cooling tubes
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voorheesh
- Posts: 603
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cooling tubes
I am having the cooling tubes installed on the rear baffles CE-170A/0300 engine. Engine has Floyd Jones oil filter. Should the tubes be directed at the filter/oil pump? Do these tubes help keep oil temp down? Is there an STC for an oil cooler? It is hot out here in Fresno!
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cessna170bdriver
- Posts: 4115
- Joined: Mon Apr 22, 2002 5:13 pm
The tubes should be directed at the bottom of the accessory case where the screens and/or oil filter are installed, one on the left one on the right. There have been discussions on this forum on their effectiveness and the general consensus is that they are effective. From the way your post is written, it sounds like you may not have had the blast tubes installed. An old myth is that they only cool the oil temp probe and not the oil, so some folks may have (illegally) removed them. In reality, you can't cool the probe without also cooling the oil it's immersed in, so they DO work.
I'm not familiar with the Floyd Jones filter, so I don't know how that would affect blast tube installation. I just installed an F&M oil filter. The installation instructions say to modify the right blast tube to clear the filter if necessary. It was NOT necessary on my engine.
The illustrated parts catalog for the engine shows an oil cooler, but I've never seen one installed on a 170. High engine temps have been discussed here before and I seem to remember the general consensus is that the engine will remain within limits on most days if the baffling and blast tubes are in good shape and properly installed. More often than not high temps are due to worn or improperly installed baffling. Also note that if you are running straight 50wt oil, allowable oil temp is increased to 240F.
Good luck, and if you're ever down around Tehachapi, stop by. I get up to Fresno occasionally, and will do the same.
Miles
I'm not familiar with the Floyd Jones filter, so I don't know how that would affect blast tube installation. I just installed an F&M oil filter. The installation instructions say to modify the right blast tube to clear the filter if necessary. It was NOT necessary on my engine.
The illustrated parts catalog for the engine shows an oil cooler, but I've never seen one installed on a 170. High engine temps have been discussed here before and I seem to remember the general consensus is that the engine will remain within limits on most days if the baffling and blast tubes are in good shape and properly installed. More often than not high temps are due to worn or improperly installed baffling. Also note that if you are running straight 50wt oil, allowable oil temp is increased to 240F.
Good luck, and if you're ever down around Tehachapi, stop by. I get up to Fresno occasionally, and will do the same.
Miles
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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voorheesh
- Posts: 603
- Joined: Tue Jan 04, 2005 5:22 am
cooling tubes
Thx for the info. The oil filter is per an STC issued to Floyd Jones #SE8409SW. It is a spin on filter/adapter that essentially replaces the old screen. There are no ADs for it. My ship didn't have the tubes and I found a pair at Del Air in Porterville. Harry does the 180 hp conversion and has a lot of good stuff if you need used parts for the C145/0300. I have good baffles, a seaplane air deflector on the lower cowl, and a correct/calibrated temp guage. I see about 3/4 scale indication in climb and it settles back to 2/3 scale in cruise on 80-90deg days. I am hoping these tubes will help on the 100 plus days that happen alot around here. I think an oil cooler might be overkill on these old planes. Another thing that really helps is to keep a good airspeed in the climb. Anyway I'm based at Fresno Chandler (friends with John Puglese and Bob Anderson) Give me a buzz if you get up this way. (I dont know if youre supposed to give contact info on this site)
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GAHorn
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As long as the contact info is, your OWN and not someone else's without their permission,... and as long as it's personal and not commercial,...and if you don't mind the WWW having the info...
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
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cessna170bdriver
- Posts: 4115
- Joined: Mon Apr 22, 2002 5:13 pm
Harlow,
Say hi to both John and Bob for me. I'll try to get up to a Central Valley Aviation Association meeting soon. I ALWAYS enjoy their flyouts. I'll PM you with my cell # in case you ever get down this way.
Miles
Say hi to both John and Bob for me. I'll try to get up to a Central Valley Aviation Association meeting soon. I ALWAYS enjoy their flyouts. I'll PM you with my cell # in case you ever get down this way.
Miles
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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Romeo Tango
- Posts: 74
- Joined: Tue Sep 02, 2003 10:32 pm
Blast Tubes
Following on - please confirm that the blast tubes were optional for the C-145 as installed in the 1948 C170? I don't have any installed (if they are, as described, ports on the rear baffling off the engine, to scavenge the impact air that flows over the engine). I am definitely seeing higher oil temperatures than I'd like. I will do the calibration test on the temperature sensor and the gauge, but I'd be inclined to add the cooling tubes as a modification.
I had a Jasco alternator installed when I purchased the airplane, so I don't know if the original cowling blast tube was directed at the oil filter (I have the Airwolf spin-on filter STC installed).
Would it be unorthodox to split the incoming air from that blast tube with a Y - having part go to the alternator and part go to the oil filter? I'd use a smaller diameter tube to the oil filter as that would be unopposed and I don't want to overheat the alternator.
