1972 2.4T to 3.0 conversion questions

Montara22 · 01:31 PM

Hello everyone.

I've been a lurker here for a while, and I finally have a few questions put together for my '72 2.4 to '82 3.0 conversion project.

The car came to me as a rolling chassis. The original engine was disassembled and put into boxes about 20 years ago, and is in very poor shape. I bought a 3.0 SC engine about a year ago, and am just getting the funds together to finish the project. The transmission, while dirty, is assumed to be in good working order.. at least, according to the PO. I plan on using the old tranny on the new motor, and in fact it is already bolted up with a new clutch kit.

I recently decided to change out the CIS for PMO carbs, and will also be installing the Clewett HPX single plug distributorless ignition system. I'm also going to put the exhaust system from my '72 2.4 engine on the 3.0. The chassis upgrades for the CIS system were just too much trouble for me, as I'm doing the upgrade by myself in my small garage.

I have never owned or driven any kind of porsche, so some of my terminology may be somewhat off. And BTW, if anybody has any idea what this car may drive like with the 3.0 engine, I'd be more than happy to hear!

And now for the questions:

1) What oil lines will I need for the '72 oil tank setup? The 3.0 has a large coarse thread fitting where the old engine had a compression fitting. (The line that runs around the bottom of the engine and into the bottom of the oil tank)

2) Should I go to the expense of replacing all of the original '72 oil hoses?

3) What should I do with the old tranny besides drain the old oil and replace with swepco?

4) Does anyone have any references on the best place to buy some fake fuche (sp?) wheels? I have the original fenders, so I assume that 15x6 is the biggest thing I can run.. is this correct?

5) Any opinions on using large zip ties instead of the usual clamps on the CV joint rebuilds?

6) Will my gauges work ok with the 3.0 sensors?

7) Are PMO carbs best bought from the manufacturer, or is there a place that sells them cheaper? $3k seems a little steep.

Thanks for any help you can provide!

Best Regards,
Tim

chuckw951 · 01:53 PM

Hi,

A number of your questions have been answered in previous threads, try searching for "swap" or "conversion" and "oil lines" and "gauges" etc. I'm sure others will weigh in as well...but there's gold in the archives.

You would probably be better off with real Fuch wheels vs. replicas. This too has been discussed, though not everyone agrees.

PMOs are expensive, but very nice. I'm a fan of the HPX system too. Good luck with your project; a 3.0+ in an early car is fun to drive.

Chuck

Montara22 · 02-29-2004, 02:03 PM

Actually your car was the one that inspired the switch to PMOs and ignition. Great ride!

I honestly have searched quite a bit about most of these things, but one thing in particular was the oil lines. The '72 has a different oil tank than any other year model, so I'm wondering specifically about this year oil tank -> a 3.0.

I realize that many of these things have been covered, sorry if my post is a little redundant. I just wanted to see if there were any fresh opinions out there, as many of the search results were quite old. Also wanted to see if my setup presents any questions in return that may not have been covered in those posts.

Thanks,
Tim

Shuie · 02-29-2004, 03:16 PM

Here's a couple specific to a '72

3.0 engine swap into a '72

'emptyo' has posted a couple of really good ones also

Need Wiring/Fuel/Oil Connection Help Part 1.
Need Wiring/Fuel/Oil Connection Help Part 2.

Montara22 · 02-29-2004, 04:07 PM

OK, now I'm ashamed at my searching skills.

Thanks for the links, somehow I had completely missed them.

Maybe it's just the "project finally coming together, did I think of everything?" panic

Tim

rennch · rennch's Garage

Yea...I did it into mine. I used Aeroquip lines for the oil lines, if that helps.

Zeke · 02-29-2004, 07:09 PM

Montarra, you have a Private Message.

Schrup · Schrup's Garage

Tim, I commend you on your project. I'm sure it will go like snot when your done. I have to echo Chucks thoughts on the Fuchs, you can find them pretty resonable on ebay at times. I sympathize with you on the small garage, I am using my mother-in-laws tiny garage right now. Can't wait to get my own. Please post some pics of your project in progress.

Early_S_Man · 03-01-2004, 07:15 AM

Tim,

You will need to transfer the 2.4 oil temperature and pressure sensors to the 3.0 engine in order for your gauges to read properly.

The '72 scavenge line adapter will bolt directly to the 3.0 engine block ... if the existing junction piece isn't correct. In essence, you will use all of the '72 oil system.

chuckw951 · 03-01-2004, 07:26 AM

See this thread, re: oil pressure sensor.

'72 oil pressure sender in '84 engine

With the tach I used a 911SC tach from partsheaven for $100.

chuckw951 · 07:38 AM

"5) Any opinions on using large zip ties instead of the usual clamps on the CV joint rebuilds?"

I would not use zip ties, they are not up to the task. Also you need clamps with a low profile. I replaced my axles back in November with rebuilt units. The old ones had a standard hose clamp on one side. The clamp was too big, the clamp had bumped into the bottom of the rear shock and dented it.

I think most any local axle shop can rebuild your axles and/or replace the boots with the proper clamp. Replacing the axles isn't too difficult. Just make sure you have good jack stands and chock the wheels. (note: I should have chocked the front wheel on both sides)

Sunday project - installing half shafts - 911e

Mike Bonkalski · 03-01-2004, 07:34 AM

Lindsey Racing will make a custom fuch in 7.5 x 16 with 911R offset and backspacing. I am still trying to find out if they will fit, but the good be a good solution for narrow-body cars. I have a post floating around somewhere with the pricing.

