Rebuilding 911 2.4T to Hybrid 2.4E/S...Advice needed!!!

[M491Cabriolet]

Hello all. I am gathering parts and information before I begin the process of having my 911T 2.4 engine rebuilt. The car is a 1972 T, FYI I have some questions and hope the experts will be able to answer some or all of them and advise me if I'm on the right track. This is a car that will be driven of the street most of the time, and may be tracked at times, but rarely if ever. Here is some background and a bunch of questions. I'm beginning to become overwhelmed by all the variables and want to avoid making any costly mistakes.

1) The engine is currently stock now except for the Weber 40IDAs installed.

2) I may want to eventually reinstall the MFI (way down the road)

3) I plan to install a set of new 2.2 S Mahle 84P8 pistons and Mahle Nikasil cylinders.

4) I have a set of OEM RS camshafts with MFI drive and a set of E profile camshafts with MFI drive. Regarding the cams, I know the S cams are empty below 5000 RPMs, and the E cams are more "well-rounded". Would the E cams be preferable, or would the S cams in combination with the 2.2 pistons and 2.4 displacement make them more usable? I wonder where the torque would kick in on the S cams and E cams... Which cams should I have put in?

5) I have an RS distributor that I plan to install.

6) Regarding the heads, would I have to enlarge the ports from the stock 32mm? Should both intake and exhaust ports be the same size? What would be the optimal ports sizes for this setup? Is there any negative effect on power and/mileage in making the ports "too big" (36mm?)?

7) What is a reasonable price for a set of new Mahle pistons and cylinders, and how much can I realistically expect to spend (and should I budget)?

8) Will I have to make any changes to the piston rods and valve springs to support the extra revving and compression? If so, which rods and springs are suggested?

9) With this setup, E or S cams, how should my carbs be set up (jetting, etc.)?

10) Will the compression ratio with the 2.2 S pistons and E or S cams be too high for everyday use on normal pump gasoline? Will it be too high for the normal T starter?

11) Does this planned engine generally good? Could it be improved in terms of the equilibrium of power/usability/fun?

I know that's a whole load of questions. I hope I don't get a lot of questions instead of answers in response because I am beginning to get a headache over all the questions I already have and have no clear answers to! Thanks very much in advance for all of your help.

[M491Cabriolet]

Anyone??? Can anyone help on any of my questions, please? Thanks.

[jbell959]

I'll give it a shot...

1) Great

2) As long as your heads have the injector port and your cams have the MFI drive you can always to back to MFI at a later date without digging into the top end.

3) 2.2S Pistons on your 70.4 crank is going to give you a very high compression ratio. I would think it is going to be over 10:1 and too high for pump gas.

4) This really depends on what you are trying to accomplish. If you are going to a 2.4S type engine go with 2.4S pistons and S cams. Otherwise find yourself a set of 2.4E pistons and E cams.

5) I don't think I would go with an RS distributor. The advance on that distributor is setup for 2.7 RS Pistons (8.5:1), S cams, and MFI. Find yourself a nice 2.4 distributor. All the 2.4 distributors have the same advance curve - all that was different was the rev limiting rotor that was installed.

6) Don't make the ports too big. Go with a proven combination. If you build a 2.4E type motor with E pistons and cams you can stick with the smaller ports. It's the combination of these parts that gives it the E characteristics. If you go with the 2.4S setup then enlarge the ports to 35/35

7) Who knows... I would figure $800-$1000 for a good used set up to 3 times that for new parts - or anywhere in-between.

8) If you stick to a 2.4E or 2.4S setup you will not need to make any changes to the rods.

9) There are a ton of posts on the board that will help you choose a setup (do a search)

10) Yes

11) That's an open-ended question. It can always be improved with $$$ but really depends on the intended use.

Good Luck... and use the Seach Feature. There are lots of others that have done the same thing