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Who is making plenums?

dwranda

Well Known Member
I am looking for someone who makes plenums for the James cowl. I know I could just get one from James, but have seen many websites showing the horror stories of getting them to fit. I'm not in a crazy hurry to get it. I am almost done with the baffles, but I have plenty to keep me busy if it were to take a few months.
 
Bill Lane makes a well designed three piece plenum for the Sam James cowls. It works with the Van's baffle kit and just requires two new pieces for the front of the engine, for which Bill provides a full sized template. The intakes on his design opens up significantly more than the Sam James plenum and are adjustable, which makes the installation easy. Bill charged the same price as the Sam James version, which requires a lot of extra work to install.




Frank Huber
RV-7A Completed in August, test flown and in the paint shop now.
 
Bill Lane makes a well designed three piece plenum for the Sam James cowls. It works with the Van's baffle kit and just requires two new pieces for the front of the engine, for which Bill provides a full sized template. The intakes on his design opens up significantly more than the Sam James plenum and are adjustable, which makes the installation easy. Bill charged the same price as the Sam James version, which requires a lot of extra work to install.




Frank Huber
RV-7A Completed in August, test flown and in the paint shop now.

I know about Bill and would prefer his plenum, but I haven't had any luck getting one from him. He finished his plane and had been flying with no time to make one. I also emailed him recently with no success so I thought I'd see if there were others around better than the James version.
 
Clint at Vetterman is also working on his own plenum design. You can find pictures the VAF facebook page.
 
Email me

I have several pictures of Frank Huber?s install (he was kind enough to show us how it?s done) and more of our install.

Email me if you want me to send them to you. Unfortunately I have not taken the time to learn how to imbed (embed if you prefer) pictures on this forum.

Krea dot Ellis at gmail dot com
 
VAF has a facebook page?

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https://scontent-dfw5-1.xx.fbcdn.ne...=21883cca0556047de5d455a89b467ad7&oe=5C9A47AF
 
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Well he has a point, they look pretty simple to make yourself. Then again folks will pay actual money for cover plate kits too so...

Trying not to be thin skinned here(don't have my flame suit on) but in my defense I am not done with the canopy or the cowling and have never done a lick of fiberglass work. Maybe by the time I am done doing the fiberglass on those 2 items I may want to attempt the plenum. Or if I can find a plenum like Bills that looks like a piece of art to me I would rather go that route and save some time. I am trying to get this thing in flying shape next year. Maybe I should have just scratch built a plane from plans. Then I can say I built everything on it!!
 
Dan is right,

I doubt there will ever be an easy on / off the shelf solution. Because these are hand built aircraft with different engines, propellors and various spinners, the cowls and cowl noses end up in different locations. As a result the inlets and inlet transitions are just as unique. Most likely a good understanding of what works and what does not work in terms of inlet shape and inlet air velocity vs exit area and velocity is more important than what looks pretty. Dan and others have repeatedly provided great material for consideration. ( I expect there could be some more links to refresh material already posted)

showthread.php


Equally as important to proper cooling as the plenum is baffling
showthread.php
 
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Trying not to be thin skinned here(don't have my flame suit on) but in my defense I am not done with the canopy or the cowling and have never done a lick of fiberglass work. Maybe by the time I am done doing the fiberglass on those 2 items I may want to attempt the plenum. Or if I can find a plenum like Bills that looks like a piece of art to me I would rather go that route and save some time. I am trying to get this thing in flying shape next year. Maybe I should have just scratch built a plane from plans. Then I can say I built everything on it!!

Dave I am in the same boat. Folks are being kind of harsh... if you can't say something nice or helpful don't..... Ha ha. You are doing good. My 1958 PA-23-160 (Piper Apache Twin) had metal plenums! Yes it had a plenum and did not rely on the cowl to seal the top of the engine... Just saying 1958 they "done that been there".

