CyDStang

Hey guys. About two weeks ago, I installed BBK Ceramic Long Tubes and a matching BBK shorty O/R X on my 2007 Mustang GT. I'm also running SLP Loudmouths. I was told by a local mechanic that running the offroad pipe along with the LTs and SLP mufflers (or lack thereof) will eventually lead to a burned valve(s). A buddy of mine also told me that because I have a crossover X that there's enough back pressure to keep this from happening, so I'm kind of confused. Essentially, I'm just wondering if I could cause any long term damage to my engine running my current setup, or if I should switch to a catted X. Thanks.

Rik08GTvert

sorry i cant answer that cuz i honestly dont know.
but i wanna get that setup so let me know plz what people say about it?

157dB

Have him explain the problem and why it will cause burned valves.
Whats different over the OEM setup?
The exhaust is still being carried by tubes away from the engine... ???
Does a more free flowing exhaust cause the valve burning?
I always thought a improperly closing exhaust valve got the burn.

CyDStang

The setup is ludicrously loud. The drone is pretty intense but at WOT the sound is unbelievable. The car is also my daily driver.

Rik08GTvert

yeah im gonna get bbk lt and catted x with catback boom tubes. dont know what that will sound like but im excited now cuz i got good feed back from both of those mods. cant wait to afford them. im getn a new job so ill be able to get the boom tubes at the end of the month, but the lt and x will have to wait till the end of april.
thanks for posting me back though. my minds made up now

candymanjl

there's no way an exhaust would burn a valve. you would have to have some other problem or run really lean or something to burn a valve. having it burn because of the exhaust just doesn't make any sense at all.

I found this article, scroll down to "why valves fail" and what they're saying makes sense.

http://www.aa1car.com/library/ar1192.htm

if you don't want to read the whole thing basically 75% of a valve's cooling is through direct contact with the head through the valve seat. corrosion build up and/or the wrong valve lash causing the valve not to fully seat against the valve seat will increase the temperature of the valve till it fails.

CyDStang

Thanks for the post, some good info there. I noticed that when I did the headers/Offroad X that I got a very pungent unburned fuel odor coming from the car. Could my car running too lean like this possibly harm the engine or is it just a tune-able fix?

candymanjl

that's just the smell you get without cats, just from not being as clean of an exhaust. only way to tell about your tune is to check it out with a wideband O2. you can either get a wideband gauge and install it in your car or go to the dyno and use their wideband on a couple of runs.

siggyfreud

This again goes back to the idea that having back pressure is a good thing. It's not. Do some google searches regarding back pressure and you'll see it's a long-standing myth that will eventually be dispelled.

siggyfreud

The smell of unburnt fuel generally means you're running too rich, not too lean.