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Fred.Stucklen(at)UTCPower
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 Posted: Wed Jul 23, 2008 5:11 am Post subject: Throttle/Mixture bracket Vertical Draft IO-360 RV-7A |
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Just to get this into the Archives, here's what is needed for an IO-360 vertical induction system on an RV-7A with a Bendix or Silver Hawk fuel body.
Both cables go through the firewall just below the centrally located firewall heater box. Both firewall holes are located directly behind their respective cable mounting holes on the bracket when it's installed between the fuel body and the engine sump. The throttle cable will enter the cabin area through a grommet in the cover in that area. The mixture cable will penetrate the lower portion of the heater box panel (but under the enclosed heater box) and will require a cable grommet. The cables cross over inside the cockpit if they are horizontally located on the sub panel. The mixture cable is a tad long, but the next shorter cable is too short.
This list assumes the use of a Bendix or Silver Hawk Fuel body.
CT BLK THROTTLE 44.5 Throttle Cable, 44.5"
CT RED VMIXTURE 50.5 Mixture Cable 50.5"
VA-182-PC KIT Bracket IO-320/360/540 Vertical Induction
FAB-360/540 O-360/540 Vertical Draft
The next step is to mount the airbox. The Airbox comes with a bracket that allows the fuel body mixture arm to move below the plane of the airbox top surface. I personally think that this overly complicates the airbox construction. I'm planning on putting a 3/4" Delron spacer between the bottom of the fuel body and the Airbox to allow for free movement of the mixture arm with no airbox modifications. There appears to be 10.25 " between the inside surface of the lower cowl just under the airbox, to the bottom surface of the of the sump where the fuel body mounts. The total height of the airbox, spacer, and fuel body, is only 9.25", leaving a inch clearance between the lower surface of the bottom surface of the airbox and the cowl. The airbox also easily clears the nose wheel gear leg. I've seen this done on other RV-7A aircraft, and it seems to work out OK with the interface to the lower cowl snout.
I still have a question as to what to do about an alternate fuel body air source. There has been documented instances of the air filter becoming clogged with snow. Van came out with an alternate air source fix that takes the lower cowl air directly into the fuel body, bypassing the filter. This certainly qualifies as a solution, but it doesn't prevent filter blockage from occurring (like the Carb Heat flap control on carbureted systems can do). When I fly serious IFR in heavy rain or snow, I think it's prudent to keep as much of that precipitation out of the air box, and air filter, as possible. Van's alternate air fix should be used as a last resort, while the Carb Heat solution would be used as the first line of defense. So, I thinking that it would be prudent to have both controls, but not necessarily heated air into the Carb Heat type flapper control.....
Another issue for an IFR RV Aircraft is the current design of the tank vents. It does not meet my requirements of system redundancy (only one vent method per tank). Yes, there are two tanks. But the same IFR conditions that plug one vent (inadvertent penetration into ice or snow) can plug the second tank vent. Virtually all certified IFR aircraft have fuel tank venting redundancy (tank vents plus cap vents in most cases). Van's design does not. Van's design utilizes the tank vent position behind the cowl (engine heat) to help mitigate this issue. While I have never seen IFR conditions where this vent was compromised, it may be possible under the right conditions.
With conventional RV design, I don't have a solution for this issue. I unsuccessfully attempted making vents in the tank fuel caps. In my installations of tip tanks, I still utilize the same fuselage vent, but, in the tip tank vent line (which, because of the fuel system plumbing, is the vent for the main tank as well), I put a small cut into the vent line so that if the fuselage vent becomes plugged, there is still a method to vent the tank.
Fred Stucklen
RV-7A N924V
From: Emrath [mailto:emrath(at)comcast.net]
Sent: Tuesday, July 22, 2008 10:22 PM
To: Stucklen, Frederic W UTPWR
Subject: RE: Re Throttle/Mixture bracket
Fred,
Try Part number VA-149-360-PC KIT in the Vans web catalog.
This is listed as an item included in the RV-10 firewall Forward kit. Under the "List" it says $18 and included the extra gasket needed. This is for use between the carb and the sump, but works equally well between the servo and the sump. At least it did for me on my 0-360 converted to Fuel Injection, updraft Bendix system.
Marty Ò¿Ó¬
[quote]
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webmaster(at)flion.com
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| Posted: Wed Jul 23, 2008 5:39 am Post subject: Throttle/Mixture bracket Vertical Draft IO-360 RV-7A |
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Regarding alternate air: With my FWF kit (I think it’s in the instructions for the FAB) there are instructions for a filter bypass. Basically it’s a hole in the FAB bowl beneath the filter and a pivoting plate that covers it operated by a Bowden cable. It is not reclosable in flight; you have to land and remove the cowl to ‘reset’ it. Then again, if your filter is clogged you should be landing anyway. I have heard that injected engines don’t need carb heat so, to avoid confusion, I am only installing the bypass and not the heated air flapper; I may revisit that at another time.
