NSR FXR, the new No45

[husaberg]

Well now the new engine is coming along it is time to think about the next one.

I do like the idea of a plain bearing bottom end and as grumph has mentioned the cbr 600 92/94 rods will work with some crank mods. 45.2mm.

So I surpose some reading and asking of knowledge is required. Oil pressure needs to be raised and crank balance would be critical. But what revs could it pull and last a season? 15? Don't know. Will all the seals be ok with extra oil pressure? Is it worth the bother.

I came across something interesting the other day (related with Plain bearing)
friction increases by a factor to the cube of its Diameter.
So when say the ZZR600 became the ZXR600 the bearing diameter was reduced from 32 to 30mm for a allegedly substantial reduction in friction losses. (this was referring to the mains)


Ducati when they developed the Supermono would have preferred to use a bush type bearing but they were not available in as higher spec as the two piece shells.They of course used a one piece rod to keep the crankcase as compact as possible and the Rod as light as posible

I mentioned the BSA Starfire as it was one of the few engines that i can think of the other being the Mille Ducati were a roller big end was was substituted to the plain big end into a basic roller being design.
the Starfire B25 while it suffered from problems (An alloy rod with a finite fatigue limit Alloy bodied oil pump rather than the later steel) initially) it was as a result of quality control and being aimed at a learner market that wouldn't change oil filters etc. Rather than any problems with its design.
I think also the New CBR250 single also has a plain mains but yet a needle big end (WTF) so if you have a look there it may help.


I have a few articles that show the detailed mode performed on so older round-case Ducatis to convert these to plain big ends and i will post these if you are interested.

I also remembered this it was a Aussie LSR project based on a Honda 125 with a modded FZR600 head with a plain big end mod well worth a look.

[F5 Dave]

Wot a lash up. Clearly timing is going to be affected where the knot goes over the rollers, he should have found a continuous bit of string + he needs to cut a bit of a slot in the cases.

[husaberg]

I guess there is a few loose ends to tie up.
But did you have a look at the thread?
its quite an undertaking all jokes aside.
OK Not that fast in the end but a bloody impressive piece of bush engineering.
http://www.dlra.org.au/forum/viewtopic.php?f=18&t=556

[richban]

Just for Jason.

[jasonu]

[QUOTE=richban;1130454071]Just for Jason.


Cheers mate.

Last time I will pester you (for now anyway)
What is the model number for that carb?
What is the inside width measurement of the frame spars where the motor sits? It looks like you have a ton of sideways clearence.

[richban]

[QUOTE=jasonu;1130454087]

Just for Jason.


Cheers mate.

Last time I will pester you (for now anyway)
What is the model number for that carb?
What is the inside width measurement of the frame spars where the motor sits? It looks like you have a ton of sideways clearence.

All good will have a look later. Yep heaps of room in the NSR.

[richban]

Well after a good couple of days playing on the bike at the home track I almost have a tyre pressure and suspension setting that works good. On Friday I ran my rather rooted super soft bridgstone backwards as one side was almost brand new. After some sedate practice laps it cleaned up and started to work nice. But when I tryed to go quicker it quickly ripped to bits. Even after 4 laps of not so hard on the throttle. I ran through a few pressure changes but nothing really improved. The front is a super soft as well but has been fab. Cold pressure for the front is at 26.

On Saturday I did the same thing with a used bridgstone soft cold pressure 27. It cleaned up quick and started to work way better than the YDC. It was a massive difference for sure. I was great all day until the last race that was a little longer 15 laps and I was pushing from the start. Still better than the other tyre but if the race was 20 laps it might be dead. I am thinking of trying a 600 front on the rear next. Any recommendations welcome. Not sure how the low profile would feel on the rear.

I am making a new header to try on the dyno soon and also will do a back to back with the old carb.

Also Leigh had the noise meter out at the track mine was consistently a high 91db. Good to know.

[goose8]

Get a super bike front Dunlop will last for ages

[F5 Dave]

Get a touring Cheng Shin front, that will last a few seasons. And slow you down ya prick.

[richban]

New distraction.

Bucket legal and already on 17s. yes I now own a rather nice C90. Engine will be coming apart next week.

[Yow Ling]

New distraction.

Bucket legal and already on 17s. yes I now own a rather nice C90. Engine will be coming apart next week.

Nice, even nicer than my Honda Lead (the noun)

[husaberg]

Its a little known secret that i, kind of like Honda's

[koba]

New distraction.

Bucket legal and already on 17s. yes I now own a rather nice C90. Engine will be coming apart next week.

Are you going to hit Glen up for a supercharger?

[cotswold]

New distraction.

Bucket legal and already on 17s. yes I now own a rather nice C90. Engine will be coming apart next week.

At least you wont have to worry about the front diving under braking.

[richban]

Are you going to hit Glen up for a supercharger?

Now that my friend is a grand idea. Injected supercharged C90. no no no. Just a little freshen up with some valves porting and a cam. Oh and exhaust and carb of course.