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Rod Bower?s Air Induction System (with pics)

AX-O

AX-O

Well Known Member
All,
Just wanted to give you some feedback on the Rod Bower http://www.ramairforhomebuilts.com/contactus.htm. I contacted him and told him I was interested on fitting his system on my RV-4 (narrow deck IO-320). He said we could give it a try. I drove 3.5 hours to Visalia, CA to see him. I took my FM-100 fuel meter, my lower SJ cowling and my Superior cold air sump. I met Rod and a couple of his buds (good guys). We started looking at possibilities for the installation. Some of the existing parts he had would not work with my fuel meter. After unsuccessfully trying to find an air filter that would work without mods he decided the best thing to do would be to make an adapter. The adapter fits the current filter then reduces the ID to fit the fuel servo. We cut the cowling then he gave me 2 different units so I could play with them at home. BTW he did not take a dime. Then I drove 3.5 hours back home.

Yesterday, the adaptor showed up (he had to fabricate it). I fitted the system in about 4 hours (still have lots of glass work on the cowl). The only thing that did not go as plan was the bracket that holds the alternator. It was just a bit too long and kept the induction system from fitting nicely in its location. I called Rod and told him about it. He told me the same thing happen with his RV-8. So I carefully filled the alternator bracket. Here are some pics of the current installation. The system in these pictures is missing a couple of parts. I am really excited about this mod. I hope between the cold air sump and this induction system, I get better performance. I am trying to figure out how far forward to mount the intake ring. I think if I move it flush with the front of the cowling, I will get better MP. Figure that out later.

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Inlet radius

Need to put a radius on the tube that sticks out from the cowl. 1/4-1/2 inch radius will do. You will get a lot of loss and turbulence with the sharp edge of the tube.

Don
 
Don,
The tube is there only to hold the scoop in the correct location in relation to your fuel meter. That way I can move the scoop forward or aft and know that I am lined up. The connection from the scoop to the fuel meter will be made out of wet suit material. An aluminum ring (with radius) will be attached to the front of the scoop. Thanks for telling us about the potential for losses.

Do you know what would work best? Leaving the scoop were it is in the picture or moving the scoop forward so it will be flush with the front of the cowling.

Thanks for any help or guidance.
 
Axle, I put Rod's system on my 7 and I have the intake lip about 1/2" back from the front of the cowl. I get 1 3/4" more MAP from filtered to ram air. I adapted his 8 intake scoop to my 7 and it was not all that much work with great results. Don
 
Rod Bower

Rod is in declining health and is not actively supporting his business at this time.

HFS
 
Does anyone have a picture of Rod's RV8 in military green that he built many years ago? It was just amazing!!! and for sale at the time. I think it ended up in Australia.
 
I have molds to make fiberglass copies of some of the Bower system components, with some differences.

Rather than have the filtered intake come in through reed-valve flaps on the outer chamber, I made a duct to go up to the left cooling intake ramp. The fiberglass chamber could be fitted with the reed valves, but I think that is less desirable.

The fiberglass parts to form the chamber for the conical K&N filter are what I have the molds for. To roll your own, you would have to make an adapter to connect the chamber to your fuel servo, and the butterfly valve that goes in front of the chamber to open the center to ram intake.

We might be persuaded to machine those parts if there was some demand.
 
Sorry to hear about Rod's health.

Anyone have a source for the UHMW plastic he used? He would send me some every few years. He told me he gets it in large rolls. Should have asked him more details when I had the chance.
 
gasman said:
Does anyone have a picture of Rod's RV8 in military green that he built many years ago? It was just amazing!!! and for sale at the time. I think it ended up in Australia.
Click to expand...

I’m pretty sure it’s still at YWBN.
I have some pics I took a while ago, 2010. I’ll take a look for them
Nice plane.
Google VH-KVI
 
Dead Grass Award

I tool a picture of the ground around the plane after Rod left, framed it, and gave it to him - as the "Dead Grass Award" for that year. 2008? (Maybe).

HFS
 
Richard Connell said:
I’m pretty sure it’s still at YWBN.
I have some pics I took a while ago, 2010. I’ll take a look for them
Nice plane.
Google VH-KVI
Click to expand...

