Subject: injector problems RX8 injector cost
From: Rotary Engine
Date: 3/7/2011, 4:31 PM
To: AAA Put this in the To box


 snips...

 Also, I am sorry to say, those Seimans injectors do not fit the
 injector holders or the fuel rail. My mistake. I'll buy them
 from you
 and keep them around. However you need four RX8 yellow fuel
 injectors.

 Paul Lamar

 Paul,
 Bill Bradbury described what's happening with his engine, and it sounds
 pretty much the same as what's going on with mine. Below staging, it's
 smooth, but above, it runs rich and in flight there's a lot of popping
 and surging.

 He then reports that he has had good results by switching his stock red
 and blue injectors to the yellow ones, that I 'm assuming, but I'll
 check are yellow RX-8 injectors. Will they fit my 93 13 BREW and where
 can I get them for as little $ as possible, and how much would that be?

 On another note, I still have not gotten the last few pages of the plans
 for my RV off to you, I still have to get up to the hangar and get them
 off to you.

 Brian Trubee


 I have not researched the supply yet but Michael Hart is about to do
 that so
 he will let us know.

 Sounds to me like the trim map is wrong on the top end. You could have
 one or more partially clogged injectors. It takes a special circuit
 and a burette to test injectors. The fuel coming out should be
 directly proportional to the pulse width.

 Here is a schematic of a DIY test device.

 Also you could sample the air pressure in the runner with a couple
 of pressure sensors and a data acq system. If my plate was not running
 over I could come up and do that. It will be the end of April before
 I am free enough to do that.

 I don't think the RX8 injectors will fit your current injector holders.
 You could get RX8 injectors and they might not change things. If not
 it is the trim map. If they do you may currently have one or more bad
 injector. Getting them tested may be the first thing to do.
 There are some companies around that specialize in cleaning and
 calibrating. Paul Yaw may still do it. http://www.yawpower.com/ New
 ones are getting so
 cheap it might not be worth it.

 Where are Bill's injectors mounted?

 I see your secondary injectors are on the outer tubes a foot or so
 from the port. What happens when you lean them out?

 Is that a damper I see on the end of the secondary fuel rail?

 Take some closer pictures of the EFI system.

 Don't worry about the plans. Michael White kindly made me a gift of
 a set he was not using. Thank you Michael. They came in.

 Paul Lamar


 I had the injectors cleaned and flow tested just prior to engine start.
 The thing you see on the end of the secondary rail is the fuel pressure
 regulator.

 The other day I went out and ran the engine up on the ground,
 specifically looking at EGTs for a mis-match of EGTs above the staging
 point. What I saw was that the EGTs were pretty consistent all the way
 up and down the RPM range. So, I'm thinking that I'm just rich up in the
 areas above staging. Well, the EC2 should be able to compensate if I
 tune it right, so I'll keep twiddling the program knob. When it runs
 smoothly, it's like silk. I"m just a bit tired of the tower getting
 calls from the local communities about a plane in distress overflying
 them. Also developing a crease in the bottom seat cushion from excessive
 pinching.

 Brian Trubee

 Well when I get time I am going to work on the engine monitoring
 system that will read and store the history of the injector pulse
 widths using a USB port to a PC. I think that is going to help
trouble shoot
 these kinds of problems. Should be about the end of April.

 Paul Lamar

Hi Paul,

Here is the story about the Denso injectors.The cheapest I can find is
the Denso 195500-4450 which is rated @ 450cc/min at 3 bar.These cost
$75.00 per injectors and $70.00 if you buy 4 of them.These can be found
at  www.fiveomotorsport.com/fuel-injectors/mazda/rx-8/  .The second
cheapest is the Denso 297-0041 and these cost $129.00 and can be found
at http://www.densoproducts.com/resultsSearch.asp.The problem is that
for the life of me I could not get the specs on the 297-0041,I googled
them in many ways but could not find the specs,however they are listed
as the original for Mazda RX8.So I do not know which one to buy,can you
take a look at these and let me know.BTW the remote filter bracket is on
the way.Thanks.

Michael

450 cubic centimeter = 0.118 877 423 56 gallon for the 195500-4450.
AKA 7 gallons an hour. 28 gallons per hour total for four.
3 bar is 45 psi.

Sounds like it will do the job at 45 psi.
Mazdatrix tells me the factory is charging about $150 each.

Paul Lamar

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