89blackm

Hey.....in the next few days my cam is going to be broken in. Will i need my exhaust on for backpressure or would it be fine just to do it with open headers????(Exhaust is true 3"duals going into 2 dynomax bullets dumped right before the axle)Id like to get a few opinions on this......thanks mike

Air_Adam

You don't need backpressure... open exhaust manifolds or headers is fine.

ede

backpressure = monkey spank

my3rdgen

I tried to break in my cam with open headers.


The neighbor got pissed off and created problems I didn't need.

ME Leigh

I tried breaking in my cam with open headers. It was loud as *** * and i had foot long flames shooting out of them. Its not cool, i would totally advise against it.

Air_Adam

True... but its not going to hurt the cam to break it in with open headers... just annoying as hell.

sellmanb

Use your manifolds. The heat from the cam breakin kills off the ceramic coating on the headers, which causes it to flake off, and then you lose out on the 200 for coating.

IHI

iTrader: (1)

Not only that but it's nice when everything is as quite as can be so you can keep an ear out for any tell tale "bad noises"

Open headers sound cool, no doubt. But breaking in an engine sucks to do this way. Even with your bullets it wont be much better than open, but should still be a little quiter and easier for everybody around you to take.

89blackm

Ok so it sounds like its not big deal then.Im not worried about the noise issue as they are annoyed with the car from last summer I was just worried about burning valves up or doing damage to the engine due to not having as much back pressure

ME Leigh

You do not want back pressure. Back pressure is a restriction that reduces power. You do not want back pressure. The back pressure myth started back in the dark ages of engines, when people didn't know **** and the old timers that didn't know **** are still passing it on today. Damn old people!

AsphaltAssalter

I've never heard of this, I guess you mean that keeping the engine at 1500 RPM or so for 20-30 min. will overheat the headers? Do you have any proof of this or did it just happen to you? I have ceramic coated headers but didn't need a break in cause it's a roller, one more good reason to run a roller I guess.

Red Devil

Most companies void their warranty explicitly for this. The problem is that most people do not have their timing and mixture dead on when breaking in new components.

89blkm... is the cam a roller by chance?

AJ_92RS

What Lucifer said.

If the mixture and/or ignition timing isn't dead on (and how can it be?) while breaking in the cam, a lean condition can cause the headers to glow red hot, literally.

I don't care how "good" ceramic coating is, it can't stand that much heat for very long.

89blackm

No its not.......its comp cams xe-274 if u wanna check it out