Thats coo, at 12am I just made a sound clip video. Its like all dark but you can hear it. Ha
http://s214.photobucket.com/albums/c...t=MVI_0544.flv

 

thats a load of crap

 

What do you mean by thats a load of crap? Are you referring to the statement about the valves? If so, I agree with you. If that were true then why do drag cars run open headers? In another thread backpressure is discussed and has nothing to do with this. The engine is like an air pump. The more air in and out the better.

As far as sound goes though, the farther the muffler is from the engine the deeper the sound, and the farther back the tailpipe exits the quiter it is. This is what I have always seen to be true.

 

Ya ..I was referring to the statement about the valves, nothing annoys me more than people spouting insubstantiated non-sense, and if that's not an oxymoron tell me what is, and yes the further from the engine the muffler is the more efficient

 

First,
I apologize for not being more specific on WHICH VALVE would get hot and deteriorate.-this would be the exhaust valves.
And,..I dont agree with you,
..-And It Looks as though FLOWMASTER doesnt agree with your education on the subject either.
Take the time, AND READ THE ENTIRE PAGE CAREFULLY at this website address:
HTTP://www.flowmastermufflers.com/backpressure.html

I dont think youll find these people dealing in the business of un-substantiated nonsense. -I havent got the time for it either.
This is "old school" information by the way.

Have a nice day.

 

-OR, go to Google and type:
"exhaust valve backpressure", click on FLOWMASTER,Inc

 

was wondering how long it would take you to find something on the net, you are taking statements out of context, written I might add by someone intent on selling a product, Oh I agree that a good exhaust system can have less bp due to scavenging etc. etc which is why you would use long tubes for TQ, and why REAL tri-y headers are built according to firing order NOT convenience....zoomies are still prefered for high rpm.......all that said I still say the statement about burning valves due to choice of exhaust system is crap..YES there are marginal differences in temp. but nothing sigificant enough to worry about, especially in an engine built for a truck. BTW I agree burning lean will cause damage to valves, thats why we have an o2 sensor or manual adjustment on carbs

 

Sorry I didnt get back to ya sooner,-I was cutting my mufflers off.
I wasnt taking ANYTHING out of context. I was simply backing up my statement. This is what happens to engine valves without back pressure in an exhaust system.
VAlhunter23 stated in his original post that he was running a straight pipe for an exhaust to make a louder sound.
Straight pipes on a stock motor burn exhaust valves.
I could care less if you had a Flowmaster, or a tomatoe can,
I chose that arcticle from Flowmaster because its pretty much stated what I was taught about heads and valves 25 years ago.
That article-that wasnt a sales pitch, its a fact of what happens. there using the information to back up their product,as every other muffler company does. its has more to do with physics than mufflers.
Its is a fact that the exhaust valves will burn out without the full duration assisted by the backpressure in the pipes of a stock motor. period.

Drag Motors, or engines with big lift cams, and milled out heads have the room for a fully open valve which takes away the need for any backpressure.- and these motors are ripped down on a regular basis as well to compensate for expected issues...-like.. exhaust valves.
A stock motor with an open exhaust isnt going to last very long.
O2 sensors work with the idea that theres a muffler on the engine, and when the muffler is gone, the O2 sensor gets pinned against its limit, and burns out as well. - nothing to worry about?, yea, mabey not at first, but gradually..once those backfires begin, and it gets harder to start, youll be ripping those heads off soon enough.

 

Quite frankly I have no more time to waste trying to educate you...obviously you didn't get it, personally I run mufflers 'cause I hate noise..........but I've never known ANYBODY to burn a valve b/c they dropped their mufflers...and NO you haven't proven your point, it's like I said in my first post..unsubstantiated -like the 250mpg carb.

 

250mph carb??
anyway, Yea, I did prove my point. I guess it just fell on deaf ears,-but youll catch on someday.

 

I really do like to see other people going at it occassionally.......and no matter how much I dislike ssidney for the WAY he says things...I have to agree, YES your exhaust will be louder with shorter pipes...and yes the sound will get dulled with the more length the fumes have to travel...however, running straight pipes at a short distance won't fry your valves...ya'll are worried about backpressure, but quake you said come out under the doors...by that you are referring to the way Chris has the exhaust set up on his truck...even MINIMAL bends in the pipe will cause backpressure......hell if you ran open manifolds it would have backpressure...manifolds are as we all know cast iron castings...they are no where near as efficient as a good pair of headers....headers are mandrel bent as well as a decent exhaust that is done right...but even the roughly 45 degree angle coming down from the manifolds to the underbelly of the truck will give a little backpressure...if you wanna burn up valves....take the manifolds off completely and have the exhaust coming out ride off the heads...then you'll fry something.

JR

 

Well, I guess we all have beliefs, and seen, or more importantly, worked on things that show proof in one way or another, I gotta say -too each his own, some people agree with things, and some dont.
Right now I got an axel and a bad leafspring thats takin up my time, so... if I blow out a valve in the near future, I'll probably be out here sqwawkin about it while lookin for parts, or dodgin' the weather.
So, carry on the fight my good man, and keep your head low.
-out.

 

yeah pull your cat then listen to it it will sound like a whole different truck

 

haha i never really thought about frying my valves, but i think im gonna go with a super 40 flowmaster and let yall kno how it is and if its not loud enough i will look for a high flow cat

 

That '92 F150 will have a cat at the confluence of the Y pipe and another cat a little ways back. Unless you remove at least the second cat you'll never get it to be very loud. Too much sound disapated through the cats. The best scenario, if you need a cat for emissions, is a new Y pipe without the front cat and a high flow cat followed by a flow through muffler. Plenty of backpressure for Q-n-Q and loud enough for you. I don't like the sound of my Cherry Bomb glass-pack and am swapping it for a super 40. A little deeper rumble.

I like 2.5" pipe to drop a little of the back pressure the smaller pipe causes.