Porsche 356 Engine Repair RennsportKC

Had this little 356C come into the shop with a running issue. At first we thought the carbs were out of balance, but after retuning them, something still wasn’t right. Wes eventually pulled the plugs and found a smashed plug on #3. Then he broke down and did a compression test, which gave us a 0% reading in cylinder 3. A borescope was run down the motor, and we saw a severely beaten up piston. So out comes the motor. Initial guess is a mechanical overrev did the damage.

Such a tiny little thing.

And a tiny hole! Note the transaxle still in place.

Breaking down the suspect bank. This 356 has been a driver, so unfortunately a lot of the tins, muffler, etc are pretty rotten. Once we got everything on the table, we did a leakdown test, and have air rushing past both the intake and exhaust ports.

With the cylinder head off, this is what we have. A really beat up head. Ouch. It is hard to see in pictures, but something has really pounded the heck out of the metal.

And the cylinder removed. Once the piston was removed, I grabbed the rod and was able to wiggle it ALOT on the crankshaft. This motor was gone through not too long ago, and we are wondering if maybe the wrong sized bearings were used. Unfortunately we will have to dig a little deeper after finding this stuff.