Topic: 2.5 liter exhaust manifold - banks - Cracked again!

[cz777]

after  seeing all them cracks ,MMM! this maybe off subject a bit but it bears to see things! the man who i work for had a hot copper water pipe crack open 14 days after ,he installed -it was at the seam joint ! it turns out who made the pipe ,it was brazed too cold and /or dirt in joint etc! stainless steel is very wild stuff ,getting it right is not easy -the heat of welding in drew out too much of the carbon or some else like poor alloying ! wow !!

[brokenwrist21]

one thing is right the pipes are getting far to hot. but it appears that at the collector theres not enough room for the pipes to expand, so when they expand whats happening is there pushing out against the collector tube. effectivley creating enough pressure to crack the collector. a slightly larger collector pipe around the individual pipes would probably solve this problem. i've never cracked a manifold, my exhaust leak is because one of the manifold bolts has come completely out of the block. i would take a laser thermometer and check the exhuast temps after driving for awhile and see what it reads back, then figure out what it should be if it is off. its either a case of not enough fuel or too much fuel.

[TN00TJ]

I'm convinced it boils down (no pun) to Chrysler's clumsy fuel scheduling to make their CAFE numbers.

Their theory must have been, "If you can't FIGURE it out, just LEAN it out." 

I had my Banks header Jet Hot coated because I knew it was going to crack anyway and I was looking for some kind of alternative to changing headers every six months.

I chose their sterling sliver ceramic as it's "good to" 1700 F, whatever "good to" means.

After about 3 hours of service, there was a crystalline layer all over the header and head pipe (had the head pipe done as well) that you could wipe off with your hand.

Yesterday, after nearly six months in service, Dan Groff from Jet Hot calls me out of the blue and asks me how it's going with their coating and the Banks header, so I ask him about the crystal-like deposits.

He said that ain't normal and wants to recoat at their expense under warranty, freight paid both ways. (Imagine that)

He and I both want to see if there's a cheaper way to prevent the Banks headers from cracking so he's motivated to help as he'd like to tap the Banks user market if there's a viable product here. (Cheaper than having the header rebuilt - I am NOT going to replace a header every six months just because Banks warrants them - got better things to do with my time.)

Frankly, I'm going to have the header and pipe recoated one more time and then I'll get rid of the junk Dodge Caravan motor and put an LS1 in its place.

Either way, I'm a "lifer" with Jet Hot coatings.

That sounded awfully much like a rant, didn't it?

[chardrc]

then I'll get rid of the junk Dodge Caravan motor and put an LS1 in its place.

The jeep amc 2.5 was never in a dodge caravan