Found oil pressure problem, Out of round crank Options

[Chad911sc]

So when I built my engine, I took the crank to a local central Florida machine shop. I asked for it to be checked in every way and turn it down .010 if needed. They called me back up a week later for pickup, and said it was all good and my mains were well within spec for standard bearings. All they did was micro polish it. Before putting it in the case, I checked with a set of micrometers that I had purchased and it was in spec. The car had 85lbs of oil pressure on start up, but would fall to 5lbs after up to 220. I tried everything from different oil pump to the tangerine oil pressure valve, but nothing helped, so I tore it all back apart and started over. The bearings on the ends of the crank looked perfect, but the middle bearing was wiping on both thrust sides. So I bought a bore gauge and checked my case after torquing it back together, and it checked out perfectly. I thought I was going to need a line bore of the case due to stretching, but that wasn’t the issue. So I took my crank to another shop to get it checked out and he put it on the machine right in front of me, and wouldn’t you know the crank was out of round on the middle bearing by .008 ! So I see now why the middle bearing had such extreme wear and my oil pressure was disappearing. They are going to turn it down .010 on the mains and straighten it for me.
I am also putting an o-ringed oil pump back in as well to solve the improper fit issue with the type 1 pump. When I checked the bore of the case and the oil pump that came out of it, they were the exact same size. So the press fit was lacking a bit. Hopefully will be putting back together in a couple weeks once the parts are back in and the machine work is done.

[Chad911sc]

The “machine shops” around central Florida have changed drastically over the past 10 years or so. My best friend is a Toyota Master Tech that builds mud race truck engines every weekend, and he always points me to the right direction for my machine work needs. But he couldn’t give me a good place for my crank work, because his guy moved out of state and the work that he had to have done lately, had been hit and miss. All the air cooled gurus have retired and or passed away. When I moved here in 1992, there were quite a few very good air cooled machine/build shops here. Now there are none. I rolled the dice with a machine shop I had never used, but had very good reviews from all different types of engines. I figured any machine shop could easily check and turn a crankshaft. I will take nothing for granted this time and will check it all. I am very disappointed to have this engine back apart in my living room, but also I love to learn and see how things work. Having it apart again and being able to tweak a few other things that I would have done differently, it’s a great learning experience and a chance to overcome some adversity.