Rephasing, What is it?

[inxs]

- welcome to the club skull

 

[650Skull]

Time out from the internet and staying out of google's eye.

Looking for any differences in the Japanese XSC electrical system. A club member has one with the black tank B style Stencils, ..........Don't happen to have something tucked away in your cubbyhole INXS

 

[650Skull]

Looking for any differences in the Japanese XSC electrical system. A club member has one with the black tank B style Stencils, ..........Don't happen to have something tucked away in your cubbyhole INXS

Thanks Bro, Hope you enjoy the Ascot TT article

 

[650Skull]

Thanks for the PM INXS, looking for a diagram for the wiring (Japanese XS650C) if any one else can help

 

[TwoJugs]

I have read alot about this and watched the vids numerous times. It is a cool bit of engineering that was worked out to do this but I have never read any true tech results about gains. H.P., torque, top end speeds, 1/4 miles gains??? I have a bunch of XSs that I play with and they are pretty much in all different froms of builds. I love the sound and the torque is awesome but they are not what I consider a performance motor by any means. They are reliable, easy to work on, the best parts and tech support of any classic motor you will find. I just don't get why some choose to put big money into trying to make these into performance machines? I do just the opposite. I try to keep them as stock as possible, maybe a bore job on the standard sleeves to clean them up, clean the ports but thats about all. They run great when you get the ignition and carbs set up perfect. Most I see are'nt even close in that department and they are chasing power in all the wrong places. Unless you have lots of cash and time I feel that the XS is best at what it does stock and if you want a motor that likes to scream, smooth, and has lots of room for performance gains try building up an older inline 4. Some 550 inlines 4s I built would run circles around worked XSs with half the expense. I am not knocking the XS, just want to let those who have not done certain mods not feel like they are obliged too or missing something. Get your motor running as close to production new and you will have a great bike. Then pick on another to turn into your drag bike or road race project if you really want to tear it up. My next build is going to be a vintage road racer but I will again stay with a stock motor but get it running as new and know that basic service with easily gotten parts and techniques will give me miles of enjoyment with little money out of pocket. Less wrenching, more riding!

 

[Punkskalar]

TwoJugs,

All good points.... BUT, there is minimal expense if you do all the work yourself... All mine cost me was a Pamco Ignition, some new coils, and talking sweet to a machinist to help with the cam....

 

[yamaman]

2jugs, I have a road racer, as do a few others around here. My motor is not over the top at all & maybe has 5 or 10 hp over a stocker.......Road racing needs the bike to handle #1 (and mine certainly does that). I have no trouble keeping up (and sometimes beating) the RD 350 LC's, CB 750's (so long as they're not fire breathing 1000cc 100hp +)
Build a racer, enjoy!

 

[sasquatch]

Here's a vid off a rephased xs650 running....sounds Awesome!!

Here is the build link to Punkskalars bike in this video Thanks for all the info Hugh!!!

http://www.pirate4x4.com/forum/showthread.php?t=719041

 

[PhatTony]

I've rephased my crank already but now I'm looking to cut and rephase my cam to 277 but cannot find anyone locally that will touch it. Anyone who has done this have a trusted guy to get it done? I know about Webcams and Megacycle. $400 is a bit much to much to swallow right now. Especially since I need to buy a Pamco to run it as well.

 

[cooltouch]

Webcam's price for rephased cams used to be a lot cheaper, since they grind the camshaft down to the base circle and build the lobes back up anyway. To them it didn't matter where the lobes were placed -- you just told them where you wanted them. But they changed their prices once they noticed what Megacycle was getting for theirs. Pissed me off. $400 for a 4-valve cam is unquestionably usurious. But whatcha gonna do? Know any cam grinders?

 

[Flexplorer]

I'm researching building a rephased 750. I talked to megacycle about the cam. they said to let them know if I put the right or left piston ahead of the other & what profile I want. Everything I've read, people are putting the right piston ahead, is there a reason for this?

also, anyone has suggestions for a cam profile. this is my daily driver. I'm thinking of the 250-20 all around street cam. any feedback on this?

thanks. doug.

