ENGINE WORK  August, 2006

A lot of what I am doing right now is wiring related toward getting the engine ready to start.  If it's strictly engine wiring, it on this page.  If it's more general supporting wiring, it's on the avionics/electric page, so be sure to check there for details

Aug 1 - Received solenoid valve order.  The valve is quite large and VERY HEAVY - about 2 pounds.  Even though the valve body is aluminum, the solenoid is quite heavy.  Also, it says on the side of it that it has to be mounted with the solenoid vertical.  I tested it, and it is NC and draws about 1a while open.   It came with some papers, but no useful info in them.  It has two red wires and a green one, so I guess the green is frame ground.  It doesn't seem to care which red wire is + or - .  Other than the weight, it seems fine.  Worked awhile on checking the fit.  It looks like it will fit well on the RT intercooler pipe; right between the 2 heater connections.  It's difficult to decide - should I add a whopping 2 pounds of weight or should I accept the small air losses with the butterfly valve?   I am not sure.  I decided to take the butterfly valve apart and see if I can get it to seal better.  Reading emails on Eggenfellner STi list about the oxy sensors and if they are really needed or not.  Because Jan decided to have us remove the Mass Air Flow sensor, Jim Skala thinks the engine will not operate in closed loop any more.  I asked Jan to confirm, but no reply.  If true, that really sucks, as the whole closed loop EFI thing was a major reason in choosing this engine.  If we are not in closed loop, then why bother having oxygen sensors at all?     0.5 hr

  Here is the solenoid valve I ordered.  Even though the body is aluminum, the coil is very heavy.

Aug 2 - More discussion on Eggenfellner STi list about the oxy sensors.  Still no reply from Jan on it.  Update web site.  2.0 hr doc

Aug 3 - remove butterfly valve from SC tubing, scrub off sealant, soak in gas to dissolve remaining sealant.  0.25 hr

Aug 7 - depressing info on Eggenfellner STi list - no closed loop operation & imprecise mixture control.  Cleaned gas & sealant off butterfly valve - still no better sealing.  0.5 hr

Aug 8 - more emails with other STi users about open loop mode, "limp-home" mode.

Aug 9 - more emails with other STi users about open loop mode, "limp-home" mode.  Used valve lapping compound to lap butterfly valve plate to body.  Solenoid valve I bought will have to go back - it says max ambient operating temperature is 105 degrees.  2.0 hr

Aug 10 - more lapping butterfly valve plate to body, to try to get it to seal better.  1.0 hr

  Here is the butterfly valve after lapping the edge of the valve plate to the valve body.  It was originally painted in machinist's red, so you can see the line where the plate is lapped to the body.  It may have improved the seal some, but I'm still looking for better.

Aug 12 - bought a couple 1/2" and 3/8" ordinary plumbing ball valves.  I went through the bins at LaValley's and found ones with the least turning resistance.  This may work better than the butterfly valve.  The problem with a butterfly valve is that it is not designed to completely shut off flow.  I think I got my butterfly valve to seal better, after lots of lapping, but it still isn't a tight seal.  If I am going to all this expense, effort, and weight to have a supercharger, I darn sure want to get all of its output.  Started working on Bowden cable and clamp I got from ACS.  I can use this to operate the ball valve.  The problem is that, even though ACS says this clamp is meant for this cable, it isn't even close.  The clamp ID is 0.188" and the cable OD is 0.218".  Had to blow another $20 ordering a 5.5mm (0.2165") reamer from MSC to ream the clamp so it will fit the cable.  I drilled it to #3 (0.213"), but it's still not big enough to get the cable into it.  I decided to go with one of the 1/2" ball valves, so I had to order some AN912-4D from ACS.   2.5 hr

I had planned to start installing my mufflers, but now there's talk on the Eggenfellner list about some people having to cut and reweld the  headers to prevent them from interfering with cowl fit.  That may affect the muffler mount points, so I am now reluctant to install the mufflers.  Between this and all the uncertainty about the open/closed loop operation, it's hard to get enthused about continuing to beat my head on this engine.

Aug 14 - wrote an email to Eggenfellner STi list, summarizing all the issues and questions about the open vs closed loop situation with the STi engine.  It generated quite a bit of discussion.  The whole problem is that Jan & Robert Paisley found that the Mass Airflow sensor doesn't work with the supercharger, as it was designed for a turbocharged installation.  This then results in a constant ECM warning light, and the engine won't operate in closed loop mode.  I'm very unhappy about this, as the closed loop EFI was one of the main reasons I chose a Subaru engine.  Now, I am just trying to work through the issues, so we can get the engines running with the proper mixture.  To summarize a long story, an air/fuel meter is now part of the required equipment for this engine, and we diddle mixture by playing with fuel pressure.  I don't like it much, but it's the best solution we have so far.  1.0 hr

Aug 15 - received 5.5mm reamer from MSC.  Reamed out the Bowden cable clamp - it's now a perfect fit.  More responses on Eggenfellner STi list about my email about the mixture control and open vs closed loop.  0.25 hr

Aug 18 - received undrilled ball halves for Schultz metal eyeball grommets.

  I got 3 matched sets of undrilled split balls for Schultz Engineering's metal eyeball firewall grommet.  This is so I can drill multiple holes if I want to.

Aug 20 - packed up the solenoid valve to return it.  Drilled one of the undrilled split eyeballs with 2 holes to take both the starter wire and the alternator B wire.  One hole is approximately 1/4" and the other is just under 3/8".  1.75 hr

Aug 21 - Finished and polished holes in firewall grommet eyeball.  0.5 hr

  Here is one of the Schultz firewall eyeballs drilled with 2 holes.  One is for the 6AWG wire to the starter and the other is for the Alt B wire.

Aug 23 - away at a 3 day whitewater kayak training class.  It's ironic that I gave up motorcycle road racing for this season, so I could focus on the plane.  Yet, I haven't worked on the plane all that much, and I've been busy with lots of other things.  It's also been depressing with all the engine-related problems and uncertainty.  We got a LOT of rain all spring and the first half of summer.  So, I've gotten into kayaking to take advantage of the higher-than-usual summer river levels.  Update web site with Aug entries.  I haven't  had time to keep the web site up to date.  I haven't updated the index in months, and it's so far behind now, I'll probably never find time to bring it that much up to date.  2.0 hr doc

Aug 30 - Cut end of 1/2" reducer AN912-4D to 2 1/8" diameter arc to match SC tubing.  Fit reducer to tubing.   Fit rest of wastegate components to tubing.  1.0 hr

  Here, I am cutting the 2.125" diameter arc on the AN912-4D coupler, so it will match the SC tubing for welding.


  Temporarily fit the AN912, ball valve, and Bowden cable components to a piece of the SC tubing.  I'll need to get the AN912 welded on, as well as something to hold the Bowden cable clamp.

Aug 31 - update web site  2.0 hr doc

go to SEPTEMBER, 2006 engine