Exhaust downpipe gaskets - Honda Prelude Forum

Zimmlude · 06-02-2003, 06:13 PM

Hey guys,

My swap is fast approaching and I have a problem. I got a VTEC downpipe from hmotorsonline with my engine. I also ordered the stock exhaust gaskets from hondaautomotiveparts.com with the thought that they might fit, I was wrong. The gaskets for header to downpipe fit perfectly but the one for the downpipe to the cat didn't fit. The one I got from hondaautomotiveparts.com is too big to fit into the groove in the downpipe.

My question is, what did you that have done the swap do with this gasket? Is it possible that I have the auto VTEC downpipe and it has a smaller cat flange and hence, smaller gasket?

Please help

Thanks,

Zimmlude · 06-03-2003, 02:35 PM

So no one has ever had this problem??? Any suggestions?

cifer6425 · 06-06-2003, 07:16 AM

i have not gotten to the gasket stage yet. i have ran into the problem of the down pipe i for from h-motors not monting up to my old (usdm) cat back pipe. i thought about drilling the holes out, but have decided to cut the old flang off of the h23 down pipe and have the flange welded onto the h22 down pipe. this will allow everything to bolt up.

i imagine that if you did something like this you would be able to use your gasket.

Zimmlude · 06-06-2003, 09:20 AM

Hey,

You really don't need to do that. I just elongated the holes in the JDM one and it bolts up fine. The problem with welding back on it that creates a weak spot.

cifer6425 · 06-06-2003, 09:46 AM

do you know what size drill bit you used to enlarge the holes?

Zimmlude · 06-06-2003, 01:27 PM

I actually used an oxy-acelene (sp?) torch to elongate the holes toward the center. They only need to be enlarged by about 1/4" or so.

With this gasket annoyance though it might be a better idea to just weld on the flange so you can get the proper gasket. It's your call.

cifer6425 · 06-06-2003, 03:34 PM

cool cool... good luck with you engine. learn from my mistakes... LABEL EVERYTHING. i labed almost everything and that is where i ran into problems at.

Zimmlude · 06-06-2003, 05:04 PM

Label as far as connectors? Yeah, I am planning on labeling every plug off my H23 as it is unplugged. I have had my engine on a stand since the end of March so I have had some time to look it over

. I have spent $2300 on the engine and parts. I hope that will be the end of it.

Are you done with your swap? In the middle?

Good luck to you.