KiloWhiskey1
Well Known Member
Here is my last pic of the scoop. I will post another when I put the prop back on.
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Van's Air Force
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Tip: Ram Air Cowl Mod Part 1
- Thread starter KiloWhiskey1
- Start date
KiloWhiskey1
Well Known Member
Ram Air Cowl Mod Part 2
The Next step was to lay up some fiberglass layers over the mesh. I used four layers on the outside of the cowl. Not too pretty, but this will get filled and sanded later.
Here is a shot from the inside. I finished cutting the cowl opening in a circle to meet up with the edges of the mesh screen that was attached earlier on the outside. The cut can be made only after the outside fiberglass layers dry. The outside fiberglass provides the structural support for the scoop. After the inside cut was made, I applied two layers of fiberglass to the inside. This makes a total of six layers and is very strong.
After a healthy supply of Superfil and quite a bit of sanding I ended up with a nice looking scoop.
This picture shows the rubber fitting that is attached to the cowl's new intake scoop.
Here is how the two rubber pieces fit together. Perfecto! The fitting that attaches to the valve is 3.5? on the valve end and 4? on the open end, while the rubber fitting that attaches to the aluminum intake ring and cowl is 3? and 3.5? on opposing ends. The rubber attached to the cowl needs to be trimmed to slide into the 4? opening of the rubber on the ram air valve. I hope that makes sense.
Tada! Here it is, primed and ready for flight. I am very pleased with the way the cowl turned out. Hopefully it will provide a little extra manifold pressure while providing a good alternate air source. I don?t have a good picture of the alternate air side of the valve, however it looks identical to the ram air inlet. The alternate air inlet will be covered with screen that is secured with a hose clamp. Some people have used filters; however the fit for my application is too tight for any filter that I have seen. All in all, this mod took about three days of work to complete (minus the priming). Most of the time was spent sanding and waiting for epoxy or filler to dry (actual work was probably no more than eight hours). I have not installed one of Van's intake systems, but I understand that they can be challenging. In comparison, my cowl mod required a lot of thinking and re-thinking for planning as well as some guts to start cutting a big hole in the cowl. The skills that are required are basic fiberglass skills and some patience with filling and sanding until you get the result that you want.
The Next step was to lay up some fiberglass layers over the mesh. I used four layers on the outside of the cowl. Not too pretty, but this will get filled and sanded later.
Here is a shot from the inside. I finished cutting the cowl opening in a circle to meet up with the edges of the mesh screen that was attached earlier on the outside. The cut can be made only after the outside fiberglass layers dry. The outside fiberglass provides the structural support for the scoop. After the inside cut was made, I applied two layers of fiberglass to the inside. This makes a total of six layers and is very strong.
After a healthy supply of Superfil and quite a bit of sanding I ended up with a nice looking scoop.
This picture shows the rubber fitting that is attached to the cowl's new intake scoop.
Here is how the two rubber pieces fit together. Perfecto! The fitting that attaches to the valve is 3.5? on the valve end and 4? on the open end, while the rubber fitting that attaches to the aluminum intake ring and cowl is 3? and 3.5? on opposing ends. The rubber attached to the cowl needs to be trimmed to slide into the 4? opening of the rubber on the ram air valve. I hope that makes sense.
Tada! Here it is, primed and ready for flight. I am very pleased with the way the cowl turned out. Hopefully it will provide a little extra manifold pressure while providing a good alternate air source. I don?t have a good picture of the alternate air side of the valve, however it looks identical to the ram air inlet. The alternate air inlet will be covered with screen that is secured with a hose clamp. Some people have used filters; however the fit for my application is too tight for any filter that I have seen. All in all, this mod took about three days of work to complete (minus the priming). Most of the time was spent sanding and waiting for epoxy or filler to dry (actual work was probably no more than eight hours). I have not installed one of Van's intake systems, but I understand that they can be challenging. In comparison, my cowl mod required a lot of thinking and re-thinking for planning as well as some guts to start cutting a big hole in the cowl. The skills that are required are basic fiberglass skills and some patience with filling and sanding until you get the result that you want.
