold starts.

What version of Megasquirt and firmware are you planning to use. A lot of people use Ford EDIS wasted spark for ignition which is fairly cheap to install, but the stock ignition can be retained if desired.

[colingreene]

i dont know why you would not want the idle control valve. why go to the trouble to put modern injection on it to not have modern features.
Also do the full electronic ignition. its well worth it.

[Nux]

Originally Posted by colingreene

i dont know why you would not want the idle control valve. why go to the trouble to put modern injection on it to not have modern features.
Also do the full electronic ignition. its well worth it.

Well I guess you're right. I'm just considering my options, since the induction on this build will be completely from scratch. There is nothing right now - besides a good looking raw manifold.

[Nux]

Originally Posted by dap930

Nux,

You do not absolutely need an electronic IAC valve, you can set the warm idle with the throttle stop. But, if the car does not have a hand throttle, it make cold starts hard. You could use the CIS AAR for cold starts.

What version of Megasquirt and firmware are you planning to use. A lot of people use Ford EDIS wasted spark for ignition which is fairly cheap to install, but the stock ignition can be retained if desired.

I have both MS1 extra and MS2. Never really tried MS3. MS1 extra is perhaps a little rudimentary, but does the job.

The MS2 firmware is 3.1.0 and has the EDIS option. A completely new MS2 ECU is about 700$ over here, so not too bad in case the one I have doesn't work correct.

[Nux]

Update.....

well things have changed. I noticed after pulling the CIS, that the heads were not from a 3.2 as the owner had been told....And I should have seen this when we pulled the exhaust.



So standard early SC heads then. No porting.

It's a 3.2 case, so maybe they put together a 3.2 with a big-port CIS top then?

But no......





Erheemmm allright, change of plans then!

Current plan: Wössner 10.5:1 CR pistons, 993SS cam, Twin plug, EFI on the 3.2 manifold and finished off with SSI's or maybe the new M&K active exhaust.

The engine was rebuilt less than 30tm ago, so we're not going to split the case. I suppose it is possible to check the #3 rod bearing without splitting the case to make sure?

[Tippy]

For the idle control valve, Volvo uses the same one that is far cheaper than the Porsche one.

Gotta love the Porsche tax!

[Nux]

Found the oil leak: Broken top seal.


I've been thinking about cams.....again. I know the 993SS/10.5cr/plenum/EFI combo works. 964 and 20/21 are too mild for my taste.

Maybe you guys have an alternative?

[brighton911]

Re your injector injector question, I'm running Ford Motorsport purple 24 lb on my 3.4 10:1 compression with MS2 management and duty cycle is no more than 50% . As they are a EV6 connector, a new harness had to be made up, no biggie. This is on a 3.2 engine with 964 cams, no barn door air floor meter, stock heat exchangers with no cat and free flow muffler.

[Nux]

New year update.

Dougherty special grind DC24/21 cams are on the way from the US. Wössner 10.5:1 pistons are inbound from UK, heads are being twin plugged in DK.

Head studs changed, wiring is ready for EFI and engine is ready for a shiny new finish. Should be good!

[75 911s]

Looking good Nux. Careful, you might give up your other line of work and open a Porsche resto shop. :-)

[lvporschepilot]

Originally Posted by brighton911

Re your injector injector question, I'm running Ford Motorsport purple 24 lb on my 3.4 10:1 compression with MS2 management and duty cycle is no more than 50% . As they are a EV6 connector, a new harness had to be made up, no biggie. This is on a 3.2 engine with 964 cams, no barn door air floor meter, stock heat exchangers with no cat and free flow muffler.

That's interesting. I just adjusted (raised) fuel pressure to some 60psi on a 3L semi-race engine running twin plug ITB EFI using those same injectors because it was getting too close to the duty cycle max at high rpm (7k+). Engine makes about 300bhp.

Sorry to derail!

[996AE]

what octane are you planning on running with this set up

[cgarr]

are you dumping the old SC cylinders too?

[Nux]

Originally Posted by 75 911s

Looking good Nux. Careful, you might give up your other line of work and open a Porsche resto shop. :-)

Haha don't think I haven't thunk about it!

I really injoy working in these cars. And the engine is my absolute favorite!

[Nux]

Originally Posted by 996AE

what octane are you planning on running with this set up

We all use 100 or even 102 RON here.

[Nux]

Originally Posted by cgarr

are you dumping the old SC cylinders too?

Sadly no. Budget is tight.

[Nux]

Finally I've got all the parts home again. Powdercoated everything.

Heads opened up to 41.5mm and matched to the 3.2 Carrera intake. Ported nicely - and twin plugged of course.



However, I noticed that the new plug hole sits a little deep. This means that the plug will protrude somewhat in to the combustion chamber. I'm worried that it actually might interfere with the piston.




A little difficult to see, but the right plug is not level with surface of the combustion chamber. Should I shim it up a bit??

German Wössner pistons 10.5CR - nice:



And US based John Dougherty special grind 24/21 cams:



Twin plug dizzy on it's way from Tuthill, England.

To be assembled in Denmark.

This is truly a trans global build