solex or "E" cams?

[Raymond]

what is the performance difference between Solex and factory "E" cams on a 2.2T? and if one was to install either set of cams, what other modifications would be necessary? thinking of possibly doing this, but want to understand all the work it'll take to get it back up and running. thanks!

[steveW]

Raymond, I've got a similar problem - no money, but want to get my 71 2.2 to go faster.

Solex cams are scarce compared to 'E' s, and as far as I know 'T' cams cam be reground to 'E' profiles, but some people have said its not worth doing it.

I'm thinking of 9.5 cr pistons (JE), 'E' cams and enlarging the ports to 'E' and 'S' sizes - the inlets will be 36 mm inlet and 35 exhaust compared to std 32 inlet.

This would be a milder, but torquier motor than an 'S' and produce about 170 bhp. I'm not sure about the figures and if anybody has done something similar, please let me know.

I will be doing it in stages. Fitting cams first and doing the ports when I get pistons.

Cheers

[RoninLB]

Not experienced w/2.2. My 2.7 has E-cams waiting in the closet. The Solex would have been a good mid way comprise between E and S cams. I was told that porting would be a day/nite difference if I went w/early Solex and still be streetable. Early Solex is a great cam w/proper head work and more streetable than the S cam. I looked at torque curves before deciding. New E-cams from Stoddard cost me $600...

[steveW]

Me again,

I did a search on 2.2 Performance and someone mentioned fly-cutting heads to bump up the compression of T motors for use with Solex cams.

I have doubts about this though. Surely then the motor would be too narrow and cam chains, valve clearances etc would become a problem. I also discovered that the T crank is worth a bit more than E or S as it doesnt have counterweights and will therefore pick up revs quicker.

Personally I would rather stick with E cams, 9.5 cr pistons and enlarging the ports - any better ideas?

[Phoenix-MN]

I rebuilt my 2.2 several years ago using 2.7 p/c and had the stock "T" cams hardwelded and reground to "SOLEX" specs. If you look at the specs for "E" "S" and "Solex" the solex cams seem to be right inbetween the "E" and "S" spec. The resulting displacement of this combo is a little over 2.5L and the compression may be on the low side but this combo works very well, goes like the devil and runs on any premium pump gas

[StuttgartDavid]

Steve W: Careful about you plans to change cams before changing pistons. Double check piston to valve clearance with the increased lift and duration - your T pistons may not clear.

[Raymond]

steve, what kind of induction are you running? webers?

[pwd72s]

Originally posted by StuttgartDavid
Steve W: Careful about you plans to change cams before changing pistons. Double check piston to valve clearance with the increased lift and duration - your T pistons may not clear.

This one bears repeating!

[bjola]

Steve,
where do you buy your JE pistons and what's the price. I am looking for 2.0 S like pistons.

[steveW]

Hi,

I've got std Zeniths which have just been serviced and cleaned out.

With regards to valve/piston clearance, surely there wouldn't be a problem with the std low comp pistons unless the heads are fly-cut, but I really appreciate the warning - I would have dropped the motor, fitted cams, jumped in and driven off with an extra 20 hp - mistake!!!!

[jluetjen]

BTW: 2.2 and 2.4, T and E heads are all the same. 2.2 and 2.4 S heads are the same. Using "E" cams with "T" heads is no different then what shipped with the factory E's.

[steveW]

Has anybody done this conversion i.e S pistons, E cams and S ports on Zenith carbs - everything else as per std 2.2T If so what sort of power was achieved and are there any snags?

Why is it that nobody seems to like 2.2 engines?

Thanks

[gaijinda]

I think 2.2 & 2.4 T,E & S heads are the same casting. The combustion chambers are the same.. I dont know about the T & E, but the 2.2"S" head as a little bit smaller exhaust port than the 2.4"S". The 2.2 "S" pistons have a higher compression ratio compared to the 2.4 "S"

Originally posted by jluetjen
BTW: 2.2 and 2.4, T and E heads are all the same. 2.2 and 2.4 S heads are the same. Using "E" cams with "T" heads is no different then what shipped with the factory E's.

[TimT]

Ive done the conversion your wondering about, the only difference is I run webers on my car and the cam is a web-cam 158R grind which is very similar to the solex grind.

I had the car on a chassis dyno a few yrs ago and it made 145 hp at the rear wheels, which is something like 170 flywheel hp.

You dont want to flycut the heads to get more compression, you run into issues with the cams not being centered in the chain housing ( i guess you could flycut the chain housing to), but you still have issues because the chains will be to long

Id get a set of JE pistons they are offered in 9.5, 9.8, 10.5 CR's
an higher CRs to order
( check ebs racing , pistons should run about $900 US)

and definately open the ports up in the heads,

and while you doing the rebuild have the oil modification done, install piston squiters, and maybe shuffle pin the case ( the old magnesium cases can use this)

here is my engine:

9.8:1 JE pistons
web cam 158R cam
shuffle pinned
oil bypass mod
piston squirters
930 oil pump
tall intake manifolds (PMO)

i know EBS has a website but i cant remember the addy...... try a search

[StuttgartDavid]

Haven't done it, but here are my thoughts, based in part on my 2.0 S engine:

The 2.2s are great engines. People always want bigger, because in the end their is no substitute for cc's. However, the 2.0 started a legend, and the 2.2 has 10% more displacement and torque. I would love to run one if my rules allowed. They also run cooler, resist detonation better, and don't warp heads and jugs the way the larger engines do. In a light car, they work very nicely.

One thing in favor of the 2.0 and 2.2 engines is their reliability in high rpm use - the 66mm stroke cranks can spin higher than the 2.4 stroke without stressing the case and pounding bearins with vibration and harmonics. Things like shuffle pinning are generally only required with the longer stroke. I don't like them, because they need to be done right, or they can hurt more than help by knocking the bearing saddles out of alignment, etc.

