Regardless of whether the suction screen has a female fitting in it or not--mine does not -- the proper place for the temp probe is in the pressure screen,right? Or in the corresponding place in the filter adapter. Can't see where this point needs further debate.
I've never heard that the suction screen shouldn't be removed. True,stuff that would get by there will get caught in the pressure screen due to it's finer mesh. But I usually pull mine about once a year,just in case. Ya never know!
George is right, the F&M paperwork tells ya where to put the probe. It WILL thread into the F&M filter assembly without an adapter bushing, but it'll leak. The little flange on the temp probe needs to seat against the inside of the adapter bushing. The temp probe can APPEAR to be installed OK directly into the filter assembly,but the tip of the probe is then bearing up against a surface inside the filter assembly. It is not sealing against a seat,it will leak (possibly in a catestrophic fashion!),and in the meantime you can cause damage to the probe tip and/or the probe flange. I hate to admit it,but I been there & done that!
Eric, you have the El Reno version, right? (Not that it makes any difference in this particular thread, but it might.) I've installed 4 of the FM Enterprises and none of them have yet to leak. Perhaps the oil temp probe was not seated correctly as Eric alluded to.
Just be certain it's centered and your probe "skirt" is not damaged.
Tighten it snug and then one more flat on a new one, 1/2-flat on a used one.
'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.
I am getting around to changing out the Airwolf remote filter that I have for the FM filter. I don't like the hoses, and think the FM will be a tidy installation. With the airwolf, I have the mechanical temp probe on the suction screen. I am also going to change out the mechanical probe for an electric. That is where my original question came from. It looks like I have the option of putting the probe in either place. Which would be better? The suction screen would measure the oil at rest in the sump, where the filter position would measure after the pump has applied the pressure.
BTW, referring to the earlier posts about getting the correct torque, I have a 1 3/16 twelve point socket that fits the square on top of the FM unit. no crows foot and lever multiplying.
Dave
Dave,if it was me, I'd put the probe in the pressure screen area. That's where it was in the stock 170/C-145 installation,so that's where it's gonna be reading the oil temp that God (& Cessna) intended it to read.
Also,I'd be kinda careful using that 1-3/16" 12-point socket. The F&M filter assembly is supposed to be torked to 65 foot-pounds,that's a lot of umph! I think if you check,you'll see that not a whole lot of socket is actually bearing on the 1" square head of the "oil transefer cylinder". It's aluminum, so it might not be too hard to round the square corners right off when you reef down on the wrench.
The TCDS for the engine specifies the "oil inlet" temperuature. I agree with Eric that by definition, the oil pump exit (pressure screen/oil filter area) is the oil (gallery) inlet. That's also where the STC specifies to place it. You'd likely have to explain why you put it somewhere else if some nosey F-- questioned it. (didn't want to use foul language on a family site, so I represented the last two capital "A"s with hyphens.)
'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.
I just did an oil change and had not thought much about this until George's recent article in the 170 News.
It still feels a bit unsecure that the temp probe isn't a safety wired item.
Anyway, what is meant by "one flat" or "1/2 flat"? Does it mean to move the nut using one point as the reference bringing the next point of the nut to that spot?
I doo need to take a hard look at this probe since it's been slightly rounded by prior folks using just an open ended wrench.
Kyle
54 B N1932C
57 BMW Isetta
Best original 170B - Dearborn, MI 2005
There is no movement to the probe so no safety wire is required. (Think about your cyl hold down nuts....no washer even.) Plus, brass is a soft metal that deforms and creates additional friction to resist loosening.
Just don't make the mistake of always tightneing it "one more flat" each time it's removed. The initial "one flat" instruction is intended for a new installation. Subsequent removal/re-installations simply brng it snug to the former position. (The point is: DON"T overtighten this or your WILL lose ALL your oil.)
'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.
Reviving an old discussion here. Scott gives specific torque values in the instructions shown below.
Click to Enlarge
For those concerned about this nut not being safetied one can buy a jig to drill a safety wire hole. Pegasus Racing has some good advice on how to use the tool.
Unfortunately those instructs only offer a minimum torque. Keep this in mind... a slightly UNDER-torque condition will only result in a small, messy seep. An OVER-torque will result in a HUGE leak that will dump ALL your oil in a few minutes.
'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.