 

[Punkskalar]

I've rephased my crank already but now I'm looking to cut and rephase my cam to 277 but cannot find anyone locally that will touch it. Anyone who has done this have a trusted guy to get it done? I know about Webcams and Megacycle. $400 is a bit much to much to swallow right now. Especially since I need to buy a Pamco to run it as well.

I am now doing my own cams for $185 on exchange, email me for more info:

HughsHandBuilt@gmail.com

 

[Punkskalar]

I'm researching building a rephased 750. I talked to megacycle about the cam. they said to let them know if I put the right or left piston ahead of the other & what profile I want. Everything I've read, people are putting the right piston ahead, is there a reason for this?

also, anyone has suggestions for a cam profile. this is my daily driver. I'm thinking of the 250-20 all around street cam. any feedback on this?

thanks. doug.

The reason for doing so is simple. The timing marks are on the left side of the engine, and keeping that cylinder in time makes things a bit simpler. It would work either way, just a little more work making new timing marks and such.

 

[Flexplorer]

The reason for doing so is simple. The timing marks are on the left side of the engine, and keeping that cylinder in time makes things a bit simpler. It would work either way, just a little more work making new timing marks and such.

ahhhh... yes, of course. now that you say that, it does make perfect sense, thanks.

 

[Punkskalar]

Finally got a quick little demo of the cranks and rods in action! Don't mind the bumbling idiot talking in the video (me, haha)

 

[bluejean]

I read your thread in pirate 4x4.(awesome by the way) How smooth is the 277 degree? At what speed or rpm does it vibrate? Have you ever tried building a 270 degree?

 

[Punkskalar]

I read your thread in pirate 4x4.(awesome by the way) How smooth is the 277 degree? At what speed or rpm does it vibrate? Have you ever tried building a 270 degree?

Lets just say that I am not sure of a measurement for smoothness

I do know that I can run over 100 MPH all day long on a rigid frame, super low forks, solid aluminum handgrips and my feet and hands are not vibrating or numb at the end of the ride like on a standard engine. There is no engine speed that vibrations seem any stronger, it is smooth throughout the entire RPM range. I have not tried a 270, as the pins are just too $$$ to have made here in the states.

Hugh

 

[thrashin]

So if I've been reading this correctly, then I can't rephase a 72'? As a matter of fact I really can't find any good internals for it.?? Can someone point me in the right direction so I can get a handle on this engine. Or should I start looking for a 74+? I'de like to know more about the history and what can be swapped and upgraded for future reference. Thanks the newb here

 

[Punkskalar]

So if I've been reading this correctly, then I can't rephase a 72'? As a matter of fact I really can't find any good internals for it.?? Can someone point me in the right direction so I can get a handle on this engine. Or should I start looking for a 74+? I'de like to know more about the history and what can be swapped and upgraded for future reference. Thanks the newb here

If the rods have 22MM wrist pins, then you have a 256 Engine. MOST Engine Numbers Starting with S650 are 256's. You CAN install a 477 Crank, Pistons, Cam Gear, Timing Chain and all the Tensioner assembly and chain guides though in a 256 Engine so long as you have a 6 bolt tensioner on the cylinders. Sounds worse than it is if you have the parts, but you can probably pick up a parts motor much cheaper than piecing it together.... The 72 Cam is nice to have, its very similar in spec to a Shell Cam. The Early Heads are nicer castings as well and flow a little bit better.

 

[xjwmx]

This subject keeps popping up in my reading about the venerable XS650. What is it? I know the crank rotates both pistons up and down together, and fire alternately. So is rephasing a change in the crankshaft and camshaft? If so, why? What is the advantage.

Here's yer re-phase. Skip the text and go straight to the pictures. You'll see what I mean.

http://www.sense.net/~blaine/twin/twin.html

Supposedly 270 buzzes in a galloping horse rhythm instead of the uncomplicated buzz we know and love.