2.2T Engine Upgrade Feedback
 

I'm just about ready to take my basically stock 71T in for a new paint job. While it's being painted I want to rebuild/upgrade the engine.

The engine was last rebuild only 30K miles ago and it doesn't leak any oil. So... since I have 2 other projects going and this is a street car/daily driver I want to limit the upgrades to the top end.

Here is what I have:

- I'm running 40IDAs already
- I'm planning on replacing the P&Cs with good used 2.2E P&Cs.
- I had a set of heads ported to I36/E33 to give it a little more air.
- The camshaft selection is where I'm looking for some feedback based on what others have built. I have 3 sets of cams ready to go: E cams, Solex Cams, and DC30(Mod-Solex)

So the questions are:

- Which cams would you run?
- What size should I make the ports on the intake manifold (bottoms)?
- How should I setup the carbs?

I would keep the ports small and use the ‘E’ cams. That will make for a great street engine. It will also allow for future mods if you want. (I suspect you won’t.)

Best,
Grady

Thanks Grady...

So are you suggesting I stick with the stock T heads I32/E32? or use the I36/E33 heads I have and go with 32mm ports on the bottom of the manifolds?

I agree with Grady. 2.2E pistons, E cams, 32/32mm ports for a street motor. (I'm sure he meant the T heads) If you get the urge to go deeper get a 70.4mm crank to go with the above to make a nice punchy 2.4E. You'll be faster than any 2.4S to 100mph.

I think 36mm ports on a 2.2 are not what I would call ideal for a street motor. Personally I don't see using 36mm ports on anything less than a 2.7L for a daily use street car.

Remember the 73'RS had a 2.7L with 36mm ports. The overwhelming popularity of that car had a lot to do with the combination of that displacement matched with the S cam and and 36mm S ports.

Hi Bobby - Thanks for the post.. sounds like that's the way to go.

Question - I already have the 36/33 heads rebuilt and ready to go. What is the effect if I go with the stock T manifolds (I think they are 32mm at the bottom) on these heads? I was trying to get all the parts ready to go so the rebuild would go quick without having to wait for parts to be machined. Or am I better off having the stock 32/32 heads rebuilt for this application?

Also... How would you suggest I setup the carbs?

`I don't have the first hand experience with such a combination but it doesn't sound ideal. The larger ports will counteract the efficiency of the "E" setup to perform well in it's designed torque range.

Think of it like this. Imagine you want to take a small sip of a drink. You use a thin straw to take small sips. If the straw had an en-largened area in the middle of it it would be harder to take that controlled sip.

Conversely if you want to take a large gulp you would use a large straw because it's too difficult to try and get that gulp through a thin straw. Even having an en-largened area in the middle of the straw would not help you take the gulp because you are still limited by the thin straw.

The thin straw is of course the E ports and the large straw is the S ports in this analogy. Having the 36mm ports with an otherwise E setup will not help you take big S gulps and will only work against the efficiency of the E setup.

Keep in mind it's just my opinion on what is ideal for a daily/street car. The 2.2S has the 36mm intake ports just like the 2.4S, 2.7RS and for that matter even the 2.0S. I just don't consider the 2.2S an ideal daily driver/street car. To me it's a track ready hot rod motor which is really cool and puts a big grin on your face when it hits 6500RPM but it's not my idea of a daily use street car.

P.S. Someone else can advise you on carb jetting. I've rebuilt carbs before which is easy but I otherwise don't know jack about jetting them. I remember Bruce Anderson had some good guidelines for jetting in his performance handbook.

Hi John - Thanks for the link. I had read that thread in the past but it seemed as if he was after a different target then me. I ruled out swapping cranks since the bottom end is in great shape and this is purely a street car. I also want to retain the matching number engine since the car is being restored basically stock.

It sounds like E cams are the way to go based on the feedback thus far. The question now is whether or not I can use the heads that I had rebuilt and ported to I36/E33 or if I need to rebuild the stock T heads and leave the ports alone. The other area that I could use some wisdom in is a good starting point for the carb setup.

