172 mufflers

56alpha · Post by **56alpha** » Sun Dec 08, 2002 2:17 am

I know someone thats has a 48 170 and it has the large dia. 172 mufflers on it. Any one know of an stc or 337 for this.

thanks
9156A 49
Jay

Bill Venohr · Post by **Bill Venohr** » Sun Dec 08, 2002 4:31 am

I'm not sure of "large" diameter mufflers, but I recently sent a copy of a 337 I had approved in September to install 172 mufflers in my '48 to the association.

56alpha · Post by **56alpha** » Sun Dec 08, 2002 5:05 am

I will get a part#. They are big, the scat tube is about 2.5-3 inches and the diameter of the muff. is about 8 inches (thats just off the top of my head). The cowl was modified to fit them and the carb heat box was modified to take the lager tube.

Thanks
9156A 48
Jay

zero.one.victor · Post by **zero.one.victor** » Sun Dec 08, 2002 6:06 am

A friend of mine has a ragwing & it has blisters in the lower cowl for muffler clearance . It's his second ragwing,the previous one had similar blisters for the same reason. Those are the only 170's I've seen with these blisters. I'm told there are 2 different size round (Hanlon-Wilson) mufflers,the later (172) version being larger diameter. Anyone wanting to convert to H-W's better be careful,if possible get the small ones as used on the 170B. The blisters in question are,shall we say,not especially pretty!
(sorry Larry!)

Eric

Bill Venohr · Post by **Bill Venohr** » Mon Dec 09, 2002 4:22 am

My 172 mufflers required no cowling or heat box modifications.

zero.one.victor · Post by **zero.one.victor** » Mon Dec 09, 2002 7:03 am

Re-reading the original post re: STC/337--
The 170/A/B TCDS includes item 110:"Hanlon-Wilson exhaust manifolds and carburetor air heater (Cessna Dwg. 0550157)".
So,an STC shouldn't be required. A 337 might be,along with a logbook entry.
Interestingly,the TCDS does NOT seem to include the pancake style exhaust,as original on the ragwing and A models. George,you seem to be up on this Cessna documentation--any thoughts?

Eric

Post by **GAHorn** » Mon Dec 09, 2002 9:18 pm

I think you've might have misread the TCDS, Eric. Only the 170B is eligible for item 110 according to my copy of the TCDS (but I'm looking at Revision 50. Rev. 51 has errors in it that the FAA has not corrected yet.) The 170 and 170A requires item 103, which is commonly referred to as the pancakes. (In the files I inherited from Tom Hall it says that since the Hanlon Wilson is listed in the TCDs for later planes it's only a logbook entry. This might boil down to a FSDO inspector's opinion. Hanlon Wilson may have an STC for this.)
I spent a great deal of time back in the summer trying to locate all the shrouds, etc. for the cabin heat/carb heat sytem for Hanlon Wilsons for one of our members. If you're considering this change, get all the parts located or arranged for before laying out the money. It wasn't easy finding it all and they weren't cheap when found.
(There should be no reason to require cowl modifications, tho', and I'm curious about the "bumps" that were mentioned. Sounds like someone has used a different model of muffs or installed them differently.)

CAS · Post by **CAS** » Tue Dec 10, 2002 2:45 am

My C170A S/N 19090 has HW mufflers and the unsightly bumps on the cowl. I will check on the size of the mufflers and see if I can find any mention of them in the log books.

David.

56alpha · Post by **56alpha** » Thu Dec 12, 2002 9:59 pm

Since I don't have access to the '48 170 in question I dug around the hanger and found a set of large 172 mufflers that came with our O-300D, these are the same size that are on the '48 170 with ugly bisters on the cowl. I also found a H&W (part# 0050157-0) 170B round muffler. I have the dimensions for both.

172: "can" diameter is 6", length is 11.75", and the air In&Outlets are 3"
170: "can" diameter is 4.75", length is 10.5", and the air In&Outlets are 2"

So if anyone has a and idea about getting the mufflers certified let me know.

Thanks
9156A '49
jaymstokes@hotmail.com

Larry Holtz · Post by **Larry Holtz** » Sat Dec 14, 2002 7:19 pm

zero.one.victor wrote:A friend of mine has a ragwing & it has blisters in the lower cowl for muffler clearance . It's his second ragwing,the previous one had similar blisters for the same reason. Those are the only 170's I've seen with these blisters. I'm told there are 2 different size round (Hanlon-Wilson) mufflers,the later (172) version being larger diameter. Anyone wanting to convert to H-W's better be careful,if possible get the small ones as used on the 170B. The blisters in question are,shall we say,not especially pretty!
(sorry Larry!)

Eric

Eric
I've checked the logs and find nothing about the muffler change or the blisters being added. The original engine was replaced with a new 145 at 238 hrs. and still going.
BTW, it's now at GTF. I was coming home after spending Thanksgiving in LWT and had to turn back at MSO because of the ice fog that stayed in Western Montana and Eastern Washington for a couple of weeks. I had to ride the hound home.
Larry

zero.one.victor · Post by **zero.one.victor** » Sun Dec 15, 2002 6:23 am

Sorry to hear about your "hound" return trip,Larry. Dean almost got fogged in at Jefferson about a month ago,the fog rolled in while he was eating lunch--he sat at the counter with his back to the windows! Luckily,it rolled back out again after about 2 hours just as he was tying down & getting ready to go hotel it for the night.
Planning to retrieve your airplane soon? Looks like the weather is gonna be crummy for a while yet. Good luck with it.

Eric

CAS · Post by **CAS** » Sun Dec 22, 2002 7:04 am

My C170A S/N 19090 has H&W mufflers and the unsightly bumps on the cowl.
I checked the size of the mufflers - they are approx 12" long and 6" in diameter.
The holes in the cowl where the exhaust pipes exit appear to have been moved.
There is a reinforced hole in the centre lower rear of the cowl about 1 1/2" diameter with no apparent purpose. Does anyone have any idea what this hole is/was for?

David.

The International Cessna 170 Association

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