Time to tear into #666 again, This thing is the devil Options

[DNHunt]

This engine is cursed. Time for another teardown. At the least a rering but, I'm gonna check everything I can on the way down.

Dave

[DNHunt]

Poor ring seat again. This is the second set of pistons and cylinders I've tried. First were Nickies and JE pistons and I fussed with them 3 different times. Oil consumption was in the range of a quart every 300 miles and compression in 2 cylinders was poor. Leakdown was from 12 to 60% and into the case. Anyway Jake and Charles took these back and replaced them.

This interesting this time. These are the FREE REPLACEMENT jugs and slugs from Jake and Charles and the pistons are KB's with Hastings rings. Their support has been great. All the numbers are a little better this time but not right and the bad holes the first time are the poor holes this time. Because of that fact I can't help but wonder if the problem is somewhere beside the jugs so, I'm going to check everything on the way down. Cold leakdown test, endplay, deckheight, check rod bearings and measure everthing including the cylinders on the way down.

Here's the other part. I have to take responsibilty for the problems if it's the rings cause I redid the top end when Jake was on his honeymoon in France and I made a couple of decisions that affected the rings. KB says to use a very large ring gap on the first compression ring (.028 in my case). This is so the portion above the top ring land doesn't go Kablam. I followed KB's suggestion but, Jake wanted it to be .016 because of the aluminum cylinder's expansion. The second issue is a little harder to explain but, it arises from the fact that part of the oil control ring land overlaps the wrist pin. KB puts a pin in the land to keep the ring from rotating and they suggest a ring gap of .065 to fit over the pin. Jake came up with a cool way to notch the ring so the gap deoesn't have to be this wide. It is shown in Jake's build articles in "Dune Buggies and Hot VWs". I didn't see that so I put that huge gap in. It is certainly possible that this time around all the problems arise from the way I installed the rings but, I can't be sure so I'm going to look at everything.

I usually fall asleep thinking about this problem. I've wondered if the crank is ground wrong so the pistons sit cocked. Measuring deck height on both sides of the piston and looking at the rod bearings wear should give me an idea of whether the rods are not perpendicular to the crankshaft center line. Has endplay grown and is the crank thereby out of position? Are the rods bent or bushed wrong? Is the case deck bad? Are the cylinders round and true? I have a lot of questions to answer. I'd appreciate any other suggestions.

The good news is I sure have learned a lot.

Dave