Exhaust risers - REPLY to N9149A

Post by **GAHorn** » Mon Jun 10, 2002 5:42 pm

Bruce F. (in the Events Forum) wanted to know where I was obtaining my exhaust risers.(170B, SN-25713)
Knisley Welding, 916/652-5891 makes them new, with 1/4" flanges! Nice and strong. WagAero 800/558-6868, also sells Knisley's product at the same price.
The short straight ones are 0550157-7's $51.50.
The curved one is 0550157-8 and is $87.50.

N170BP · Post by **N170BP** » Tue Dec 06, 2005 3:55 pm

So for those of you who have purchased these Knisley / Wag
Aero risers with the thicker 1/4" flanges, did you have
to use longer exhaust studs? Or did you use a different
(lower profile) fastener to mount the risers?

TIA,

lowNslow · Post by **lowNslow** » Tue Dec 06, 2005 5:37 pm

N170BP wrote:So for those of you who have purchased these Knisley / Wag
Aero risers with the thicker 1/4" flanges, did you have
to use longer exhaust studs? Or did you use a different
(lower profile) fastener to mount the risers?

TIA,

No. Standard hardware worked fine for mine.

N170BP · Post by **N170BP** » Tue Dec 06, 2005 6:10 pm

Very good, thanks!

Post by **GAHorn** » Wed Dec 07, 2005 12:26 pm

Bela, I had to replace a cylinder and was supplied a Millenium for the purpose. (I'd asked for TCM but the shop boo-boo'd and by the time the cylinder arrived, I needed to get airborne and could not wait for my preference.) The exhaust studs were too short to completely protrude thru the brass exhaust nuts. You might wish to consider high-temp steel nuts instead.

N170BP · Post by **N170BP** » Wed Dec 07, 2005 4:36 pm

Thanks George.

Would something like an MS21043 / NAS1291C nut
work? These are silver plated stainless steel lock
nuts that are good to 800 degrees F.

Cad-plated steel lock nuts are only good to 450 degrees F (I
think cyl. head temp redline is 525).

I have the former (MS21043) with stainless AN bolts holding
all the exhaust riser clamps together.

dacker · Post by **dacker** » Wed Dec 07, 2005 8:05 pm

I replaced all of my risers with the Wag Aero / Knisely product on my engine rebuild. When it came time to put it all back together the long ones didn't fit very well. I sent everything (risers, mufflers, stacks, and clamps) to Dawley Aircraft Exhausts where they put it all on a jig and inspected and fitted everything. They wound up manufacturing the two longer risers. I was very happy with their service and thought the risers that they made were better than the Knisely risers. The Knisely risers are not welded on the inside so that the pipe is not attached to the flange on the inside... I am not sure that it makes a difference but it looks sloppy. I did not need different studs on mine. Hope this helps.
David

dacker · Post by **dacker** » Wed Dec 07, 2005 8:14 pm

By the way, the Dawley Aircraft number is 1-800-338-5420.

N2865C · Post by **N2865C** » Wed Dec 07, 2005 8:51 pm

I can highly recommend Dawley. When there was a problem with fit on some stacks they "repaired" for me they paid for overnight shipping both ways and made it right. I think they "repaired" one half of my stack and then "repaired" the other half. When they were finished I couldn't find any old material. Great customer service.
http://www.dawley.net/

Post by **GAHorn** » Thu Dec 08, 2005 1:34 am

N170BP wrote:Thanks George.

Would something like an MS21043 / NAS1291C nut
work? These are silver plated stainless steel lock
nuts that are good to 800 degrees F.

Cad-plated steel lock nuts are only good to 450 degrees F (I
think cyl. head temp redline is 525).

I have the former (MS21043) with stainless AN bolts holding
all the exhaust riser clamps together.

Just remember that they are 5/16 studs with 24 pitch threads. (5/16-24) So the MS21043-5 nuts should work great.

N170BP · Post by **N170BP** » Thu Dec 08, 2005 5:08 am

Got it, thanks again George.

