Going Racing

[The Prophet of Doom]

Today I did a little powder coating for the crank bolt cover.  After stripping and polishing I sprayed in black powder then wiped my finger gently over to clear the powder on the raised parts.  Did the same with the copper YICS badge, but powdered red first.  It will need a little tidying with gloss enamel.  There's not a huge profile there and even this good took a few goes.

Not overly happy with the red - supposed to be a deep red but it's more of a brown when over dark colours it seems.

[Rikugun]

Looks great to me. Do you have a "before" pic for comparison?

[Re-Vision]

What brand of powder are you using? I'm waiting on delivery of a dual-voltage Eastwood and I'll order powders later.      BDC

[The Prophet of Doom]

I didn't take a before snap, but it was in pretty rough shape - the alloy was furry and took ages to get a polished look happening. 

All my powders are Dulux at the moment just because they are easily available.  I'm putting an order in with http://www.prismaticpowders.com/ for my next lot.  They get good reviews - especially for blacks, clears and translucents

[motoracer8]

 Keep the engine, throw everything else away.

[fret not]

That sounds like the voice of experience.  Tell us about what was done to the motor(s) you used and how they performed. ;)  Did you run 650, 750, or ?  What about the carburetors and ignition?

A while back I discussed the XZ motor with Craig Hanson, and he said they could be bored to 650 with new sleeves and boring the cases to accept the larger sleeves, but to get to 750 you have to stroke the crank in addition to the larger bore.

[The Prophet of Doom]

Seems that there will be certification problems with my big-arse brake mod.  So rather than hassle I'll put stock back on for the meantime.  Trouble is I sold my good rebuilt calipers with the 400.

These are off a bike that was actually being used.  30Yr old lines with age cracks, one piston completely seized, missing copper washers, both covered in something like fork oil or semen and brake fluid the colour and texture of chocolate sauce.

[QBS]

Fret, I've read similar opinions regarding the search for more cubes.  The version I remember said the plan was to bore the stock cylinders to 650 and get the additional 100 via  a stroked crank.  No mention was made replacing cylinders or boring cases to get the 650.  I remember the quote, "all bore no stroke".  Seem to recall the guys name was Wilcox, but could be mistaken.  This was a while back.  He ran a successful 750 V back in the '80s.

[fret not]

Eddie Willbanks

[QBS]

Right you are.  My apologies to Mr. Willbanks for getting his name wrong.

[motoracer8]

 Hi Mike, It's been long ago that hot rodded a Vision engine. It was for the dirt track so the rest of the cycle parts were not much good.

I could dig out my notes but I believe mine was about 670cc's sleeves and bore, any more would have had to come from stroke.
JT made the pistons and I used Carrello rods 1/2" longer than stock. Megacycle cams, I had Jim make me a couple different grinds.

Alittle bigger intake valves but I don't remember the size. Several hours on Gerolomy's flow bench with 40mm Delorto carbs.

The engine put out about 72 Hp at 9500 rpm.

That project was 30 years ago now.

Craig and I have been life long friends, I've known him for over 50 years now.

He just balanced my Norton crankshaft for me as it's going through alittle renovation.

Last year about this time I pulled the engine out of the Vision. It really didn't need much but I replaced the rod bearings and rings, touched up the valves.

[fret not]

Longer rods, interesting.  So is that to lessen the side thrust of the piston skirt against the cylinder wall?

72HP on dirt!  I guess that's not so much nowadays, but I remember when Harley Davidson was running the KR flat heads and winning national events, and I would guess they didn't have that much.

[QBS]

If my math is correct, Motoracer8s' 670cc V engine was putting out 1.76 hp per cubic inch.  An impressive figure for sure.

[The Prophet of Doom]

Yes, Please do dig out your notes Motoracer8.  I wasn't going to do much to the engine except a hone and new rings, but a 100+ increase in cc would be pretty cool

[dingleberry]

72HP on dirt!  I guess that's not so much nowadays

Wasn't much back in the old days either. King Kenny's TZ750 put out something like 125 hp on the dirt back in 1975.
My last Jawa 500 had about 75hp and only weighed about 75kg. Now that would pull ya arms of hooking up out of a turn ;D

[motoracer8]

 The longer rods give a better angle against the crankshaft and that helps mid range power. They do reduce the side thrust on the pistons some.

A friend of mine, an engineer at Aerojet, made the ignition system for it. It was similar to the std Yamaha unit but with better parts, bigger capacity output transisters to run higher output coils. The advance curve could be altered with a couple of trim pots.

It wouldn't quite pull off the turns with the Harleys, they probably were making 90 HP or more then but were 25 lbs heavier. The Vision engine would spin the tire but the Harleys put it on the ground.  The long rods were an attempt to get better traction off the corners.

Ken

[motoracer8]

 An extra 100cc would be expensive. I used nikasil coated aluminum liners, custom made JT pistons, you have to buy 4 at a time.

Another reason for the Carrello rods, Vision rods have no wrist pin bushings, they just copper plate the wrist pin bore. More power over heats the wrist pins.

A Vision with a rattily top end are most likely loose wrist pins.

$1000 to $1500 for another 100cc's for a flexi flier like a Vision is probably money not well spent.

[The Prophet of Doom]

Hmmm, may have to wait till I win the lottery. That's about the amount I have left in my wife's very restrictive bike budget -   I have to spend it or I won't get it again next year - a bit like a government department, but I do have other essentials to buy.

[pinholenz]

And then there is the cost of the 40mm  Delorto carbs, increased road tax for going over 650cc and another year without getting your beloved project on the road. Yeah, Nah. - Go have some fun on your bike!

As an aside, I notice on the Learner Approved Motorcycle lists for NZ and Australia, all the British 650's of the same vintage as the XZ550 are approved for learners. But our not-so-tame XZ 550's aren't. The approved power to weight ratio for a learner is 0.15 (150kw/1000kg) whereas the XZ550 comes in at 0.22. (48kw/212kg) The XZ400 is approved for learners.

[fret not]

I just looked it up, and the '72 new alloy XR750 was making 70 - 79 horse power, and by 2008 they were making estimated 100HP.

I remember when Kenny Roberts ran his TZ750 flat tracker and it just wasn't fair to put a 2 stroke road race motor on the dirt.  From what I understand he didn't like riding it but some people will do just about anything to mess with other folk's minds.  With that much horse power  on the dirt it's like riding on marbles.  Tweaky quick two stroke power is hard enough to ride on pavement, must have been more than a handful on dirt.