CharlieWaffles
Well Known Member
How hot does the scat tube get in the tunnel? I'm trying to figure out how to route some oxygen tubing from Mountain High in proximity to the scat tube.
Van's Air Force
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Scat tube in Tunnel
- Thread starter CharlieWaffles
- Start date
blahphish
Well Known Member
Not sure how hot the scat tube gets but I wanted to mention that I believe the tunnel heat issue is radiated heat from the heater box when the heater doors are closed and the hot air off the muffs are blowing on the closed doors. If the heater vents are open the hot air passes through the tubes and into the cabin so I'm not so sure insulating the scat tubes is a good counter measure to tunnel heat problem. Instead, you might consider the stainless steel heater box or using something to insulate the aluminum one from the firewall plus the use of a blast tube on the closed heater doors.
Mark, how long until you would like to run the o2 lines? I could try to fly with the tunnel cover off and the heat blazing and get a gauge of them for you. Since its summer time I would probably have to go to like FL350 to not die of heat stroke but I'll give it a try for you at 10.5
Mark, how long until you would like to run the o2 lines? I could try to fly with the tunnel cover off and the heat blazing and get a gauge of them for you. Since its summer time I would probably have to go to like FL350 to not die of heat stroke but I'll give it a try for you at 10.5
CharlieWaffles
Well Known Member
I ran them yesterday, but now questioning my routing in regards to the scat tube. If you get a chance, let me know.
I wrapped my scat tubing with aluminum-faced tape, used the stainless steel heat valves, and insulated the floor of the tunnel. The tunnel is comfortable to the touch flying in 100* F weather(heat off) and 10-15* F winter weather(heat on). I don't have any idea how much the tunnel temp is due to the tape versus the valves or insulation, but the combination works great. I would estimate my tunnel temp is 80-90*. I will put a probe on the tunnel when I fly later today in 90* heat.
Jim Berry
RV-10
Jim Berry
RV-10
douglassmt
Well Known Member
Mine's fine
I used the SS boxes and insulated the floor and firewall in the tunnel. I've flown in very cold wx and very hot weather and the sides of the tunnel are at most slightly warm. I did not insulate my scat tube.
I used the SS boxes and insulated the floor and firewall in the tunnel. I've flown in very cold wx and very hot weather and the sides of the tunnel are at most slightly warm. I did not insulate my scat tube.
Just fly with the aft heat on (if you can take it!) with a thermometer in the aft heat outlet. That will tell you, pretty close, how hot the SCAT gets.
My tunnel top is much warmer when aft heat is on. But the heat is only on when it's cold out, so the warm top feels good then!
My tunnel top is much warmer when aft heat is on. But the heat is only on when it's cold out, so the warm top feels good then!
This is a timely thread as I am closing up the tunnel, although there is a little drift!
I have used the stainless steel heater box with insulation between it and the firewall. I have insulated the bottom of the tunnel and back of the firewall. The final step is to insulate the scat tube. That should do it!
I am fitting an OAT probe to monitor the temperature. Can anyone advise on good figures for caution and warning settings? - preferably with the reasons.
And sorry, Mark, but no idea about the oxygen tubes.........
I have used the stainless steel heater box with insulation between it and the firewall. I have insulated the bottom of the tunnel and back of the firewall. The final step is to insulate the scat tube. That should do it!
I am fitting an OAT probe to monitor the temperature. Can anyone advise on good figures for caution and warning settings? - preferably with the reasons.
And sorry, Mark, but no idea about the oxygen tubes.........
Bill.Peyton
Well Known Member
Our original plan was to split the two heat valves up. I was going to split the right valve and supply both the front and rear with heat using just that side. I was going to use the left valve for cold air and install eyeball vents in the sides of the tunnel to provide cool air to the foot well area.
I spoke with Vetterman, who suggested that if I remove the left heat muff I should install a heat shield on the top side of the muffler to deflect the heat down and out the back of the cowl.
I changed my mind and just hooked it up per the plans and used stainless heat valves with insulation between them and the firewall. I have layered 1/4" fibrefrax, covered by 1/2" fireproof insulation on the entire floor, including the tunnel floor and the entire firewall. My plan is to see how it does. If the tunnel is too warm I will then make the mod that I was originally going to incorporate.
After reading all of the posts on the tunnel heat issue, it seems that most of the issues are resolved by the newer extended exhaust system, adding floor insulation, and the use of the stainless valves.
The only other thing that would improve the overall heat dispersion would be if the heat valves had a scat tube outlet so you could dump the heat at the exit at the bottom of the firewall rather than so far up on the firewall.
I spoke with Vetterman, who suggested that if I remove the left heat muff I should install a heat shield on the top side of the muffler to deflect the heat down and out the back of the cowl.
I changed my mind and just hooked it up per the plans and used stainless heat valves with insulation between them and the firewall. I have layered 1/4" fibrefrax, covered by 1/2" fireproof insulation on the entire floor, including the tunnel floor and the entire firewall. My plan is to see how it does. If the tunnel is too warm I will then make the mod that I was originally going to incorporate.
After reading all of the posts on the tunnel heat issue, it seems that most of the issues are resolved by the newer extended exhaust system, adding floor insulation, and the use of the stainless valves.
The only other thing that would improve the overall heat dispersion would be if the heat valves had a scat tube outlet so you could dump the heat at the exit at the bottom of the firewall rather than so far up on the firewall.
Wayne Gillispie
Well Known Member
I did not measure the temp, but I would estimate 150-180F.
I have all of the above mentioned precautions and my tunnel forward area may have gotten to 110F on ocassion this summer. Like Bill said, devise a method of dumping hot air down lower and everything would be even cooler. It is acceptable so I am sticking with it. My only fuel vaporization/starting problems occur after 5-60 min shutdowns on a hot day.
I have a 250F cooling air outlet temperature limit switch installed and no red LED has illuminated this summer, so I know all of that hot air gets dilluted very well.
I have all of the above mentioned precautions and my tunnel forward area may have gotten to 110F on ocassion this summer. Like Bill said, devise a method of dumping hot air down lower and everything would be even cooler. It is acceptable so I am sticking with it. My only fuel vaporization/starting problems occur after 5-60 min shutdowns on a hot day.
I have a 250F cooling air outlet temperature limit switch installed and no red LED has illuminated this summer, so I know all of that hot air gets dilluted very well.