Good luck with your project! It should be awesome when you are finished.

thomas j · 03-01-2004, 08:39 AM

Tim,
I just finished a sim. swap. The HPV/HPX solves some wiring issues...good thing...
Your tach will work fine as the signal is pulled from the coil pack base.
Caveats: make sure you pull the 12v source for the coil pack from a clean high amp source. Ground,ground and ground some more .Use the ground wire on the coil pack.ground the chassis of the pack and run yet another one from the #A pack to the engine. Smart racing/Jerry Woods sells some great plug wire (by the foot) at a savings over some other venders.You'll need to build your own wires if you go that route. Read the manual regarding advance curves (I had to read them more than once)they are a progressive curve and had me a bit confused at first.
Any how I just dyno"d an engine that is simular to yours in set-up and you wont be dissapointed with the results.
Good luck and happy motoring,
Thomas

chuckw951 · 12:56 PM

Quote:

Originally posted by thomas j
Tim,
I just finished a sim. swap. The HPV/HPX solves some wiring issues...good thing...
Your tach will work fine as the signal is pulled from the coil pack base.
Caveats: make sure you pull the 12v source for the coil pack from a clean high amp source. Ground,ground and ground some more .Use the ground wire on the coil pack.ground the chassis of the pack and run yet another one from the #A pack to the engine. Smart racing/Jerry Woods sells some great plug wire (by the foot) at a savings over some other venders.You'll need to build your own wires if you go that route. Read the manual regarding advance curves (I had to read them more than once)they are a progressive curve and had me a bit confused at first.
Any how I just dyno"d an engine that is simular to yours in set-up and you wont be dissapointed with the results.
Good luck and happy motoring,
Thomas

Settings for the advance curves can be tweaked...I agree read the directions a couple of times. I still don't truly understand what the book is talking about and how it all works. There is another thread around here about this subject. I was amazed how much difference tweaking the curve makes. Right now I've got my set to make HP on the top end. I think with a stock distributor you would be locked into an advance curve, with the HPX it's all adjustable (watchout for detontation though). Heck I think there's even a controller available for N20 (to retard timing under "NOS"). No laughing gas for my motor though. Also, if you get the HPX from Clewett look at the relay he sends closely...the wire colors on the relay don't match up with the instructions he sent me. This could have been corrected by now...so just look closely. Clewett has wires premade for use with this set up and nifty platform for the HPX to sit on. None of these items were cheap...but off the shelf is the path of least resistance. Have you mounted the trigger wheel yet? I had a hell of time getting the stock pulley off...used an impact wrench. And no you will not be disappointed.

thomas j · 03-01-2004, 01:39 PM

Chuck,
Agreed on all counts,I went with the system beacuse of a bad CD box and the need to recurve the dist.,if you factor in the cost of those 2 items I was pretty close to the cost of the HPX,plus its fun to play with the advance curves.We did that while on the dyno and it was really interesting to see the HP and torque #s move around at different advance settings. I think the system is really suited for carbed cars due to the high output spark and the exhaust stroke firing .
Im a convert for sure,plus it looks all clean and nifty in the engine compartment

Best,
thomas

chuckw951 · 03-01-2004, 02:48 PM

Quote:

Originally posted by thomas j
Chuck,
We did that while on the dyno and it was really interesting to see the HP and torque #s move around at different advance settings.

Hey, hey, hey do you have some results to share!?!
What settings are you running or do you expect to run.

Chuck

thomas j · 03-01-2004, 03:45 PM

Chuck,
Sure,I dont much go in for braggin' and mostly use the dyno as a tuning device (truth be told,to have the shop owner tune it)and bench mark and data points for real quantifiable changes made to the engine. I fell it worth every penny to know that the engine is as sweet as possible and having messed with webers alot I feel I can get them about 85% on,but that last 15% is what makes the difference for me.In this case the dyno/tuning was worth about 18hp and a known good A/F mixture setting.
The great thing is now I know where peak hp is and I can set my limiter at 6700,which should make for a long lasting track engine.

The engine specs are:
78 3.0
weber 40s 36 veturies etc.
Tall 40/39 manifolds
ssi headers w/heater boxes cut off (that was fun to do )
Sport muffler (home made)
electromotive crankfire
small fan/underdrive pully
964 cams
234.4 hp@ 6250 to 6500 A.T.C.
Thats about it
We gained about 15/18 hp with carb tuning,ignition and underdriving the fan
I can P/M you the full run down on the torque and ignition if you like.

Thomas

chuckw951 · 03-01-2004, 04:05 PM

Quote:

Originally posted by thomas j
Chuck,
Sure,I dont much go in for braggin' and mostly use the dyno as a tuning device...

Oh, I didn't mean to imply that. But is sounds like your motor is tuned well. So is the 234.5 number at the wheels?

I was wondering what settings you are using on the HPX. Right now I'm running:

Initial Advance at +10 degrees
3000 RPM Adv at +15
8000 RPM Adv at +5

Here is the other thread about HPX settings..

Settings for Electromotive HPX ignition

thomas j · 03-01-2004, 04:58 PM

Chuck,
Oh no problem,I really do like to brag...just false modesty

No,234.4 at the crank,I wish that was at the wheels,But the tuner had other cars with the same engines as data points and that seams in line for these mods. Maybe a bit more hp to be found w/ compression and a few other things but he seem to think not to much more available,givin the parameters of this engine. we are running 36/37 deg total advance,but beware that requierd a jet change to bring the A/F reading in line,without that known A/F reading I would be wary of detonation.

Best,
Thomas