Huckster79
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Huckster79
I recently built an Engine Dehumidifier, very similar to commercially available unit called the Engine Saver. I believe the Engine Saver retails around $325, I have $40 into mine. The idea is our engines are humid regions from combustion gasses making their way into the crank case, and moisture is a necessary element for our arch enemy: corrosion. I have heard it debated if these are effective but my thought is for $40 I'll take my chances its a wasted $40... Im not the inventor of the DIY version, I believe its been floated around online from some EAA groups, and like any home built rig there are variations.
Basic concept is to pull air over a desiccant, usually silica gel to dry the air. There are open looped units that just pull ambient air over desiccant and pump it in the oil fill tube and let it vent out the vent tube. There's a closed loop systems that pump it in, but also captures it on its way out recirculating the same, or hopefully most of the same air back in. I went with a closed loop unit but am going to use it in both fashions. At shutdown I plan on hooking up the "In" and leaving it open loop as I pack up for the day and closing the loop before going. Thought being the crank is filled with nasty corrosive gasses at shutdown I'd rather just push those out and have them gone. But the closed loop system I believe has an advantage in that desiccant dehumidifying isn't mechanical dehumidifying and takes time, always drawing ambient air I don't believe gives the desiccant long enough to absorb the humidity.
Basic design is two rubbermaid tubs for "left overs" one has the largest aquarium pump I could buy, a 60 gallon unit. It was double outlet so I put a "T" in to combine it from the two tiny aquarium hoses into one old air compressor hose I had. I sealed the pump in the tub, siliconing the cord and hoses coming out. I placed a hygrometer that reads current RH and also historic High and Low RH in the tub. For the air draw into the pump tub I used another chunk of the air compressor hose and ran that to the same type of tub. In that tub I drilled a hole near the bottom and one near top. I put fibrous aquarium filter material over the air hose end going out the upper hold, and then same material on the bottom of container over top of the inlet hose so the silica wasn't tight around the inlet hose end. The cheapest way I have found to buy Silica is "Crystal Kitty Litter" its a pure silica gel kitty litter they sell at Wally World. Then filled that container with the silica.
On the outgoing air from the pump I put an oil/water/particulate filter for air compressor tools in the line to catch any silica dust, though undisturbed and low flow of air I doubt there will be much, but don't want to pump it into the Continental if there is... I ran the hose from the pump to a rubber drain pipe adapter I bought at hardware that was 1 1/2" to 2", bought a plug for the 1 1/2" side and drilled it out for the hose. So to install I remove the dipstick and put this over the oil fill and a couple quicks twists on the attached hose clamp clamps it down to the oil fill tube. On the hose for the air inlet to the silica I run that to the vent tube and by chance it fits snuggly right in it.
One of the EAA designs built in a light bulb to "dry off" the Silica periodically. I'm not convinced thats enough heat to really dry it, and the $9 bag of Silica I bought will fill up this tub multiple times over. A rise in the RH on the hygrometer should tell me when the Silica is saturated. At that point I can swap it out for fresh and once I have most of my bag of fresh used up I will cook off the used stuff in the oven (One of the many advantages of keeping my home-front a bachelor pad)
I plugged it in yesterday and I stopped this morning to check on it, it was 42% and had been up to a high of 57% after originally plugging it in. So it seems to be doing something. Again I can't say with any guaranteed certainty this will help my engine last longer, but I am hard pressed to find a reason it would hurt. I understand frequent operation is best but my thought is having torn apart car engines that once the oil drips off a part it can get a light surface rust on it in a nights time... So I understand there are plenty that will say it will help nothing, but I'm not sure either side of that argument can truly prove definitively either way. I'm willing to gamble my $40 it will do something to help and if I'm wrong I'm out 8 gallons of AvGas money...
Basic concept is to pull air over a desiccant, usually silica gel to dry the air. There are open looped units that just pull ambient air over desiccant and pump it in the oil fill tube and let it vent out the vent tube. There's a closed loop systems that pump it in, but also captures it on its way out recirculating the same, or hopefully most of the same air back in. I went with a closed loop unit but am going to use it in both fashions. At shutdown I plan on hooking up the "In" and leaving it open loop as I pack up for the day and closing the loop before going. Thought being the crank is filled with nasty corrosive gasses at shutdown I'd rather just push those out and have them gone. But the closed loop system I believe has an advantage in that desiccant dehumidifying isn't mechanical dehumidifying and takes time, always drawing ambient air I don't believe gives the desiccant long enough to absorb the humidity.
Basic design is two rubbermaid tubs for "left overs" one has the largest aquarium pump I could buy, a 60 gallon unit. It was double outlet so I put a "T" in to combine it from the two tiny aquarium hoses into one old air compressor hose I had. I sealed the pump in the tub, siliconing the cord and hoses coming out. I placed a hygrometer that reads current RH and also historic High and Low RH in the tub. For the air draw into the pump tub I used another chunk of the air compressor hose and ran that to the same type of tub. In that tub I drilled a hole near the bottom and one near top. I put fibrous aquarium filter material over the air hose end going out the upper hold, and then same material on the bottom of container over top of the inlet hose so the silica wasn't tight around the inlet hose end. The cheapest way I have found to buy Silica is "Crystal Kitty Litter" its a pure silica gel kitty litter they sell at Wally World. Then filled that container with the silica.
On the outgoing air from the pump I put an oil/water/particulate filter for air compressor tools in the line to catch any silica dust, though undisturbed and low flow of air I doubt there will be much, but don't want to pump it into the Continental if there is... I ran the hose from the pump to a rubber drain pipe adapter I bought at hardware that was 1 1/2" to 2", bought a plug for the 1 1/2" side and drilled it out for the hose. So to install I remove the dipstick and put this over the oil fill and a couple quicks twists on the attached hose clamp clamps it down to the oil fill tube. On the hose for the air inlet to the silica I run that to the vent tube and by chance it fits snuggly right in it.
One of the EAA designs built in a light bulb to "dry off" the Silica periodically. I'm not convinced thats enough heat to really dry it, and the $9 bag of Silica I bought will fill up this tub multiple times over. A rise in the RH on the hygrometer should tell me when the Silica is saturated. At that point I can swap it out for fresh and once I have most of my bag of fresh used up I will cook off the used stuff in the oven (One of the many advantages of keeping my home-front a bachelor pad)
I plugged it in yesterday and I stopped this morning to check on it, it was 42% and had been up to a high of 57% after originally plugging it in. So it seems to be doing something. Again I can't say with any guaranteed certainty this will help my engine last longer, but I am hard pressed to find a reason it would hurt. I understand frequent operation is best but my thought is having torn apart car engines that once the oil drips off a part it can get a light surface rust on it in a nights time... So I understand there are plenty that will say it will help nothing, but I'm not sure either side of that argument can truly prove definitively either way. I'm willing to gamble my $40 it will do something to help and if I'm wrong I'm out 8 gallons of AvGas money...
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