What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

RV12 exhaust cut

daveyator

Well Known Member
I’m at the point where the instructions have us trim the exhaust outlet to “not less than 4 inches below the cowl.” Curious as to what others have done. Have you just done a straight cut, or have you ‘slash cut’ the pipe?
Any reasons or advantage either way? I’m inclined to just cut it straight, as the original is supplied, but can see a slash cut maybe looking a bit tidier
Cheers DaveH
 
Last edited:
The longer the better, IMO. I love my 12 but cleaning its bottom is no fun. I installed the pipe uncut, as supplied. Note, my ship is an early build with the new muffler retrofitted as pictured.
 

Attachments

  • IMG_2975.jpg
    IMG_2975.jpg
    180.9 KB · Views: 80
Hi Dave
Your post made me sit up & take notice since I didn't recall any such instruction to trim the exhaust pipe.
I checked section 48 of the KAI for both models (original & current) and don't see anything about trimming the exhaust?
Bob
 
exhaust space

whatever you do: keep in mind that dismantling and re-attach the bottom cowl of the 12 is no fun on your own. It is da-able, but only if the space in the bottom cowling is enough to 'wiggle' a bit with the cowling. There isn' t much space between the nose-fork (including cover), the exhaust and the spinner.
Two people is a bit better, but still you need space around the exhaust.
 
whatever you do: keep in mind that dismantling and re-attach the bottom cowl of the 12 is no fun on your own.

Try removing the lower cowling with a three bladed prop. It is even less fun. If my exhaust stack was any longer I wouldn't be able to get the lower cowl off.
 

Attachments

  • N233VA Outside Crop.jpg
    N233VA Outside Crop.jpg
    208.3 KB · Views: 85
There may be a good reason to cut exhaust pipe to a shorter length... On my last annual condition inspection I found cracks on the muffler end bell where the exhaust stack is welded. I'm thinking the long cantilever exhaust stack imparts stress on the welded joint from vibration. Tony T had same problem...
-
 

Attachments

  • Screenshot 2022-12-05 at 2.36.56 PM.png
    Screenshot 2022-12-05 at 2.36.56 PM.png
    2.5 MB · Views: 48
Hi Dave
Your post made me sit up & take notice since I didn't recall any such instruction to trim the exhaust pipe.
I checked section 48 of the KAI for both models (original & current) and don't see anything about trimming the exhaust?
Bob
I didn’t make it up.:D
DaveH
 

Attachments

  • BFC062F9-EA18-4C4A-8EA0-E4FBD80FBF5E.jpg
    BFC062F9-EA18-4C4A-8EA0-E4FBD80FBF5E.jpg
    239.8 KB · Views: 150
I trimmed mine at an angle - basically parallel to the ground. Thought it looked a bit better. Mine is the original style exhaust - probably the same as yours.
 
I didn’t make it up.:D
DaveH

An important note for you (as well as for others who likely have newer parts/plans): The version of the plans you posted the clip of is a version that has been revised multiple times since, as have the RV-12 exhaust parts. The version you are looking at appears to be pre-2015, and since then we've changed the spacing between the muffler and oil cooler, among a number of other exhaust system changes.
 
Last edited:
An important note for you (as well as for others who likely have newer parts/plans): The version of the plans you posted the clip of is a version that has been revised multiple times since, as have the RV-12 exhaust parts. The version you are looking at appears to be pre-2015, and since then we've changed the spacing between the muffler and oil cooler, among a number of other exhaust system changes.

I understand there have been changes. The section I quoted is from the plans that apply to my particular exhaust system. Let’s say I am working on possibly the world’s slowest RV12 build. Although I normally try to stay up to date with plan revisions, in this case I thought I should use the plans applicable to my exhaust. Are you suggesting I should simply ignore this as it does not apply to later exhausts?
At some point I will probably install a newer system, but that is a costly option given the state of the Australian dollar, freight costs etc.
Cheers DaveH
120485
 
Last edited:
I understand there have been changes. The section I quoted is from the plans that apply to my particular exhaust system. Let’s say I am working on possibly the world’s slowest RV12 build. Although I normally try to stay up to date with plan revisions, in this case I thought I should use the plans applicable to my particular exhaust. Are you suggesting I should simply ignore this as it does not apply to later exhausts?
At some point I will probably install a newer system, but that is a costly option given the state of the Australian dollar, freight costs etc.
Cheers DaveH
120485

No, just pointing out that most people here will have plans and parts that are newer is all, since at times people will find this thread while searching for help, and it's important to know things have changed. And yes, you do need to use the plans applicable to the kit parts you're installing!

We'll be excited to see your airplane flying!
 
fwiw, removing one stop bolt in the front gear fork and turning the nosewheel 180 deg. may make some installations easier to remove the lower cowling.if the plane is parked with several sheets of paper under the nose gear it turns easy.
 
Back
Top