I had a Jasco alternator installed when I purchased the airplane, so I don't know if the original cowling blast tube was directed at the oil filter (I have the Airwolf spin-on filter STC installed).
Would it be unorthodox to split the incoming air from that blast tube with a Y - having part go to the alternator and part go to the oil filter? I'd use a smaller diameter tube to the oil filter as that would be unopposed and I don't want to overheat the alternator.
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GAHorn
- Posts: 21294
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The alternator has it's own internal cooling fan and should not require additional cooling.
I would recommend you locate some original blast tubes and re-install them directed as depicted in the IPC. Also, use SAE 50 wt oil, such as AeroShell 100W.
I would recommend you locate some original blast tubes and re-install them directed as depicted in the IPC. Also, use SAE 50 wt oil, such as AeroShell 100W.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
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cessna170bdriver
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- Joined: Mon Apr 22, 2002 5:13 pm
Not so on the Jasco alternators. The installation instructions are very clear that the alternator is NOT to be run without cooling air. http://www.skytronicsinc.com/ram_air_in ... _jasco.htm That's why the Jasco alternators have a shroud with a scat hose adapter. The very old ones were one inch, later ones are 2-inch. I wouldn't recommend y-ing off either of the blast tubes, as it would provide inadequate cooling for the alternator.gahorn wrote:The alternator has it's own internal cooling fan and should not require additional cooling.
I would recommend you locate some original blast tubes and re-install them directed as depicted in the IPC...
Miles
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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Romeo Tango
- Posts: 74
- Joined: Tue Sep 02, 2003 10:32 pm
Cooling
I concur - I just read the STC paperwork, and the blast air is required for the Jasco alternator.
What I need to do is secure replacement rear baffles with the blast ducts and get them put in at my next annual. By then it will be ambiently cooler and thus no longer imperative, but then next year will be happier. A climb out of Lake Tahoe can be harsh on an engine (field elevation 6264, density altitudes of >10,000 are not uncommon).
What I need to do is secure replacement rear baffles with the blast ducts and get them put in at my next annual. By then it will be ambiently cooler and thus no longer imperative, but then next year will be happier. A climb out of Lake Tahoe can be harsh on an engine (field elevation 6264, density altitudes of >10,000 are not uncommon).
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cessna170bdriver
- Posts: 4115
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I don't have a source for the blast tubes, but find the part numbers in the IPC and try http://www.cessnaparts.com/parts.cfm. If you really need a new rear baffle, you could make one, but that would be the most difficult of all the baffles to fabricate. At $345 for a new un-powdercoated rear baffle, http://www.airframesinc.com is a bit pricey, but they do a good job of building baffles (among other things).
Miles
Miles
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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GAHorn
- Posts: 21294
- Joined: Fri Apr 12, 2002 8:45 pm
Well, ... he DID say he had a Jasco! Doh! 
Sorry about that. I noticed that they also want the ram air to come from outside the cowl...with a scoop.
Being a fan (sorry) of generators, it's also worth remembering that 35A gens also require add'l help for cooling. Smaller gens benefit from it but aren't mandated to have it. I added another flange to the rear baffle and used sceet tubing to cool my gen.
Sorry about that. I noticed that they also want the ram air to come from outside the cowl...with a scoop.
Being a fan (sorry) of generators, it's also worth remembering that 35A gens also require add'l help for cooling. Smaller gens benefit from it but aren't mandated to have it. I added another flange to the rear baffle and used sceet tubing to cool my gen.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons.
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cessna170bdriver
- Posts: 4115
- Joined: Mon Apr 22, 2002 5:13 pm
I also grimaced at the thought of an external scoop. When I installed my Jasco in 1990 I added a 2" flange on the right side of the rear baffle for the SCAT hose. I temporarily installed a CHT and did't see anything over 380 degrees in cruise, and the alternator is still alternating after 16 years. When I installed my new baffing this time, I installed the flange for alternator cooling in the very center, near the top of the rear baffle. It took a bit more hose, but better pleases my sense of symmetrygahorn wrote:Well, ... he DID say he had a Jasco! Doh!
Sorry about that. I noticed that they also want the ram air to come from outside the cowl...with a scoop.
Being a fan (sorry) of generators, it's also worth remembering that 35A gens also require add'l help for cooling. Smaller gens benefit from it but aren't mandated to have it. I added another flange to the rear baffle and used sceet tubing to cool my gen.
.Miles
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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cessna170bdriver
- Posts: 4115
- Joined: Mon Apr 22, 2002 5:13 pm
Even the plenum-type cooling system on the '52 had 1" openings in the rear baffle where the rigid blast tubes bolted on. Your setup would be a modification of some sort. Optionally, there was a remote oil filter and an oil dilution system available, but no oil cooler. Apparently your blast tubes were removed to allow for the scat hose flanges. How big are your scat hoses? Any way you could get us a few pictures of your installation?Dward wrote:Did all "B" models have cooling tubes? My 52 has openings on either side of the rear baffling that feed a firewall mounted oil cooler through two scat hoses.
Miles
Miles
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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steve grewing
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