3.0 CIS into 2.4 T body, who has done it?

Last night I found a guy who has late
82 SC engine (complete with electronics) for a somewhat reasonable price. I am thinking of dumping my 2.4T to 2.4S endeavor due
to my family time constraints. Is there
folks here who have done 3.0 liter conversion on an older pre-CIS car who can point me in the right direction? Checking
the archives gave some insight but
not a complete how-to. I am not
prepared to go the 3.6 route as our
man Jack has done.

My favorite wrench told me that I need a new
gas tank, as the higher pressure
CIS fuel pump will vapor lock with an
older tank, is that true? That might
be a show stopper right there.

What I do know is I need are the following:
a new fuel pump,
a wiring diagram for electronics,
fuel accumulator,
and what else....?
Thank in advance for any insight
you might share.

Bill
72T with its heart just extracted
tonight.

ps. I would do the conversion myself.
I do like my MFI but I am tired of
always seeing the ass end of SCs during our local PCA/RMR DE events.

Hey Bill,

I can't help you with your engine questions, but as the driver of one of those SC's you speak of....I think it will take more than a new engine

This has got to be one of the easier conversions to do. First you already have a 915 gearbox so you're not going to have to do any significant tranny to the bell housing. There may be a clutch issue regarding the flywheel but my memory's locked up right now, perhaps someone else can elaborate on that. As far as fuel tank I do not think you have a problem, but even if you had to switch to a later tank it's a bolt in switch, not a problem. As far as electronics, again one of the easier swaps. Get the harness and relay panel from the SC and a few evening with the wiring diagrams you should be able to figure out the wiring. I don't have a step by step but I'm pretty confident this is an easy conversion in the scheme of things. Oh, don't forget you'll also want at least a trombone cooler or better yet a finned cooler up front. If your car does not already have this you'll want it. Budget for the oil line etc, and they will bolt onto your existing tank.

Enjoy!

Bill,

I think you need to find a different wrench, or better yet, get a set of factory manuals, and start doing your own work! The MFI fuel tank has a return fitting, just like the CIS cars do ... and it sounds like somebody confused it with a carbureted 'T' fuel tank, which did not have the return fitting! Not someone I would trust on this conversion!

Just for comparison, a US SC engine was only rated at SAE net 172 bhp, whereas a 2.4 's' engine was rated at SAE net 181 bhp! And your car is lighter than the SC's around 150-200 lbs!

One final note, assuming you do the disassembly and assembly work on the engine, there is very little difference in the cost of parts for converting to RS 2.7 specs for your engine, versus 2.4 'S' specs ... an additional 20 hp and a much better torque curve from 2500 rpm to the 7300 rpm redline!

Additionally, you now have the corrosion issue with an 18-19 year-old SC, so a used engine will not necessarily be more reliable engine than a freshly rebuilt MFI 'S' or RS 2.7 engine. And, if you have never driven an early 'S' car, please do so, and compare the seat of the pants feelings with an SC ... you will be decidedly find quite a difference in the rev range and 'kick-in-the-tail' when an 'S' engine comes on cam! Only you can say whether the big 'T' torque curve and rev range of an SC engine is better than an 'S' engine for you, but for very little difference in cost you CAN have 30 DIN hp more than the SC engine, just as reliable, and more thrilling to drive car! You won't be having any more problems keeping up with SC's with an 'S' engine in your cars' tail ... the cards will definitely be turned around for hapless SC's!

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Warren Hall
1973 911S Targa

Just did it.
Wish I had done it to a '72 instead of a '70....
The CIS system is just about a straight plug in. Just make sure you get both wiring diagrams for each, your car and the '82 sc.
The SC doesn't have a brain, so all you have to do is make sure you get the power to what needs power. Most wires are consistently colored, even from my '70 to the '83 motor I put in.
As far as the tranny goes. Make sure you get the flywheel with the engine. You will need the pressure plate, t/o bearing, and disc from your original set-up. They'll bolt right together.
Exhaust is easy. Take the exhaust off of your '72 and bolt it right on the '82.
This is soo easy. Should take you a day to take out your old engine/tranny, split them, add new engine, then put back in.
It took me a week to suss out the electrics only because I was so worried about screwing something up. It turned out the first time I put it together(in 5 minutes) was the right way.
Things you will need, I'll try not to forget anything, but I'm sure someone else will chime in:
New Engine
SC flywheel
SC Tach, when you get to this, I'll tell you where you need to jump a wire.
Clutch kit for your 915, unless yours is new
Motor and tranny mounts, good time to do this
This is really an easy upgrade. If you get your motor for about 4-5k you will be very happy with the product. Doesn't have the high rpm jolt that an early S engine has, but more all around HP, if you get a good one. And the durability is more than worth it. Some guy has a complete trombone cooler set-up with a thermostat on e-bay right now. That's where I got mine (for $300).
This isn't cheap, but your 2.4 will not be cheap to rebuild, will it?

