I have had Aermore exhaust whistles on my Ts for almost forty years, the present one being on my '15 for the last 10 years. Last year it began to act up in that it sounded continuously at a low 'hum' even when idling and would increase in volume as I accelerated or when easing up on the throttle quickly. I have checked the adjustment on the chain, made sure the butterfly was adjusted properly and working freely to fully open and close exhaust paths alternately between exhaust and whistle. Depressing the foot pedal gives great volume but the sound only stops completely if I'm driving at a constant speed on a level road without accelerating or slowing down. If I leave the car running at an idle and crawl underneath, I cannot make the whistle stop even with the cable linkage disconnected and me moving the cutout lever to any position. The sound did go away last year after lubricating the butterfly post and a lot of tinkering. I thought the problem was solved until my car backfired once the other day. The gasket appears to be okay. Is there a manifold gasket/exhaust sealer I can use with the gasket to ensure a proper seal? If this keeps sounding in my ears I will either have to give up the car/whistle or my Bachelor of Music degree because the sound is, although relatively low in volume deafening to me! What gives? Flute was always the hardest instrument to get students to create a sustained sound on and now I have four of the damn things that just won't quit!
Maybe the door or flap is burnt away or rusted.
The obvious reason, it seems to me, is that the interior flap is not closing completely. Either it is bent and not sealing, is worn away and not sealing or something built up or stuck between the flap and the seal.
Other than remove it from the car and examine the inner workings, I don't think it's a backflow or back pressure or bypass isue.
Welcome to the forum!
Earnie, I use this stuff on manifolds and exhaust systems.
It contains sodium silicate and expands and sets with heat. It is the consistency of thick toothpaste and is very handy to hold gland tings and crush rings in place when fitting T manifolds.
You should be able to find s US equivalent.
Hope this helps.
Allan from down under.
Thanks for the advice guys. I will try a Canadian version of the manifold exhaust sealant since I have had the cutout off today and the butterfly seems to work fine. I'm still perplexed as to why air would be sucked into the flutes when the butterfly is completely open, parallel to the exhaust pipe. When the flap is closed fully the horn is extremely loud. It works fine but doesn't stop sounding completely when I take my foot off of the floor pedal. I'm now thinking that one of the inner pipes in the muffler has moved and is partially blocking the exhaust exiting the muffler. The problem occurred immediately after a loud backfire.
Thanks for the welcome to a very informative forum.
Ernie (from up above!)
Also, check the coil spring tension on the valve shaft. the spring may have lost the original tension from heat over the years of use (assuming its not a new valve). I have a brand new valve (the type marketed back in the 60's and 70's which just clamped the the pipe (unlike the Texas T version which replaces a section of pipe. The spring on it leaves no doubt that it has adequate tension.
Earnie, on my RHD cars I have a rod linkage from the pedal rather than a chain. This makes afar more positive connection. One relies on the return spring at the butterfly shaft, the other has an additional spring at the pedal. This may or may not help.
Allan from down under.
Thanks Terry and Allan,
I have the aermore cutout that is mounted through a slot in the pipe but I am thinking of making an adjustable rod to clean up the linkage. As I have said above, the whistle makes a really loud sound when the pedal is depressed but the issue is the quiet continuous hum and slightly louder hum when accelerating or decelerating.
I'm going to take it off again and check it but everything seems to work smoothly as far as the butterfly is concerned.
My guess would be the exhaust pressure is forcing it to open slightly.