4th Gen & 5th Gen 360 crank mod

Some may recall Ron Grant & Tony Scott tuning the older 1980's VFR750's, and somewhere along the line Ron, Tony or the pair of them cut and shut a 180 crank to make a 360. I'm planning to do the same to either a 4th or 5th Gen motor and I've a good idea how it was done, but does anyone know how they did it? Of course the cams would need to be done as well, although RC30/45 cams would suffice if it's not possible to mod the standard ones. I've been told the std. cams are two piece and are pressed together, anyone know for sure?

Why do I want to do it?

I love a challenge, the drone sound and want to build either an RC30 or RC45 replica.

[image: View Post]chuwachi, on 18 July 2010 - 04:20 AM, said:

Some may recall Ron Grant & Tony Scott tuning the older 1980's VFR750's, and somewhere along the line Ron, Tony or the pair of them cut and shut a 180 crank to make a 360. I'm planning to do the same to either a 4th or 5th Gen motor and I've a good idea how it was done, but does anyone know how they did it? Of course the cams would need to be done as well, although RC30/45 cams would suffice if it's not possible to mod the standard ones. I've been told the std. cams are two piece and are pressed together, anyone know for sure?

Why do I want to do it?

I love a challenge, the drone sound and want to build either an RC30 or RC45 replica.



What do you hope to gain? How long would your mod. take and how much would it cost?
If the change from 360 to 180 was worth writing about, by now surely there would be substantial write up.....
A big bore, tuning/lightening engine mods and carb. tweaks would i think give easier and more reliable results.
My VFR 4th gen. is ready for engine mods, I'm rubbish at engine stuff!
The racing exhaust system im now using drones and sounds awesome!
The bike is racing here on the island .....
If your really handy and are on the Isle of man like myself, come and look me up !

[image: View Post]chuwachi, on 18 July 2010 - 04:20 AM, said:

Some may recall Ron Grant & Tony Scott tuning the older 1980's VFR750's, and somewhere along the line Ron, Tony or the pair of them cut and shut a 180 crank to make a 360. I'm planning to do the same to either a 4th or 5th Gen motor and I've a good idea how it was done, but does anyone know how they did it? Of course the cams would need to be done as well, although RC30/45 cams would suffice if it's not possible to mod the standard ones. I've been told the std. cams are two piece and are pressed together, anyone know for sure?

Why do I want to do it?

I love a challenge, the drone sound and want to build either an RC30 or RC45 replica.


You may want to give these guys a ring, though they are in the U.S. http://mngforce.typepad.com/ They had some custom stroker cranks made for the NC30/35's. There is some interesting info on their site regarding V4 engine building. Pretty impressive power gains with the baby V4!

Yes Kev I'm definately fom the Isle of Man, Ballasalla to be precise but I'm still in Perth WA, next time you're at the airfield ask John Ridout (one of the Scrutineers) who's Oggy ?

Depending on what age you are you may not have heard of the mod. Ron Haslam rode one in the late 80's that had the mod done and it did produce good track results, albeit with a motor tweaked by Grant and/or Scott. That would be the first thing I'd like to do to the motor, seemingly the RC30 type firing pattern gives greater driveability and a fantastic sound to boot, nothing at all like the RC36. The mod looks on the face of it fairly straight forward, although it means sacrificing a second crank which are reasonably cheap and easy to find nowadays. The machining part will be a breese for a guy I know, so it'll cost me a few quid but not too big a wedge.
I'll be looking you up when I return home!

Thanks for the info kostritzer, I'll be taking a good long look at that site!

[image: View Post]chuwachi, on 24 July 2010 - 06:17 AM, said:

Yes Kev I'm definately fom the Isle of Man, Ballasalla to be precise but I'm still in Perth WA, next time you're at the airfield ask John Ridout (one of the Scrutineer) who is Oggy ?

Depending on what age you are you may not have heard of the mod. Ron Haslam rode one in the late 80's that had the mod done and it did produce good track results, albeit with a motor tweaked by Grant and/or Scott. That would be the first thing I'd like to do to the motor, seemingly the RC30 type firing pattern gives greater driveability and a fantastic sound to boot, nothing at all like the RC36. The mod looks on the face of it fairly straight forward, although it means sacrificing a second crank which are reasonably cheap and easy to find nowadays. The machining part will be a breese for a guy I know, so it'll cost me a few quid but not too big a wedge.
I'll be looking you up when I return home!

Thanks for the info kostritzer, I'll be taking a good long look at that site!



HI Oggy.
In the late 80's i was still in school, so the finer points of VFR motorcycles were far from my exam syllabus. But since finding an interest in the VFR's from around the mid 90's i have indeed heard of the mod before, but only as a passing thought.
I do hope to be up at Jurby next week for the local meeting and am sure i know John, as you know he is a local face.
For passed 3 years I've been running a small motorcycle accessories shop in the middle of Douglas, next door to the 'Duke' DVD shop. Look me up if you are local again soon!
I was thinking of asking Slick to do my motor as hes local and hes still doing the tools. But i dont think i will ever find enough Groats to buy a big bore kit, never mind get it fitted by Carl Foggarty's spanner man....(Carl was in me shop here last week tho! lol)
Which side of the globe will your experiment likely to be? Will i get some interesting competition? lol