2.0T Questions

[BobRoberts]

Yes, I know I could just buy a 2.2 or 2.4 outright... but I'd rather build my existing motor, which is tired and has a tiny leak from the case halves. It doesn't make any strange noises, and from partial maintenance records, I don't think it's ever been apart. The car has about 90,000 miles on the odometer, and I have no reason to believe it's been flipped. The PO was pretty honest about everything.

Reading Waynes Top Engine Picks, I had a couple of questions:

1. S-Piston/E-Cam. How much low end would I lose going to this motor? Anyone have some dyno sheets on what the before/after should look like?

2. The 2.0->2.2 Upgrade. Wayne says that it's more cost effective than option 1. Is that really so, once you factor in new heads, new cams, new P&Cs and the 44 Webers? Can it be done well with 40s?

thank you for your time.

Bob

[YTNUKLR]

1) You'll lose some low-end, but it's an excellent street engine nonetheless. 2.0/2.2S crank, S pistons (in your current T cyls?), 2.2/2.4/2.7 heads, reground cams.

2) Yep, it's more cost-effective. You can use the 40mm webers that you have on your engine now (or should have). 84mm mahle 2.2S p/c (Pelican sells these), 2.0/2.2S crankshaft, E cams, 2.2/2.4/2.7 heads.


You're going to need new cams (regrind your T to E), new heads and new pistons (at least) anyway, so it's really worth it to just do the 2.2. If you're going to rev anything up (E or S cams) you really need a 2.0/2.2 911S crankshaft (maybe $500--I have one, BTW). You can also find used pistons and cylinders for cheap (mid hundreds maybe). Rebuild your carbs. Good luck.

[SteveF_911]

I have a 2.0 with S piston and E cams.

Gives me 152Hp at the crank and it is a nice street engine that pulls well from about 3000 to 7000. Much nicer than the T because it revs harder.

[Henry Schmidt]

One way to make this engine work, might be to bore your existing cylinders to 82mm. There is plenty of wall thickness for this process. Have JE make you a set of 9.5 to 1 compression pistons to fit 82mm cylinders. S pistons have perhaps a little to much compression for today's fuel. I would run a set of solex cams. Better than "E" cams and easier cams to drive than "S". Next some slight port work (35 or 36mm) on the stock 2.0 heads and your set. The small valve 2.0 heads will work amazingly well. Good power band, safe for today's fuel and the least number of expensive changes. No new heads, same crank and rods and even the distributor will work.

[KobaltBlau]

That would save a lot of money, and it sounds like a very nice engine!

[BobRoberts]

All, thank you for taking the time to reply. 150 hp is a huge jump for me. I guess with some piston squirters, the engine would still be bulletproof. I can only afford to build this motor once, so I'm doing it for longevity.

Henry, I've been reading what you post, and it seems like most of this is old hat for you.

When you say solex cams, do you mean having mine reground/hardened to solex specs, or just getting new cams? I checked the PP catalog, and didn't see solex cams. In fact, I didn't see any cams for anything earlier than a '74.

thank you
Bob

[jluetjen]

Just to second SteveF_911, I too have a 2.0E with S pistons. The only place in the rev range where a T might make more torque is coming off of idle, so say below 2000 RPM. The only caveat that I'd add is that my E has MFI which seems to help the engine pull smoothly from below 2000 and develop a few more HP at peak RPM. Carefully tuned carbs should still be able to pull smoothly. I'd strongly suggest an MSD (or equivelent) multi-spark ignition since the combustion chamber resulting from using the 2.0S pistons is prone to fouling at low rev's.

Given that original forged 2.0S pistons are no longer as available as they once were, you'll most likely end up going with something like JE pistons. If you are going to do that, you might as well overbore your cylinders a couple of MM's to get the "while you are in there" benefit since I doubt that there is much of a cost difference between 2.0 9.5+:1 pistons and 2.1 or 2.2's.

As far as cams go, the '69E cams (I doublecheck my shop manuals and the 2.2's and 2.4's had the latter spec cams) were the same as Solex's with the exception of the MFI drive off of the left one.

