Twinflex manifolds, more flex than you would like

[cobalt6700]

Ever since i put a Twinflex on the jeep ive had an exhaust blow. I guessed it was from a cracked gasket/weld somewhere.

On taking my manifold off and scraping it to clean it, i noticed that the mating face wasn't very flat.

Got the ruler out to do the old light trick

How it should be:

http://img.photobucket.com/albums/v248/cobalt6700/a6b32b37.jpg

How it was:

http://img.photobucket.com/albums/v248/cobalt6700/a5ac7cba.jpg

There was about 1.5mm worth of gap there, no wonder it had been leaking!

Filed it down and now should be cushty:

http://img.photobucket.com/albums/v248/cobalt6700/b5f9b0b9.jpg

Just a heads up for those of you that come to install them - check the flatness. 8-)

[4.3LXJ]

That was really bent. Shouldn't be anywhere near that.

[bluedragon436]

Yeah that is def. no good right there.. Seems like something the company should have taken care of for you..

[cobalt6700]

I bought the manifold off of ebay end of last year/start of this, and i dont think it was a reseller.

Just seemed easier to sort it and get the jeep back on the road rather than waiting for twinflex to sort me a new one.

Its a heads up for people to check them anyway, maybe i should send a mail to twinflex to let them know....

[LizardRunner]

Every vehicle I've replaced the exaust or intake manifold on, I've had the pieces decked before ever installing. One set of Hooker Headers had to have 3 thousandths removed to get the mating surface flat. I consider it just good sense to have these parts decked so the mating surface is true flat. It doesn't cost much to have this done most I've paid was 25 bucks for a pair of headers.

[4.3LXJ]

Having owned several sets of headers, I check mine. The JBA headers I have were perfectly flat, no issues.

[cobalt6700]

Every vehicle I've replaced the exaust or intake manifold on, I've had the pieces decked before ever installing. One set of Hooker Headers had to have 3 thousandths removed to get the mating surface flat. I consider it just good sense to have these parts decked so the mating surface is true flat. It doesn't cost much to have this done most I've paid was 25 bucks for a pair of headers.

And while that's good practice having them checked, why should you have to do it?

I work for a large engineering firm and I am an engineer. I don't expect customers to have to refinish my products before they use them.

[4.3LXJ]

And while that's good practice having them checked, why should you have to do it?

I work for a large engineering firm and I am an engineer. I don't expect customers to have to refinish my products before they use them.

In theory, you shouldn't have to. But the fact is that headers are notorious for not being straight. I just lay a good straight edge on them. If there is any deviation, then they need to be decked. Having real straight flanges has not been an industry standard.

[cobalt6700]

Hmm, I have to say I havent had a lot of experience with aftermarket exhausts. Seems crap that they arn't shipped flat. ahh well. :)

Was trying to find them to email them.....anyone know who they are made by?? :?

[LizardRunner]

I think the reason so many get bent is the shipping method but there is also the welding them up. Heat does wonderous things to steel. I have never had a set that straight edged good enough to suit me. Even one set, that was built right on the block they were going to live on warped slightly during cool down. Reason that happened.... because they had to be removed to weld the inside.

[4.3LXJ]

That was not the case with my JBA headers. They welded thin tubes to half inch steel. The way headers used to be made is with 1/4" flanges and lots of heat. The problem with XJ headers is that they need to be the same thickness as the factory flange so they will be compatible with the intake flange. You just have to check them.