Engine angle

[hangtime]

Howdy,
Does anyone know if changing the angle of the engine will affect the performance?? I am wondering if tilting the engine counter clockwise to clear the wishbone will throw a hitch in the  giddyup.
Thanks

[gowen]

That's an intresting question. But, I don't see the performance loss. Except you understand you will have to change alot of stuff, being the air box, carb, exhaust, ect. ? Also, depending on how far CC you are planning on rotating it?

[hangtime]

This is all part of my aluminum frame conversion (I should have mentioned). As I study my photos of the KX450F, I notice that the cradle offers a lot of room to the bottom of the cases. If I rotate the engine with the swingarm bolt in place, the front of the engine looks as if it could go down quite a bit. I'm sure I'll still have to cut the down tube and raise  the wishbone, but maybe not as much and maybe not move the Left radiator. The air box and boot are going to be a pain in the ass.

[Gonzo]

I wouldn't see how changing the engine angle on a 2-stroke would cause any detrimental effects, but on a 4-stroke it's a different story cuz you gotta make sure the gearbox oil sits in the right place for the pickup pipe. If that makes any sense at all.

But yeah, lining everything up is gonna be fun.

[alan]

It could effect the float level in the carb, however you could off set that with a slight angle on a custom reed spacer. 

[gowen]

It could effect the float level in the carb, however you could off set that with a slight angle on a custom reed spacer. 

That was my thoughts, but now I see he is making a custom frame. That makes sense. I can't imagine it is much diffrent than a wheelie or climbing a hill.

Good luck with the project.

[Arigato]

I've seen a few CR500 conversions that do the same thing.  However, the Service Honda version uses their own billet wishbone(that clears the exhaust) that they weld into place. This allows them to mount the engine at the angle it would normally be.

[KXcam22]

Hangtime,
  It won't effect performance but it could effect the handling a touch.  The location of the crank centerline (rotational mass of enertia) has an effect on how much weight gets put on the front wheel in cornering.  Over the years of development of dirtbikes they have been playing with engine position moving it a few mm here and there.  Even the CRF450 has had small engine position changes (I recall) from inception to the latest model.  That being said, I would go ahead a do what you need to make it fit, you likely will not notice anything (other that riding the coolest aluminum framed KX500 around). There is a book (a can't Recall the name - something about chassis design) around for a few years that talks about chassis design and handling of motorcycles.  maybe someone has a copy that can post it as a .pdf. good luck. Cam.

[hangtime]

If I rotate the engine CC would this deliver more inertia/weight transfer to the front end? If so that would be good for me as I am 6'4" and tend to sit further back on the seat. I like the idea of milling a reed spacer to help align the carb to the boot, thanks Alan.

[Arigato]

If I rotate the engine CC would this deliver more inertia/weight transfer to the front end? If so that would be good for me as I am 6'4" and tend to sit further back on the seat. I like the idea of milling a reed spacer to help align the carb to the boot, thanks Alan.

Yes, it would.  On the Service Honda bikes, they rotate the engine just a little even with the custom wishbone piece.  They are noticeably more front heavy than a steel frame CR.

[gowen]

That was my dream bike when they first released it. I ended up with a KX though.. Still the most beautiful 500 available.

[Gonzo]

Nah. I prefer the looks of the KX over the CR meself. Seems a bit more substantial-looking if you get me. CR always looked a bit fragile to me.

[gowen]

I agree, don't like the look of a CR500R, but I'm down with the CR500AF. That was what I was meaning. If I wanted a CR500 I'd purchased one, the CR5AF is not out of price range, but was being sold for a crazy amount for a dirtbike 

Ended up with way more in my kx. 

[Arigato]

I had an AF for a while, but got bored with it and went the thumper route.  Dumb move!  As soon as I got the money together, I got my K5 and will keep it forever.  The motor is just way sweeter on the KX.