2.2 & 2.4 Cylinders??

patkeefe · 11-20-2007, 12:16 PM

Is there a physical difference between 2.2 and 2.4 cylinders?
Thanks!
Pat

dtw · 03:00 PM

No.

Of course, there are the usual differences among the population. Cast iron (T) versus Biral (E & S), and the differing height and bore groups. Make sure to match your parts up if you are working with a mixed bag.

patkeefe · 11-20-2007, 02:00 PM

Thanks. I have a 2.2 cylinder with broken fins. Figured I could check the sizes on the 2.4T cylinders I have and see if they will work. Guess I'll dig them out of the garage and put the bore gauge on them.
Pat

304065 · 11-20-2007, 02:15 PM

Yes, they are both 84mm but height groups are different and the fin pattern is different between the cast-iron and the Biral.

patkeefe · 11-20-2007, 02:24 PM

Thanks John:
I'll have to see what the 2.4 cyls look like. What exactly is Biral? Another of Porsches metallurgical experiments?

dtw · 11-20-2007, 02:59 PM

Biral is the term for the cylinder type w/the aluminum external casting and press-fit iron cylinder liner. I believe there are also factory replacement cylinders using Nikasil process, that are out there too. The cast iron T jugs are easy enough to identify, they are much heavier and the fins are usually nice and rusty.

What's up with the cylinders pictures - are those your 2.4T cylinders? More broken fins...If you call around to some shops you can probably find some good used replacements if nothing in your collection works.

Make sure to match height groups at least in threes on each bank, so you don't bind up your cam(s).

patkeefe · 11-20-2007, 04:22 PM

Thanks again, Dave:
That is the bad 2.2 cylinder in the photos. If it was a VW, I would use it without hesitation. I think I may need the cooling on that end of the cylinder. IIRC, the 2.4 cylinders I have look just like those...CI. I'm going to build a little science project spare parts engine this winter. 4R 2.4 case, 2.7 crank and rods, 2.2 dome pistons cut for E cams, small port 2.4 MFI T heads. I figure that should make a 2.4 with about 10:1 CR with E cams. Going to be the little engine for the 914. Still thinking about cams and port velocities...

dtw · 11-20-2007, 05:06 PM

Seems like you're building my motor - which is in turn a 'take' on a motor that Tyson Schmidt built some years ago. I'm at an estimated 9.8:1 on relieved 2.2E pistons. My cams are Crane 288s, which are like Solexes with a tad more lift and duration.

My heads began life as 29mm intake T heads. I bored them out to 34mm and they breathe really great. Induction is 2.4E throttles and stacks.

Runs like a scalded dog - probably about as fast overall as a well sorted SC, with much less torque but more noticeably more top end and a helluva lot more throttle response. Like, neck-snapping throttle response. It just leapsaround when you floor it.

You are going to love your motor. Caveat: I had definite cooling issues with this motor at anything above a low-rpm cruise. When I took the car apart for paint & restoration I bought a high-zoot Carrera cooler setup - there was no external cooler on the car prior to that.

patkeefe · 11-20-2007, 05:16 PM

I'm relieved to know I'm not starting out in left field!! I figure it should be good for the 1900 pound 914 at the track. Neck snapping is good regarding throttle response...