[Henry Schmidt]

When you say solex cams, do you mean having mine reground/hardened to solex specs, or just getting new cams?
If you look around you can probably find a good used set of factory Solex cams for less than regrinds. Call me I might have some.

Bruce Anderson's book says that Solex and "E" cams are the same but that is an error.
"E" cams = I 270 .405 102 lobe center
E 260 .390
Timed at 3.0- 3.3 mm

Solex cam= I 280 .440 97 L C
E 270 .405
Timed at 4.2-4.6

Very different and in a small bore carbureted or MFI engine the improvement is thrilling.
I used them in my own 2.7 RS spec 914-6 and couldn't be happier.

[jluetjen]

Henry;
The problem is that there wasn't just one "E" cam. Porsche changed the 2.2E's supposedly by at least increasing the lobe angle.

Are you saying that the '69 E's were different then the Solexes (excepting the MFI drive)?

[Henry Schmidt]

I guess you don't believe the specs I posted. The specs below are from the Elgin web site. What I am saying is that Solex cams are completely different from any "E" cam. As listed in the earlier post, the cam specs are defferent. They are as different as "T" and "E".

PORSCHE DURATIONS .040" .050" VALVE LIFT CENTERLINE SETTING
2.7 CIS S I 226 220 .405" 110 3.0-3.3 mm E 206 200 .350"
E & L I 238 230 .405" 102 3.0-3.3 mm E 226 222 .393"
SOLEX I 248 242 .455" 97 4.2-4.6 mm E 236 230 .414"
EARLY "S" I 268 263 .455" 98 5.0-5.4 mm E 240 235 .399"
SC I 236 228 .450" 113 1.4-1.7 mm E 224 218 .395"
964 I 246 238 .470" 113 1.26 mm E 232 226 .430"
3.8 SUPER CUP I 248 242 .490" 112 2.0 mm E 234 228 .455"
GT II TURBO I 254 248 .485" 112 2.5 mm E 238 232 .470"
962 I .450" 5.0-5.4 mm E .450"
3.0 RSR I 278 272 .470" 101 Sprint cam E 267 262 .450"
906 I 290 283 .463" 96 6.8 mm C-6 E 262 255 .460"
3.8 RSR I 280 275 .490" 109 4.6 mm E 264 258 .490"

[Henry Schmidt]

Perhaps the confusion stems from the fact that 911 "E" and 911 "L" cams are the same. The first chart is from the factory spec book and show and "E"&"L" specs. The second shows the Solex cam."

[jluetjen]

OK; bear with me. I'm just trying to get to the bottom of this. Henry; here are a couple of pages from my '69-71 Spec Book.

BTW; Just to confirm that I'm not confusing the '69's with the 2.2's, here is the beginning of that section in the manual -- 2 pages earlier.



Hmmmm

[Henry Schmidt]

Both Webcam ( webcaminc.com) and Elgin (elgincams.com) state on their web sites that the "E" and Solex cams are different. I have two factory spec books that state that "E" cam are different from Solex. I told you the specs. At this point I've run out of ways to make the point.
Believe what you like.
Good luck

[jluetjen]

Henry; I'm not trying to "bust your chops" or pick a fight. Everyone seems to quote someone else. I agree that the 2.2E's and 2.4E's seem to use the same profile as the earlier L's. The 2.0E's cam seems to be an anomoly or a typo. Right now my 2.0E is happily being used almost daily on the street so I'm not going to measure the cams on it for at least a few months. I'm just trying get the facts.

The 2.2 and 2.4E's that I've driven do seem to be significantly milder then the tune of my car, although it's hard to tell how much of that is the cam and how much is just the larger motor, tuning and other factors.

BTW, the 2.2E that I have driven in the past now has one of your 2.7's in it that you built for my neighbor Ray. I think it has high(er) compression pistons, 2.7S heads and E cams. After 500 miles it's running like a charm and I can't get the smile off of Ray's face.

[Wayne 962]

Some info:

- The 2.0 and 2.2 'E' engines used the same camshaft.

- The 2.4 'E' has a slightly different profile, which results in the intakes and exhaust opening at slightly different times.

