Author Topic: Big intake heads from Cycle X  (Read 1996 times)

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Offline slikwilli420

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Big intake heads from Cycle X
« on: June 15, 2020, 07:34:32 am »
Perusing the website today just to kill some time, and look what I find, some new go-fast bits that look like monster intakes on a stock head. I don't see any details, but the new intake runners look substantially bigger than the stock versions. With some Mike Rieck magic these could flow huge numbers and really make a big bore, high compression bike make great power. Will be thinking hard about something like this to get the most out of my superbike build.

http://www.cyclexchange.net/Honda%20Page.htm

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Offline Rocketman

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Big intake heads from Cycle X
« Reply #1 on: June 15, 2020, 08:17:54 am »
Wow, those look nice!  :o  Its the old saying, how fast do you want to go?  How much do you want to spend!  Thank goodness for understanding wives!   :-*

Offline dragracer

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Re: Big intake heads from Cycle X
« Reply #2 on: June 15, 2020, 09:19:47 am »
Good option for big power.  Hopefully they'll also install oversized valve seats.

Offline slikwilli420

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Re: Big intake heads from Cycle X
« Reply #3 on: June 15, 2020, 09:43:24 am »
Good option for big power.  Hopefully they'll also install oversized valve seats.

Good call Frank. Be nice if Kenny did it before going to final porting. Thinking I could squeeze a 36mm or 37mm intake in there with 72mm pistons and with the bigger intake tract make really strong power.
All you gotta do is do what you gotta do.

Vintage Speed Parts Mashup: http://forums.sohc4.net/index.php?topic=133638.0
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Big intake heads from Cycle X
« Reply #4 on: June 15, 2020, 11:00:32 am »
It's about time! I saw his original BIG valve head. No way you could come close using a stock head. Highly modified. I'm hoping Kenny will be throwing a leg over that beast and setting some records this fall.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Big intake heads from Cycle X
« Reply #5 on: June 15, 2020, 11:08:35 am »
Good option for big power.  Hopefully they'll also install oversized valve seats.

They will HAVE to Frank. On the original big valve head I saw the valves were probably bigger (not telling size. top secret) than that the OD of the stock seats.
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline dragracer

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Re: Big intake heads from Cycle X
« Reply #6 on: June 15, 2020, 07:36:37 pm »
Good option for big power.  Hopefully they'll also install oversized valve seats.

They will HAVE to Frank. On the original big valve head I saw the valves were probably bigger (not telling size. top secret) than that the OD of the stock seats.

Jerry, the original head had straight port spigots.  This head just appears to have larger intake runners in the stock location.  No doubt this particular will flow well but not like the one on Kenny's dragbike.

Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Big intake heads from Cycle X
« Reply #7 on: June 15, 2020, 07:43:43 pm »
Agreed. Interested to see what $$$$. Looks like a nice upgrade that can handle larger valves >34mm flow
As of today 3/13/2012 my original owner 75 CB750F has made it through 3 wives, er EX-wives. Free at last.  ;-)

Offline dragracer

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Re: Big intake heads from Cycle X
« Reply #8 on: January 02, 2021, 08:31:25 pm »
Has anyone gotten their hands on one of these heads yet?? Any feedback on performance?? Price??  Come on people,  don't hold back.

Offline Sam Green Racing

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Re: Big intake heads from Cycle X
« Reply #9 on: January 03, 2021, 04:29:05 am »
J Frankie, why not just phone and ask Kenny.
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: Big intake heads from Cycle X
« Reply #10 on: January 03, 2021, 07:13:49 am »
Your ticket into the 9 second bracket Frank?
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Offline dragracer

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Re: Big intake heads from Cycle X
« Reply #11 on: January 03, 2021, 05:32:56 pm »
J Frankie, why not just phone and ask Kenny.

Thank Sam, but I'm actually trying to get feedback from someone that has purchased and used the head. I know Kenny can give me pricing, but my main question is related to real world performance.

