Subaru carb heat

[marshawk 82]

Just wondering if you guys that are running the Subaru's have carb heat on them,if so if you have a picture of your setup that would be great .

Thanks

[SuberAvid 617]

Hi Willis,

I decided to run carb heat on mine and spent quite a bit of time setting it up. That said; in a year + of flying from 70 degrees in summer to -25 degrees in winter and some 30's to 40's degrees in rain I have yet to need it. I think the fact that the airboxes are inside the cowl make the intake air warm enough that it will rarely be needed. I have about decided to add NACA air inlets for outside air to the airboxes to get cold intake air and will probably need the carb heat then.

I used separate carb heat/air boxes; one for each carb and used a cable splitter box to run the separate cables from one push/pull knob. I added the 2.75" flanges to fit the air filters and fabricated the cable clamps to hold the cable housings at the gate lever. I built the heat muff on the exhaust pipe and used 2" scat hose from the heat muff to the carb heat/air boxes and from the boxes to the carbs. The pics are attached.

[marshawk 82]

Hi Willis,

I decided to run carb heat on mine and spent quite a bit of time setting it up. That said; in a year + of flying from 70 degrees in summer to -25 degrees in winter and some 30's to 40's degrees in rain I have yet to need it. I think the fact that the airboxes are inside the cowl make the intake air warm enough that it will rarely be needed. I have about decided to add NACA air inlets for outside air to the airboxes to get cold intake air and will probably need the carb heat then.

I used separate carb heat/air boxes; one for each carb and used a cable splitter box to run the separate cables from one push/pull knob. I added the 2.75" flanges to fit the air filters and fabricated the cable clamps to hold the cable housings at the gate lever. I built the heat muff on the exhaust pipe and used 2" scat hose from the heat muff to the carb heat/air boxes and from the boxes to the carbs. The pics are attached.

Thanks for the reply Randy,nice job on the airboxes. My setup is a little different. I just have one Throttle body Injection carb that I just bought that sits in the center of the intake.The problem I am running into is I only have about 1 1/2" clearance from the top cowling.I probably have enough room for a k+n air filter but building an airbox would diffently be tight. I was told because the TBI is sitting on top of the intake that there should be enough heat off the

engine to prevent iceing but just looking for any advice.

Thanks Again

[EDMO 1078]

Thanks for the reply Randy,nice job on the airboxes. My setup is a little different. I just have one Throttle body Injection carb that I just bought that sits in the center of the intake.The problem I am running into is I only have about 1 1/2" clearance from the top cowling.I probably have enough room for a k+n air filter but building an airbox would diffently be tight. I was told because the TBI is sitting on top of the intake that there should be enough heat off the

engine to prevent iceing but just looking for any advice.

Thanks Again

Don't know if it will fit your throttle body, unless it is same size as a Holly 2 brl: I read in Mick Myal's book, (I think), that a Chrysler / Dodge / Horizon? carb intake cover with the snout on it, can be cut down to about one inch or less in height, and the heat tube connected under the bottom of it. It said that the filter is in the snout? again, can't verify this until I go back and check the book.

Mine has a slightly different setup, and not sure what it is. I could check dimensions and get photos later on if really needed to help you. Don't know how you would shut off heat with the Horizon setup, unless you built a box under the cover or made a sliding valve setup. On second thought, My old machinist wheels turn slow, I worked for Chrysler from 65 til 91, and remember some of those snouts had heat riser tubes on the bottom and a flap controlled by a thermostat. Try scrounging the junk yards for one.

Hope this helps some.

Ed in MO - Reductions EA81 in Highly Modified Kitfox Clone

Edited 9 Mar 2012 by Ed In Missouri

[EDMO 1078]

Hi Willis,

I decided to run carb heat on mine and spent quite a bit of time setting it up. That said; in a year + of flying from 70 degrees in summer to -25 degrees in winter and some 30's to 40's degrees in rain I have yet to need it. I think the fact that the airboxes are inside the cowl make the intake air warm enough that it will rarely be needed. I have about decided to add NACA air inlets for outside air to the airboxes to get cold intake air and will probably need the carb heat then.

I used separate carb heat/air boxes; one for each carb and used a cable splitter box to run the separate cables from one push/pull knob. I added the 2.75" flanges to fit the air filters and fabricated the cable clamps to hold the cable housings at the gate lever. I built the heat muff on the exhaust pipe and used 2" scat hose from the heat muff to the carb heat/air boxes and from the boxes to the carbs. The pics are attached.

Is that a Stratus EA81? Are those the rads that Stratus supplies? How much does he charge if sold seperately? Can you measure them for me?

I still don't know if I want some like that or stick with my Rabbit rad? Probably flight testing, if I ever get there, will tell.

Thanks, Ed in MO Reductions EA81

[marshawk 82]

Don't know if it will fit your throttle body, unless it is same size as a Holly 2 brl: I read in Mick Myal's book, (I think), that a Chrysler / Dodge / Horizon? carb intake cover with the snout on it, can be cut down to about one inch or less in height, and the heat tube connected under the bottom of it. It said that the filter is in the snout? again, can't verify this until I go back and check the book.

