Backfire!

[Cumminsduallyguy04]

My friend used to drive a diesel dumptruck that he could make backfire and scare people to death. What makes diesels backfire? And can a ve pumped truck be configured to do such. I want to have fun in the bad sections of the city.

 

[Dieselnut59]

I wonder if he had the exhaust valve brake? A TRUE "Jake brake"? Those pop loud with a straight exhaust. Only time I have ever seen a diesel backfire was when I had the timing chain a link off on my Polaris Diesel when I had replaced the head on the OHC engine. It was louder than ANY gasoline backfire I have ever heard and ONE pop (BOOM!) smoked up the entire shop! It ran like crap too. You would not want to do that to your engine. You may could make a propane injection system in the exhaust, with a spark plug ignition system.

I used to have an old gasoline (350/4bbl, 4 speed) Suburban in high school. We used to backfire our old gasoline vehicles all the time by cutting the switch off while going down the road, loading a little fuel into the exhaust and cutting the switch back on at the desired target (dog, horse, bicyclist, left lane lagger, friend we meet in the road, etc) and it would BOOM! God that was FUN! I taught several people how to do it with propane/gasoline forklifts and even the UPS guy when he used to drive a gasoline package truck. All the years of us doing this and the worst we ever did was blow off a few mufflers. Wasnever a problem with me with straight exhaust or glasspack mufflers. :-laf

 

[Wingate]

hhmmm... typically, if/when you hear a diesel backfire, its because it has dropped a valve, or the mechanical timing is off... .

I had a 3512 Cat running about 2250hp@1900rpm and the geartrain failed, causing it to jump time and bend/break every valve in the engine... . talk about a backfire... It popped 3 different times and almost send me to the bathroom to clean out my shorts!!!. .

 

[BarryG]

Honestly dont think that is something I want my truck to be able to do. When my vp44 went out a few years ago I was driving through the Eisenhower tunnel (approx 1 mile long) and my truck backfired twice in the tunnel. I darn near did need to clean out my pants. Son in law was driving behind me said it appeared to shoot out a 3 foot flame from the exhaust. You are right in the fact the sound will scare the heck out anyone around though for the health of my vehicle that is not something I want to happen either accidently or on purpose.