911 E upgrade

[leung]

Hi I have a 1972 Europan 911 E with a sportomatic box that I would like to upgrade. i have talked to motor meister who suggested that i can change to a 2.4 S or 2.5. given that my car is a eurpean model, will the 2.4S or 2.5 still increase the power substantially? motor meister also suggests that i shoudl get rid of the sport box. anybody out there who has any ideas?

[smestas]

I dont have any information regarding your question but I would run from the guys at Motor Meister. Do a search for "motor meister" and youll see what I mean.

[Luke Hudson]

cheapest, easiest "upgrade" is to add 2.2S pistons. Get hold of either our Host's book on modifying porsche engines and/or Bruce Anderson's 911 Permormance handbook.

2.5 conversions are much more complicated and expensive.

Also run a search on this site for Motormeister it's interesting reading

[leung]

thanks guys! are the european and american pistons identical for pre-74? can the 2.4E cylinders work for the S pistons?

[smestas]

leung,

Im sorry I dont have an answer for you but you should try to re-post your question in the engine rebuilding forum. If you post there youll probably get more replies.

Heres a link:
http://forums.pelicanparts.com/911-engine-rebuilding-forum/

[P4Life]

Stay away from Motor Meister...but they are right that you need to lose the Sportomatic. A stock, well-tuned '72 911E with a 915 5-speed should have plenty of power. That Sporto box is sapping a lot of your power. The 911E is faster than a 911S below 100mph. Replace the tranny and give her a chance before going with engine mods.

[jluetjen]

Get a 911 box, not a 915. Along with the better shift pattern, the shifting is lighter. You can often pick one up for less then $200 easy.

[Jim Richards]

Euro and US 911E's are the same, except for the exterior lighting. I'm not positive but I thought that the Es and Ss had the same cylinders. This need confirmation from guys like Early_S_man (Warren).

John, will the 911 box easily bolt into a 72-73? You got me thinking about this for my car.

[Tim Walsh]

Yes, the 2.4E and S cylinders are both the same, and they're also the same at the 2.2E and S cylinders @84mm.

The 2.2S pistons fit just fine since the change was in stroke,not bore. This also raises your compression ratio up a bit to ~9.6.

Do a search for 2.4T and partial name "walsh" and you'll find LOTS of threads that pertain to upgrading 2.4 engines.

[Jim Richards]

Tim, are the E and S cylinders made of the same material? The T's are different, right?

[Zeke]

T's are cast iron. And I would like a shot at your E pistons if you change out for something else.

Oh, did I just give away my feelings about E pistons? Actually, are the 2.4 E pistons the same as 2.2 E's? I know the S pistons differ, not by bore, but by compression.

IMHO, the E cams and HP are good. The torque is enen better. When I build my 2.4, I will be shooting for more of an E setup.

You did right by coming here and asking. Especially about MM.

[dtw]

The 2.4E pistons have far less dome than the 2.2E pistons, which is why us 2.4 guys love the 2.2 pistons so much. All E and S pistons from 2.2 to 2.4 are the exact same unit...there were 2 different height groups throughout the series, but that varies from motor to motor and has no bearing on a particular model.

I'd suggest another option - keep the pistons you've got (they're great, everybody wants them, including me), and upgrade your crank to the 70.4mm unit so you've got 2.4L displacement. Consider also upgrading to the mod-S or other aftermarket cams. But I think it would be mistake to get rid of the 2.2E pistons....the consensus is generally that those are the best pistons Porsche ever put in a street engine below 3.0L.

[jluetjen]

John, will the 911 box easily bolt into a 72-73? You got me thinking about this for my car.

I dunno. The clutch set-up is pretty much the same, but the shifter might be different. But I've heard of people using 915 short shifters on 901/911's, so they can't be that different.

[Luke Hudson]

dtw, I belive Leung already has a 2.4 engine if it's a1972 that's why I suggested the higher domed 2.2 pistons to increase his compression ratio but remain 2.4 displacement.

basically leung you ahve a lot of options but it all comes down to how much you want to spend

[leung]

Hey everybody

thanks very much for all your mails, they are all useful. my mechanic told me that a 901 gearbox cannot fit (because it comes from a 2.2S) and he recommended me a 915 for about 3000 US, not rebuilt. is he lying to me? I thought a 901 gearbox fits all 911's with capacity lower than 2.7.

if i do decide to go for a gearbox change, what things do i need?

thanks again.

[Eagledriver]

Your mechanic is correct that the 915 will be much easier. The "911" refered to here is really a 901 and has a different gear pattern as well as different clutch/flywheel setup. The 915 also is stronger and should be more available. 3000 dollars sounds abit high for one that is in unknown condition. I don't know how hard it is to retrofit the tranny into a sportomatic car though.

-Andy

[leung]

thanks a lot, eagledriver. do you know who in the US is a relaible source for rebuilt boxes? i am from singapore.

thanks