Patrick Kelley – RV-6A Superior XPIO-360 – Should be flying soon
From: owner-rv-list-server(at)matronics.com [mailto:owner-rv-list-server(at)matronics.com] On Behalf Of Stucklen, Frederic W UTPWR
Sent: Wednesday, July 23, 2008 6:05 AM
To: RV-List
Subject: Throttle/Mixture bracket Vertical Draft IO-360 RV-7A
Just to get this into the Archives, here's what is needed for an IO-360 vertical induction system on an RV-7A with a Bendix or Silver Hawk fuel body.
Both cables go through the firewall just below the centrally located firewall heater box. Both firewall holes are located directly behind their respective cable mounting holes on the bracket when it's installed between the fuel body and the engine sump. The throttle cable will enter the cabin area through a grommet in the cover in that area. The mixture cable will penetrate the lower portion of the heater box panel (but under the enclosed heater box) and will require a cable grommet. The cables cross over inside the cockpit if they are horizontally located on the sub panel. The mixture cable is a tad long, but the next shorter cable is too short.
This list assumes the use of a Bendix or Silver Hawk Fuel body.
CT BLK THROTTLE 44.5 Throttle Cable, 44.5"
CT RED VMIXTURE 50.5 Mixture Cable 50.5"
VA-182-PC KIT Bracket IO-320/360/540 Vertical Induction
FAB-360/540 O-360/540 Vertical Draft
The next step is to mount the airbox. The Airbox comes with a bracket that allows the fuel body mixture arm to move below the plane of the airbox top surface. I personally think that this overly complicates the airbox construction. I'm planning on putting a 3/4" Delron spacer between the bottom of the fuel body and the Airbox to allow for free movement of the mixture arm with no airbox modifications. There appears to be 10.25 " between the inside surface of the lower cowl just under the airbox, to the bottom surface of the of the sump where the fuel body mounts. The total height of the airbox, spacer, and fuel body, is only 9.25", leaving a inch clearance between the lower surface of the bottom surface of the airbox and the cowl. The airbox also easily clears the nose wheel gear leg. I've seen this done on other RV-7A aircraft, and it seems to work out OK with the interface to the lower cowl snout.
I still have a question as to what to do about an alternate fuel body air source. There has been documented instances of the air filter becoming clogged with snow. Van came out with an alternate air source fix that takes the lower cowl air directly into the fuel body, bypassing the filter. This certainly qualifies as a solution, but it doesn't prevent filter blockage from occurring (like the Carb Heat flap control on carbureted systems can do). When I fly serious IFR in heavy rain or snow, I think it's prudent to keep as much of that precipitation out of the air box, and air filter, as possible. Van's alternate air fix should be used as a last resort, while the Carb Heat solution would be used as the first line of defense. So, I thinking that it would be prudent to have both controls, but not necessarily heated air into the Carb Heat type flapper control.....
Another issue for an IFR RV Aircraft is the current design of the tank vents. It does not meet my requirements of system redundancy (only one vent method per tank). Yes, there are two tanks. But the same IFR conditions that plug one vent (inadvertent penetration into ice or snow) can plug the second tank vent. Virtually all certified IFR aircraft have fuel tank venting redundancy (tank vents plus cap vents in most cases). Van's design does not. Van's design utilizes the tank vent position behind the cowl (engine heat) to help mitigate this issue. While I have never seen IFR conditions where this vent was compromised, it may be possible under the right conditions.
With conventional RV design, I don't have a solution for this issue. I unsuccessfully attempted making vents in the tank fuel caps. In my installations of tip tanks, I still utilize the same fuselage vent, but, in the tip tank vent line (which, because of the fuel system plumbing, is the vent for the main tank as well), I put a small cut into the vent line so that if the fuselage vent becomes plugged, there is still a method to vent the tank.
Fred Stucklen
RV-7A N924V
From: Emrath [mailto:emrath(at)comcast.net]
Sent: Tuesday, July 22, 2008 10:22 PM
To: Stucklen, Frederic W UTPWR
Subject: RE: Re Throttle/Mixture bracket
Fred,
Try Part number VA-149-360-PC KIT in the Vans web catalog.
This is listed as an item included in the RV-10 firewall Forward kit. Under the "List" it says $18 and included the extra gasket needed. This is for use between the carb and the sump, but works equally well between the servo and the sump. At least it did for me on my 0-360 converted to Fuel Injection, updraft Bendix system.
Marty Ò¿Ó¬ [quote]
--
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http://www.matronics.com/Navigator?RV-List |
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