Northern Mooniac Posted February 17, 2018 Report Posted February 17, 2018 My plane went in for annual and just got word my exhaust was developing a hole. So....new exhaust. Any suggestions?
carusoam Posted February 17, 2018 Report Posted February 17, 2018 Expect welding to be an option... There are a couple aviation welding shops that rebuild exhaust systems from a single screw... How is your CO monitor? Best regards, -a-
milotron Posted February 17, 2018 Report Posted February 17, 2018 My K had some exhaust welding in it's history also. Do you know where the leak is?
Northern Mooniac Posted February 17, 2018 Author Report Posted February 17, 2018 Not sure where the leak is. Nothing on co yet. It’s just starting to form a bubble. What does the high performance exhaust do for it?
carusoam Posted February 17, 2018 Report Posted February 17, 2018 You caught my post while in edit... With the 231 (turbo) you are going to have some limitations. The exhaust is part of the turbo drive system. The PF exhaust is an add-on for NA engines to minimize back pressure, increasing hp. Exhaust wear is exacerbated in turbo planes because of the additional pressure kept inside the system. Check the wall thickness on the first tube while there... this is the tube from the engine to the turbo. Highest temp and pressure the system sees. Best regards, -a-
milotron Posted February 17, 2018 Report Posted February 17, 2018 Bubble from soap bubble test I presume? There are Powerflow exhausts for J and other models. Nothing for us turbo boys, that I am aware of. Likely would not help much, we already have no muffler.
CaptRJM Posted February 17, 2018 Report Posted February 17, 2018 If it gets too extensive you may want to contact Aerospace Welding in Minneapolis. They will duplicate any single piece or the entire system if necessary.
DonMuncy Posted February 17, 2018 Report Posted February 17, 2018 Try Dawley. They can rebuild any or all parts. Fairly reasonable.
Guest Posted February 17, 2018 Report Posted February 17, 2018 Acorn Welding in Edmonton should be able to help you. But you may want to send them the entire system. Clarence
Northern Mooniac Posted February 18, 2018 Author Report Posted February 18, 2018 i'll try and get some pics and see if its worth fixing it just put in a new exhaust.
carusoam Posted February 19, 2018 Report Posted February 19, 2018 NM, do you have a preffered TIT that you use all the time? Some people are more religious about keeping things cooler than others... this is the area where temp matters more... the TIT is further down the pipe from the collector. So the collector is seeing some very high average temps compared to the single EGTs and the TIT.... PP thoughts only, not a mechanic... Best regards, -a-
vance.k Posted February 19, 2018 Report Posted February 19, 2018 NM, I feel your pain. I'm in the throws of the same issue right now. Found a leak near the #6 (exhaust dust and blistered paint on the engine mount). We pulled the whole left side exhaust and sent it to Knisley. Was supposed to be 2 weeks, but took over 5. Ugh. Then, once we got it back, big leak on the crossover between the new and old. Our mistake for not taking everything off and sending it all together. Good advice above to do that...wish I had known. I actually didn't realize they basically just rebuild everything instead of patching. Works for me...I just didn't know. Knisley basically said it would be another 4+ weeks. Dawley said the same. It is killing me having the plane down (I fly quite a bit and hate taking the 'bus'), so I overnighted everything to Aerospace Welding in MN as they indicated 1-1.5 week turnaround. We will see. Check those v-bands while you have it apart. Found a crack on one of mine. Good luck! Vance 1
Northern Mooniac Posted February 19, 2018 Author Report Posted February 19, 2018 I’ve been running LOP a lot, especially in the hot summers, I find it easier to keep the engine cool vs rop. i sit around 1590 lop and 32-34” and 2450-2500 rpm. Not or flying over 12500 right now, but those numbers work well for 9500 to 12500 1
Northern Mooniac Posted March 9, 2018 Author Report Posted March 9, 2018 Got the exhaust fixed for $500 Canadian!
vance.k Posted March 15, 2018 Report Posted March 15, 2018 Hey @Northern Mooniac, Congrats on getting it fixed. I'm curious, what all was done for the repair? I basically ended up with a completely rebuilt exhaust. I know they are supposed to keep some portion of the original component in order to 'repair', but I swear each shop basically built a new system. Anyway, I'm back flying with what I would say is a 100% new exhaust, but it cost many multiples of $500 Canadian. Thanks! Vance
jlunseth Posted March 15, 2018 Report Posted March 15, 2018 The bigger problem (than high heat), is contact with something on the exterior. There are at least two heatshields that are just pieces of sheet metal between the collector and other engine components. Usually they are just bent metal supported at one edge. Over time, the metal bends down and contacts the collector and then starts to wear a slit along the edge where the heatshield is rubbing against the collector.
78victor Posted March 18, 2018 Report Posted March 18, 2018 we have a good exhaust system that we just removed from a 58 m20. Our was totally rebuilt last year so we are using the engine from the 58 and our own exhaust. Parting our make an offer.
carusoam Posted March 19, 2018 Report Posted March 19, 2018 Welcome aboard, 78Vic. Can you clear up the description of what you are selling? You might consider starting a new thread specific to your plane and parts... This thread is more specific to its title. An M20K... Thread drift is more than OK. It happens often. But, i’m Thinking, you want people to find what you have... A proper title will be helpful for that. Pictures of the 58 M20 are always appreciated! Best regards, -a-
Northern Mooniac Posted March 19, 2018 Author Report Posted March 19, 2018 Well, if it makes your feel any better. I'm having heat issues again in climb...ugh.
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