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Offline CBR954AD

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Install Cylinder Head Reversed
« on: December 01, 2014, 10:12:55 AM »
Hello CB lovers,
Has any one attempted to install the cylinder head backwards, have the carbs in front and exhaust ports in rear. I am thinking of doing this. but first need look at few things, if reversed head do the oil chambers, bolt pattern line up. next if there is room for carbs to be installed in front. maybe custom intake plate or something.
any comments
thank you
Cheers
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Offline SOHC4 Cafe Racer Fan

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Re: Install Cylinder Head Reversed
« Reply #1 on: December 01, 2014, 10:23:24 AM »
Is this for your 650 engine?  If so, you may want to specify and or check out the 650-specific forum:  www.hondacb650.com
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"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

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1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline strynboen

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Re: Install Cylinder Head Reversed
« Reply #2 on: December 01, 2014, 10:46:36 AM »
you have to get made a cam ..vho are reversed grindet/veldet..so the valve train can run backverd/or thange inlet to autlet..and/or let the head sit as it is
« Last Edit: December 01, 2014, 10:54:18 AM by strynboen »
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Offline SOHC4 Cafe Racer Fan

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Re: Install Cylinder Head Reversed
« Reply #3 on: December 01, 2014, 10:51:04 AM »
You will also need to think about your exhaust.  Not only will you need custom pipes, but you will need to route them with sufficient length so you don't lose performance.  You will be losing a significant amount of length by running them straight out the back.
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1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline MidnightLamp

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Re: Install Cylinder Head Reversed
« Reply #4 on: December 01, 2014, 10:56:11 AM »
I hate to be that guy to say this, but if you wouldn't be able to figure out your questions yourself it is doubtful that you would be able to reverse the head. It is a LOT of work for pretty much zero gain.
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Offline SOHC4 Cafe Racer Fan

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Re: Install Cylinder Head Reversed
« Reply #5 on: December 01, 2014, 11:03:17 AM »
Quote from: MidnightLamp on December 01, 2014, 10:56:11 AM
I hate to be that guy to say this, but if you wouldn't be able to figure out your questions yourself it is doubtful that you would be able to reverse the head. It is a LOT of work for pretty much zero gain.

If this is for your 650 motor in a 550 frame build, that you are trying to DIY to control costs, you will be shelling out some $ for a custom reverse grind cam.  I think the motor will intake air better but I am not sure you will gain so much performance.  The engine head will also not cool as much on the exhaust port side if it is facing down draft and not getting fresh air flow.  It makes for a neat trick though.
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1975 CB550K1 "Blue" Stockish Restomod (http://forums.sohc4.net/index.php?topic=135005.0)
1975 CB550F1 frame/CB650 engine hybrid "The Hot Mess" (http://forums.sohc4.net/index.php/topic,150220.0.html)
2008 Triumph Thruxton (http://forums.sohc4.net/index.php/topic,190956.0.html)
2014 MV Agusta Brutale Dragster 800
2015 Yamaha FZ-09 (http://forums.sohc4.net/index.php/topic,186861.0.html)

"There are some things nobody needs in this world, and a bright-red, hunch-back, warp-speed 900cc cafe racer is one of them — but I want one anyway, and on some days I actually believe I need one.... Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles, Bubba." Hunter S. Thompson, Song of the Sausage Creature, Cycle World, March 1995.  (http://www.latexnet.org/~csmith/sausage.html and https://magazine.cycleworld.com/article/1995/3/1/song-of-the-sausage-creature)

Sold/Emeritus
1973 CB750K2 "Bionic Mongrel" (http://forums.sohc4.net/index.php?topic=132734.0) - Sold
1977 CB750K7 "Nine Lives" Restomod (http://forums.sohc4.net/index.php?topic=50490.0) - Sold
2005 RVT1000RR RC51-SP2 "El Diablo" - Sold
2016+ Triumph Thruxton 1200 R (http://forums.sohc4.net/index.php/topic,170198.0.html) - Sold

Offline calj737

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Re: Install Cylinder Head Reversed
« Reply #6 on: December 01, 2014, 01:06:16 PM »
Quote from: CB750 Cafe Racer Fan on December 01, 2014, 11:03:17 AM
I think the motor will intake air better but I am not sure you will gain so much performance.
This is a presumption. This would be true if you adopted a ram air inlet. The stock airbox is about controlled volume, turbulence, and air pressure. Simply ramming more air down the throat of the carb won't necessarily accomplish more performance. You would then need to match intake ports, valve train, pistons, and very importantly, the exhaust for proper flow and the velocity of that flow.

If you want a cool project that is suitable for a DIY investment, then tinker with different types of air boxes. You can fab them together as tests pretty inexpensively from plastics, or sheet metal until you find the desired results. I'm all for experiementing, but this is not one I see being worth the undertaking.
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Offline seanbarney41

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Re: Install Cylinder Head Reversed
« Reply #7 on: December 01, 2014, 01:18:43 PM »
There is an old thread here somewhere, a guy tried it, never finished it...probably because it wouldn't really work.  You might try searching "Reverse Port" to find the thread.
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Offline Retro Rocket

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Re: Install Cylinder Head Reversed
« Reply #8 on: December 01, 2014, 01:21:48 PM »
Quote from: CBR954AD on December 01, 2014, 10:12:55 AM
Hello CB lovers,
Has any one attempted to install the cylinder head backwards, have the carbs in front and exhaust ports in rear. I am thinking of doing this. but first need look at few things, if reversed head do the oil chambers, bolt pattern line up. next if there is room for carbs to be installed in front. maybe custom intake plate or something.
any comments
thank you
Cheers

Yes its been done, although i can't say how successful it was... Actually, after searching for it it seems its a reverse port engine...

http://forums.sohc4.net/index.php?topic=80234.450

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Offline bwaller

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Re: Install Cylinder Head Reversed
« Reply #9 on: December 01, 2014, 02:45:27 PM »
Yeah that guy had a really big family, or at least many brothers.
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Offline CBR954AD

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Re: Install Cylinder Head Reversed
« Reply #10 on: December 02, 2014, 08:54:16 AM »
thank you for the feedback, yes I was thinking of doing this on my CB650. I watched a one of those Cafe Racer show on MavTV and a guy on East coast reversed the head on I think BSA or something. he made it sound simple, from what I saw he just installed the head 180 degrees, however that bike had a single carburetor as it was 1 piston engine. and it looked awesome. I read some where it is possible as long as the when I install head 180 deg, the ports patch, like oil and etc. I didn't think about the cam. The exhaust would not be too difficult to build, I have TIG welding experience and a welder at home. I have build a few Honda Civic exhaust and build a set of headers for a B18 motor, in the past, never for a bike with limited estate.
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Offline 754

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Re: Install Cylinder Head Reversed
« Reply #11 on: December 02, 2014, 09:31:22 AM »
Some motors are easier to reverse heads on, these are not..
 You see reversed head Kawis in dragracing..
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