Topic: Install Cylinder Head Reversed

[CBR954AD]

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

[SOHC4 Cafe Racer Fan]

Is this for your 650 engine?  If so, you may want to specify and or check out the 650-specific forum:  www.hondacb650.com

[strynboen]

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

[SOHC4 Cafe Racer Fan]

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.

[MidnightLamp]

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.

[SOHC4 Cafe Racer Fan]

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.

[calj737]

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.

[seanbarney41]

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.

[Retro Rocket]

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

[bwaller]

Yeah that guy had a really big family, or at least many brothers.

[CBR954AD]

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.

[754]

Some motors are easier to reverse heads on, these are not..
 You see reversed head Kawis in dragracing..