First off, get rid of the screens on the stacks and get a real air filter. The stacks and plate above have a purpose with impulse reflection and ‘reversion’. This is a significant part of the intake tuning, even very important with “E” cams. I agree about the progressive intake diameters and venture size.

All of the above posts have very valid input.

If I were to pick & choose, the 70.4 mm crank and necessary rods would be high on my list (there is no substitute for displacement). As you raise the CR with the 2.2E P&Cs, twin plug starts to become important even with this seemingly ‘mild’ street engine. Compared to most automobiles, “E” cams are still pretty radical.

Your use pretty much determines the cam choice. With short gears and the opportunity to perform, the “S” and hotter are really fun. For sporting street driving the “E” cams are great. For a good ‘daily’ the “T” cams were properly designed. CIS engines gave up way too much for emissions IMHO, although they are OK with large displacement, twin plug and slightly higher CR.

There are appropriate arguments on all parts of this discussion. I don’t think any one point of view is absolutely correct. So much for my lame observations.

Best,
Grady

Hi Grady... Not lame at all. I'm just trying to digest all the input and come up with something. I definitely don't want to dig into the bottom of this engine so I'm stuck with the 66mm non-CW crank. I'm also building an rs-clone car and a 3.5MFI rsr-type car so I'm content with keeping this a 2.2 daily driver.

I think I've decided on the E cams along with E pistons. The stacks with the screens are really a vanity item (with the air filter off). I'll be running the factory air cleaner setup. So the open questions are:

1- Is it a problem to use these velocity stacks since the bottoms are 42mm versus the standard 46mm?

2 - Can I run a 32mm or 34mm manifold on top of the heads with the 36mm intake port? If that will work should I go 32mm or 34mm? or do I need to go back to stock heads with 32mm intake ports?

Thanks for all the feedback

JBell,

The point I was trying to make about the straws in post #6 was that mix and matching 36mm S ports with E manifolds is that you'll end up with a setup that's not optimal in either E or S torque ranges. Having that S port at the end of E manifolds will kill the velocity and the consequent midrange torque that comes from an E setup. You also will not gain any top end torque because the E manifolds will choke that rev range.

Porsche optimized these different setups years ago for their desired performance ranges. T "touring" being a street motor, E being a compromise between street and track, S being a "sport" or track ready combo.

Mixing the setups will result in a motor that will not perform as well as either of the motors that it derived parts from.

Build yourself an E motor top to bottom and you won't be disappointed.

jbell,

Let's not forget the pair of factory rallye engines with assigned engine 'Type Numbers' ... that used stock 'T' heads from the 1968 parts bin, along with 'S' cams and carbs! They were down 10 hp [150 DIN instead of 160 DIN for one version - with OEM muffler] at the top end, but gained a bunch of torque on the bottom end ... obviously, pro rallye drivers like Elfort valued torque over peaky power when they rejected engines like the infamous twin-cam 916 [envision a 908 engine with two less cylinders and one less liter displacement] engine and its' inflexible 9000 rpm power peak!

Quite right, this is the little-known 901/30 2,0 liter with 39/35 valves and 32mm ports. . . with 46IDA webers!

My own saga, a long one, detailed here:http://forums.pelicanparts.com/911-engine-rebuilding-forum/221927-suggestions-warmed-over-2-0-901-05-a.html?highlight=warmed+over+901

After thinking about it my compromise between originality and modern performance is 81x66, 9.5:1 JEs, Dougherty Cams, stock 40IDA and all the other invisible updates. I'm hoping for 150 HP, but the torque curve is what I really can't wait to see.

Hi John - That's a great thread.

OK OK... I guess I'll need to find a set of stock 2.2/2.4 T/E heads and go that route. I can use the ones on the engine but I want to have everything ready to go so it's a quick rebuild. Maybe my wife wont even notice ;)