901 trans question(s)

[bobt4945]

bought a 73 2.4 motor to put in my 69T, what if any issues am I looking at in mating the 2.4 to the 901? early fly wheel/ pressure plate, clutch going to be a straight bolt up to the engine? starter shouldn't be a problem? any insight /thoughts/experience appreciated. lots of info on going to a 915 box on early cars but can't find anything about late motors to early trans. thanks and GOD BLESS.

bob

[Trackrash]

If you use the '69 flywheel, and clutch assembly, you should not have a problem.

The oil line from the bottom of the motor may need to be back-dated or adapted. The oil line form the engine cooler to the tank will need to be finagled as well.

Other issues could include the ignition/distributer, tachometer, and the wiring harness. If you want to run the fuel injection from the 2,4, that is another project entirely.

[frosty2]

Hi Gordon I am running some what the same set up, I have a 73 with a 2.4 and am using it with a 901 transmission. The PO installed it and I have no issues with it it works fine and I believe my clutch ass'y,pressure plate and fly wheel are a 1971.

[Trackrash]

Originally Posted by frosty2

Hi Gordon I am running some what the same set up, I have a 73 with a 2.4 and am using it with a 901 transmission. The PO installed it and I have no issues with it it works fine and I believe my clutch ass'y,pressure plate and fly wheel are a 1971.

The flywheel and PP were changed in '70/ '71 to a flat flywheel and a pull type pressure plate. The clutch disk went from 215 to 225mm. The transmissions in '70/'71 were type 911, not 901, and unique to those years.

Nothing directly interchanges between '69 and '70 with respect to the trans and clutch/flywheel setup.

Show us a picture of your clutch cable where it attaches to your transmission or the numbers on the bottom of your transmission and we can be sure of what you are running.

[frosty2]

Yes sorry my mistake it is a 911/57 transmission

[bobt4945]

thanks Gordon, the engine is one I got off the forum here, it is a 2.5 (2.4 case 2.7 heads) with CIS injections (from a 76/77), so I believe I will need the CIS fuel pump(which I actually have), will the harness need any modifications to hook up to my 69 existing wiring? any other concerns/issues I need to look at. thanks so much for your help and input. have a great afternoon and GOD BLESS.

bob

[Trackrash]

I'm not an expert on CIS or '69s.

From what I have seen there will need to be some adapting of your '69s harness to adapt to the newer motor's wiring.

If your 69 has the Bosch CDI that will make your ignition (and tachometer) plug and play, but you will have to figure out the connections.

You will have to figure out what electrical supply/adapters your CIS needs.

Your fuel supply and gas tank will need to be updated for the CIS.

When you get the motor, post a picture of it and your engine compartment and hopefully others that have been down that road will chime in with more specific advice.

[bobt4945]

thanks Gordon and will do

[jpnovak]

First question: Which 2.4T did you buy? A 73T MFI or a 73.5T CIS? Either will require modifications to the fuel system and electrical.

The easiest method for installation:
1. use your existing flywheel and clutch setup. It will bolt up to a 6-bolt 70.4mm crank in a 2.4. No changes.
2. Pull the engine wiring harness off the 69 and install on the 73 engine. Sensor and alternator connections will be the same. What changes is the terminal ends of the engine harness to the chassis. The 69 is a series of plugs at the rear of the engine bay - a carryover from the SWB cars. In 1970 there was a wiring changeover.

Otherwise, Have Timmy2 make you a new wiring harness that will mate the 73 engine to the 69 chassis.

3. Fuel system. Take off the carbs from the 69 and bolt them to the 73. This solves the fuel system problems. Both a 73 MFI and CIS cars will require a return fuel line. I don't think a 69T fuel tank has a fuel return line. This means a new gas tank as well.

4. Engine oil cooler. The 69 and 73 engine oil coolers have different fittings. The 69 will have a threaded supply line and the 73 uses a clamped S hose. The body oil tanks are also different. Easiest is to bolt the 69 oil cooler to the 73 engine and use your existing lines and system. Oh, the 73 oil tank will not fit in the 73 chassis without cutting. The filler neck and filter assembly are in different locations between years.

Good luck with the swap. Any engine is an improvement over the 69T motor. Easily the least powerful 911 motor ever built.