Thanks for the thoughts! Sorry I have neglected to reply to them. The current oil setup, including the fittings, was modeled after the Huebbe brother's setup. They've been stage rallying their car without oil issues for a few years now, which is why I figured it was the safest way to go. I have been looking into new fittings on the pump, however, as I think you're right...they do look pretty restrictive. Only the fittings on the pump are the steel industrial units, everything else is a proper aluminum -8AN fitting. The steel fittings on the pump are the same fittings the Huebbe's and I have used without problems (until now)...but at this stage I should be tweaking everything I can.
Upon reassembly I obviously measured everything, once again, but this time found one item which I had missed on previous builds. The magnetic drain plug was long enough to be touching the screen. While it *shouldn't* cause a problem, with heat I suppose it's possible that it could have reduced the opening gap for the pickup. Next time I have the engine apart I plan to cut the pickup on an angle to reduce the chances of a occurrence. For now I've tossed a washer in as a spacer. Sometimes the quick fix is just as good. The motor has been back together for two weeks, and I've put almost 2,500km on it. So far the engine has been trouble free, and I'm even letting it idle for short periods while I walk away. I guess you could say I'm testing my luck, but so far there hasn't been any problems.
A new issue, which is probably related, is that the Accusump stopped holding pressure. Now to be fair, I think this was an issue prior to the big failure...but I broke the gauge on the Accusump months ago and haven't fixed it. In order to swap out the gauge I needed to remove the Accusump, so I was simply waiting until an oil change with some time. Over the previous months I've noticed it was slowly leaking down pressure, like if I left the car for a week or more it wouldn't have the pressure to pre-oil. Without having the gauge on the unit I couldn't tell if it was the ball-valve leaking down, or an issue with the Accusump. Once installed with the new gauge, I quickly determined it was leaking down. Within a couple of days of use, it wasn't holding any pressure (or indeed building pressure when the engine was running). A few emails to Canton Racing and it was agreed the internal seals on the piston were probably in need of replacing. Considering I've been using it daily, not really surprised.
The Accusump isn't designed for user-servicing. Canton requires that all units are sent back to the factory, except for a few teams who do refurbish their own. I was given the go-ahead, and a list of mistakes to avoid. But first, one has to create a key to get into the secret vault...
With that done, I popped open the Accusump and immediately found the problem. The first thing they check when rebuilding these units is scoring on the cylinders. If the cylinder is scored, the unit needs to be replaced...and I won the bad-luck lottery. Obviously the Accusump ate some hard particles at some point, which I suppose isn't surprising considering I've roasted a couple of motors with it. The score marks are also on "the bottom" of the cylinder with respects to how I had it mounted, so the particle(s) were probably settled on the bottom and then caught up in the seals.
A few emails back and forth with Canton, and I'm going to need a new Cylinder. Since they don't sell refurbishment parts, that's going to be a challenge as I missed the production run for the year. Hmmmm. They're looking to see if they can find a cosmetic blemish unit, and in the meantime I've decided to clean up the scoring marks. While waiting for the correct sized O-rings, I figured I would try the closest-fit from the local industrial shop, just to see if I'm wasting my time. In went the O-rings, in went the Accusump and voila! Holding pressure...for a while. Interestingly it's now holding oil pressure, but not holding pressure on the air-side of the chamber. I suspect with the proper sized o-rings it will all work as planned. Might make it without a new cylinder after all!
Also started on a new project for the car, I've been getting tired of 'bouncy tach', and tore apart a spare Stewart-Warner performance Tach to start playing around with sizes. It's going to take a bit of work to get it to fit/work in a 914 Tach housing, but i have some ideas on how to make it work.
I also spent some time tuning the gas heater this week. I was having some issues with it cutting out, or taking a long time to fire up. Through adjustments to the flame switch I think I've finally got it running close to factory spec. It now runs continuously without cutting out, which is great. I should be getting just a bit more heat out of it, but my fuel pump adjustment is maxed out. That's the Achilles heel with using a gas heater these days, the pumps aren't available new and everyone I have is just slightly under the factory spec for output.
-Dave