Cabin Heat prob with horizontal cowl ?

Im getting ready to order my -7 finish kit and I really want to get the smooth cowl ( horizontal induction ) but now and then I've been hearing RV's in northern climates are having lack of cabin heat with this set up. Is this true ?? If it is has anyone found a way around this to get good cabin heat ?


Thanks

It hasn't gotten real cold in ND this fall, but so far I have way plenty of heat. When I got my vetterman exhaust, I had them put 1 1/2" fittings on the heat muff, and I put 1 1/2" fittings on my heater valve. You do not need 2" hose, it actually allows so much air flow that it can't pick up the heat. When you need more heat, pull the valve open more and all you get is luke warm, high volume air.

The 1 1/2" hose routes easier as well. If you are stuck with 2" hose, then make your opening in the baffle only 1 1/2". Some folks stick brillo pads in the hose to reduce the flow.

Seal everything

Many guys seals the little trinagular openings on the sides of the baggage back piece with silicon. Also put on stick boots and aileron torque tube seals on the sides of the fuselage.

Some felt under the skirt of the canopy will help seal and the side skirts allow cold air. The RV's seem to have adequate heat if the cold air can be kept out.

Best,

Pierre

Thanks for the good sealing info, guess I'll make sure any possible air leak in the cabin is sealed as you recommended. Do you know where to get theses boots for the aileron and elevator push tubes ?


NDRV8R

I'll be ordering my finish kit around the middle of November, Id appreciate more feed back that you may have to offer as it gets colder with your set up. Guess I'll start looking for a stainless heat box with a 1 1/2 inlet.

Thanks

wilco on the feed back. I am about to take it down for paint and it will be down for a few weeks. I may not be flying it all that much when I get it back. It seems the thermometer has a proportional effect on my desire to fly.

Here is my attempt at warming up a -M1B cabin

First, I should say that I have done all the cabin sealing stuff on an RV7. Aileron boots, closed the spar holes, closed the corrugation holes in the baggage bulkhead and other minor stuff. The standard heater was OK (mild winter last year) but this winter I had two flights that were cold to the point of being dangerous. I was shivering when landing.

I designed and ordered a custom muff from Rick Robbins. The plan is to move my air inlet to the back of the oil cooler (because I run that some percent blocked all the time), through the custom muff on #4 and then across to the std muff and then on to the cabin.

Not tested yet. I will report here after I do.

First is the SCAT flange and bracket I fabbed for mounting on the Oil Cooler.




Here it is mounted with the SCAT slid in place.



SCAT going to the custom muff





This is a tight spot. The cowl is very close to the servo. I have the hose "nested" up in a hollow spot in the servo and zip tied in place. I will watch for scuff marks on the cowl here.


I flipped the standard muff upside down to make the cross tube connection better, but it forced the cabin tube inside the intake tubes. It's kinda' tight in there so I will probably get a new muff to get this SCAT tube back outside where it was.


The "per-plans" inlet hole on the #1 cylinder ramp has been blocked. It will be interesting to see if there are any noticable differences in CHTs with the closure of that 2" hole bypassing the cylinder fins and pressuring the post cylinder area.

New exhaust

HI everyone, here in the next few weeks we will be offering a new muffler type system for the forward facing sumps. It has outstanding cabin heat, and impressive performance numbers. We are finishing up the testing on Larry's RV-7a. IF you want more details, give us a call. We will be posting a full report soon. Clint/Vetterman Exhaust (605) 891-1290

Diane and I flew to Mt. Airy MWK today for a stop at the "Snappy Lunch", a place that has been there for 91 years and is famous for its pork chop sandwich. MWK has a crew car for the short hop into main street. It was good to see the place again (we lived there in the 80's). The place has gone crazy with Mayberry memorabilia.

Tested the heater installation, which was on the flight agenda:

1) Yes, hot air comes out but with the weather not being frigid, it is hard to know whether this is a permanent fix.
2) No detriment to oil temperature. Before the mod, I ran 50% blocked on the cooler. I removed some tape to be 25% blocked for this flight. Oil temps were down a little so I can choose to wait for summer or maybe put a little tape back on.
3) CHTs normal. I was too busy with other testing (redoing climb and glide testing) to really see if things were different. if they were, it was really minor.