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Project X

Posted: Sat Jul 22, 2017 6:20 pm
by madforitkev
Having just finished my first Kettle restoration, I became more and more intrigued by the motor and how tune-able it potentially was.


So here is the cunning plan!

1. Tune a kettle to a high street/track level of tune so it is still be rideable to the pub (just).
2. Add a few sexy engine bits like a dry clutch and 6 speed.

3. Make it stop and handle.

Pretty simple goal over a pint?

So I acquired barrels, a head and a set of trashed (sacrificial) casings (I knew this might be a grinder-fest!).

This post will start with the chassis development thus far and then move into the motor and cosmetics as it progresses.

I can't promise how long this will take, but I would like to not be retired when it is complete!

So which basic chassis and look?

I have always liked 'suspended engines' like the Honda VFR800 and want a single sided swinging arm look, but this is a quantum shift in Kettle mounting! Sounds like a challenge, so as someone wise once said on this forum, "why? because I can!"


Having bought some VFR casings, arm and main frame, the fun began.


The VFR has three engine mounts and the swinging arm is through the rear of the engine.

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I started with the arm as this was the real unknown.

First I took all the vital statistics to make sure I could get close to them when I finished the 'Frankenbike'.
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Suspension angle, arm angle, rake angle etc. All recorded.

The VFR also uses a fancy lower suspension mount casting so the whole thing had to be assembled and dimension taken down.
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Plan A was to try to get the swinging arm mount inside the engine casings like the VFR. Out with the grinder!
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By removing the kick start assembly, I had a nice location for an arm axle shaft. This was duly machined and fitted (more about how I was going to start it later).

Well it kinda worked and made a lovely short wheel base but the more I got the position close to having the primary and rear drives line up the more the centre of the line bike went west and the more grinding I did, which just meant more welding later to create a sump again!
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Plan B

Forget mounting the arm axle inside the motor.

I decided to use the upper and lower rear engine mounts and make a combined suspension lower mount and rear engine mount. Hopefully the two mounts with a third on the rear of the barrels should be enough support (more of the rest of the mountings later).


The pic is still a prototype but I made two 'boomerang' mounts bolted through the Kettle engine mounts (now solidly bushed). The lower of the two also locates the lower suspension mount (still a proto - metal to be removed yet for weight reduction) block.
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Big plus with this is I dont have to hack the cases nearly as much!

Re: Project X

Posted: Sun Jul 23, 2017 8:43 am
by madforitkev
So with the suspension mount installed, I moved to the barrel mounts. The VFR had 2 but I plan to remove one from the frame to make room for larger carbs. So the one (pair) remaining had to be pretty robust.

I designed 2 blocks that fit into the fins of the barrel and can be easily welded in place.For now I am tacking them on in case the carbs become a challenge and if I decide to add reed valves (which I would weld the housings in for first).
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The rear top mounts (the 4th pair now) are already on the VFR frame and line up fairly well with my boomerang mounts so in the final design I will add some meat and threads in there to take those.
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So I think as a start it looks pretty slick! And the primary and rear drive are only 5mm out of line! Easy to fix.
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I kinda like the flip -top design. Should make servicing easier!

I have chosen my wheels (CBR1000R) although for my retro-ish look I want, I might chrome them.

Front end is a nice GSXR750 inverted Showa pair with lots of room to play with settings.

So welders tomorrow.

Re: Project X

Posted: Sun Jul 23, 2017 9:56 am
by Alan H
Certaiinly different. I like different.

Re: Project X

Posted: Sun Jul 23, 2017 11:35 am
by PaulD738
Alan H wrote: I like different.
Now why doesn't that surprise me? :lol:

Re: Project X

Posted: Sun Jul 23, 2017 9:21 pm
by teazer
That is a seriously mad project. I like that. Q: how is wheel alignment? The reason I ask is that a GT motor isn't exactly symmetrical and I suspect that if the sprocket is almost in line with the rear, the motor or wheel may be offset relative to the chassis centerline.

Or maybe you got lucky. :)

Re: Project X

Posted: Mon Jul 24, 2017 7:45 am
by madforitkev
Teazer

ON the VFR the rear shock and rear wheel centre are slightly offset which initially confused me until I finished all the measuring. In the end the engine is only about 20mm of centre line. Not too shabby!

Once the head is welded I will get into porting properly which will drive the exhaust design. I am trying to get all three to come out under the seat.

Did you recover from the garage flood?

More later

Re: Project X

Posted: Thu Jul 27, 2017 9:09 pm
by madforitkev
Got the barrel engine mounts back from the welders. Just tacked on for now....
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The other two mounts at the rear of the barrel mounts can be cut off now (grinder fun!)
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Final line up check. All square and engine centre line is about 3 mm off as far as I can see. Shock looks weird because it is offset anyway.

Now I need to get into porting to sort the exhausts.

I am a complete porting novice so I have started boneing up. Some of the forum guys have been really helpful (thanks Teazer) so I feel I can make a start.

As a test I am going to map what I have. Run it through a simulation to test the simulation, then go from there.

So a couple of goes at a porting map......
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Will let you know how I get on :lol:

Re: Project X

Posted: Fri Jul 28, 2017 4:43 pm
by madforitkev
Having tried to measure the two tracings and comparing to actual measurements where I can I have come up with the following map.
ports std.jpg
The black horizontal lines are me working out the blow down timing/area (time to transfers opening from exhaust opening).

Hopefully it is fairly accurate although I noted that while I show similar parts and the same height there is a bit of difference there. Port widths also seem to vary a bit but that could be a tracing/circumference issue?

Does anyone have a port tracing for an A for comparison?

Re: Project X

Posted: Fri Jul 28, 2017 8:02 pm
by mutisnuts74
Hi, I may be wrong here due to camera angle but studying your photo with the string line it does look a little to the left please check your measurements again if so and I did my special the same way although not ant where near your ambitious and fantastic looking example

Steve

Re: Project X

Posted: Sat Jul 29, 2017 11:53 am
by garry55
I was thinking it actually needed to go more to the left - the string line runs through the centre of the middle inlet port, which isn't the centre of the engine?