Project X

[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.

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'.

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.

Plan A was to try to get the swinging arm mount inside the engine casings like the VFR. Out with the grinder!

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!

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.

Big plus with this is I dont have to hack the cases nearly as much!

[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).

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.

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.

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.

[Alan H]

Certaiinly different. I like different.

[PaulD738]

I like different.

Now why doesn't that surprise me?

[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.

[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

[madforitkev]

Got the barrel engine mounts back from the welders. Just tacked on for now....

The other two mounts at the rear of the barrel mounts can be cut off now (grinder fun!)

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......

Will let you know how I get on

[madforitkev]

Having tried to measure the two tracings and comparing to actual measurements where I can I have come up with the following map.

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?

[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

[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?