Sorry forgot something,
SC fuel pump. Located up front. My '70 "T" had a returm line on the tank, it was just capped. The SC tanks had a swirling tank inside the fuel tank. This minimized the vapor-lock for the SC. Two good mechanics said that having the fuel pump up front helps, and that I might not have any problems. And I haven't yet. They both said that a good oil cooling system would help just as much.
Ed

What an inspiration you are Warren!
I am not afraid of doing the work
myself, as I have done it in the past on this same engine. I even have the first set of the factory manuals. However, on my
top end refresh a couple years ago, I made a
critical mistake-- I went the cheap path which was a big mistake. Where I should have replaced my pistons, I had top ring spacers machined/installed instead. The regular rings apparently broke on several pistons after this year's hard track season. I blew serious smoke at the last RMR autocross. A leakdown confirm things, with % values 46, 26 17 on the 1,2,&3 side.
Good values on the other side. So far, I have found some "good" 2.4S pistons and have researched the path of building an S engine from the my components. Into the mix, enter the wife (CFO), who has made it known that
it would not be a good thing for me to be in the garage all winter again this year.
She rather have buy a mid '80s Carrera
and dump the '72, yikes!

My mechanic is good (actually there are two
of them in the shop) but they rarely work
on my car, rather they are my primary
parts supplier meeting most mailorder prices.
Advice come for the price I paid for it.
I think in this case of the fuel tank
he just was not interested in finishing
the process if I turned it over to him
with the engine installed.

So Thursday night, I found this SC engine and
hence my post. According to the owner, this
is a late '82 engine makes 201hp and with my heat exchangers and my two outlet sport muffler I should be somewhere around 215+. It is an enticing way to go. However, I would blow out my PCA/RMR classification and the car would be seriously undertired and under braked. More $$$ on the fire. Decisions.

Finally, yes Warren I have driven 69S as my
brother had one for 12 years and have rode
in several early Ss during track events. I likened the ride in one awesome MFI 2.9 twin plugged '70S as riding on an enraged, big ass bumble bee. Yes, the "on cams" feeling is like nothing else in this world.

So one option is quick and expedient and the other (S option) is right one. Stay tune. This will go on for a week or so.
Thanks again.

Bill

ps Jess you better be watching you mirrors
next year either way and remember your
passing signals. However, you probably will
NOT have to lift!

Jeez, Bill!!!

Maybe your CFO needs to be reminded that the attachment to an MFI car, once you've been bitten, is just as permanent as, well, you know, some CFO's ... and that she can go out and get a '80's Carrera for less than a new Neon or Honda, but your '72 is special, and upgrades you do to it yourself, besides making you feel taller, as 'the Superman' puts it, as well as being fun, and the later engines just aren't that 'GLORIOUS' to look at or listen to, or drive, though an '83 thru'86 Cabrio does have a certain 'appeal,' though a bit sedated in the exhaust note department!

I'm sure you know by now that a front fender external oil cooler is a given, regardless of which higher-power engine upgrade you decide to go with ...

Another project to 'freshen-up' your 915 transaxle could be a lot of fun for you, too! My 'target' goal for the 'perfect' Donohue (late, but not forgotten for his test for Car and Driver of the whole '69 Porsche lineup) 915 gears would essentially duplicate the early 901/904 'Airport' optional gear ratios ... with a bit more 'punch' in the first three gears!

The 1969 901/77 'Airport Circuit racing' optional gearbox had 4.429 (7:31) R & P, 1st -- 2.83 (12:34), 2nd -- 1.89 (18:34), 3rd -- 1.48 (21:31), 4th -- 1.22 (23:28), 5th -- 1.04

My 'Donohue-915' would have 4.429 (7:31) R & P, 1st -- 3.182 (11:35), 2nd -- 2.000 (15:30), 3rd -- 1.600 (20:32), 4th -- 1.261 (23:29), 5th -- 1.000 (26:26)

And, finally, a 'sport' muffler with dual 4" outlets should give those SC drivers in your mirrors a bit of envy as you disappear in the distance!

Finally, I don't think there was such a thing as a US 201 hp SC engine, but seller may be confused over the ROW, or Euro-engine ... definitely not the same as a late USA-spec engine! Maybe you should have the seller get the 'Type number' and serial number from the engine block so you can look up its' specs in Bruce Anderson's Handbook!

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Warren Hall
1973 911S Targa