N170CT · Post by **N170CT** » Thu Dec 08, 2005 5:46 pm

I wholeheartedly second the above comments on Dawley. I purchased rebuilt mufflers and risers from them and was/am very happy with their prices, attitude and service. Everything fit just as it should, right outta the box

. Good folks.

In contrast, I had purchased rebuilt risers from another source and the flanges were too wide (not too thick) to install. Probably could have ground them down to fit, but was too annoyed

at the time lost.

By the way, not sure about the actual numbers, but would expect the temperature of the exhaust risers/flanges to be substantially higher than cylinder head temperatures. Just a thought.

Regards,
chuck

lowNslow · Post by **lowNslow** » Thu Dec 08, 2005 6:54 pm

gahorn wrote:Bela, I had to replace a cylinder and was supplied a Millenium for the purpose. (I'd asked for TCM but the shop boo-boo'd and by the time the cylinder arrived, I needed to get airborne and could not wait for my preference.) The exhaust studs were too short to completely protrude thru the brass exhaust nuts. You might wish to consider high-temp steel nuts instead.

I should have stated in my previous post that I have new Continental cylinders, and the standard hardware worked fine with the thicker risers.

N170BP · Post by **N170BP** » Fri Dec 09, 2005 8:24 am

Just finished hanging the exhaust with the Knisley risers. Had
no problems with fit / tolerances.... (?). The thing went right
back together like the new parts had always been there.

The upper feeder tubes to the muffler (where the lower portion
of the risers goes in) were a bit out of round (too many torque
sequences with the clamps with Mr. Universe manning the torque
wrench I guess) but I "convinced" them to get round again
with the proper tools.

In my case, the thicker riser flanges made it impossible to use the
original brass nuts... I used MS21043-5 nuts (thanks again George)
and the lower profile of these fasteners makes for a perfect match
with the thicker flanges.

Somebody needs to start making Hanlon Wilson parts again (my
cabin heat shroud, although serviceable, looks like the devil).

A good buddy is contemplating buying a used tube bending machine
and getting into the exhaust manufacturing business (he's Mr. Welder).
I'm thinking the sheet metal parts need to be made new again.
Guess if I wanted to make a million bucks in aviation, I better
start with 2 million....

Post by **GAHorn** » Fri Dec 09, 2005 9:44 pm

Bela, Charlie up at AWI in Minnesota made a new cabin heat shroud for my 53 model. It's a work of art, and really was well done. It's slightly thicker gauge sheet metal than the original and fit up very nicely.
The only complaint(s) I have are:
I sent him mine for a "model". It was in excellent shape. I only wanted a spare in return for letting them use mine to copy. I had no idea he'd destroy my original while reverse-engineering it. (Not a problem if your own is worn out, but in my case I only thought I was being helpful to them by letting them use mine for a model to make a die so they'd go into production for the benefit of the rest of the world.)
When mine was ready, Charlie called and told me he couldn't find the supplier for the original spot-welded stainless tinnerman-style nuts which were integral to the design and spot welded on....so he informed me he was shipping it to me with a handful of loose tinnerman nuts and for me to drill the holes to match my current muffler and use the tinnermans to hold the new screws. I told him baloney! I had sent one to him with spot-welded tinnermans and I expected to get one back that way....and if I could drill holes in the new shroud using my muffler for a pattern...then HE could drill them using my original shroud for a pattern....and weld the tinnermans in place! (There's no way to slip one's hand between the muff and shroud to hold a tinnerman in place so one can install a screw!)
He took a breath and said, "....Welll.. OK."
I got the new shroud back about a month after I'd sent it to him.

Now truly, it IS a work of art. It's beautiful. It fit perfectly. Unfortunately I lost my original to him. And Unfortunately ...the new one came without the Hanlon Wilson dataplate attached. It was totally missing.
I called back up there and talked to a worker in the shop who found my old one in the trash and dug it out and mailed it to me. It's in my deskdrawer instead of spot-welded onto my shroud.
And it cost me $278 to do them the favor of letting them use my shroud for a "model"...which I never got back.
Other than that.... they can probably make you a nice shroud.