Oil filter

How to keep the Cessna 170 flying and airworthy.

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zero.one.victor
Posts: 2271
Joined: Tue Apr 23, 2002 12:11 am

oil filter as cooler

Post by zero.one.victor »

Dave,I think you're right about the filter releasing some heat. How can it help but radiate heat? I read a couple articles in the 170 News going further with this:
1) One guy made a finned heat-sink which wrapped around the oil filter to radiate more heat out of the oil.
2) Another guy made an aluminum shroud which fit around the filter,then he ran a scat hose from the scoop at the nosebowl inlet area to a little spigot on this shroud,for forced-air cooling of the filter.
I don't recall if they got approvals on these mods or if they were bootlegged,I don't think I'll try either one. I think if I did reroute my blast tubes to blow on the temp sensor,it'd indicate a little lower temps but the oil going into the engine would still be the same temp as it is now,so I'm not gonna worry about it. Doesn't get that hot around here anyway!

Eric
Dave Clark
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Joined: Mon Apr 22, 2002 6:25 pm

Post by Dave Clark »

Eric

So now we're talking alternative oil coolers? The fins on the oil filter sounds like a neat idea, I'm sure it would help some. Someone could come up with that and STC it, produce it reasonably and make a bundle of money, Maybe.

When I overhauled the 220 Franklin for the Stinson a couple of years ago I put on the ADC screen type bulkhead mount oil filter. They claim that this unit has a Delta T (reduction/ change in temp) of 20 degrees. The casting is black and finned. I also installed an oil cooler similar to the small Lycoming installation (and got it approved) so I don't know what help the oil filter was in reducing the temps. I was going to put this same ADC filter on the 170 but after doing some research I found the claims made by ADC for the fine screen filter were perhaps overstated and decided to stick to paper filters.

The "AZ mod" mentioned by me previously is to open the air intake for the pan cooling about as large as the pan baffle allows. Of course it involves fabricating a new doubler piece and riveting it in place. It's also not approved....BUT I think it really works a bunch. I decided to do this before adding any more size and drag to the lower cowl lip which of course is the old Champ and many seaplane fixes for better cooling.

One of my problems in being real scientific about this is that I've been changing more than one thing at a time so I don't know which one works the best.

May have to go to Tucson today for a week as it looks like Grandchild #2 is coming. I'm done with the plane except for a day or so on the new intercom installation. Then clean it up, do a bunch of paperwork, close down here for the Summer and head your way. I need some shrimp!
Dave
N92CP ("Clark's Plane")
1953 C-180
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GAHorn
Posts: 20968
Joined: Fri Apr 12, 2002 8:45 pm

Re: oil filter as cooler

Post by GAHorn »

zero.one.victor wrote:Dave,I think you're right about the filter releasing some heat. How can it help but radiate heat? I read a couple articles in the 170 News going further with this:
1) One guy made a finned heat-sink which wrapped around the oil filter to radiate more heat out of the oil.
2) Another guy made an aluminum shroud which fit around the filter,then he ran a scat hose from the scoop at the nosebowl inlet area to a little spigot on this shroud,for forced-air cooling of the filter.
I don't recall if they got approvals on these mods or if they were bootlegged,I don't think I'll try either one. I think if I did reroute my blast tubes to blow on the temp sensor,it'd indicate a little lower temps but the oil going into the engine would still be the same temp as it is now,so I'm not gonna worry about it. Doesn't get that hot around here anyway!

Eric
I thought about the slip-on fins for the oil filter years ago while installing heat-sinks on some transistors in an electronics project. By the time I got off my dead b--- and mfr'd a prototype I saw that someone else was making it already, so I had some small interest in seeing if the idea took off or not. It hasn't taken the market by storm yet, but it's only been out now for about ten years. :?
It would be important to run an accurate control to determine effectiveness, but I suspect that it doesn't work too well. In order to cool things off you've got to blow cool air upon it. You'd have to steal that cool air from above the cylinders, ...and there's none to spare for that.
Meanwhile we've got an oil filter sitting downstream in the hot exhaust-air of the cowling. It may actually be an oil-warmer :? down there. (just joking) Clearly it's not in the best place to cool oil down. If cylinder head temps are running 350 degrees F, and exhaust stacks are running 1100 degrees F, ...what could the ambient air heading for the exit at the lower cowl be running? 180 F ? 220 ?
Dave Clark
Posts: 894
Joined: Mon Apr 22, 2002 6:25 pm

Post by Dave Clark »

Good points George!!!
Dave
N92CP ("Clark's Plane")
1953 C-180
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Jay
Posts: 11
Joined: Tue Apr 16, 2002 12:35 am

Oil Filter

Post by Jay »

As far as the heat sink around an oil filter; I made one up years ago when the El Reno filter adapter first came out. I made it out of aluminum with numerous fins with flange & 3 an screws to clamp it on. The cooling effect was marginal at best. I also later built a can with a 1 1/2" inlet and approx 1/2" spacing around the filter,with outlet on bottom; ran a scat hose to the back baffle dam above the cylinders. The cooling effect of this was also maginal. I tried this as an experiment; maybe if I'd ran the scat to the front of the cowling, it may have worked better. The best way I know of to keep the oil temps down is to tighten up the baffling as much as possible and throw a set of pistons and rings in, if you have a lot of blowby. I believe I still have the filter heat sink and also the pressure can laying around in my basement somewhere. If I lived in a high temp area, I would possibly look at an oil cooler or just live with it. Run W80 or w100 oil. I believe there are a couple of 170s running around with an oil cooler on a field approval.
Jay
zero.one.victor
Posts: 2271
Joined: Tue Apr 23, 2002 12:11 am

oil cooler

Post by zero.one.victor »

The C-145 parts book page 19,figure 11 shows "oil cooler equipment",it connects via a sort of tee fitting at the oil screen. A guy I know with a C-145 powered Swift has an oil cooler,but I don't know if it is this same one or something different.

Eric
Dave Clark
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Joined: Mon Apr 22, 2002 6:25 pm

Post by Dave Clark »

I flew the plane this morning after reinstalling the El Reno oil filter and redirecting the blast tube to the temp sending unit area (actually blasts on the housing about centerline with the oil filter). It was 65-70 degrees at 5,000 ft elevation eight AM full fuel with wife in right seat. Climbed to 9,500' at full throttle. I took off leaned just rich of max power leaned to slight rough. My mistake was to leave the mixture that lean for the first few minutes. It sent the oil temp about 2/3 up the scale before I richened it a bit which stopped the temp rising. I don't know yet but I think it's a bit cooler than it was with the blast tube in the original location as it was when I got the plane two years ago filter installed. It's definately warmer than it was in the stock setup with just the screen last summer but I'm optomistic it will not be as big of a problem as it was two years ago. That prompted me to run with just the screen last year because I had no time to chase the problem. We'll find out when we go through southern CA in a few weeks heading to the summer home in WA. Sorry if I rambled but it makes sense to me!
Dave
N92CP ("Clark's Plane")
1953 C-180
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