Boom! Just got this from Bisi

[F22Chris]

Notice the diameters are stepped a little ways off the flange, too. Aside from simple tube lengths, are the bends before the merge going to do anything? I would think they might slow down the flow a bit, but again the diameters are stepped up before the major bends. Between the smaller diameter before the bends and a true merge collector after, maybe these things aid velocity enough that the bends don't matter so much?

I think the header was great in terms of velocity for the RPM ranges Bisi's engine made power. The stepped parts could be for further help on scavenging. The steps slowly taper out to compliment the size of the collector.

If you get the header design down well enough, you get an increase in intake velocity as well. Thus making more power. Kind of like a turbo, but with vacuum made from a crazy well engineered exhaust.

[thatoneuser]

It was a bit of an over site on my part I was going to wrap the areas needing to be welded but while dealing with other crap I forgot and sprayed them. So I said the hell with it and finished I'm just going to media blast the areas I need clean for welding then recoat so no biggy.

I'm definitely doing my own research but being that I'm surrounded by peers with mad xp I prefer starting off with word of mouth tips etc.

Every days a learning experience for me and being that this is my first cb7 I'm really going through the whole car by hand still getting familiar with it. So far the only things I haven't had my hands in is working with the pistons and tranny synchros.

I'm basically going through everything and restoring and replacing the bits and pieces to make sure its gonna run reliably before I change major components such as cams pistons and that good stuff.

I'm really pleased with how informative this thread has become tho. I was only expecting a few cools or good finds haha

[f22ax_Rocks]

all the bisi talk. but hey its true few years ago i tried to contact him about his forged internals on facebook but he never replied back. Sad thng he was the man who motivated me to get my f22 swap going.

[Chrisnick]

I think it would be the same for all vehicles using the calculators online. Bisi used 24" equal length runners if I remember. But runner size is seriously based on RPM ranges of power production. The calculators that I found use bore, stroke, RPM range, displacement, and max HP/TQ rpm. Calculators are great, but I want to see the actual math behind it, not just the outcome of the set equation.

It just looks like he took the longest length runners while still being able to utilize accessories like AC and power steering components. And then just put it at 1342 to increase velocity and scavenging.

24" is about the right length for a stock camshaft profile if I recall correctly. I'll have to read through my emails with Ghost to find out for sure. The biggest problem with that header design is that it's a 4-1; without secondaries, you're losing a LOT of mid-range torque. Not really a problem with an engine that is really only for drag racing, but below 4500rpm, it's probably sacrificing a good 10-15lbs/ft of torque. Secondaries with a 10-12" length would do wonders for that header as they'll boost torque and not sacrifice top end in any way; pairing of the cylinders doesn't matter as much on a 4-cylinder as you may think, so pairing F and R tubes, rather than R and L, would probably be best packaging wise. From what I can tell, it probably has 1.75" diameter primaries, which probably helps with velocity with those tight bends right off the flange like that. Collector design plays a big part as well, the Bisi collector actually looked like a fairly decent design, although 2.5" at the collector's exit was probably sacrificing some velocity for volume. Definitely some design vs manufacturing compromises in the header, but nothing that can't be worked around. The upper portion is a pretty good start, adding some good 2-1 collectors off upper, 10-12" long 2" diameter secondaries dumping into a final 2.25" 2-1 collector and tapering up to 2.5" would net big mid-range gains over the original 4-1 single collector design. It won't be cheap or easy(due to packaging concerns, probably the reason for the single 4-1 collector in the first place), but would be a great way to have a quality header for under about $1000 all invested. Heat and velocity that far upstream in the exhaust system are your friend.

[deevergote]

all the bisi talk. but hey its true few years ago i tried to contact him about his forged internals on facebook but he never replied back. Sad thng he was the man who motivated me to get my f22 swap going.

The demand for F22A performance parts and info went through the roof when Bisi gained popularity. He is right in that the F22A offers enormous potential. But yeah... I'm still waiting for a return phone call that I was promised when I called to order an H22A header... in 2008.

[CyborgGT]

Love your thinking, Chrisnick. I'm going to save that info for later ideas...

