Cross roads between a big /4 and a big/6, Share your experience Options

[Montreal914]

I am at a cross road in my narrow body restoration project. This is not an original build, but rather a sleeper 914 with nice elements. The chassis will be reinforced with an inner kit and outer RD clamshell.

The car will be converted to 5 lugs using the right 3" 911 struts/hubs and drilled rear hubs. The braking system is Alfa Brembo calipers in the front and 914-6 reproduction rears with appropriate 19mm MC. Sport Bilstein all around and 140 rear springs. Front 19mm and std rear sway bar.

Wheels will either be Fuchs 15" x 6" or 16" x 6". I have no intentions of shoehorning 7" wide wheels in the back, no fender stretching.

My engine options are as follow:

I have all the nice bits to build a 2.3 4 cylinder (HAM heads, Nickies, rods, crank, block with large studs, Tangerine headers, yadi yada...). I would setup a modern EFI to it and should conservatively get 150-160 HP out of it.

I have an opportunity to get a 3.2 Motronic 6 cylinder, 200+ HP.

I plan on using a 901 gearbox and I already have the Tarett heavy duty CV/shafts kit.


Although it may seem obvious that the desired option would be to go with the six, again, this is a narrow body with 6" wide wheels. My concern is the drastic amount of power and the additional mass on this car's configuration.

A while back I remember reading a comment from Pete Stout @horizontally-opposed , where I recall him saying somethnig like he felt the 914 has a better balance with a 4 cylinder engine, but he was willing to make that tradeoff to have the sound, smoothness and pleasure of a 6 cylinder. That being said, his beautiful car (reference narrow body in my book (IMG:style_emoticons/default/wub.gif) ) is equipped with a small 2.2 six.

I have some engine weight data that looks like this:

4 cylinder: ~321lbs
2.4 six cylinder: ~400
3.2 six cylinder: ~485lbs

I have never riden let alone driven a 6 cylinder powered 914, but I do have 10 years of daily California canyon driving mine (4 cylinder 2056). I know how the 4 cylinder car feels and I can probably picture how it would drive with a large /4.

I would like to hear what people have experience with their narrow bodied 3.2 conversion (I am sure there must be some), and what they prefer, their old 4 or their new six.

I appreciate and value all of your comments! (IMG:style_emoticons/default/smilie_pokal.gif)

Thank you,

Eric

[Montreal914]

Yes, this is a good turnout of information. I really appreciate. One thing I need to dig up is what is involved in the 6 conversion, more specifically a 3.2.

My quick list is:
Engine mount
Oil tank
Oil lines
Headers/hex
Muffler
Engine tin
Clutch/flywheel adapter to the 901
High torque starter (maybe?)
Gearbox bell housing modification for some 3.2 sensor??
Shift linkage rod modification
Oil cooler elbow (or is the 3.2 different?)
Oil thermostat
Oil lines/front cooler
Accelerator cable?
Cables heat shielding sleeve
Fuel line size?
3.2 fuel pump
Harness to car
DME installation
3.2 Tachometer
Air filter modification?
Heating blower connection to Hex.

I am sure I am missing a few items but that is what is coming to mind at the moment. I will have questions about all of the above items. I did search 3.2 conversion threads but haven’t found one that was very complete… (IMG:style_emoticons/default/sad.gif)

I am not saying this is the route I am going, just establishing what is involved. Once I have the full picture, then I will be able to make a decision. (IMG:style_emoticons/default/smile.gif)

Yes, the big four is straight forward, especially since I have all the bits for it except that nice plenum Eric is teasing us with. (IMG:style_emoticons/default/poke.gif) From the picture I am recognizing a Subaru STI center and 3D printed adapters to the standard DRLA manifold. I would assume the STI throttle body would be used too. Just wondering why the injectors aren’t lower in the DRLA manifold. (IMG:style_emoticons/default/confused24.gif)

Fun stuff! (IMG:style_emoticons/default/driving.gif)

[mepstein]

[quote name='Montreal914' date='Sep 5 2024, 07:32 PM' post='3165770']
Yes, this is a good turnout of information. I really appreciate. One thing I need to dig up is what is involved in the 6 conversion, more specifically a 3.2.

My quick list is:
Engine mount
Oil tank
Oil lines
Headers/hex
Muffler
Engine tin
Clutch/flywheel adapter to the 901-kep or pms kit
High torque starter (maybe?) or regular 911 starter
Gearbox bell housing modification for some 3.2 sensor?? - 10 minutes with some small power tools.
Shift linkage rod modification - straight rod
Oil cooler elbow (or is the 3.2 different?) Ben does this. Use the carrera cooler and have him weld on the fitting
Oil thermostat
Oil lines/front cooler - You can always get the car running and then add in a cooler.
Accelerator cable? - Rich Johnson makes a nice kit
Cables heat shielding sleeve
Fuel line size?
3.2 fuel pump
Harness to car - PMS
DME installation drill a hole through the dimple at back of floor pan.
3.2 Tachometer - You can use any 911 tach or use a 914 tach with a tach adapt.
Air filter modification? 4" tube plastic tube. Flaps sells a kit for $15 and you cut off the bend on a chop saw.
Heating blower connection to Hex. Drill a 1" hole in your flapper boxes to duplicate a 914-6 heat flapper box.

Add in the brass oil line restrictor that's on 911 oil lines.

It's all been done many times. Maybe not a single thread of everything but it's all out there and plenty of people who will answer questions.