Topic: Strange question - anyone flipped their cylinders/head around?

[nick5446]

I've seen it done on a handful of old Triumphs, but never on a CB. I've got a "nothing to lose" type of project going on and was thinking about trying it if it seems do-able. I'd love to have the carbs sticking out front sucking in cold air and the pipes going straight out the back.

I don't know a lot about Triumphs, but I've heard it's an easy switch. The only big issue I can see on the CB750 is the cam chain spinning the wrong way. I'm having a tough time wrapping my brain around how I could work around this. The other issue would be bolt holes potentially not lining up, but I should be able to work around that if I can figure out the cam chain. The frame is/will be totally custom so I should be able to make everything fit.

Picture for reference.

[DJ_AX]

I don't know the answer to your question .... but ... Why?

[nick5446]

I don't know the answer to your question .... but ... Why?

Why not?

[cabrala]

Yes it has been done. I agree with the "why" and will accept your "why not". There is plenty of reading in the link below.

http://forums.sohc4.net/index.php?topic=80234.0

Interesting to note is that there seems to be no information about that bike being finished or running for that matter. Much of the debate in that thread was about how the engine would perform, but the OP never laid down the proof.

[pangloss]

That's not an engine. It's a sculpture... Anyway triumph is easy coz its twin cams which can be switched front to back

[nick5446]

That's not an engine. It's a sculpture... Anyway triumph is easy coz its twin cams which can be switched front to back

That makes sense, thanks!

[nick5446]

Yes it has been done. I agree with the "why" and will accept your "why not". There is plenty of reading in the link below.

http://forums.sohc4.net/index.php?topic=80234.0

Interesting to note is that there seems to be no information about that bike being finished or running for that matter. Much of the debate in that thread was about how the engine would perform, but the OP never laid down the proof.

I got some reading to do, thanks!

[iron_worker]

You could potentially get a custom cam ground for a reverse rotation engine but I can't imagine it would be cheap.

If you flip the cylinders then the oil pressure and return lines won't line up with the case anymore. If you don't flip the cylinders then your chain tensioner is on the wrong side.

There will be a myriad of problems you'll encounter and they will require some custom design and machine work to overcome I believe. It's an interesting idea but seems a bit far fetched.

IW

[DustyRags]

Keep posting here if you do this! I'd love to see this insanity happening! 

[nick5446]

Yeah, looking over that 550 thread it's not looking too promising. A custom cam would work, but like you said, not cheap.

Oh well, not heart broken, just wanted to look into it.

[seanbarney41]

Keep posting here if you do this! I'd love to see this insanity happening! 

...and all the popcorn a poppin'...

[DustyRags]

Hey, never forget, some lunatic built one with a sideways engine: http://forums.sohc4.net/index.php?topic=116469.msg1337072#msg1337072

[nick5446]

Hey, never forget, some lunatic built one with a sideways engine: http://forums.sohc4.net/index.php?topic=116469.msg1337072#msg1337072

Hahaha....now THAT is something I can get behind.

I'm going to pull the motor out of the frame tonight and strip the paint off of each of them and see what I'm working with.

Someone mentioned that if I flipped it all over, and the cam was spinning in reverse, I could maybe adjust the timing 180 and then I'd be all good. Any thoughts on that?

By the way, this is a Hondamatic that I'm working with, so it's going to be an odd bike no matter which way the motor faces.

[Bob Wessner]

Hey, never forget, some lunatic built one with a sideways engine: http://forums.sohc4.net/index.php?topic=116469.msg1337072#msg1337072

Some how missed that one. Having looked now, how does that exhaust arrangement impact engine performance? Must require some compensation mods??

[754]

Cam can be  turned, lf you run an external belt drive...one problem solved..
Where you at.. I have worked on stranger parts before....like the CHEVarlay..

[nick5446]

Cam can be  turned, l you runan external belt drive...one problem solved..
Where you at.. I have worked on stranger parts before....like the CHEVarlay..

I'm a little ways south of you in Portland, OR

[Schnell]

That explains some. I've heard of the lenient pot laws there.

[brewsky]

It actually does make sense from an efficiency standpoint, as the intake and exhaust flows wouldn't have to turn 180 degrees each to get where they are going.

Yamaha started using the "reverse head" design on the YZ450F in 2010.

[LesterPiglet]

What about this then?

http://www.dwmsracing.com/forum/index.php?topic=14.0

[lrutt]

Have to keep in mind that on an air cooled motor it is especially important to keep the exhaust valves / seats / ports cool to prevent distortion / cracking. hard to do when they would be on the back side.

[cabrala]

What about this then?

http://www.dwmsracing.com/forum/index.php?topic=14.0

I linked to his SOHC4 thread above. Seems like your link might be the place to keep track of recent progress.

[LesterPiglet]

What about this then?

http://www.dwmsracing.com/forum/index.php?topic=14.0

I linked to his SOHC4 thread above. Seems like your link might be the place to keep track of recent progress.

I wonder how I missed that.

[Xnavylfr]

Here you go guys/gals something else to wrap your brain around!!!

http://hondachopper.yuku.com/topic/50336/1975-8-cylinder-Honda-engine#.UYEc10pLkg8

Xnavylfr(CHUCK)

[Schnell]

Here you go guys/gals something else to wrap your brain around!!!

http://hondachopper.yuku.com/topic/50336/1975-8-cylinder-Honda-engine#.UYEc10pLkg8

Xnavylfr(CHUCK)

Conjoined quads!

[754]

Cool, have not seen him on here much. I have a small bmw rear end NOS that may be of use to him with that setup.