The International Cessna^® 170 Association

n2582d wrote:

And last, a little contest to see how close attention to detail others pay to 170s. How do I know looking at the picture of the dpowells cowl, that it is a '48 or '49 cowl?

I'll bite. The air scoop assembly is shorter on the early model cowl?

Maybe it is that the very same lip being discussed here is cut off squarely at the ends as opposed to tapering gradually to the ends

Pictures of 1951 N1715D on the left with a 3/4" cowl lip and 1951 N1714D on the right with a 3" cowl lip. These are consecutive s/n airplanes with 2 different cowl lip heights. Both cowl lips appear original.

N1715D with a 3/4" lip ran at 205°-210°F with Phillips 20w-50 in cruise across west Texas and southern NM in 95°-100° ambient temps on the ground and 70°OAT at 6500'msl.

Click on picture to enlarge

n2582d wrote:

And last, a little contest to see how close attention to detail others pay to 170s. How do I know looking at the picture of the dpowells cowl, that it is a '48 or '49 cowl?

I'll bite. The air scoop assembly is shorter on the early model cowl?

johneeb wrote: Maybe it is that the very same lip being discussed here is cut off squarely at the ends as opposed to tapering gradually to the ends

Gary may be correct and it is a detail I have to investigate but it is not the obvious detail easily recognized.

John got it. The ends of the lip in the '48 and '49 (or prior to 19200) are squared of rather than a nice arching from edge to edge.

Bruce Fenstermacher wrote:...

Gahorn wrote:Anecdotally, I've heard the size of the lip is not of much import except on seaplanes (for which the increased lip size is often called a "seaplane" lip.)

Did you know there is no seaplane lip for the '48 to '49. do you know there is no seaplane lip for a '48 and '49 or cowls prior to 19200? ...

I think the reason there is no seaplane lip for the '48 and '49 cowls is that Cessna never certified this early model on floats.

I have nothing to add to this conversation. I just wanted to comment that this is exactly why the TIC170A is a great type club. Specific, detailed information that really help owners and pilots. There may be a little tension some times, but I love the passionate discussions. I will own a 1952 170B with classic piano key switches someday and this club will help me all the way. Look forward to seeing some of you at Oshkosh on Saturday and Sunday.

I could buy that for the '48 Gary, but the '49 is approved for floats. It didn't need a seaplane lip cause the lip was already 3".

Bruce,
I should have said, "Cessna never certified the straight 170 or the 1949 170a (s/n 18003-19199) on floats with the 3"-40° lip style cowl." If a 1949 170a is to be operated as a seaplane it has to be converted to the later style cowling. Here's a clip from the TCDS "Specifications Pertinent to All Models":The 0552000 cowling is the 1948-1949 cowling, the 0552001 cowling is found on the 1950-1952 170a and 170b, and the 0552002 cowling is the late 170b style without the classic grill and top hinge. I think what confuses a lot of us is that we assume the earliest cowling has a "seaplane lip" because it is 3" wide. In actuality, the seaplane lip, (p/n 0552001-60) is a strip of aluminum which is fastened to the skinny later style 3/4"-45° lip.

I suspect the 3 inch lip was actually added to the 1948 after production started maybe due to cooling issues. My 48 S/N 18608 has the 3 inch lip. However my project S/N 18041 has a short approx 3/4 inch lip. It appears to be original and no damage recorded that would make me think it was changed.

I would be interested to hear if any other early 48's also had the short lip.

What dimension of the lip is being measured, the entire lip or just the portion that is angled down and exposed? I can measure when I get back to the hangar, but want to make sure I am measuring the correct portion of the lip. 1948 170, S# 18118.

DWood wrote:I suspect the 3 inch lip was actually added to the 1948 after production started maybe due to cooling issues. My 48 S/N 18608 has the 3 inch lip. However my project S/N 18041 has a short approx 3/4 inch lip. It appears to be original and no damage recorded that would make me think it was changed.

I would be interested to hear if any other early 48's also had the short lip.

Not having a record of damage... does not equate to "no damage history". Neither does the statement "no damage history" in logs. The short lip was a later design so I suspect your cowl is not original.

One of the most egregious acts in the eyes of FAA is the failure or deliberate refusal to record all maintenance/modifications/repairs.

What dimension of the lip is being measured, the entire lip or just the portion that is angled down and exposed? I can measure when I get back to the hangar, but want to make sure I am measuring the correct portion of the lip. 1948 170, S# 18118.

Just the lip that hangs down. Should be either approx 3/4 " or 3 "

DWood wrote:?.. However my project S/N 18041 has a short approx 3/4 inch lip. ...

Dan, That's interesting. Is this 3/4" lip a shorter version of the straight 170 lip - i.e. with the squared off ends, or is it the longer arcing style of later B model cowls?

DWood wrote:I suspect the 3 inch lip was actually added to the 1948 after production started maybe due to cooling issues. My 48 S/N 18608 has the 3 inch lip. However my project S/N 18041 has a short approx 3/4 inch lip. It appears to be original and no damage recorded that would make me think it was changed.

I would be interested to hear if any other early 48's also had the short lip.

My '48, S/N 18073 has the narrow lip, with squared-off ends. Having only owned it since 2004, I cannot say whether it is original.

I know of another, S/N 185xx which also has a narrow lip, with squared-off ends.

Gary
Squared off

I certainly understand as I'd wonder if I owned a '48 with squared end lip that is only 3/4", if it was original. But, as there is no evidence Cessna made the lips 3/4" on the squared of cowl and so I think it much more likely they were all 3" but some modified down to 3/4" to mimic the later cowl and achieve higher temps.

Of course having a '49 with a 2-1/2" lip myself, should I ever see another 2-1/2" lip on a '49, I may start thinking it's a movement only Cessna might have made.