Here are a few threads or web pages
http://www.n54sg.com/baffle-kit-diffusers-and-plenum/

http://www.vansairforce.com/community/showthread.php?t=35428

Work of art - He makes a plug then a mold.. It is not round but you get the idea.
https://www.youtube.com/watch?v=5pfPhFCPccE

This is like making plenum inlets, in that you lay up on foam plug and cut the foam out (loss of form/plug one time use)
https://www.youtube.com/watch?v=8QQPRb8CHmA

Good channel and liked the free form cowl mod with expanding foam (which many folks use with great results and some not so great).
https://www.youtube.com/watch?v=U-QqCkMj0t4

Not round inlet plenum but nicely done with a lot of metal and screws. I am going to have a flange molded into the fiberglass plenum top, at edge, to attach to the metal baffle kit. This is stiffer and less fasteners and you don't need metal angles to at top of baffle to attach to. However either way is fine.
http://www.vansairforce.com/community/showthread.php?t=145867

The tread by "crabandy" (link below) starting bottom pg 40, is great example for making a plenum to connect cowl to plenum. He goes into a very elaborate soft rubber material. I am making mine ridged and connecting with neoprene sleeves to rings in cowl. I like this because he also modified a stock cowl, which I am doing as well. There is a world of possibilities. For the inlets he makes them flexible with rubber... I'm not doing that but interesting. (Dan H. - the school teacher who scolded you, also has a thread with the inlets to plenum flexible ducts.) http://www.vansairforce.com/community/showthread.php?t=43391

http://www.vansairforce.com/community/showthread.php?t=94648&page=41

Youtube part 1 of several on basic fiberglass work making motorcycle seat. This is not making a Plenum, but seeing people make fiberglass/carbon fiber parts gives you a sense of how it is done.
https://www.youtube.com/watch?v=MAinuf5I_dw
https://www.youtube.com/watch?v=CtvnRVtNVpk
https://www.youtube.com/watch?v=ZIXfZe3hCL4
https://www.youtube.com/watch?v=yfzwRaIJf0c
https://www.youtube.com/watch?v=6wvRfuSW9UI
(You can use almost any material from a boat shop, but most use West Systems epoxy and E glass. Some use carbon, but not needed for strength.)

This is tip of iceberg. Do some Google'ing or YouTube'ing for inspiration. For detailed fiberglass basics of making parts, try Sam James how to CD. I think most people use West system epoxy and bid (bi directional 8.5 oz cloth, E glass) for general use. There are some good tools and technique to cut cloth... Otherwise you mix it up and impregnate the ply you cut out, lay it up. You can apply the resin to ply flat one plastic wrap and transfer to your form/plug. This controls the wetting and keeps it a little lighter. You can also put dry ply on form/plug and apply resin (with brush). It is not "rocket surgery or brain science". :D .

Making a plenum, I'm going to start with the Van's metal baffle kit. The plenum will be 3 piece, with a top cover and two inlets LHS and RHS, three sepetate pieces connected with mechanical fasteners. One piece like SJ's plenum is better unless it does not line up. The connection to the cowl inlet ring, will be neoprene tubes to allow movement of engine.

The top cover (should be easy to make) - lay up on a form plug, shaped with files, sanders, eyeball and templates. Bondo (car body filler) if desired to even out and make smooth surface. Sand some more, repeat over and over. You put tape or parting film down on the plug to keep glass from sticking to plug. After laying up last ply, put "Peal ply" on last glass ply, keeps the glass smooth (several layers of 8.8 oz bid). This makes for less work after. However this is not going to be a show piece... Another option is using the top of cowl as form (protected with tape or parting ply). Take a splash from top of cowl, then use that as top of plenum or as form/plug/mold to lay up on, to fit the baffle.

You have an option to make metal angles to attach plenum top or make the plenum top with flanges to attach to baffle. In link above, honeycomb like material was used as core to add stiffness, with less plies. Weight, be aware to not over wet it. If you put peal ply on last ply this will reduce work after to make it smooth. (An option is vacuum bagging, which squeezes plies and extra resin out making it lighter with same or greater strength. Also heat blanket or lamps may be needed if in cold work shop.)

The inlets are made from foam plugs, (see links above). One way is total loss where you lay up on foam plug and cut the foam out (or dissolved with solvent). Another way is to make plug, than make mold (in two halves) from the plug. Then you lay up inside the mold which splits into two. This makes is so you can use the mold over again, to make more than one part. There are lots of YouTube videos on glass part making process... boats, custom motorcycle and car guys, do it all the time.

