Rev Hard Manifold - Warped and Cracked - Help!

[cpuls]

I've got some Rev-Hard turbo manifold woes that I could use some advice on:

I just pulled off my Rev-Hard Manifold off of my turbo KA for the SECOND time now to find that this time, not only is warped again (caused exhaust leaks out of #1 and #4 exhaust ports), but this time I find a crack in the bottom! The last time I pulled it off the ports were way off of being flat (I had an 1/8" inch gap when I put the flanges against a straight edge). I flattened all the surfaces and put it all back together and it held great for regular street driving. But then when I took it to the track again for about eight 20 minute sessions at high revs - the exhaust leaks came back. This time the warpage isn't as much on the manifold flanges (maybe 1/16"), but I did find a crack. Argghhh!

Oh and did I mention that my Turbocrapnetics Wastegate froze up resulting in boost hitting 21 psi! Fortunately, I've got plenty of fuel delivery and a completely built bottom end - so no worries on the motor.

I've got the wastegate problem solved with a new Tial 38mm, but now I'm not sure what to do about the manifold. I've heard that by cutting between the runners you can avoid warpage and cracking - has anyone on this forum done that? How's it holding together - what kind of boost levels are you running?

Also, any advice on alternatives to the Rev Hard would be welcome.

Thanks!

[C-Kwik]

I just replaced my revhard. Cutting the flange fo each port has it's own flange will relieve a lot of warping issues. The single piece flange was probably the cause of the crack and the warping. But you should also remove the cast flashings and any sharp edges. This is where cracks are most likely to start.

You can have the crack repaired by welding. but make sure they know how to weld cast metal. It's critical the manifold be preheated, then welded with a gas welder, then cooled slowly over about a 24 hour period of time. If this isn't done, it will likely crack again as it cools down. Then, after it cools smooth out the edges of the weld. My first manifold was welded before, but it cracked along the edge of the weld. The weld itself was strong. The edge gave it a fault line tocrack along though. I anticipate my new manifold will be problem free. I spent about 4-6 hours prepping it including some heavy porting.

[BadMojo]

Any thoughts on this?

http://www.executivecleancar.c...x.htm

There are a few threads about this over @ FA. The manifolds are made by a gentleman by the name of Tom Rice.

Supposed to be very nicely done, but a bit pricey.

[C-Kwik]

He posts here as well. I'd say the cost is pretty good considering the quality. Tom's mani will probably flow better and last longer. The rev hard should be fine with good prep work, but after all the porting I did, I was still displeased with the way it was working out. There just isn't enough material there to be able to port it out to have really good flow. The exhaust air has to come down out of the heads and then take a slight turn back up. Even with decent porting. Tom's mani's come port matched. So for the price I consider it a steal. The Revhard replacement I got cost me $511 with tax on short notice.

[Structure240sx]

my nsport kit should be hear anyday now minus the intercooler due to back order. what do u use to cut the flanges? i was goin to get the one from tom to put together my own kit but decided to go with nsport. maybe i will sell the revhard then get his should be worth it and i dont mind waitin anymore since i have so much already

does anyone have his NICO name or email? i used to but not anymore

[C-Kwik]

I used a 5" cutoff wheel on a grinder.