I read somewhere that the vfr valves are bigger too, was on here somewhere!!

It says it here that the inlet va;ves are 1mm bigger:

http://www.v4power.co.uk/html/nc30_vs_nc35.html

Yakama wrote:It says it here that the inlet va;ves are 1mm bigger:

http://www.v4power.co.uk/html/nc30_vs_nc35.html

I must be blind! whereabouts does it say that?

Its on that page under the carb section:

The intake ports in the NC35 engine are narrower; this will increase the velocity of the air entering the combustion chambers. Ports measure 19mm in diameter, 1mm smaller than the NC30. Exhaust valve diameters are unchanged but cam profiles are revised (see Cams).

lukemillar wrote:

Yakama wrote:It says it here that the inlet va;ves are 1mm bigger:

http://www.v4power.co.uk/html/nc30_vs_nc35.html

I must be blind! whereabouts does it say that?

Says it next to carburettors, 20mm intake valve for the VFR 19mil for the RVF, knew i wasnt pulling that one out of my arse!

Thanks for the link btw Liam, not seen that before.

I think that article's referring to the different port diameter, both engines use the same sized intake valves (same part number now too).

Mike Norman has some info on his website about the port changes between the two engines.

Edit - here under point 5 (ports): http://mngforce.typepad.com/nc450vdev/n ... st-go.html

Ok my bad

Will be interesting to know what sort of gains i get with RVF camshafts fitted to a VFR engine, Rick-o thinks i will see some increase in power, plus the fact that RVF camshafts are lighter will help too id imagine.

After reading Mike Normans blog on the port intake size it seems that fitting the NC35 heads would be the better option, however he seems to think the NC35 had an extra 5bhp over the 30 whereas other sources say that the power was actually lower due to the licensing laws changing, it is also said that the late 90's GSXR400's where down on power over the earlier models due to a change in the rules


Also a small update:

Given the frame a bit of a scrub. Before,

After,



Removed the valves from the front head,

The water cooler at work donated a few plastic cups which make perfect sized containers for the valve components

Got to work cleaning the remains of the head gasket and as much of the carbon deposits as i could for now.


I also cleaned up the valve faces with a brass wire wire wheel, couldnt get decent before/after photos but they have come up like new! And thats all for today am still waiting on quite a few parts to come back from the painters so hopefully there will be some nice freshly painted parts for me to drool over in the coming weeks.

Small update for now, got the rear head from this:

To this

Before i realised that this had happened whilst the engine was still being used!

It seems that the valve guide has slipped down, anyway it wouldnt have been worth repairing the head, so i spoke to Tony and we swapped my bad head, for one with 2 broken valves but crucially no damage to the main body. So i will swap my good valves for the broken ones and we should be ok with that.
Also got hold of some headlight rubbers that need a bit of a clean,

Bagged up ready to be zinc coated,

Gave the front head a good clean and have lapped in the valves, alls thats needed now are stem seals.



Next up is painting the clutch, alternator and rocker covers in what im hoping is going to be a decent match to the original colours. This will be my first attempt at painting so wish me luck!

Almost finished painting the engine cases now so so a few pictures of my progress on that and other little bits:

Just need one more coat of lacquer on the rockers and to finish the clutch cover.


Unfortunatly there is quite a difference between the new colour and standard.


Still looks pretty smart especially for my first go at spraying.



Got started on the replacement head.


Bent valve, Piston had spun a main bearing wrecking the valves in one cylinder luckily i have 8 spares to choose from .


Given the linkages a clean and sprayed, excuse the manky shock spring.


Footrests cleaned up, not perfect but alot better than before.


Straightened my bent screen brace, and given the headlight rubbers a clean.