I'm using vans cowl and cutting the inlets in like the link above. Sam James is a champ and made me some pieces to splice in the cowl. My rings are from Dave Anders. Plenum will match the cowl (or vise a verse). It is a lot of work but will be a learning experience... If you screw the pooch just do it again. :eek:

Although this is not plenum making, Mr. Mike Arnold made the AR5 and in early 1990's made and held world record for very light aircraft for a decade or more (+213 MPH on 65 hp). He sadly passed a few years ago. However his family made his videos available for free on youtube, which were sold on video tape/CD at one time. He made his record breaking plane and later the Reno racer AR6 from mold-less process the AR5 ( and like a Long-EZ). These videos are pure genius and inspiration on what can be done with fiberglass and imagination. Here is a link to the channel. All videos are gold. The making the mold-less wheel pants is most accessible for making a plenum.

https://www.youtube.com/channel/UCVDILmX2ylWP1YLQmYi9nPw

Bottom line is buy some materials and practice on some small parts. You can buy cheaper polyester/vinylester resin and cloth from hardware store, auto parts or boat store to practice with. Epoxy (West system) is better stuff. NOTE RESINS IN GENERAL DON'T MIX AND SOME EAT PLEXIGLAS (YOUR CANOPY). Do some research, but Epoxy is what you want for all your actual parts. If you belong to EAA the local chapter might be a great place to start. Someone who has "done that been there" with fiberglass can speed up your learning curve and improve quality.... It makes it fun to have a helper... fiberglass can be done by one, but two people is often a good thing, when you have your gloves full of epoxy and need something. Also once done do not leave your epoxy in a cup any place.. it gets VERY HOT and you might want to put it outside to let it cure, unless you like fires in your workshop...Seriously epoxy gets hot if left in cup.
 
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Well I am psyched!! Bill emailed me and will be making me a plenum!! That's right I'm being a wuss and just buying one. I'm very appreciative to Bill for his hard work developing these and passing this beautiful product on to us newbies. Maybe if I build a second or 3rd plane I'll attempt some custom fiberglass stuff.
 
Trying not to be thin skinned here(don't have my flame suit on) but in my defense I am not done with the canopy or the cowling and have never done a lick of fiberglass work. Maybe by the time I am done doing the fiberglass on those 2 items I may want to attempt the plenum. Or if I can find a plenum like Bills that looks like a piece of art to me I would rather go that route and save some time. I am trying to get this thing in flying shape next year. Maybe I should have just scratch built a plane from plans. Then I can say I built everything on it!!

Well you're not really a builder until you smelt some aluminum from bauxite you pulled out of the ground yourself and form it into at least 50% of your structure :D

Glad you're getting your parts though, that's good news!
 
Oooo, that is pretty. Look at Bill's diffuser shapes, and the cored layup, and the flange attachment, and the.....

Whoops, sorry Krea, babbling again. The blue paint is nice too. ;)
 
Dan is definitely one of the glass masters around here, so you?ll have to just grin and bear it. However, it looks like you are a long way from needing a plenum, so take some time to read up on fiberglass. If you can whittle with a pocketknife and have ever played with paper machet, you?ve already learned enough to do fiberglass. I remade my leg fairings about 5 times now... each time I did it better and learned something new.. all were functional, and they were small enough that I didn?t feel like I wasted time or money on it.

I?m certainly not a master of the process... I was about where you are when I started, but I?m glad I took the time to do it myself.

Trying not to be thin skinned here(don't have my flame suit on) but in my defense I am not done with the canopy or the cowling and have never done a lick of fiberglass work. Maybe by the time I am done doing the fiberglass on those 2 items I may want to attempt the plenum. Or if I can find a plenum like Bills that looks like a piece of art to me I would rather go that route and save some time. I am trying to get this thing in flying shape next year. Maybe I should have just scratch built a plane from plans. Then I can say I built everything on it!!
 
SJC

Sam sends you the plans for the aluminum baffles real easy to make for the James plemums.
Bob
 
Well I am psyched!! Bill emailed me and will be making me a plenum!! That's right I'm being a wuss and just buying one. I'm very appreciative to Bill for his hard work developing these and passing this beautiful product on to us newbies. Maybe if I build a second or 3rd plane I'll attempt some custom fiberglass stuff.

I understand the time vs money argument and often take "the easy way out"... No judgement. That said, non structural composite work is not very difficult to learn, very forgiving of mistakes, and not expensive. Here's a thread I have going which shows some of my "self taught" composite work (starting on post # 18).

Simple enough for a caveman:

http://www.homebuiltairplanes.com/forums/showthread.php?t=26077&page=2

There is a TON of good info available to learn from on the web. Just buy some raw material and start making a mess!
 
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Thanks to everyone for all the information. Wow Gmcjetpilot that was quite the informative post! Bill just sent me all his photos, drawings and instructions. Amazingly detailed and I am now assured that getting his plenum is absolutely the right decision. I don't blame any of the guys who told me to just build one myself, but I'd like to get this thing flying so I can start enjoying trips to the Bahamas or hopefully fly to Alaska with Vlad before I'm too old!! It's all good!!
 