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KiloWhiskey1
Well Known Member
Ram Air Cowl Mod Part 1
This first picture is my starting point. Under the cowl is an IO-360-M1B with a horizontal sump. The engine was built at Don?s Dream Machines in Griffin, GA and has 9.5-1 pistons, dual Lazers and 4 in to 1 exhaust. I purchased a ram air/alternate air valve from Airflow Performance in Greeneville, SC. Now it is time to modify the cowl to allow for the ram air induction to work with the horizontal intake.
Here is a picture of the ram air valve with a pliable rubber fitting installed on the end. Ultimately the rubber fitting will mate with another smaller male fitting that is attached to the aft portion of the cowl air intake inlet. The rubber fittings were purchased at Pep Boys. The smaller fitting slides into the larger fitting and creates a very nice seal and transition that requires no clamps or other means of securing together. This is important because you need a way to get the cowling on and off easily. With this setup you simply fit the two rubber pieces together while you are attaching the bottom cowl.
The first step in the process is to cut a hole that allows the cowling to fit around the ram air valve. The hole needs to be large enough to allow for the valve mechanism to move freely. Additionally the hole is cut in an asymmetrical fashion to allow room for the alternate air valve which protrudes from the ram air valve at a 45 degree angle.
I purchased this intake scoop kit from the Holy Cowl folks. This picture was taken after I cut a portion of each side off. I also installed the aluminum intake ring prior to snapping this photo. The ring and flox come with the kit. You simply cut the hole and insert the ring. The intake ring is permanently set in place with a thick epoxy/flox mixture. I used five minute epoxy so I could get on with the project.
Next I attached the scoop to the cowl with epoxy. I used liberal amounts of epoxy on all contact points. The scoop and the cowl will require additional cuts at a later point. Of special note, I clamped a piece of sheet aluminum to the forward face of the cowling, so that I could get the scoop set in perfect alignment.
Here you can see that the aft portion of the scoop has been cut off. I used a die grinder with a fresh blade to make these cuts. This picture also shows the mesh that I used to create the contour and smooth transition between scoop and cowl. The material is screened window mesh. You can purchase aluminum or fiberglass screen (Home Depot or Lowes). I used aluminum in order to hold the contours better. I would probably use fiberglass if I had the choice again. The aluminum ends can stick up and poke through your fiberglass layers and your filler. No big deal, but it is something to consider. As you can see, I used clecos to shape the mesh to the desired contour. After I got the shape that I liked, I cut the excess away.
Here I used a thick bead of epoxy to attach the mesh to the scoop and cowl. If you look closely you can see a black Sharpie line, just inboard of the epoxy, the line was used to space out clecos to mark the outer edges for the epoxy bond. The clecos remained until the epoxy was dry.
This first picture is my starting point. Under the cowl is an IO-360-M1B with a horizontal sump. The engine was built at Don?s Dream Machines in Griffin, GA and has 9.5-1 pistons, dual Lazers and 4 in to 1 exhaust. I purchased a ram air/alternate air valve from Airflow Performance in Greeneville, SC. Now it is time to modify the cowl to allow for the ram air induction to work with the horizontal intake.
Here is a picture of the ram air valve with a pliable rubber fitting installed on the end. Ultimately the rubber fitting will mate with another smaller male fitting that is attached to the aft portion of the cowl air intake inlet. The rubber fittings were purchased at Pep Boys. The smaller fitting slides into the larger fitting and creates a very nice seal and transition that requires no clamps or other means of securing together. This is important because you need a way to get the cowling on and off easily. With this setup you simply fit the two rubber pieces together while you are attaching the bottom cowl.
The first step in the process is to cut a hole that allows the cowling to fit around the ram air valve. The hole needs to be large enough to allow for the valve mechanism to move freely. Additionally the hole is cut in an asymmetrical fashion to allow room for the alternate air valve which protrudes from the ram air valve at a 45 degree angle.