If you get another chance to see this aircraft, take a close look at the rivets. When Rod brought it to Oshkosh he showed me the rivets on the wing and said that before he paints one of his planes, he squeegees tank sealant over the rivets, then immediately try's to wipe all of it off with solvent?? can't remember what it was. The results was each head was sealed and the paint had a solid surface to adhere to. But the rivets were still very visible but a prefect fit. It sure looked good back then. I think that was 2008.
 
Rodney's Stewart S-51

If you liked his -8, you should have seen his S-51!

An OSH winner for sure - if it ever gets there.

Phase 1 flown off & being offered for sale.

YMMV - but it won't look as good as this!

HFS
 
Rod's Stewart S-51 - Pic

From Trade-a-Plane:

Elliot Seguin, noted test pilot and Reno racer flew off the Phase 1 time.

HFS
 

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HFS said:
I tool a picture of the ground around the plane after Rod left, framed it, and gave it to him - as the "Dead Grass Award" for that year. 2008? (Maybe).

HFS
Click to expand...

Hummmmm i know a dead grass award a certain RV should have won in 2022.

Break

Someone contacted me asking for Rod’s number. I dont have it. Also, i dont have his system installed any longer. I rolled my own.
 
AX-O said:
Hummmmm i know a dead grass award a certain RV should have won in 2022.
.
Click to expand...

Yes! Sorry for the thread drift, but the RV-15 probably won the dead grass award for all time. They will retire the award after that! And deservedly so!!
 
Regarding the Rod Bower reed valves: I bought several varieties of plastic binders from Office Depot to make replacement reed valves. I found the 0.7 mm thickness work best. They have lasted 4 years so far and seem to work well. Go to the store armed with your micrometer!
 
I may be wrong (and usually am) but ...

I think there may be two sizes, depending on whether you have a 4 or 6 cylinder system.

HFS
 
HFS said:
I may be wrong (and usually am) but ...

I think there may be two sizes, depending on whether you have a 4 or 6 cylinder system.

HFS
Click to expand...

I don’t know definitely, but I don’t recall seeing two can sizes. You can use the link in #23 to look at Rod’s site from an archive.

Or you can measure your filter and compare it to the filter in the previous post. That one fits the unit in my Rv-10. If yours is a different size, then you just have to find the correct size k&n filter.

K&N filters are available from numerous sources. They aren’t hard to find.
 
On my Bower system the number of the K&N filter was written with a felt maker on the outside. You have to cut the rubber end out of the replacement filter media but that's easy.

-Marc
 
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HFS said:
I may be wrong (and usually am) but ...

I think there may be two sizes, depending on whether you have a 4 or 6 cylinder system.

HFS
Click to expand...

This seems to be true. At least in the early first generation intakes. Gene Evans gave me one that he had so I can reverse-engineer it.. It was for a Rocket, and it has an RU-3600, noticeably bigger than the RU-4250.

Both are 5" long.

This was an early intake that had the bypass duct for filtered air that takes air from a window in the ram air duct ahead of the butterfly valve and brings it to the filter housing. An advantage of this scheme was that there was no reverse circulation through the filter when the ram air butterfly is open. A disadvantage is that it makes the assembly much longer, won't fit in a standard Vans cowl. It would fit in a Sam James or an extended Vans cowl that requires a prop extension.

When I looked at my housing, I think it was only 4.5" long, raising the possibility of a third size? When I get home from the Reno Air Races, I will disassemble mine and measure.

My hope/plan is to offer the ram-air butterfly valve installed on the filter canister, with filter and intake adapter for RSA5 and FM150, and leave it to the builder to install one of three concepts for supplying alternate air to the filter. 1) bypass duct from the ram air duct, 2) a snorkel bringing air from the upper cooling plenum, 3) reed valves in the filter canister.

I personally do not like option 3, as it brings air from the lower cowl plenum, which is warm and lower pressure. But that is the configuration of the later Bower systems. I currently have option 2 on my RV8, and I have 1/2" lower MAP on alternate filtered air than ram air. Part of that loss is through the filter, and part of it through the lack of full ram recovery in the upper cowl plenum and losses through the snorkel. I do not have a well-designed intake for the snorkel--it is just a flanged tube attached to the front cooling ramp, with sharp corners. a radiused lip, or even a small scoop might increase MAP some. Note also that with this scheme, there is probably some loss of MAP when on RAM air, because reverse flow can go out through the filter and through the snorkel up into the cooling plenum, if the pressure is substantially lower there. Honestly I think this is a very small effect.

Stay tuned this winter as I work on getting the parts made to re-introduce the system.
 
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