Gsxr750 wn-ws with rf900 valves? Wot power gains expected?

[Madb]

Question to the technical bods. 

Wot power gains would be expected vs cost and how much would i pay do have it done. All gain worth having but..

Has anyone done this and have dyno read outs. Cheers.

[Madb]

The head is going on rf900 for my track day bike in a gsxr wp frame.

[TL1000R]

Did you do the swap yet? how much bigger are the valves and are they completely interchangeable stem diameter stem length and keeper grooves all the same?? The net gain is determined how well you increased air flow going to the valves as well. The sum of the whole package

[Madb]

Hi tl1000r, not done it yet as no spare money. The valves are same in stem size, collets, length etc, but valve( inlet )for rf are 1mm bigger in dia. I know i will gain as you say " sum of parts"  just wondered on cost and gain in hp, tho its for track only I'm  thinking maybe gain better mid range?

[Gixer1460]

Depends on the quality of the porting work - its as easy to lose flow as it is to gain it. All things being equal, bigger valves tend to work mid to upper rpm's but sometimes the same can be achieved with longer duration cams and std valves? Could be a pricey solution - 8 / 16 valves + head work + maybe piston pocket work against a set of cams and springs?

[Madb]

As this is the start of a very long journey of prototyping,  me like the thinking @gixer1460 approach of cams and springs is the budget end of tuning I'll go that way as the spring board.

This will be my first in tuning a multi gsxr so any advise as i go is always appreciated.  Thank you for all for your input.  I've done the two stroke tuning thing and many a four stroke but things have moved on greatly so one needs to get up to speed.

Right, I've done the big bore by adding rf900 crank, rods,pistons, barrels from three or four sets and weighed them till i got a matching set. All within half gram or less. Yippee! 

Crank? Balance and lightened? Or just check for balance? 

Head will just be" milded clean " in the ports, exhaust port polished. Done this before on 750 and worked a treat. Good starting point. 38mm from 750w/p with ramair socks. Carbs will be fettled with rebuild.

Should keep be busy over winter.

Edited November 22, 2016 by Madb
Forgot measurment.

[Madb]

Ok. Cant find anyone who sells cams for 750wn-ws models.  

Anyone know who does them? Or do i need to send standard cams to be profiled. Maybe pops?  

I know these models were hated when first released but surely someone made tuning parts for them! Its hard enough trying to find rearsets.... grrr

Cheers.

[Madb]

Oh and dont need rearsets as i made adapter plates to take later models. 

Dont wish to send engine away for someone else to tune as thats where i get my kicks from by Doing it myself but some things i cant do like making cams, etc.  Sometimes wish it were an oil boiler! But hey... 

[Gixer1460]

If you can track down Phil Joy / Joy Cams? he can regrind standard cams or re-weld the cam noses to regrind and keep the stock base circle / clearances - best talk to him first.

[Madb]

Cheers gixer1460. 

[Swirl]

this fellow

[Madb]

Cheers swirl.