Offline dragracer

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Re: Big intake heads from Cycle X
« Reply #12 on: January 03, 2021, 06:33:25 pm »
Your ticket into the 9 second bracket Frank?

Yes Jerry,  a better flowing head should get me into the 9's.  My local guy did a great job with the head on the bike which netted a low 10 second pass after just 8-10 or so passes. I'm extremely satisfied with the return on investment, but i will need a  better flowing head to crack that elusive nine barrier. Of course a stroker crank would bring added value to the package. We're only talking money and everyone knows it grows on trees all over the place. Hahaha. 

I'm just having wintertime delusions right now. I'm subject to come up with all kinds of crazy ideas to go fast and not implement any of them.

Offline scottly

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Re: Big intake heads from Cycle X
« Reply #13 on: January 03, 2021, 08:08:19 pm »
I don't see the big intake head on the cycle x site???
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Offline bear

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Re: Big intake heads from Cycle X
« Reply #14 on: January 03, 2021, 08:25:21 pm »
I'm not exactly on the cutting edge when it comes to HP SOHC Honda motors these days, so tend not to get involved in these types of discussions.
But I wonder if a larger intake spigot would deliver any worthwhile improvements to a large displacement SOHC motor.
It was one of the rabbit holes we went down many year's ago with our 1200cc methanol motors.
We attributed the disappointing results to the loss of induction velocity.

At some stage along the journey I realised it's more about balance than big and enhancing the strengths of these motors rather than trying to turn them into something that they are not.

But it was a long time ago and I'm an old man. ;)

Cheers,
Brian
« Last Edit: January 04, 2021, 04:47:06 am by bear »
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Offline Alan F.

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Re: Big intake heads from Cycle X
« Reply #15 on: January 03, 2021, 10:33:35 pm »
Scroll down, but if I'm not mistaken I thought these were going to be new castings sold outright.

http://www.cyclexchange.net/Machine%20Work%20&%20Services.htm

Offline PeWe

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Re: Big intake heads from Cycle X
« Reply #16 on: January 03, 2021, 11:58:35 pm »
I'm not exactly on the cutting edge when it comes to HP SOHC Honda motors these day's, so tend not to get involved in these types of discussions.
But I wonder if a larger intake spigot would deliver any worthwhile improvements to a large displacement SOHC motor.
It was one of the rabbit holes we went down many year's ago with our 1200cc methanol motors.
We attributed the disappointing results to the loss of induction velocity.

At some stage along the journey I realised it's more about balance than big and enhancing the strengths of these motors rather than trying to turn them into something that they are not.

But it was a long time ago and I'm an old man. ;)

Cheers,
Brian

Brian, which carbs and size did you use on your high powered engines?

Offline bear

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Re: Big intake heads from Cycle X
« Reply #17 on: January 04, 2021, 04:54:02 am »
I'm not exactly on the cutting edge when it comes to HP SOHC Honda motors these day's, so tend not to get involved in these types of discussions.
But I wonder if a larger intake spigot would deliver any worthwhile improvements to a large displacement SOHC motor.
It was one of the rabbit holes we went down many year's ago with our 1200cc methanol motors.
We attributed the disappointing results to the loss of induction velocity.

At some stage along the journey I realised it's more about balance than big and enhancing the strengths of these motors rather than trying to turn them into something that they are not.

But it was a long time ago and I'm an old man. ;)

Cheers,
Brian

Brian, which carbs and size did you use on your high powered engines?


We used 33mm Kehin's on the big tracks like Phillip Island  and 40DCOE Webber's on the smaller tracks Per.
The historic rules prevented the use of more modern carbs.
« Last Edit: January 04, 2021, 04:57:29 am by bear »
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Offline PeWe

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Re: Big intake heads from Cycle X
« Reply #18 on: January 04, 2021, 05:05:58 am »
I have thoughts about not going too big loosing midrange response/acceleration.