- The 1969 'E' camshaft profile is *not* the same as the 911L camshaft, at least according to the Porsche spec books. Henry, you quoted the specs for the 901/06 engine, which is not a 911E engine. The 911L and 911E specs are not listed in the same spec book. The camshafts are similar, which is why I believe that Elgin has combined the profiles on their website.

As for Solex cams and 'E' cams - the fact that the intake valve overlap is differnet for those two, yet the open/close and lifts are the same, leads me to believe that there is a different parabolic lobe profile for the Solex cams.

I think everyone here is splitting hairs. In my book, I wrote: "Solex Cams have a profile that is nearly identical to th early L camshafts and are in-between the performance of E and S cams.

-Wayne

P.S. I might add that the factory information on this subject is a bit murky. The difference in 'E' cams is documented in the spec books, but the cams have the same part number. I also went through the spec books, and corrected a lot of mis-information on a variety of topics that was printed there. The only sure-fire way of telling what these profiles were is to take original, never-torn down engines, and place the cams on a cam doctor to measure their profiles.

[Henry Schmidt]

Sorry Wanye but the spec book is wrong. It is also schizophrenic. You see the book says to different things for the same cam.
The truth as I see it is that the 911 "E" cam is Porsche part number 901 105 181 00 and 901 105 110 05. These cams time @ 3.00 - 3.30 mm. and 2.70- 3.10 in the later model.
Now if we read the 1969 spec book on page 46-47 it says that 911 "E" cams have two different grinds 901/09 and 911/01. We all know that Porsche does not give identical part numbers to two different parts. So we have to conclude that one spec is incorrect. How do we choose which is incorrect. Well let's look at a later book. In the 1973 spec book the 911 "E" cam is listed on page 42-43 911/52. The part number seems the same. 901 105 181 00 and 901 105 110 05 Now in this book the cam timing is slightly different. How different? Well it's a couple of degrees different. If we look at the cam specs we'll see the specs just a couple of degrees different from one of the cams in the earlier book. Perhaps it would make sense that the spec that is just a couple of degrees different would be the correct spec 911/01. This Remembering that Porsche generally doesn't give two different parts the same number which do you choose.
Now if you chose the cam spec with the lesser lift and duration lets see if there are any cams with the same spec. Oh my. There seems to be a cam with the lesser spec in an earlier book. Yes it looks like the 911 "L" 901/06. Next lets look at the 911 "L" number 901 105 109 05 that's not the same ( oh yeh, no pump drive) and 901 105 110 05. Where have we seen that number before? Oh yeh 911"E".
It may be a little confusing but 911"E" cams and 911"L" cams are the same. Solex cams are a cam all by them selves. No other cam has the same lift at overlap and no other cam has the same part number.

[Wayne 962]

Henry - I can't argue with your statements, but I also can't pinpoint exactly where the factory documentation is wrong. Are the incorrect specs printed in the book? Or did Porsche change a part's spec and still use the same part number. I spent many, many, many hours pouring over these spec books, factory parts diagrams and other sources trying to come up with a 100% accurate table for the book. I determined it was an impossible task.

With respect to part numbers, I know a few years ago, Porsche Carrera Chain tensioners were unavailable because they were undergoing some "internal design changes" - at least that's what I read / heard from people like Terry Wells. Well, the "new" parts came out under the same old part number.

Also, we just ordered some 914 CV bolts the other day. They were six-sided hex bolts in bag that was labeled with the 12-point star bolt pattern. Same part number, two very different parts. So it does happen all the time where Porsche replaces different parts, but keeps the same part number.

I'll say it again, the only way that anyone can really know is to tear down some guaranteed original engines and measure the camshafts. I think until then, everyone (including me) will be having to make a best guess.

-Wayne

[Henry Schmidt]

You're kiddy right?
Same part number, early cam 1968 "L" same as 1969 "E" same page in the book same number1970/71 "E". back to the original 72/73. You're saying Porsche Changed the part for one year? Then changed it back. Your also saying they changed it to a cam grind they had before and didn't use the old number.
Now you're saying you can't see the typo. Please?