Mine has a slightly different setup, and not sure what it is. I could check dimensions and get photos later on if really needed to help you. Don't know how you would shut off heat with the Horizon setup, unless you built a box under the cover or made a sliding valve setup. On second thought, My old machinist wheels turn slow, I worked for Chrysler from 65 til 91, and remember some of those snouts had heat riser tubes on the bottom and a flap controlled by a thermostat. Try scrounging the junk yards for one.

Hope this helps some.

Ed in MO - Reductions EA81 in Highly Modified Kitfox Clone

Thanks For the info Ed, I really appreciate all the input.I would have to modify the way the k+n filter would attach to the TBI .If you have a picture of your set up I would diffently like to see it if you get a chance. This is all new to me but I am lucky to have a friend thats a pretty good mechanic but this is the first aircraft we are building. Do you have carb heat on your Kitfox and how do you like the performance of the soob in it. I will be looking at the local wreckers for a intake cover that may work better.

Thanks again

[SuberAvid 617]

Is that a Stratus EA81? Are those the rads that Stratus supplies? How much does he charge if sold seperately? Can you measure them for me?

I still don't know if I want some like that or stick with my Rabbit rad? Probably flight testing, if I ever get there, will tell.

Thanks, Ed in MO Reductions EA81

Hi Ed,

It's a Stratus EA81 but the rads I got from RAM Performance. I think they were the only set he had made because the cost was to much ($700) and he didn't think he could market them. You could probably have a set custom made but it is definately cheaper to go with a single radiator. I just wanted to keep the radiators in the cowl rather than underneath. I think they are 5" wide x 7" tall by 2" deep. One of them has the radiator cap and overflow tube in it so you don't have to use a separate swirl bottle.

Randy

[EDMO 1078]

Thanks For the info Ed, I really appreciate all the input.I would have to modify the way the k+n filter would attach to the TBI .If you have a picture of your set up I would diffently like to see it if you get a chance. This is all new to me but I am lucky to have a friend thats a pretty good mechanic but this is the first aircraft we are building. Do you have carb heat on your Kitfox and how do you like the performance of the soob in it. I will be looking at the local wreckers for a intake cover that may work better.

Thanks again

I wish mine was flying - unfortunately, I am doing my second build on the same fuselage and wings, with lots of modifications. Got wrecked after first build without ever starting the engine. (long story)

I have read and talked to flyers with the Soob - most love it because of the reliability, and costs. The insurance companies like it too.

Some say it is too heavy if you add floats - others say it won't climb with a 912, but will ourcruise it. Maybe the prop has something to do with that. Current flyers like Suberavid might give you better feedback.

I sacraficed HP for dollars, and got a deal on a Reductions 81, instead of buying a Stratus with more HP for more $.

I will just be happy to get back into the air, even if a J3 outclimbs and outruns my Foxy!

Always glad to be able to help anyone building. Let me know if you can't work something out on the airbox.

Ed in MO

[EDMO 1078]

Hi Ed,

It's a Stratus EA81 but the rads I got from RAM Performance. I think they were the only set he had made because the cost was to much ($700) and he didn't think he could market them. You could probably have a set custom made but it is definately cheaper to go with a single radiator. I just wanted to keep the radiators in the cowl rather than underneath. I think they are 5" wide x 7" tall by 2" deep. One of them has the radiator cap and overflow tube in it so you don't have to use a separate swirl bottle.

Randy

Thanks for the info Randy. I thought that all Stratus engines came with the twin AC condensers. Maybe not?

I have lots of book info on them, but was curious if Stratus sold them seperately or what the price would be. Guess I should contact them.

Donno which way I will go yet. Depends on how things get setup on mine, and of course, prices.

Ed in MO

[SuberAvid 617]

Thanks for the info Randy. I thought that all Stratus engines came with the twin AC condensers. Maybe not?

I have lots of book info on them, but was curious if Stratus sold them seperately or what the price would be. Guess I should contact them.

Donno which way I will go yet. Depends on how things get setup on mine, and of course, prices.

Ed in MO

Hi Ed,

I don't think Stratus sells radiators; just the engines, redrives, exhaust, prop extensions as complete packages or parts. I just ordered a short prop extension for mine this week from Mykal at Stratus. I am putting on the IVO and find that I can change my 4" prop extension to a 2.5" and also switch out the 1.25" spacer that comes with the IVO to a 3/8" spacer to get teh prop back tight to the cowling.

I contemplated using the heater cores but heard that they do not transfer the hear as well because the air flow through them is much more restricted. The other part I didn't like was that I could not find any with 3/4" inlets and outlets, they all seemed to restric the outlets. I think the only way to know for sure would be to try them and I didn't so if you use them you will have to report how they work.

Randy