Somewhere I was reading that one of the exhaust manifolds on the Duramax has a pinch in it for clearance of some sort. I think it was an advertisement for a replacement manifold that didn't have the restriction caused by the pinch. Can anyone tell me if this is on all Duramax engines or just certain ones. Also does anyone know if it will be on the LMM.

Thanks,
JBob

I actually saw this very thing yesterday. A friend of mine installed an new manifold on the driverside. He's main reason was it was already drilled for the pyro. The aftermarket manifold was not pinched which should allow more air flow.

Check it out for yourself:
Here ya go - http://www.bd-power.com/gmc/product.php?pn=BD%20Duramax%20Manifold&tt=gmc

I've been thinking of getting one for myself, especially since the pyrometer has a drilled hole.

Gear Jammer I am confused ,I thought they were all built that way !!!!!!!!!!

I think he just worded it wrong, they're all like that.

Yea, but if the clearance is still needed for something, how can a manifold that doesn't provide the clearance, like the one from BD, fit? And if the clearance is no longer needed, why doesn't GM put manifolds without the clearance on new vehicles?:rolleyes:

BD and GM must be laying in bed together. If GM doesn't fix it BD can still sell aftermarket parts. "You scratch my back and I'll scratch yours"

it even says on the website for the steering linkage but somehow it's redesigned and comes no where near anything... go figure?

I'm with the laying in bed theory...

Yea, but if the clearance is still needed for something, how can a manifold that doesn't provide the clearance, like the one from BD, fit? And if the clearance is no longer needed, why doesn't GM put manifolds without the clearance on new vehicles?:rolleyes:


The clearance is not needed on the 2500hd or 3500 trucks, just some of the vans and cab overs. Nate

I read that the duramax was designed to fit in the older body style 1996 HD on up hence pinchin' the manifold to clear the steering shaft. I don't know if this is true but it makes sense. The BD is a great product and is really beefed up in the area the EGT probe goes. GB

it even says on the website for the steering linkage but somehow it's redesigned and comes no where near anything... Go figure? i'm with the laying in bed theory... x2

I think the clearance is for the medium duty 4500-6500's

Have many people installed the BD replacement manifold? Is it worth the trouble? Thanks.

I did it...wasn't too bad, about a 2-3 hour job. hardest part are the flange bolts that connect it to the up-pipe. Another part was getting the heat shield to fit properly after i bent the hell out of it so it would fit.

I had the BD manifold installed with just 500 miles on. They said it may conservatively add 10 hp. Under heavy load I was told that portion of the manifold upstream of the constriction glows red and results in the engine heating asymetrically which could have negative effects.

I had it changed because the constriction is just plain stupid. GM goes to all the expense of designing a top of the line diesel and leaves this wart attached to the side of it. go figure!!?? it's just wrong

What was the cost of replacement? I'm starting to get concerned as I tow a lot of weight through the southern california deserts...

costs 299 dollars.

I did it on mine just cuz I wanted to but I would do it again in a heartbeat. Like gliderrider said the restriction is just plain stupid!