The International Cessna^® 170 Association

On our O-300 engines, the exhaust clamps used between the cylinder exhaust pipe and the exhaust manifold. What is the correct description of those clamps (could not find them on Spruce)? The four bolts & nuts that secure the two halfs of the clamps above, what size are they?
Thanks!

Frank, here's what you are asking:
https://awi-ami.com/partfinder/product/ ... COMPONENTS

The bolts are AN3-4A and if you prefer AN4C will be corrosion-resistant. The nuts are MS20365-1032C.

Here's the "whole enchilada": https://awi-ami.com/cessna-170-a-b-172a.html

Tell Charlie Field I said hi...and he'll either give you a real nice discount...or he'll charge you more... one or the other..

(TIC170A discounts apply)

Wag-Aero E-505-007 See also Cessna p/n 0550157-50 and 0550176-50Fig. 51-6 calls for AN365-1032C nuts to attach the exhaust riser clamps. When I see “AN365” I automatically think “elastic stop nut”. As we all know elastic stop nuts should not be seen in the engine compartment; they are for low heat applications. AN365-1032C however is different than AN365C-1032. The former is an obsolete p/n for an all metal locknut. The latter is a stainless steel locknut with an elastic insert - you don’t want to use that here. I believe the number George gives, MS20365-1032C, supersedes the obsolete AN365-1032C. MS20365-1032C is what Cessna calls for in the ‘75-86 C-172 IPC. It’s good up to 450°F. I’d recommend using AN363C1032 (MS21046C3) all metal stainless locknuts which can be used in applications up to 800°F. Although Cessna continues to use regular AN3-4A bolts on later 172’s I’d consider using AN3C4A corrosion resistant steel bolts and AN960C10 washers which are used in applications up to 800°F according to Genuine Aircraft Hardware Co. Typical egt’s are well over 800°F though so if you gotta have the top of the line hardware - good for up to 1200°F - use MS20033-1 bolts, NAS1149E0332P (or "R" for plain finish) or NAS1587-3 washers, and MS20500-1032 nuts. Whatever you use slather on some Permatex high temp anti-seize to keep the expletives to a minimum for the next guy removing the clamps.

I love this different design that only requires two bolts! It’s worh $64 to not have to tighten the inboard ones...

Especially on the #3 and #4 risers

cessna170bdriver wrote:I love this different design that only requires two bolts! It’s worh $64 to not have to tighten the inboard ones...

Miles they are even better at the $50.64 price Gary found at Wag-Aero

https://www.wagaero.com/engine-parts/ex ... pma-d.html

Wag Aero . . . Some of their stuff can be less than top drawer. Just sayin.