I purchased this intake scoop kit from the Holy Cowl folks. This picture was taken after I cut a portion of each side off. I also installed the aluminum intake ring prior to snapping this photo. The ring and flox come with the kit. You simply cut the hole and insert the ring. The intake ring is permanently set in place with a thick epoxy/flox mixture. I used five minute epoxy so I could get on with the project.
Next I attached the scoop to the cowl with epoxy. I used liberal amounts of epoxy on all contact points. The scoop and the cowl will require additional cuts at a later point. Of special note, I clamped a piece of sheet aluminum to the forward face of the cowling, so that I could get the scoop set in perfect alignment.
Here you can see that the aft portion of the scoop has been cut off. I used a die grinder with a fresh blade to make these cuts. This picture also shows the mesh that I used to create the contour and smooth transition between scoop and cowl. The material is screened window mesh. You can purchase aluminum or fiberglass screen (Home Depot or Lowes). I used aluminum in order to hold the contours better. I would probably use fiberglass if I had the choice again. The aluminum ends can stick up and poke through your fiberglass layers and your filler. No big deal, but it is something to consider. As you can see, I used clecos to shape the mesh to the desired contour. After I got the shape that I liked, I cut the excess away.
Here I used a thick bead of epoxy to attach the mesh to the scoop and cowl. If you look closely you can see a black Sharpie line, just inboard of the epoxy, the line was used to space out clecos to mark the outer edges for the epoxy bond. The clecos remained until the epoxy was dry.
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KiloWhiskey1
Well Known Member
Dan,
Here is some info on item #s and places to find most of the parts that I used.
The alternate air valve can be found here. The picture below came from Dan Checkoway's rvproject.com site (I hope Dan doesn't mind). My valve has two gates so that when the ram air is open the alternate is fully closed and visa-versa. The price is in the $150-$200 ranger. They also sell a nice mounting ring adaptor that helps mate the valve to the throttle body. Here is the contact info:
AIRFLOW PERFORMANCE, INC.
111 Airflow Drive Spartanburg, 29306
Phone: (864) 576-4512
Fax: (864) 576-0201
E-mail: [email protected]
http://www.airflowperformance.com/
PART # DESCRIPTION APPLICATION
3010067 FM-100 Alternate Air Duct Assembly FM-100 Fuel Controllers
3020053 FM-200 Alternate Air Duct Assembly FM-200 Fuel Controllers
3020053-L FM-200 Alternate Air Duct Assembly-Long FM-200 Fuel Controllers
The Rubber couplers can be purchased at Pep Boys.
The parts are made by Spectre Industries. Here are the part numbers:
Power Adder 9741 (4" to 3.5" $12.99)
Power Adder 9761 4" to 3" $12.99)
Power Adder 9741 (3" to 2.5" $5.99)
They have many product options. Here is a link to Spectre's website and to one of the couplers. http://spectreperformance.com/#CATALOG.9741
The intake scoop was purchased through James Aircraft. The scoop was about $50 and the aluminum ring was $75. Here is their info:
Will James
James Aircraft Division 1, Inc.
178 East 10th Way
Greenville, FL 32331
850-342-9929
850-545-5862 cell
http://www.jamesaircraft.com/About_Us.html
I hope this helps.
Keith
Here is some info on item #s and places to find most of the parts that I used.
The alternate air valve can be found here. The picture below came from Dan Checkoway's rvproject.com site (I hope Dan doesn't mind). My valve has two gates so that when the ram air is open the alternate is fully closed and visa-versa. The price is in the $150-$200 ranger. They also sell a nice mounting ring adaptor that helps mate the valve to the throttle body. Here is the contact info:
AIRFLOW PERFORMANCE, INC.
111 Airflow Drive Spartanburg, 29306
Phone: (864) 576-4512
Fax: (864) 576-0201
E-mail: [email protected]
http://www.airflowperformance.com/
PART # DESCRIPTION APPLICATION
3010067 FM-100 Alternate Air Duct Assembly FM-100 Fuel Controllers
3020053 FM-200 Alternate Air Duct Assembly FM-200 Fuel Controllers
3020053-L FM-200 Alternate Air Duct Assembly-Long FM-200 Fuel Controllers
The Rubber couplers can be purchased at Pep Boys.
