308 camshaft interchange

No, they aren't the same - the 80-82 2Vi cams are much wimpier than US '77 and before carb cams.

 

contact Laurie at webcam, they can re-weld and grind in a new profile. She'll have a couple options for you as well in addition to the stock grind.
Web Cam Inc. - Performance and Racing Camshafts

 

Because of surface rust???

Those are good early cams.

Fill the motor with some Royal Purple, and start it...
They won't be rusty tomorrow.

 

There's slight improvement to be made to the profile, if you are going that far, but the early cams are pretty good for the times.

Avoid the temptation of the legendary P6 race profile, as it's not streetable at all.

 

If the bearing surfaces are pitted I'd look at the journals to make sure you don't have corrosion there as well. Sounds like the motor needs to be stripped down and gone thru. If the cams are pitted and rusty I can only imagine the condition of the bottom end.

The stamped part number on the cams will narrow down what you have btw, I've seen some early 308's with P6 cams and some with LM versions as well esp on the GT4. You never know.

 

I'd think repairing them would be about $2k, while for that price you could secure a brand new set of cams from Cat Cams. They offer a 'stock' grind which features about the same duration figures, but do have a touch more lift and a modern ramp which just make for a better overall cam than anything OEM or hard welded from Webcams or whoever. That's what I'd do. The only dealer for Cat Cams in the US are VAC motorsports in PA. Ask for Steve, he'll have to email them for their version of a 'stock' cam as they don't show it on their website.

 

From memory:

75GT4 - 260 deg dur IN / 254 deg dur EX
78-82 308 244 deg dur IN / 244 deg dur EX

There's the famous P6 grind used on the LeMans 308 that's 290, and there's a "Sport" cam that's been tried which follows the Dino which is 272. These typically need higher compression pistons to work right, otherwise the valve is open so long, the "squeeze" is lost.

Also, lobe centers are different as well as lift. IIRC, early cams lift is 9mm, and later cams are 8.4 (?)mm

The most important thing to know about cams on any motor, be it Porsche, Ferrari, Briggs & Stratton, is Don't wing it! Follow a recipe. The 244 cams might sound wimpy, but effective compression is better, and inlet charge velocity is higher with less lift. You see where that recipe plays a very important role. Ignition timing, ambient temperature, exhaust system, carburetion, fuel quality, on-and-on all play important roles. Newer cars with all the electronic feedback controls optimize tuning over a greater range of conditions. Ferrari wizards did a great job tuning the 308, and you want to follow as close as possible to given specs. BTW - Dima Elgin is very very talented. He really understands the kinematics of cam profiles. He has done many Ferrari motors and aircraft motors. Also, he used to have Cal Dyno right next door, and he has seen the results of many talented engine builders trying to get the smoothest running, tractable mid range, with highest peak horsepower possible using his cams. He's worked on cams for a few Ferrari motors for me, and I would really not enjoy doing a motor if his talent was not available.