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Snorkel - less

rph56

I'm New Here
New to the RV and learning...I've noticed many advertised fuel injected RVs w/the snorkel engine cowling and some without. I would think the IO- would have air induction through the engine inlet sans snorkel. Can someone clarify what determines which configuration? Thx
 
New to the RV and learning...I've noticed many advertised fuel injected RVs w/the snorkel engine cowling and some without. I would think the IO- would have air induction through the engine inlet sans snorkel. Can someone clarify what determines which configuration? Thx

Ahh, Welcome! Completely up to the builder. Van's per plans is a smooth front without the "snout" (technical term from Paul) for the injected configuration as you describe. However, some of us choose not to do it that way and use forward ram air instead.
 
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One additional clarification that can avoid massive confusion on threads - "snorkel" is usually used with reference to an internal air duct that gets air from the right-side cooling inlet to a horizontal-induction fuel sevo. The cowl for the "Snorkel" configurations are smooth - they have no "snout", which is what the forward-facing inlet is usually called. Conversations where these two are (understandibly) confused turn into a "who's on first" type routine....

Smooth cowls have an internal "snorkel", the rest have a "snout"....
 
As somewhat of a newbie and looking at the various models I also have a "snorkel" question.

Does Vans offer a snorkel cowl for the 9(A) model IO-320 equipped airframe? I don't recall seeing any with the smooth cowl.
 
Does Vans offer a snorkel cowl for the 9(A) model IO-320 equipped airframe? I don't recall seeing any with the smooth cowl.

In Van's catalog there is a note about the IO-320 on a -9 requiring the wider scooped O-360 cowling for the -6/-7 for vertical induction. Horizontal induction can use the smooth cowl.
 
As somewhat of a newbie and looking at the various models I also have a "snorkel" question.

Does Vans offer a snorkel cowl for the 9(A) model IO-320 equipped airframe? I don't recall seeing any with the smooth cowl.
They are out there. I have one. In order to make it all work you need to order the IO-360 cowl for the RV-7 and the "snorkel".
 
Does Vans offer a snorkel cowl for the 9(A) model IO-320 equipped airframe? I don't recall seeing any with the smooth cowl.

The RV-7 style smooth cowl will fit on the RV-9 fuselage. More than one RV-9 powered by a car engine (don't ask) has used it:

20050401_N119TJ_3.jpg


I imagine an IO-320 would fit in there just fine, although you might have to get creative with baffling and/or make your own fiberglass snorkel to get it all to work. It would certainly be a cool and unique RV-9!

mcb
 
And here is mine with an ECI IO-340 with forward facing cold air induction. The standard Vans snorkel fit with no modifications at all. Standard baffles fit like a glove with no abnormal modifications at all.
IMG_7864.JPG
 
Is the performance with the IO-340 measurably better than Vans lists with the 320? That is a great looking 9A!
Thanks. It was 5 years of my life building so I wanted to make sure it looked as good as it feels to fly.

Is it measurably better? Well, I am not sure what "measurably better" actually means but it does perform very well. I think where I really see the advantage is in climb.

At present the highest I have had the plane was at 14.5K on a cross country this summer. During that trip I was cruising at 10.5K when I had to climb to get over a bank of clouds. They kept growing taller the further along I went. So I started by climbing to 12.5K. That did not work so went to 13.5K. No go. Then to 14.5K. During this particular flight I was running about 170 mph with the engine set at WOT with HP running about 69%. I was at PEAK EGT and burning about 8.5 gph. To gain altitude I did nothing to the throttle or mixture settings (fixed pitch so no prop adjustment either). I simply dialed in the new altitude on the EFIS and let the autopilot fly to the new altitude. I did notice the engine "lugging" just a bit but the RPM only dropped marginally (perhaps 100 RPM). The airplane pitched up and climbed to the new altitude at around 450-500 fpm. Even at 14.5 when I finally leveled off I was still showing 450 fpm climb without any adjustments to the throttle or mixture from the cruise settings.

I cannot specifically say that during cruise the plane is "measurably better" in performance from Van's numbers. I do think the extra HP allows me to throttle back and cruise at the given numbers while burning less fuel doing it. At any rate, I have nothing but praise for this engine setup. I think the RV9A and the ECI IO-340 are a perfect match. It all works very well for me.

Live Long and Prosper!
 
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