LOUD Raincap

[Richard]

Setup: Hit more than my fair share of branches with vertical exhaust pipe. Bent the pipe for Brutus...finally, went to muffler shop, bought new section of 2 1/2 inch OD pipe and replaced it. Old flapper on top wouldn't fit as easily, seems this 2 1/2 inch pipe is a touch wider than the old. No problem, went to Napa, for $8.00 +/- bought shiny new one /w3tcompact/icons/grin.gif

"Problem"..this shiney new one evidently has some lateral movement such that when the engine is idling to maybe 1/4 throttle, it makes such a clatter (that is magnified by the pipe itself) that you can NOT hear the engine running.. ok, literally, yes, you can hear the engine, but this clankering is amazingly loud. If you hold the flapper still, the engine purrs and all is wonderful, so I've tightened it up some but to no avail. I had the brainstorm hit me of maybe "isolating" it somehow by wrapping something around the top of the pipe to keep the noise from transferring...unsure about that idea..

Any ideas? I sure hate to make a federal case out of flappers..I spoke with the dealer and he said he wasn't sure that theirs was any better than what I had.

Richard

 

[EdKing]

You might consider putting a curved piece of pipe where the exaust exits the hood. You could divert the exaust down and to the side, eliminating the need for the flapper, and making it less likely to snag on branches. Just a thought.

 

[Youare]

Richard

It sounds like the action that is making the noise is horizontal, (<font color=blue>laterial</font color=blue>) which leads me to think that the noise is from vibration transmitted through the exhaust pipe which rattles the raincap.

Can you some how make the clearence less at the pivot point of the raincap, maybe this will help if the noise is because of play in this joint. You can purchase teflon washers from McMaster-Carr Supply Company which may be useful on either side of the riancap pivot to dampen vibration.

Teflon will withstand 500 - 600 degrees, the rain cap should not get that hot. If the noise if from a different source then that will not help. Let us know how you make out.

Randy

 

[Richard]

Yes Randy, action is horizontal. causes flapper to vibrate and shake side to side which I think THEN get's magnified by the actual exhaust pipe. Once throttle is opened further, flapper is forced up and most of the vibrations subside.

I tried (vice grips) to bend the tabs some closer together such that it would minimize the side to side. I figure if I bugger it up, I"ll just replace it. I had wondered about a washer but see no way of removing the pivot pin. I'll try to look up the M/C supply and see what I can find.

On way into work today, I saw another backhoe that had it's exhaust pipe with a 90 degree bend on top. I may take pipe back to muffler shop and see if they can bend it...

If I do that, I still fear some water getting inside..any issues on making it slightly MORE than a 90 degree bend such that the exhause is directed downward some? Sort of like a J bend but not as bent.

Richard

 

[Boondox]

How about making a 90 degree bend but cut it off diagonally so you have a bit of an overhang on the top?

Pete

 

[Richard]

yes, that is exactly what I saw today. The one today had a nice crisp CORNERED 90 degree bend in it. If the mufler shop does this, I"m sure it will have a much more..."gracious" curve than a corner!!

I really DO want to minimize this racket though. Driving me nuts.

Only downside I see with the bending angle (stupid pun intended) is it will ultimately lower the height of the outlet. As it is, it is just a couple of inches above the cab roofline. Since my cab has had most of the glass broken out over the last 15 years, the exhaust may feel invited to join me in the cab. That is the only thing thus far making this a second choice to me.

 

[Egon]

Size the bent piece of exhaust pipe so it extends above the top of the cab.

Egon

 

[Golfgar4]

I may be missing something here, but didn't this all start with the exhaust getting whacked by tree branches? Couldn't you solve both problems by installing a horizontal exhaust pipe? It may be a little more expensive, but it would seem to me that it would be the best solution all the way around /w3tcompact/icons/hmm.gif.

 

[Richard]

Unsure how to install horizontal. Exhaust is plumbed on TOP of the hood, is 2 1/2 inches od. with how big it is, amount of exhaust, loader arms, just dn't see where I can plumb it without causing issue.

Now, update..I took mans best friend (sorry Fido) VICE GRIPS and was able to SUBSTANTIALLY tighten it and reduce the noise!! /w3tcompact/icons/grin.gif Will try current setup for while.