[98vtec]

24" is about the right length for a stock camshaft profile if I recall correctly. I'll have to read through my emails with Ghost to find out for sure. The biggest problem with that header design is that it's a 4-1; without secondaries, you're losing a LOT of mid-range torque. Not really a problem with an engine that is really only for drag racing, but below 4500rpm, it's probably sacrificing a good 10-15lbs/ft of torque. Secondaries with a 10-12" length would do wonders for that header as they'll boost torque and not sacrifice top end in any way; pairing of the cylinders doesn't matter as much on a 4-cylinder as you may think, so pairing F and R tubes, rather than R and L, would probably be best packaging wise. From what I can tell, it probably has 1.75" diameter primaries, which probably helps with velocity with those tight bends right off the flange like that. Collector design plays a big part as well, the Bisi collector actually looked like a fairly decent design, although 2.5" at the collector's exit was probably sacrificing some velocity for volume. Definitely some design vs manufacturing compromises in the header, but nothing that can't be worked around. The upper portion is a pretty good start, adding some good 2-1 collectors off upper, 10-12" long 2" diameter secondaries dumping into a final 2.25" 2-1 collector and tapering up to 2.5" would net big mid-range gains over the original 4-1 single collector design. It won't be cheap or easy(due to packaging concerns, probably the reason for the single 4-1 collector in the first place), but would be a great way to have a quality header for under about $1000 all invested. Heat and velocity that far upstream in the exhaust system are your friend.

id love to see you prove that.

[Chrisnick]

If I'm wrong, I have no problems admitting that, and would love to learn the correct information; what I posted is from what I understand, which very well could be wrong. I don't have the the time, fabrication skills, or money to prove it, so it'll probably just stay theory.

[CyborgGT]

Does anyone have have the measurements on the Logic/High-End header? It's a long-tube 4-2-1 you could get ideas from to modify the Bisi. If this video (H22 Logic vs RMF vs Bisi shootout; I'm sure most of us have seen it by now) is anything to go off of, it did great across the board.

Well been meaning to do this test for a while now. I was able to get ahold of a real Bisi header thanks to Martin (zuptidi) and a logic motorsports tri y thanks to Function. I'll post more information as the questions come in, but each header was tested back to back, same day. A/f was tuned on each one. I'll let the video speak for itself.

[...]

no exhaust, each one was open header. none of them have burns collectors

http://honda-tech.com/all-motor-natu...logic-2988001/

[CyborgGT]

Just found this interesting video. H22, but interesting nonetheless. This guy's got pretty much a ported intake manifold, full exhaust (Bisi header), and a tune... and gained 40hp? Don't H22s dyno around 160 stock? That's a damn fine gain.

[jdm_inspired]

I liked the cam gears bisi made but my top dead center mark was off. No complaints performance wise but my shop had to re-mark the TDC. I also bought this years ago before the resurrection of my build and when Bisi wasnt banned on this site.

The correct marking is made with a sharpie.

[deevergote]

Bisi never actually "made" anything. His header was even manufactured elsewhere (rumor was that it was manufactured in China using cheap labor, but never confirmed... the shipping information that was discovered may just have been for the piping used.) Bisi even claimed that Randy Monroe of RMF was once his fabricator, and the infamous RMF H22A header was a stolen Bisimoto design (which is amusing, seeing as the RMF header outperformed Bisimoto's header in every test I've ever seen comparing the two!)

I truly wonder who made Bisimoto's cam gears. He advertised extreme precision, and said that his non-slip coating was superior to any other gear on the market. I believed him back then... but now, I kinda wonder if I wasn't farting smoke signals for a week after being told that.

[jdm_inspired]

Bisi never actually "made" anything. His header was even manufactured elsewhere (rumor was that it was manufactured in China using cheap labor, but never confirmed... the shipping information that was discovered may just have been for the piping used.) Bisi even claimed that Randy Monroe of RMF was once his fabricator, and the infamous RMF H22A header was a stolen Bisimoto design (which is amusing, seeing as the RMF header outperformed Bisimoto's header in every test I've ever seen comparing the two!)

I truly wonder who made Bisimoto's cam gears. He advertised extreme precision, and said that his non-slip coating was superior to any other gear on the market. I believed him back then... but now, I kinda wonder if I wasn't farting smoke signals for a week after being told that.

Hopefully mine never slips and fails. So far it holds true...and hopefully I got lucky.

[deevergote]

I haven't heard any tales of them failing, so that's good at least.

I do wonder who made them, though.

[Granite CB7]

^to take this really OT, Bisi seems to always go with Evolution Industries for the flywheels and cam gears. My flywheel was made by Evo Ind and if you google image bisimoto cam gears, if you look closely, Evo Ind. I'd also bet that they make Bisi's heatshield IM gaskets as well, they're listed on Evo's site!