flyrotary@lancaironline.net Mailing List Archive

Actually, there are photos of his intake published in his paper news letters and I think there is one on his web site. My third intake was model after Tracy's (see Photos) except I used all three ports of the throttle body. But, if you copy Tracy's be warned it will mean a bump in the top of the cowl for the TB air inlet. 91intake.jpg shows the manifold looking from the bottom and 91TOPIN.jpg shows the top of the manifold with TB and half moon dynamic chamber. Might give you an ideal of what you are looking at.

The 550 turbo and 460 NA injectors are not quite the same size although the 550s (which are a tad smaller) will fit the injector holes in the block with a small (1/16 " as best I recall) spacer. I noticed this when I removed the 550s from my current 90 turbo block and the spacer came out with the block injectors. I think you can get by without it (as I did not install it when I tried 550s - I removed them as I did not like the idle)

Tracy's tubes are around 1.25 dia for the primary and around 1.5" for the secondary. He created a dynamic chamber to mount the TB out of a wood base from which he created a half moon chamber with a metal divider to keep the primary and secondary channels separate. He then cut down the stock throttle body to just the secondary and then position them on the chamber so primary and secondary each got a bit of flow from each opening.

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC

----- Original Message -----

From: Russell Duffy

To: Rotary motors in aircraft

Sent: Saturday, April 17, 2004 2:27 PM

Subject: [FlyRotary] intake ideas?

Maybe it's safe to ask this while Ed's away :-)

I'm still thinking of what I'll do for intake #3, and I have to admit that I haven't really paid much attention to any of the dynamic tuning topics, since I didn't figure I could fit the resulting manifold in the cowl. It just dawned on me that Tracy has a good intake, which fits under his RV-4 cowl. Unfortunately, I don't remember anything about it, and can't find a picture. Does anyone have a picture that shows Tracy's intake. Actually, I'd like to see pics of anyone's intake, just to get some ideas.

The current thought is to get the primary injectors back in the block, and mount the secondary injectors as close as possible. Does anyone know if the turbo, and non-turbo injectors are interchangeable? I'm pretty sure they must fit the same hole in the block, but how about the fuel rails? FWIW, I know (all too well) that the connectors are different.

I have to admit, that it's going to be difficult to resist modifying the short, straight intake that I got from David, and using it with my old TWM TB. This will give two injectors in the block, and two in the TB. Since it will be so short (about 10 inches), it will be far less than ideal, but I can't say if it will be better or worse than my current intake until I try it. This is probably the simplest thing to try at the moment. Now that I think about it, I could probably practically bolt it on, without modification (to fit under the cowl) to see how it compares with the other intake in static rpm. Hmmmm....

Thanks,

Rusty (in search of the universal intake)

Attachment: 91INTAKE.JPG

(38K)

Attachment: 91TOPIN.JPG

(37K)