2.4 crank/rods in a 2.2

Zeke · 01-13-2004, 09:51 AM

I have been looking at putting a 2.4 crank in a 2.2. Many times in the past, putting 2.2 pistons into the 2.4 has been discussed. I have a gentleman telling me that it would be better to start with the 2.2 and go with the crank changeout. Any opinions?

Tim Walsh · Tim Walsh's Garage

Hmm.. well depending on what case you have there may not be much of a difference. If it's a 71 case then you have the case squirters (a big upgrade) and there isn't much difference between it an the 72 case. In reality there isn't much difference at all really. THe only things I can think of would be the change in the distributor holes and the case squirters.

Zeke · 01-13-2004, 11:06 AM

One of the differences that might benefit me is the flywheel. This 2.2/2.4 would go in my 914 with a 901. If I have it correct, the 901 pp is a push type and the 915 is a pull type. So deosn't a 2.2 flywheel sound like the hot tip for my 914 conversion? Another difference pointed out to me is the MFI. The 2.2 is cast and can be opened up for lager throttle plates should I want. Maybe some of this should be on the general 911 Tech BBS, but thi crank is what I'm interested in here. Isn't the 2.4 crank the first fully counterballanced crank?

Tim Walsh · Tim Walsh's Garage

Milt,
The non T 2.0/2.2 cranks were counterweighted as well but the 2.4T cranks were counterweighted as well. It is only the 2.0T cranks that aren't counterweighted.

I really have no idea about flywheels and clutches since all I've ever used is the 915 clutch and flywheel.

The MFI seems to have the same mounting configuration, it's the stacks that are different but should work straight away with a set of 2.4 throttle bodies. I don't think that's such a big deal.

Zeke · 01-13-2004, 11:17 AM

Thanks for the info. I'm in the market for a '71 2.2 for this project. I guess I need the 2.2 S pistons and S cams or something along that line.

TimT · 01-13-2004, 06:02 PM

Milt, I have 901 in my 914 with a "pull" type clutch. Ive described it in a recent thread either on this BBS or 914club.

My car is in winter hibernation now, and I dont forsee getting a chance to get any pics to help you out. PM me ill outline what has to be done to use the pull clutch in a 914 ( with the 901/914 box)

In any event with the 6 bolt flywheel used on most 2.0 and 2.2 engines you can use either the cup or plate flywheel. The 2.4 also used a 6 bolt crank, Im not sure when they went to a 9 bolt crank.

Tim Walsh · Tim Walsh's Garage

Tim,
The nine bolt crankshaft was introduced with the 3.0 SC