Search results

HomeBuiltAirplanes.com

Help Support HomeBuiltAirplanes.com:

  1. Chris Matheny

    Variable geometry turbo

    Do you have a compressor map for the turbo? As has been said at high altitude you may well be above the safe pressure ratio for it. This is especially true for the small stock turbos they use to make boost at very low RPM that cars use in takeoff.
  2. Chris Matheny

    another Autoflight gearbox failure - this time after 34 hrs

    If you and the box were still in Ohio I would measure your cases for bearing bores location for free and machine a bearing bore for the new bearing on my CNC. Not saying manual machines can't be accurate in the right hands. This just seems like a lot of hands in a messed up pot unfortunately. I...
  3. Chris Matheny

    another Autoflight gearbox failure - this time after 34 hrs

    All the bearing bores should be cut in the same setup on a CNC and should be within a few ten thousandths of an inch of each other by location and parallelism. Something is not right.
  4. Chris Matheny

    Dream workshop?

    Build as big as you can, its never big enough!
  5. Chris Matheny

    Dream workshop?

    I have an amazing shop that I love and I'll touch on the things I like and what I would change. I'm in Ohio and we get cold winter's that seem to last all but about our 3 months of hot humid weather. I put a high efficiency boiler and floor heat in. Amazing, efficient and best heat I've found...
  6. Chris Matheny

    Ignition Timing Fun On a Dyno - Lycoming

    You can retard timing only to a point then the exhaust valve starts opening while the combustion is still in growth stage and egt will start to rise and the exhaust will start glowing.
  7. Chris Matheny

    Ignition Timing Fun On a Dyno - Lycoming

    Did you have an EGT probe in on this Dyno? I'd be interested in what the temperature rise was as you retarded the timing.
  8. Chris Matheny

    GM LE2 engine conversion

    Made the prototype dual thermostat housing today. Still think I can shed some weight but hate to with the two bolt attachment and housing flex. It's very stable and would have at least triple redundancy with this design. This has a 180 a 195 and a bypass circuit. You'd know if any of them stuck...
  9. Chris Matheny

    GM LE2 engine conversion

    Machined the pulley to fit the water pump today. The water pump will now spin an equivalent RPM of 4500 at my expected cruise rpm of 3800. Also shed another .8# with the swap.
  10. Chris Matheny

    GM LE2 engine conversion

    Machined the water pump inlet housing today tapped for a -12 AN fitting for coolant hose. Nothing impressive but another .32lbs off compared to stock and uses stock housing gasket. Little by little.
  11. Chris Matheny

    GM LE2 engine conversion

    Made a block off plate for the high pressure fuel pump today, another 1.395# off the engine. Hopefully have time tomorrow to nail down the thermostat housing and machine it.
  12. Chris Matheny

    GM LE2 engine conversion

    Original alternator weight was 11.68# with pulley, new alternator with pulley I machined to make fit and final weight was 5.96#. still may machine some more off to make the mount line up but a considerable weight savings.
  13. Chris Matheny

    GM LE2 engine conversion

    Been playing with the throttle body and injectors idea, I think I'm going to make this a single injector per ECM setup at this point. Port injection smooths out low rpm idle and idle emissions but does very little for power and usually kills a little torque. I mocked up an intake today and will...
  14. Chris Matheny

    How did you choose?

    I am probably biased since I'm starting one myself but it sounds like a KR2S would fit what you are looking to do very well. I'm working on a small turbocharged engine for my plane now and will start the rest of it very soon. Good fuel range, fast travel, side by side seating and you can fit the...
  15. Chris Matheny

    Anyone deal with speeduino?

    Slower processor, if your planning on keeping the vvt and all sensors in tact on your Pentastar, I think a Megasquirt would probably be an advantage. If locking everything out and only running basic sensors it would probably suffice.
  16. Chris Matheny

    Valve Problem

    Attaching fins rather than them being part of the casting reduces their thermal transfer efficiency a lot. When they are part of the casting with the same grain, density and material they work much better.
  17. Chris Matheny

    Valve Problem

    I am fortunate to have a great cylinder head casting company (and know the guys) about 15 minutes from my house if this does take shape. I am committed at the moment to the LE2 engine conversion i'm currently working on and its taking up a lot of my spare time so until its running this would be...
  18. Chris Matheny

    Valve Problem

    Can you buy a bare casting from the better head manufacturers and have it H.I.P. processed before machining it for use? HIP is hot isostatic preessing, they basically put a head casting under pressure and heat it right to the melting point. It makes for a very strong and crack resistant casting...
  19. Chris Matheny

    GM LE2 engine conversion

    Whittled out the runners for the intake today. Now to make the plenum side and have it all welded up and machine the holes for the injectors. They sit in a recess so they can't move when welding. Slow progress is still progress.
  20. Chris Matheny

    GM LE2 engine conversion

    Made a little more progress today. Machined the adapter from the factory turbo to flip intake and exhaust sides and use a T25 flange turbo now. One more check in a box.
Top