Thanks a bunch... Cheers

Throw out some idea on a good starting point for the carb setup..

Sounds like I may need to have my stock T heads rebuilt - Is that the best bet?

A few ideas.

If this is a Street car, Solexes. They have a little more zip than the "E," Solex have a 97 lobe center vs. 102 for the E. Or the DC30, that's a better lobe design I would expect.

Keep the ported heads, 46/40 valves with 36/33 ports is pretty close to the 71S with the same valves and 36/35. You might sacrifice a little low-end torque for high end power.

Reversion. What you DON'T want is a manifold ported bigger than the port in the head, e.g. a 911T head with a 32mm port and a ported manifold with a 33mm port. This is exactly the opposite of the optimum characteristic to contain reversion, which is a pressure wave formed when the intake valve closes. In your case, the port in the head is bigger than the manifold, 36mm diameter vs a 32mm port in the manifold, which means there's a "step" of 2mm on each side that will help contain the pulses in the intake port and keep them from pushing air backward through the carb. You may want to reduce the size of the step but only a little bit, ask the experts what they think is best.

Keep the 40IDAs and start with "E" jetting, common knowledge on the BBS. If they are not in perfect shape have them rebuilt-- if you don't know the exact diameter of each jet, get the jet gauge and measure.

Thanks John... That is very helpful.

I'm torn between the E cams and Solex cams. I've had experts and enthusiasts push both ways. I guess in the end it is a matter or preference. I would say more are probably in favor of the E cams for a street car. I have all 3 sets - fresh regrinds from John Dougherty. Here are the specs from his site.

http://forums.pelicanparts.com/uploa...1193246447.jpg

The webers I have are fresh rebuilds from Harry Bieker so I just need to set them up.

I have a set of stock manifolds as well as a set PMO manifolds that are 40mm at the top and about 34mm at the bottom. I'd like to use one of those along with the 36/33 heads since I have those ready to go. The PMO manifolds I have are a little taller than the stock manifolds but not as tall as the tall PMOs. I'll post a picture.

What's not to love about the DC30? The duration and lift of the Solex with the lobe center and reduced overlap of the E.

Bieker did mine too, gorgeous.

Sounds like the PMO manifolds will work fine, make sure they clear the stock aircleaner.

Why not ask Dougherty about his thoughts? I bet he has some good insight.

Hi Milt.. I did (since he built all the cams for me). His first suggestion was the E cams. But he said the Solex would also be nice. Don't think I talk to him about the DC30s for this engine.

Here are a few pictures of the carbs. One is on the PMO manifold and the other on a stock manifold. If looks like the overall height is about 12mm more on the PMO manifold.

http://forums.pelicanparts.com/uploa...1193333643.jpg

http://forums.pelicanparts.com/uploa...1193333654.jpg

http://forums.pelicanparts.com/uploa...1193333692.jpg

That's some pretty stuff.

Thanks Milt... I've been stocking parts away for this rebuild for a while.

Anyone else have an opinion on using a 34mm manifold on top of a 36mm intake port?

You could spend a few hours with a die grinder and port match the manifolds to the heads....The PMO manifold are aluminum and will take a bit of effort to match, the Porsche manifolds are magnesium and are easy peasy to match.

I'd spend the time and remove the 34mm bottleneck

Hi Tim, The reason I was considering going with the 32mm or 34mm manifolds is because several have suggested that I would be happier with the smaller ports on this engine. I was hoping to use the manifolds as a way of restricting the air (since the heads have already been ported to 36mm and rebuilt). I think I would agree that 36mm is probably to big with E cams for a street engine.

Any other thought on this setup?

I may have another potential issue. I just looked at those "beautiful" CNC'd velocity stacks and they are only 42mm at the bottom. The stock weber stacks are 46mm and the tops of the carbs are also 46mm.

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 ;)