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Baffles Seals REV 2

Bluelabel

Well Known Member
I decided since the taxiway in front of my hangar was getting repaired for a couple weeks, I'd take the opportunity to re-do my baffle seals. My engine has always been on the hot side. Manageable, but I'd really like to have more headroom on hot days.
I though there was a pretty good chance I was getting some leaks in the back corners as the the air may have pushed the material down. We started with the original material from Van's.
I shopped a few things at Oshkosh and decided to give the McFarlan Cowl Saver stuff a try. It's extremely slick on one side and much stiffer than the original.
While I was at it, I figured I'd make it look cool too. Worst case scenario, I have the same cooling and a better look with the cowl off.
So, I whipped up new strips for both sides so the rivets had something good to bite into, off to the anodizer, and here we are.
First flight with them was on Saturday to fly young eagles. Getting the cowl on for the first time was a bear!!.
So far it seems I may have lowered the temps a couple degrees at best. Won't really know for sure until I go somewhere where I can get up high in cruise where I know exactly what temps I usually see.

Here's the before and after pics...

Before:
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After
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Cowling inlets

Hi John - thanks for sharing the photos - do you have any pic of the area around the cowl inlets? That's always a tricky area I believe.
 
Hi John - thanks for sharing the photos - do you have any pic of the area around the cowl inlets? That's always a tricky area I believe.

Those are the only pics I took. everything there is to see is there.
 
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Umm..

Excuse me for a few weeks. I'll be in the hangar redoing my baffles. They suddenly look awful...

Nice work there. Can I ask what the insulation on the wiring (?) is for?
 
Excuse me for a few weeks. I'll be in the hangar redoing my baffles. They suddenly look awful...

Nice work there. Can I ask what the insulation on the wiring (?) is for?

Thanks....Just heat shield. To protect everything as best we could. Inside, anything that's a signal wire is shielded from other signal wires as well.
 
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Hi John - thanks for sharing the photos - do you have any pic of the area around the cowl inlets? That's always a tricky area I believe.

Those are the only pics I took. everything there is to see is there clear as day

So, John, do you have seals around the inlets? I think I see rub marks on the baffle tin, but your answer suggests there are none.
 
So, John, do you have seals around the inlets? I think I see rub marks on the baffle tin, but your answer suggests there are none.

Yes, I have baffle seal material on the sides of the ramps. Same thing I've seen most other people do. That area gets a great seal.
I don't have any pictures of that. I might redo it with the new material so it's consistent.
 
Rv 10 rdd baffle kit

Anyone using the rv10 baffle kit that rdd makes? It looks like a copy of what the people that the build the sportsmen 2+2. I know it works well with the io 390 engine on the sportsmen.
 
Wow

Yesterday I replaced my original baffle seals with this same, thicker material. I thought my originals were pretty good but wasn't completely satisfied with the back corners, overlaps and transition at the inlets. I was able to install the new ones with only a couple cuts and they seal to the top cowl much better, overall a much cleaner install.

I flew today and have never seen temps this cool. #3 was down in the 330's in climb and my hottest cylinder, #4, only got to 370 in a climb to 10,000'. Cruise was +/- 350, whereas normally is around 370. Granted, it was a cool day in the mid sixties but nonetheless, it seems reworking my baffles, that I thought were good already, made a big difference.

I also tried something on my oil cooler, which mounts to the rear of the engine baffle. (Should get a picture). It seams to me that air can exit straight rearward through the cooling fins, but also through holes in the top and bottom of the oil cooler?? I took RTV sealant and closed off the holes in the top of the oil cooler, front and rear... oil temps never went over 155 (normally 170's). I think not only did this make more air travel through the fins but also decreased the amount of air pouring through the oil cooler exit.

Good day for me, maybe I can advance my pmag timing now
 
Yesterday I replaced my original baffle seals with this same, thicker material. I thought my originals were pretty good but wasn't completely satisfied with the back corners, overlaps and transition at the inlets. I was able to install the new ones with only a couple cuts and they seal to the top cowl much better, overall a much cleaner install.

I flew today and have never seen temps this cool. #3 was down in the 330's in climb and my hottest cylinder, #4, only got to 370 in a climb to 10,000'. Cruise was +/- 350, whereas normally is around 370. Granted, it was a cool day in the mid sixties but nonetheless, it seems reworking my baffles, that I thought were good already, made a big difference.

I also tried something on my oil cooler, which mounts to the rear of the engine baffle. (Should get a picture). It seams to me that air can exit straight rearward through the cooling fins, but also through holes in the top and bottom of the oil cooler?? I took RTV sealant and closed off the holes in the top of the oil cooler, front and rear... oil temps never went over 155 (normally 170's). I think not only did this make more air travel through the fins but also decreased the amount of air pouring through the oil cooler exit.

Good day for me, maybe I can advance my pmag timing now

That's good work. Except, and I think most people will agree, you are not doing your oil or you engine any justice by not getting your oil above 180. (180-200 is optimum) That's the magic number to cook off any moisture that resides after the plane sits after a flight. This is straight tout of Bill Ross's Engine Management 101
My oil temps are usually right at 180, so I actually added a butterfly valve, so in cruise, I can close off some of the air to the oil cooler and get more air to the cylinders. I let the oil come up to about 190(ish) and that gets a few more degrees cooling to #6... Just my 2 cents....
 
That's good work. Except, and I think most people will agree, you are not doing your oil or you engine any justice by not getting your oil above 180. (180-200 is optimum) That's the magic number to cook off any moisture that resides after the plane sits after a flight. This is straight tout of Bill Ross's Engine Management 101
My oil temps are usually right at 180, so I actually added a butterfly valve, so in cruise, I can close off some of the air to the oil cooler and get more air to the cylinders. I let the oil come up to about 190(ish) and that gets a few more degrees cooling to #6... Just my 2 cents....

Well yeah, I just close off the the oil cooler to bring the oil temp up. Pretty common up here in the North with 100 degree temp swings from winter to summer. I dont think there is anything magical about 180 degrees though, maybe just the speed at which it cooks off any moisture. And the duration you fly at any given temp is probably a factor as well. After all, isn't the weakest link the condition of the atmosphere at where the aircraft is parked?
 
Well yeah, I just close off the the oil cooler to bring the oil temp up. Pretty common up here in the North with 100 degree temp swings from winter to summer. I dont think there is anything magical about 180 degrees though, maybe just the speed at which it cooks off any moisture. And the duration you fly at any given temp is probably a factor as well. After all, isn't the weakest link the condition of the atmosphere at where the aircraft is parked?

That's true... I just have always followed the advice of engine builders and people who know more than me. And that advice was that you want your oil to be over 180, and that if you do go out for a short "around the patch" flight, (Like I did Friday), fly long enough to let your oil hit 180....

It might be a couple weeks before I have any high cruise flights where I can see off the new baffle seals really made a difference or not. Got a lot of short hops and sight seeing flights coming up. (not that I'm complaining)
 
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