I don't blame any of the guys who told me to just build one myself, but I'd like to get this thing flying!

The statement ''Just build one" should have been followed by: "I'll be right over to help if you need it!" :D

-Marc
 
The statement ''Just build one" should have been followed by: "I'll be right over to help if you need it!" :D

-Marc

I envy guys that have a large local builders network. My tech counselor is an hour away and I only know of 1 other builder within 2 hours of me. He just started a 14A which I went with him to look at 3 hours away and he bought the kit. The nearest active EAA chapter is 2.5 hours away. Sometimes I feel like I am alone on an island, but then there is this oasis called VAF with the fantastic network of very smart and experienced help. There is NO way I would have attempted this project without it. That is why my donation was just sent in to Doug. Gotta keep this thing running!!
 
Bill, how much composite work had you done prior to technical research on diffusers, designing a plenum, building molds, and then teaching yourself the resin infusion process?

https://www.danhorton.net/Articles/1216_ResinInfused.pdf

Sorry for a delayed response, I spent all day with Kevin Hortons spreadsheets creating some tables for my POH. What a excellent process Kevin has developed.

To the question - not much on composite work prior to launching into the project. A few patches and micro for voids in the gel coats. I made a what-went-wrong list of issues for each failure and changed the process to address. The first plenum was botched and massively heavy, so it became a buck, the 2nd & 3rd were resin infusion failures with epoxy that was too viscous. Lots of study and reading . . . The 4th one was pretty good and resulted in a well documented process.

Bottom line, it is not hard, it just takes willingness to do it and have a plan for what is going to happen after the epoxy is mixed. Small experiments are extremely helpful to understand questions, and build confidence. The PTM&W technical guy was very helpful.

I am convinced that the process you and Pete Howell used to make the layup on top of the engine is the one-off way to go. A hand layup might be a little heavier, but not much. The inlets were based on some rough drawings and made in pink styrofoam. If I had used your process, instead of making a mold, things could have turned out differently.

I can understand why plenums are not really available. There are three engine widths, plus the 540, and each plane has a different cowl. Not much volume to support capital investment, not to mention the effort of obtaining dimension for all the above. Sams plenum (according to him) is a copy of Dave Anders early one for his RV4. This is why it looks like it does.

A gallon of HTR, 4 yrds of 8oz, some pink foam and guts is all it takes. Then add micro, some body work, and cool paint. Anyone can do it. And . . free advice right here on VAF.
 
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Sorry for a delayed response, I spent all day with Kevin Hortons spreadsheets creating some tables for my POH. What a excellent process Kevin has developed.

To the question - not much on composite work prior to launching into the project. A few patches and micro for voids in the gel coats. I made a what-went-wrong list of issues for each failure and changed the process to address. The first plenum was botched and massively heavy, so it became a buck, the 2nd & 3rd were resin infusion failures with epoxy that was too viscous. Lots of study and reading . . . The 4th one was pretty good and resulted in a well documented process.

Bottom line, it is not hard, it just takes willingness to do it and have a plan for what is going to happen after the epoxy is mixed. Small experiments are extremely helpful to understand questions, and build confidence. The PTM&W technical guy was very helpful.

I am convinced that the process you and Pete Howell used to make the layup on top of the engine is the one-off way to go. A hand layup might be a little heavier, but not much. The inlets were based on some rough drawings and made in pink styrofoam. If I had used your process, instead of making a mold, things could have turned out differently.

I can understand why plenums are not really available. There are three engine widths, plus the 540, and each plane has a different cowl. Not much volume to support capital investment, not to mention the effort of obtaining dimension for all the above. Sams plenum (according to him) is a copy of Dave Anders early one for his RV4. This is why it looks like it does.

A gallon of HTR, 4 yrds of 8oz, some pink foam and guts is all it takes. Then add micro, some body work, and cool paint. Anyone can do it. And . . free advice right here on VAF.

My second plenum was too heavy, but everything else was right and I'm still using it! Well, after I modified the front end again.......it's just fiberglass.
 
A gallon of HTR, 4 yrds of 8oz, some pink foam and guts is all it takes. Then add micro, some body work, and cool paint. Anyone can do it. And . . free advice right here on VAF.
Ha ha ha ha...

Bill I tried to send PM but your inbox is full. Sent email. Hope you get it. Thanks
 
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Sam sends you the plans for the aluminum baffles real easy to make for the James plemums.
Bob

Maybe my engine setup was different but the baffle templates I got with mine were not much help. There were some big differences in what mine needed. YMMV.
 
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