The parts are made by Spectre Industries. Here are the part numbers:
Power Adder 9741 (4" to 3.5" $12.99)
Power Adder 9761 4" to 3" $12.99)
Power Adder 9741 (3" to 2.5" $5.99)
They have many product options. Here is a link to Spectre's website and to one of the couplers. http://spectreperformance.com/#CATALOG.9741
The intake scoop was purchased through James Aircraft. The scoop was about $50 and the aluminum ring was $75. Here is their info:
Will James
James Aircraft Division 1, Inc.
178 East 10th Way
Greenville, FL 32331
850-342-9929
850-545-5862 cell
http://www.jamesaircraft.com/About_Us.html
I hope this helps.
Keith
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KiloWhiskey1
Well Known Member
Thanks
Walter,
Thanks for the compliment. Outside of the panel, this was the most significant departure from the norm that I have made. It is also the project that I am most proud of. For what ever reason, I was afraid to tackle this at first and almost hired it out. I have learned that the unique challenges seem to be the most fun in the end.
Thanks again,
Keith
Walter,
Thanks for the compliment. Outside of the panel, this was the most significant departure from the norm that I have made. It is also the project that I am most proud of. For what ever reason, I was afraid to tackle this at first and almost hired it out. I have learned that the unique challenges seem to be the most fun in the end.
Thanks again,
Keith
KiloWhiskey1
Well Known Member
Results after 80 hours of flight time
Here is a final picture of the ram air inler after paint. I have flown off about 80 hours and I mainly keep the ram air open. On the way back from Oshkosh I cycled the valve several times at different altitudes. Each cycle resulted in a difference of roughly .5" to 1" of manifold pressure. The alternate air source has no screen or filter at the present time. It simply draws air from inside the lower cowl. I plan to add a screen but haven't done so yet.
Here is a final picture of the ram air inler after paint. I have flown off about 80 hours and I mainly keep the ram air open. On the way back from Oshkosh I cycled the valve several times at different altitudes. Each cycle resulted in a difference of roughly .5" to 1" of manifold pressure. The alternate air source has no screen or filter at the present time. It simply draws air from inside the lower cowl. I plan to add a screen but haven't done so yet.
db1yg
Well Known Member
Hi Keith,
Nice job!!
A couple of questions. What is the O.D. of the alternate air valve from AFP? I am hoping it is 3 inches for 3 inch scat/sceet. Also, how long is the unit?
I am trying to fab an improved alternate air/carb heat system for my James cowl equiped carbed 0360 in my 9a and want to use this valve if it would fit. Also do you have the part number?
Thanks and again--great job!
Cheers,
db
Nice job!!
A couple of questions. What is the O.D. of the alternate air valve from AFP? I am hoping it is 3 inches for 3 inch scat/sceet. Also, how long is the unit?
I am trying to fab an improved alternate air/carb heat system for my James cowl equiped carbed 0360 in my 9a and want to use this valve if it would fit. Also do you have the part number?
Thanks and again--great job!
Cheers,
db
KiloWhiskey1
Well Known Member
Size of air valve
Dave,
The OD of the air valve is 3.5". The valve itself is 6.5" long. They also make a 8.5" valve/
The ordering info for the vavle is:
AIRFLOW PERFORMANCE, INC.
111 Airflow Drive Spartanburg, 29306
Phone: (864) 576-4512
PART # DESCRIPTION APPLICATION
3020053 FM-200 Alternate Air Duct Assembly FM-200 Fuel Controllers
I hope this is helpful.
Keith
Dave,
The OD of the air valve is 3.5". The valve itself is 6.5" long. They also make a 8.5" valve/
The ordering info for the vavle is:
AIRFLOW PERFORMANCE, INC.
111 Airflow Drive Spartanburg, 29306
Phone: (864) 576-4512
PART # DESCRIPTION APPLICATION
3020053 FM-200 Alternate Air Duct Assembly FM-200 Fuel Controllers
I hope this is helpful.
Keith