Offline bear

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Re: Big intake heads from Cycle X
« Reply #19 on: January 04, 2021, 05:11:41 am »
I have thoughts about not going too big loosing midrange response/acceleration.

I think your on the right track Per.
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Offline PeWe

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Re: Big intake heads from Cycle X
« Reply #20 on: January 04, 2021, 05:40:59 am »
I have thoughts about not going too big loosing midrange response/acceleration.

I think your on the right track Per.
The question is, what is too big? ;)
120whp on not that high rpms with 33mm carbs indicate a good combination as you have shown, Brian.

The Weber DCOE 40's can be tuned, just use smaller or bigger rings for the throat/venturi. 26-36mm as I have seen. Very flexible carburetor.

More carbs should have that possibilty.  The carbs on my K6 that finally joined the +100whp club are 32mm. It would be fun to test bigger. I miss the tuning possibility with rings.
Different sizes depending on application. Before or after ~6000 rpm something.

Offline kmb69

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Re: Big intake heads from Cycle X
« Reply #21 on: January 04, 2021, 06:45:00 am »
I'm not exactly on the cutting edge when it comes to HP SOHC Honda motors these days, so tend not to get involved in these types of discussions.
But I wonder if a larger intake spigot would deliver any worthwhile improvements to a large displacement SOHC motor.
It was one of the rabbit holes we went down many year's ago with our 1200cc methanol motors.
We attributed the disappointing results to the loss of induction velocity.

At some stage along the journey I realised it's more about balance than big and enhancing the strengths of these motors rather than trying to turn them into something that they are not.

But it was a long time ago and I'm an old man. ;)

Cheers,
Brian


Bingo!
"Good head" requires volume and velocity.
The "flow benchers" always rave about volume but seldom mention velocity.

Offline PeWe

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Re: Big intake heads from Cycle X
« Reply #22 on: January 04, 2021, 07:00:09 am »
The inlet tuners by epoxy reducing the inlet, D-shaping straighten it up is on the  gas velocity path, right?

Offline dragracer

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Re: Big intake heads from Cycle X
« Reply #23 on: January 04, 2021, 07:54:34 am »
I'm not exactly on the cutting edge when it comes to HP SOHC Honda motors these days, so tend not to get involved in these types of discussions.
But I wonder if a larger intake spigot would deliver any worthwhile improvements to a large displacement SOHC motor.
It was one of the rabbit holes we went down many year's ago with our 1200cc methanol motors.
We attributed the disappointing results to the loss of induction velocity.

At some stage along the journey I realised it's more about balance than big and enhancing the strengths of these motors rather than trying to turn them into something that they are not.

But it was a long time ago and I'm an old man. ;)

Cheers,
Brian


Bingo!
"Good head" requires volume and velocity.
The "flow benchers" always rave about volume but seldom mention velocity.


Port velocity is extremely important. 

Offline Old Scrambler

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Re: Big intake heads from Cycle X
« Reply #24 on: January 04, 2021, 11:20:49 am »
Port / carb velocity is certainly important.......but so is cylinder-fill demand timing and all available air when needed. Most of the racers in the world are at or near sea-level. In my case (Bonneville Salt Flats) the effective altitude is roughly 5000 feet or more. All of the motor builders (some on this board) advised me against my carb size and cam choice........but I did not listen ;)  My 34mm carbs flow to 33mm intake tubes, a well ported head, and 35mm intake valves all servicing a 761cc motor.  The dyno-tech told me my motor was not tuned very well. I told him to open up the throttle and see what it will do above 8000 rpms. He was surprised how smooth everything was and was somewhat afraid to let it rev above 11000 rpms...........at 8000 revs and up I believe intake-velocity is sufficient to adequately feed larger bores. I think piston and rod weight need to be as light as possible to sustain high rpms in a big-bore motor which will likely require larger valves and intake capacity to carry a 500-lb. bike & rider to maximum speed. Reliability is a combo of best parts and master motor assembly.     
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