Solex cams

[speedo]

From my understanding, there are two cams. Are they the same grinds, lobes duration etc? Thinking of Waynes 2.0 to 2.2 Upgrade, or even a 2.0-2.4 stroke upgrade using the Solex cam and the 70.4 crank. Thoughts?

[Matt Monson]

I don’t remember the finer details, but I had this conversation with Steve Weiner a couple times and he always said to use Mod S over solex. While good in its day, the solex grind is outdated. That’s for the kind of build you’re talking about.

I have never heard of two different solex grinds.

[Dpmulvan]

Originally Posted by speedo

From my understanding, there are two cams. Are they the same grinds, lobes duration etc? Thinking of Waynes 2.0 to 2.2 Upgrade, or even a 2.0-2.4 stroke upgrade using the Solex cam and the 70.4 crank. Thoughts?

Solex 248/236 242/230 .455"/.414" 97 4.2-4.6 mm
DC 30’s are modified solex cams 248/236 242/230 .455"/.414" 102 3.8 mm
I have Dc 30’s in my carb 3.0

[Emo993]

And I have them in my 2.2 E engine with S pistons. DC30 mod-solex, love them.

[speedo]

Originally Posted by Dpmulvan

Solex 248/236 242/230 .455"/.414" 97 4.2-4.6 mm
DC 30’s are modified solex cams 248/236 242/230 .455"/.414" 102 3.8 mm
I have Dc 30’s in my carb 3.0

Huh! 5 degrees and .6mm lift make that noticeable a difference? I'd be curious to know what the (observable) differences are...power comes on more like an E vs S cam? I'm stroking a 2.2 to a 2.4 using 2.2 S P and Cs and Webers for my 914-6. So it will look like the stock 2.0 six (which is on the shelf), but have a few more hp.

[doswald]

For my 2.3, JB Racing recommended the Solex. I’ve been very pleased with the result. I’ve listed the engine details and engine dyno results in a post earlier this year.

dho

[targa72e]

I'd be curious to know what the (observable) differences are...power comes on more like an E vs S cam? I'm stroking a 2.2 to a 2.4 using 2.2 S P and Cs

Here are some dyno Comparisions on some early engines I built.

https://forums.pelicanparts.com/porsche-911-technical-forum/1151593-dyno-summary-testing-early-2-4l-2-5l.html

john

[john walker's workshop]

Ran a 2.7 with euro MFI P&Cs, '66 solex cams, Webers, SSI in a '69 years ago. Great throttle response. You could lug it down to 1500 RPM in 2nd and stab it with no lag to speak of. Top end not as nasty as an S, but perfect for the street and getting out of a corner when the fat cam guys are waiting for the power to come up. Pretty much the same as an E cam.

[Richey]

From my experience , Solex cams are great , a little more zip above 5000 than an E cam
but more low end than an S cam . I was disappointed with the mod S , definitely
more torque from 3000 to 5000 than an S , but they somewhat sign-off after 5500 ,
so it's really subjective and personal preference in the end . I'm talking about driving
for fun on the street , hilly roads with turns , not on a race course , and no 911 is good for stop light drags , although the mod S would probably be better than an S cam for stop light drags .
There are two Solex cam styles , center lube and regular .

[speedo]

One is definitely a right side...but the left has a weird number. Will the cam wizards chime in?
My cam book shows for 1965 Solex: Left 901 105 109 01 and Right 901 105 110 01

These cams are Left 901 105 103 01 and Right 901 105 110 OR

Can't get the pics to load.

[Henry Schmidt]

This thread speaks primarily to the effectiveness of the Solex cam and for a early clean sheet of paper, it was a great starting point.

That said, I have been building what we call a 2450 (70.4 x 86mm) the the formula was/is 9.5:1, 40mm Weber, 36mm intake ports, sport muffler, stock heater box exhaust and Mod "S" cams.
Of course all of our engines are built using modern techniques such as dry film lubricants and top quality bearing but there is no other magic. On the chassis dyno these
little engines make 180 RWHP and 6650 rpm. They tend to start pulling hard in the mid 2 thousands. Those kind of number will never be achieved with a stock "S" cam.

[Saraki]

Depending on the year and intended use, there were differences like the Solex, E, and S grinds. For the 2.0 to 2.2 or 2.4 upgrade, the Solex cam is a great middle ground, good torque and driveability with solid top-end. Pairing it with the 70.4mm crank works well, especially if you’re using Weber carbs.