The S ports are likely to be a poor choice with the E cams. The bigger cross section will reduce intake charge velocity, hurting your low end torque, which is why I assume you want to stay with the E cams and not go bigger to the S cams in the first place. At higher rpms (5000rpm+), just where the bigger ports would finally help, power with the E cam will be falling off, because it doesn't have the duration to make use of the bigger ports. Result of this combo is a lose-lose proposition for both low and high end. S ports should be used with S cams, E ports with E cams!
The venturi size of the Zeniths are likely also to be a choke point, limiting any benefit from the bigger ports. Changing venturi sizes on the T and 914/6 motors was/is a quick way to get power. The stock T venturi sizes are too small for bigger cams and higher rpms. I don't know much about Zeniths, but I understand they are not a good basis for high performance tuning. You may need to get webers unless you can change the venturi size of the Zeniths, and richen the jets to match. Even if this is possible, you will be in uncharted waters here, as opposed to the Webers, which are a known quantity.

Were I you, I would decide if I want a straightforward E or an S engine, and build to that spec depending on car weight and intended use. Don't try to make a hybrid unless it is a proven combo- you are likely to regret it.
One hybrid that is nice for street use is the 2.5 short stroke described below by Phoenix. It is not a great race motor because the low cr and mild cam limit ultimate hp, but the midrange makes it a great DE engine to learn with. The torque is fantastic for street use, and reliability is high due to the low cr (equal reduced detonation - your biggest enemy) and the 66 mm stroke. If you are buying new pistons anyway, you should look at this combo because it is rather cheap to build.
Remember - increased power only comes in two flavors - bigger displacement (which is usually cheaper and always more reliable) or higher rpm (much more expensive and much shorter-lived). American hotroders got it right - there is no substitute for cubic inches!

[steveW]

TimT and StuttgartDavid, thanks for the advice. I thought E cams, S type pistons and enlarged ports would give me a bit more torque combined with the power (almost) of an S.

All I really want to do is get a 2.2 to go well enough to blow half these 2.7 RS wannabees into the weeds - and I like the sound of a sweet revving small capacity engine. But I've been put off a bit by what I've heard, so I'll resort to plan 'B'

I was looking at the MotorMeister site and they reckon Zeniths can be improved, so I might start with optimising the breathing with what I've got and then sorting the brakes and handling. This should be cheaper than a major engine rebuild anyway.

Thanks to you all, and Raymond who started this thread anyway.

[jluetjen]

gaijinda: I recently compared some port measurements between some 2.2S heads that I have and some 2.4S heads from another BBS member and they are the same. Intake ports are 36mm's and the exhaust ports are 35mm's on both. The numbers in BA's book for the 2.4 S heads are a typo.

I agree with StuttgartDavid; If you are going to use "E" cam's, don't bother to change your heads. According to some comparative calculations that I've done, here are what the Maximum HP intake gas velocities look like:

Stock 2.2T: 87.9 meters/second
Stock 2.2E: 94.0 m/s
Stock 2.2S: 77.9 m/s
2.2S heads with E cams: 74.3 m/s
2.2E/T heads with S cams: 98.5 m/s
Stock 2.4E: 100.3 m/s

Now there was a somewhat forgotten factory 2.0 rally motor (901/30) that used T/E heads and S cams and pistons that made 150 HP. I've estimated that the Max HP intake gas velocity for that motor was 93.5 m/s. Rally motors tend to be much more flexible then race motors, so if you decided to build your 2.2 with your stock T/E heads and "S" cams and pistons, you won't be in totally virgin territory. This is also borne out in the estimated gas flow numbers I listed above. If you would rather be safe, I would recommend using the "E" cams and your stock heads and put in hi-compression "S" pistons. Using "S" pistons in a T or an E is old upgrade which really has no downside as long as you have access to premium fuel.

I recently learned on this board that you can use weber venturi in Zenith carbs(!). I don't know about the availability of the appropriate jets though. You might want to check out this thread. By the way, I came up with these calculations by calculating the gas flows through the intake ports based on published information for the different engines. Since they are all essentially the same design (air cooled 911 motors) I figure comparing them is valid.

[jluetjen]

The question has been posed before on this BBS that if there really is a correct port configuration for a head, why did Porsche keep the same size ports from 1970 through 1973 even though the engines increased in size? Especially given the 2.7 RS's. After thinking about the data and "sleeping on it" I have the following (unproveable) theory:

Porsche's T/E heads are their basic "street' heads which provide good gas velocity for efficient burning, etc. etc. etc. Since intake gas velocity is not exact -- there is a range of values with roughly the same performance -- and the motors are "choked" by the 32mm venturis in the carbs or the MFI runners, the porting is not the gating factor. Beside a couple of mm's on the port will not make any real difference in the car's performance until after the 2.4E. "S" heads might actually be "Homologation specials" since they really seem to be overkill given the gas speeds. But they would provide a great basis for competition heads (Given the FIA prep rules) by opening up the ports a little bit. Within 1 inch of the manifold face, "S" heads open up to 38mms -- the same as Porsche's competition heads! With just a little bit of machine work, "S" heads turn into competition heads. This might explain how Porsche was able to make the S heads work on anything from a 2.2S through a 2.7RS and have the rev range stay pretty much the same. You'd think that the 2.7RS would be pumping a lot more air (It is!), but the ports are not the gating issue.

Conclusion for Early (2.7 liter motors or smaller) Motors: Unless you are building a "No Holds Barred", Hi-rev race motor motor of 2.5 liters or above, getting the heads ported may not buy you much?

Responses to my theory?