cylinder liner

[iain]

Hi guys,
Does anyone have a cylinder liner close by that they can put a set of verniers on and tell me how thick they are.
Thanks heaps,
Iain
NZ

[The Prophet of Doom]

I don't have an open engine to measure, but you can see from the pic in Haynes that it's quite thick.  No spec for this in any of the documents I looked at.


If you are wondering about boring it out, Issue 21 of the Rov Newsletter mentions Greg Stephenson's vision bored out to 640cc with 90mm Ferrari Dino pistons

I have a really great site with several pictures of Vision powered race bikes. To get there you need to go to eurospares.com and then get into the graphics section. You will find the really interesting machines about 3/4 ofthe waydown in that section.
There is a picture of fellow member John Clemens Vision powered FZR400, Eddie Wilbanks awesome racebike, and a bike that is new to all of us from Greg Stephenson.
Greg built a custom frame for his Vision with a HossacklFior type front end. There is a 6 spd. transmission out of an RD 400 inside the cases and to top it off it's got a dry clutch on it Greg said he used some 90mm Ferrari Dino pistons to take the displacement out to 640cc. He was working on this bike back in the 80's and he says it is finished and rideable now. I can't believe it took us until now to find out about it. Most of you should be familiar with Eddies' bike so I won't go into detail here. Johns bike started out as an FZR400 but then was stuffed full of a Wilbanks 640 converted to chain drive. He is using 900RR carbs on it right now and it has pulled 90 or so horses on the dyno. This winters project was fuel injection and along with that getting the intake tract much shorter which he is hoping will get the hp closer to the 100 horse level.  All three bikes are really neet and very much worth a look.

[jefferson]

I got 2.75mm thick at the bottom. Not sure about what bore it is at though. The 680 motor has a 3.3mm thickness at the same place.

[fret not]

I have talked with Craig Hanson of Hanson Race Technology (Chico, CA) in the past about race prep for the XZ550.  He told me that you can bore the stock cylinders to about 650cc and the exposed cylinder walls would be very thin where they fit into the cases.  To make a 750 you need to bore out the liners and press in new ones and bore the cases to accept the larger cylinders, plus the crank needs a bit of stroke added.  That would require welding and regrinding the journal.  That is basically what the Eddie Willbanks 750 motors have.

Our own Motoracer8 used to campaign a Vision 650 on flat tracks.  He did well on the shorter tracks but half mile and larger was the territory of the Harley Davidson XR750.

[Walt_M.]

I have a stock cylinder at standard bore and it is 3mm thick.

[iain]

Thanks guys

I thought by the pictures it would have been a bit thicker,,

All good

Iain
NZ

[motoracer8]

Mike, Craig made some liners for me from aluminum water pipe, bored to size then sent to Bore Tech for plating. I did the same on a Honda single. That engine did 10 years of AHRMA motocross and shows little wear.