The International Cessna 170 Association

I need to purchase an STC that belongs to the club. Who can I talk to about purchasing it? My contact info is 701-306-4155 thanks

Or you can call Headquarters and tell Jan you'd like to join and buy the STC all in one phone call.

The International Cessna 170 Association, Inc.
22 Vista View Lane
Cody, WY 82414-9606

(307)587-6397 (Phone)
(307)587-8296 (Fax)

Email: headquarters@cessna170.org

As a matter of curiousity by a reader, just what is this STC all about?

BL installation of a continental 0-300-C,D or E with em series prop in any Cessna 170.

Thanks, Ron.

I just completed installing an O300D in my C170B using this STC. Everything worked out well, and I'm very happy with the result. One thing I'll mention is the minor detail of the dipstick. The original dipstick must be retained so the marks are in the right place for accurate level indication with the airplane in the 3-point attitude. However, the O300D dipstick tube is different than the one on the O300A or C145 engine. The D engine has a metal spring clip that engages a slot in the top of the dipstick bushing to hold the dipstick in the tube. As a result, the sealing O-ring moves to the bottom of this bushing, whereas the original had a much larger O-ring higher up the bushing where the spring clip resides. The result of these differences is that if you simply slip the old dipstick in the O300D's dipstick tube, you'll have a mist of oil blowing out around the dipstick keeping a portion of your firewall well greased. The solution chosen was to melt the brazing from the C170 dipstick and discard the old bushing. Then a new bushing was machined using the C172 dipstick as a pattern (the O-ring groove was placed slightly lower for better sealing), and brazed onto the original dipstick. The result was a much better seal, and no more oily firewall/battery box.

OIl Dipsticks (actually "OIL GAUGE ROD"s) are addressed in TCM SIL00-7A found in the MX Library.

Oil gauge rods are SPECIFIC TO THE AIRFRAME...not the engine. If one looks at the IPC for the O-300-D (or any other) one will find the oil gauge rod PN is not listed. It is "not sold" or "NS".... because it is specific to the installation.

Now, as regards the O-300-D engine: This engine was intended for the Cessna172, and as such it used oil guage rod PN 628413A1.

HOWEVER... if one looks at the SIL00-7A one will see that the oil gauge rod to be used for the O-300 (all series) in C-170 is PN 628410A1.

This oil gauge rod will have an aluminum "tab" on the rod, just above the 0-ring "bushing" which Karl mentions. (That tab is visible in his photo.) The rod will have the airframe intended for installation engraved. PN 628410A1 (for the 170) will have the identification "170" stamped on the tab.

The small groove in the "bushing" is intended for a spring-clip which is usually installed on the latest version of dipstick tubes swaged into the sump. This spring clip is intended to hold the oil gauge rod in-situ...and to insure the O-ring properly engages to prevent oil blow-by.

IN FACT... if all technicalities are followed.... the spring clip is required for utilization of the increased oil-temperature limits of 240F called for in the latest TCDS for the engine, as is the retainer-chain for the oil cap.

My 628410A1 oil gauge rod remains properly in-situ wihout the spring-clip, although it's on my "someday" wish-list.

It is important to note that most if not all the information provided in TCM SIL's applies to the LATEST versions of TCM overhauleld/rebuilt engines... not necessarily...nor even likely...to be found in a present-day Cessna 170. MOst of the engines in our airplanes are "field overhauls" or "field repairs".... and do not comply with the latest TCM overhaul data.
Most of the engines do not have dipstick tubes designed for the current 628410A1 oil gauge rod.
If you truly want your oil gauge rod to be held properly..,it must conform to the dipstick tube which is installed in YOUR engine.
Just because you might not have PN 628410A1 installed does NOT mean your setup is unairworthy. It likely only means it's not to the latest standard... but that does not make it unairworthy or incorrect.

It's also worth remembering that if your airplane is on floats that a tricycle airplane oil gauge rod will be better than a tailwheel one will.

The most important point is to change your oil.... put the appropriate amount of oil in it...and NOTE the oil level on YOUR PRESENT DIPSTICK...and use THAT information for future reference. It might be a nice thing to place a note to the effect for other users of your airplane in the ops manual/owners manual/check list used in your cockpit.

Thanks everyone!

gahorn wrote:Oil gauge rods are SPECIFIC TO THE AIRFRAME...not the engine.
The most important point is to change your oil.... put the appropriate amount of oil in it...and NOTE the oil level on YOUR PRESENT DIPSTICK...and use THAT information for future reference. It might be a nice thing to place a note to the effect for other users of your airplane in the ops manual/owners manual/check list used in your cockpit.

George,
This explains a lot but I have an additional question. I changed my oil and filter this past weekend. I prefilled the filter with about 1/2 quart, added the remaining 7.5 quarts to the sump, test ran the engine then inspected for leaks. The oil level indicated barely 7 quarts on the dipstick. Does the oil filter kit require an extra quart, for a total of 9 quarts?
Thanks,
JP

No, the oil filter only holds about a half a quart. I could be wrong, but my personal theory is that refilling the suction and pressure galleries between the pump and the rest of the engine take most of that extra half quart. As long as there's oil in the sump, the oil will stand in those galleries for a reasonable amount of time (think of a water jug inverted with only the snout in the water). When you drain the sump to change the oil, the galleries drain too.

After you've had some experience with your airplane, you may change your mind about servicing it to the full 8 quarts. You'll find that in this engine that first quart goes away very quickly, then things settle out. For short hops, I'll go with 6 quarts or maybe a little less, while even for long legs I try not fill to more than 7.

Seems to me, maybe the only difference between having 6 or 8 quarts in the engine is that with 8 quarts, the oil temperature should rise more slowly during a climb. If you're running with 6 and see normal temps in cruise, but it gets hotter than you like during a climb, put in the extra two quarts.

Or if you're crossing the Atlantic....

In my experience that 8th quart gets thrown out in about the first hour.

cessna170bdriver wrote:In my experience that 8th quart gets thrown out in about the first hour.

Maybe depends on the engine. I run 8 quarts in my Swift all the time (also O-300A powered), and it holds it. 185 SMOH on new Continental cylinders, and I'm getting at least ten hours per quart of oil.

The first quart of eight used to go out of my airplane in about the first hour too. I finally just used seven quarts and it held just fine. Never did figure out why.

I know on the truck I drove the first 1.5 qts were lost due to the crank beating the oil and I assume vaporizing. My dad chewed me out for not keeping the oil on the high mark but later moved the high mark and never lost oil as quickly. Just think of the engine positions when flying and possibly the same scenario.

John