1969 911e - looking for more power
 

I have a numbers matching (engine and trans) '69 911e that is now due for a rebuild. Car is rust free but had some body work - so not perfect or a candidate for a future concors restoration - which is fine as neither is my wallet.

I am interested in boosting the power some though; and have read a number of threads with some suggestions of what to do - and what not to do. Am interested in any suggestions anyone has for upgrades - or feedback from anyone who has done this (2.0E preferably) with lessons learned. My budget is around $12-15k all in. For what it's worth my mechanic has thrown out the idea of boring out to a 2.7l as his recommendation - I have no idea what the price tag on that is yet.

Cheers in advance.

Rob

Most bang for you $ => Engine swap!

Keep your nice 2.0E engine nice and stock in the corner of you garage. Buy an SC engine, maybe put on carbs for the sound and throttle response. Be careful in 1st gear.

Not sure if you can do this within your budget, but in the end you can sell the 3.0 put back your 2.0 and you will probably be back to zero or make a profit. if you upgrade your 2.0 for the same money that money will mostly be "lost".

Build a short stroke 2.5L with "S" cams or 906 cams, and recalibrate the MFI. Then a good set of headers and a rather open muffler. You would still have a matching numbers car, and no one could see the difference. But it would be a 250Hp screamer!!!

More engine power is all about breathing and compression. Intake and exhaust port sizes are a considerable factor in that engines ability to breath. I would definitely have the intakes opened to 38mm and exhaust to 37 or 38mm, but remember this requires modifying the MFI system as well. If you want to leave all of the MFI throttles alone (cost is considerable to modify) then forget about porting the heads. With your budget I would suggest larger displacement but without boring to 2.7. You can run 9.5-9.8:1 compression single plug. Do not twin plug as I believe it would exceed the budget. Run an S cam or DC60 and have the MFI pump space cam modified to accommodate and you should have a very nice increase in power.

Best bang for the buck is a stroke & bore conversion. The way I did my last two personal builds.
You will need a 70.4mm crank and matching rods, 84-86mm cylinders (slip-in).
Shoot for a compression ratio of 9.5:1.
The 2.0 heads can be cut to fit but 2.2/2.4 MFI heads are readily available. Porting of course.
Have the cams ground to Mod E (no welding required) and very little pump modification Probably just calibration)
From the outside it looks stock and still should produce a very driveable 200 or so hp.

How much hp are you looking for? Stock 2.0E was about 140hp? Is it still putting out this amount? Not sure about the rest of your car, but I would address in order: 1) any rust 2) brakes 3) suspension 4) hp.

As for HP, what are you looking for - 180hp? 200? 250+? go you need it to run on pump gas and be streetable or is it for racing and 100+ octane fuel? Depending how much more HP you are looking for and how you use the car, you may need to go back and address items #2 and #3 above. Maybe just a full refresh of the current motor to restore back to original hp amount?

^^^ this, but I'd do a 3.2, still a stock engine, huge HP increase and in your budget.

Thanks to all - appreciate the input.

To provide a little more data;

The car runs well, guessing it has dropped a little off the original 140hp but still goes well; running the original MFI also which definitely needs a tune. Suspension needs some work; the original hydro-pneu struts are long gone and replaced with a slightly more modern system. I will be looking at that plus the brakes as part of this project. No rust, not even surface.

The car will be used for strictly for street driving. I believe that the 901 trans is a limiting factor at some point; but as I am not really anticipating going above the 200hp range this shouldn't be an issue.

So I had a 1970 911T with an SC motor in it a few years back (the matching numbers engine came with it in pieces) and it was a blast - but having done that I am leaning towards modifying the existing engine; but generally keeping it recognizable as the correct engine - just more oomph....

I suspect I am (sadly) seriously less technically inclined than all of you - but my initial mindset was aligned with the increase in displacement. The 2.7 seemed excessive to me, but I honestly don't know enough about it to really know.

Again I greatly appreciate all of the input, any additional thoughts or suggestions are also appreciated.

Cheers,

Rob

+1 This would make a great engine

As long as you're not doing burnouts a 901 can easily handle 300+hp.
914 V8 guys do it all the time, 1st gear is the weak link.

More power equals bigger displacement.

Being somewhat in the same boat as you when I started I can highly recommend building a 2.4S engine. Leave your 2.0 alone, there are too many things to change: in the case, crank/rods, P&Cs and heads. You are better off than me in that you can reuse your E cams(for driveability) and MFI. You can reuse the 901 transmission/flywheel and mount a stronger pressure plate to handle the extra power(watch out for 1st gear).

I sourced 2.2S Mahle P&Cs from our host for higher compression ratio than stock 2.4. Then you need to find a case with the piston squirters and oil bypass mod installed and a set of 2.4S heads plus the camshaft housing and running gear, including the pressure fed chain tensioners.

You are well advised to revue your brakes/suspension as well and add a front oil cooler. I also added a front sway bar.

I decided against a 3.0L because of the added weight in the back and other car upgrades required to handle the power. Get Wayne's and Bruce Anderson's books they have excellent reference material.

I started from a 911T, running Weber carbs and this new engine is a blast.