This stupid engine modification...

[karthead]

So my friend was on about some engine modification where one cuts the camshaft and/or crankshaft, rotates them a certain amount of degrees and welds it back together, along with some machining and what not to make the camshaft/crankshaft smooth again. in doing this, half the engine will fire, then the other half and so on. there would be no gain in power of course, but seeing it run would be fricken hilarious i would imagine (he was referring to a v8 or I4 when he was talking about this). He said his uncle did it to a v8 and it was pretty crazy...

He referred to it as an actual modification, like, it actually had a name. Anyone familiar with it? Anyone heard of it being done?

The engine would be so off balance and vibrate so much the mounts wouldn't last very long i would imagine. I'm pretty sure some engines are purposely set up like this, but he was talking about four of the cylinders on a v8 firing, then the other four...

I've been trying to find videos of something similar being done, no luck. So, anyone else heard of engine modifications like these being done?

[MarJay]

Sounds like your being wound up...
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British beauty: Triumph Street Triple R; Loony stroker: KR1S; Track fun: GSXR750 L1; Commuter Missile: GSX-S1000F; Cheap project: CBR900RR FireBlade
Remember kids, bikes aren't like lego. You can't easily take a part from one bike and then fit it to another.

[Jamie.]

The question here is why?

[Suntan Sid]

Some light reading here:-

https://en.wikipedia.org/wiki/Big-bang_firing_order
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"Everybody needs money, that's why they call it money!"

[stonesie]

The main one I can think of is the current R1 with it's crossplane engine, still not a big bang engine though.

OP, you are being wound up, cutting and welding a crank is not something you can do in your garden shed, and I have never heard of it being done. It would have to be a very good and even weld to keep the crank from snapping like a twig... Friction welding might work.

[chris-red]

My TDM has a big bang engine
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[ThoughtContro...]

[stinkwheel]

[The999Kid]

[Frost]

Not madness, common sense that won honda motoGP titles

https://www.roadcarvin.com/sites/default/files/images/rc211v_engine.JPG

a 5 cylinder stroker is a bit bonkers though

[karthead]

Yeah well my friend referred to it as welding the crankshaft or camshaft or whatever. Friction welding did come across in my mind, but i would imagine it would be quite difficult to end the weld at the right angle.
So, big-bang engine, that sounds like the one
I would imagine the rpms would be pretty low.

Also there isn't really a question, its more of a discussion.

[Pete.]

You could very easily make an engine 'big bang' by cutting and welding the camshaft (or making a new one). No need to touch the crank at all. Cut the camshaft in the middle and rotate one half 180 degrees then re-join by weld/sleeve/both. Now, cylinders 1 and 4 will fire together and so will 2 and 3. Don't even have to touch the ignition.

I might do it one day just for a laff.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[The Artist]

[chris-red]

[nowhere.elysium]

[beast rider]

[Pete.]

[Fizzer Thou]

HRC Honda built the 6X which was a VFR750 with a modified crank which had been cut and rewelded to change the firing pattern,effectively changing it from a V4 with an even firing to become an engine firing two cylinders simultaneously.I seem to remember a bloke who worked for Honda UK also built one and was very successful.

Found this : https://www.youtube.com/watch?v=BoXm6aeGl_Y
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Just talk bikes.What else is there?

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[nowhere.elysium]

[Pete.]

The VFR doesn't have an even firing pattern - not possible with a shared journal vee configuration. Rotating half the crank effectively created a V4 with V-twin characteristics.
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a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[sniff6]

[400bandit]

XS650's have this done quite often, I think it's referred to as re-phasing...

Joe
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Current Bikes 650 Honda Bros, VTR1000 Firestorm // Past Bikes: Sachs Madass 50/110cc - Bandit 400 - FZR750
(+ a XS650 in lots of pieces in my garage and other places...)

[stonesie]

I will consider myself educated on this then That 5 pot stroker sounds awesome.