Engine swap - help needed

[Zain]

Hi Everyone,

I have a 1967 swb 911. Acquired a few months ago. Car is now in decent shape, drives pretty well.

Unfortunately the engine in it is not original. It is from a 69T.

Im quite keen to change it. Cosidering a 2.4S engine that I came across online. The engine comes without injection/ carbs.



Some questions:

1) Would i be able to install this into my car without any modification?
2) would i be able to mate this, without any major modification, to the 901 trans currently in my car? would you recommend that or should I change to a 915? pros/cons?
3) Will getting MFI to work with my car require a lot of work?
4) Could i use carbs instead? will there be a big loss of performance? and if so, which carbs would you recommend?

Keen to get as much power as possible without serious modifications to the car....

Thanks so much guys,

Zain

[66S]

That’s a pretty easy swap. You use the 69 flywheel and clutch with the 901 transmission. Stick with your 69T Webers (rejected) or get some PMO carbs, the manifold bottoms should be enlarged to match the intake ports, not hard to do at home. You might need an auxiliary oil cooler added if the motor runs hot. Sell the mfi and forget about a 915 transmission.

[Richy]

I would build the '69 engine as a '67S , this will be more fun than a 2.4 which has been detuned because of emission requirements , I call the 2.4's smog dogs .

[Nickelplated5s]

I don't generally respond this late but as I own a 67 so here you go;

Your car without vented S rotors is probably 1960lbs with half fuel and no driver. Your 2.0T motor is probably punching 170HP. My 2.2MFI is somewhere around 190hp, it will be on a dyno for MFI tuning in 2025. In other words it is one of the fastest cars I've been in. The other two an 05 GT and a 2020 C8.

Mine is more or less set up as a track car. First thing I suggest is suspension. I actually ordered Koni rears today for an experiment over my Boge's. Been contemplating coil overs but that will be a different thread. Second thing is brakes. I'm running a Boxster setup you can read about on this site. After that I'd suggest going through the T motor instead of an unknown 2.4.If you want post the first 3 of your VIN and country. I'm, guessing EU. My our 458 and listed in a sticky. Good luck. I've owned mine a long time....

[Zain]

Hi Guys,

Thans you for your replies.

Richy, how would I go about turning the 69T engine into a 67S? from what I've read, T's are hard/ not worth it to upgrade, am I wrong? if I could get 160+ HP from it, definitely wouldn't bother with the 2.4S... what are the steps i would need to take?

Nickelplated5s, just ordering new front and rear brakes and vented discs from PMBperformance along with a 23mm MC, definitely want to upgrade the suspension too. Will wait to hear how you get along with the Konis before making a decision. Right now mine has pretty beat up bilsteins installed.. also going to go for a front and rear say bars a little fatter than 67S bars, any recommendations? Also, my 2.0T is rated at 110hp... or am I wrong? had it been 170, wouldn't have even considered a change.. first 3 of my VIN are 307...

66S, the PMOs look great, will it be a big performance difference between lets say rejetted and tuned 69T carbs and the PMOs?

Thanks so much guys,

Zain

[66S]

No big performance increase from PMOs just more refined than Webers. If you rebuild the T motor to S spec I recommend replacing the non-counterweighted crank with a counterweighted one and consider 2.2-2.7 heads, 2.2-2.3 pistons and cylinders because they are not as prone to detonation and parts are more available than 2.0 but it will cost more. 2.4 motors had lower compression to use regular grade gas but they make good power and torque as their HP ratings show. With high compression pistons and premium gas even better power. Buying a rebuilt 911 motor is a leap of faith unless it’s from a reputable builder, better to build one. If you want originality I have a spare 901/06 aluminum crankcase.

[72targa]

This could be an interesting option as well…

https://www.early911sregistry.org/fo...67-911S-Engine

[Richy]

Hello Zain , your T engine. may have a counterweighted crankshaft , but it definitely has cylinder heads with the larger '67S valves , so a little intake porting is all that's required . Buy S pistons and cylinders and your on your way .

[Nickelplated5s]

Zain, your 23 MC is probably dual outlet, my 22.5 is. Required a little plumbing but doable. The brakes you will love but as BillV says there will be some front bias. When your'e in the motor think about piston squirters and hydro tensioners. FWIW I inherited the 69S motor with the car. Someone on PP had all the bits minus the MFI pump for sale if you want to go that route.

#307 must be very early. Get to 10 posts and give us a pic or two.

[Zain]

Hi Everyone,

Sorry for taking so long to respond. Had been caught up with some family stuff :s

The project is ongoing. Based on all your recommendations and research that I've done on the forum and other places, below is the course of action I'm planning on taking.
Please let me know your thought and if it sounds correct. Please also let me know if I've missed out on any steps. I've been using the Dempsey book as ready reference but really need help in case I've missed something important...


Going to convert my 2.0 1969 T engine into a short stroke 2.5.

Case: 2.0T

Crank: 2.0T i.e. 66mm

Pistons and Cylinders: 2.7L JE pistons and cylinders. The ones I've found online have a cast iron liner, would that be ok? theyre available with 2 diff compressions 9.5 and 10.5. I was thinking of going with the 10.5 since ill have a lower stroke. is this correct?

Heads: going to look for 2.7s or 2.7rs heads. In the meantime, would it be possible to run my 2.0T heads? or is that just a stupid idea?

Carbs: The engine currently has 40 IDT Weber's. Can i run these with some adjustments? or would i definitely need to upgrade to weber IDAs or PMOs?

Cams: What would performance be like if i keep the cams that i have? what would you guys recommend i upgrade to?
Procedure: (not in order)
- Open cylinder spigots
- Oil bypass mod
- Piston Squirters
- Hydraulic tensioner upgrade
- Head stud inserts

Is there anything ive missed? any machining that will need to be done to the case etc apart from this?

Thanks so much,

Zain