What is the Downside of doing a 4.0 Air cooled Engine?
02-07-2024, 11:44 AM
#46
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We've done about a dozen sets of 106s in the last 5 years. All have gone to Europe. No complaints, but it's certainly pushing the limits, and I wouldn't recommend it for the track. Our 105s (4.135" actually) have been out there since 2004 and are race proven as well.
However our 104s with the Mahle Motorsports pistons are by far the most popular. Not quite a true 4L, but that's what everyone calls them.
We also have a version of the above kit to go with the 80.4 crank and 130mm rods which yields 4.1L. We're out of stock on that one and Mahle Motorsport is backed up and we won't see those pistons until April-ish.
However our 104s with the Mahle Motorsports pistons are by far the most popular. Not quite a true 4L, but that's what everyone calls them.
We also have a version of the above kit to go with the 80.4 crank and 130mm rods which yields 4.1L. We're out of stock on that one and Mahle Motorsport is backed up and we won't see those pistons until April-ish.
I have a set of 12.5 to 1 105s on my 964 based 4.0L engine in my 914-6 conversion. It has been bulletproof since I built it. The only issue was a leaking seal on the (911 referenced) left bank. Granted, this is not a track car, it is a street car. I don't rev it at redline all the time, and I don't daily drive it. But I have run it all the way home to Fort Worth from Santa Fe, and it had no issues.
I still run the stock 964 crank as well. I should have bought a 993 crank for it, but I couldn't find one at the time I built the motor.
Clay Perrine
