Akunar parts FXR?

[CHOPPA]

Im want to make my FXR engine a bit quicker, im aiming for around 200hp but if I get 10% of that id be happy...

These Akunar parts seem good, im thinking a new piston, exhaust, cams, valves and a carby from them. I have heard people having problems with the pistons but I will leave the standard rev limit so hope they will be ok.

Is it the Pro R piston I need? What size pins and deck height? What size valves do I order??

Has anyone tried the cams?

I will get someone to port the head for me

http://www.akunar.com/

[Yow Ling]

if you only want 10% then you dont need to worry about the bigger valves, the cams seem to work, not sure if you need the proR but maybe you do !, just ask for a 64mm raider 150 piston

[crazy man]

think the cams are not as good as stock

[ducatilover]

I've got a 95mm piston here...and a few longer throw cranks from GN/DRs. Nobody will know.

[kel]

Some of my cam data - Akunar is the winner for duration and lift, clearly too much exhaust.

Standard FXR
in lift 6.95mm
ex lift 6.1mm
valve timing @1mm lift IVO 0 BTDC
IVC 42 ABDC 222deg
EVO 24 BBDC
EVC 3 ATDC 207deg

Kelford Cams
in lift 7.78mm
ex lift 6.63mm
valve timing @1mm lift IVO 16 BTDC
IVC 39 ABDC 235deg
EVO 42BBDC
EVC 9 ATDC 231deg

Akunar Cams
in lift 8mm
ex lift 7.6mm
valve timing @1mm lift IVO 20 BTDC
IVC 60 ABDC 260deg
EVO 57BBDC
EVC 17 ATDC 254deg

Had a pair of the GPR cams up here recently but the guys were in such a rush to put them in I didnt get any measurements.

[crazy man]

Some of my cam data - Akunar is the winner for duration and lift, clearly too much exhaust.

Standard FXR
in lift 6.95mm
ex lift 6.1mm
valve timing @1mm lift IVO 0 BTDC
IVC 42 ABDC 222deg
EVO 24 BBDC
EVC 3 ATDC 207deg

Kelford Cams
in lift 7.78mm
ex lift 6.63mm
valve timing @1mm lift IVO 16 BTDC
IVC 39 ABDC 235deg
EVO 42BBDC
EVC 9 ATDC 231deg

Akunar Cams
in lift 8mm
ex lift 7.6mm
valve timing @1mm lift IVO 20 BTDC
IVC 60 ABDC 260deg
EVO 57BBDC
EVC 17 ATDC 254deg

Had a pair of the GPR cams up here recently but the guys were in such a rush to put them in I didnt get any measurements.

Akunar Cams
dont seem to bad after all but need to see the hole read out. will post a read out of the yoshy grind tomorrow

[Grumph]

Interesting - first time I've seen this comparison. Have to say that Kelfords are the only ones close to what I'd consider correct lobe centers. Most of the 600 fours run best around 102/104...
akunar are coming into the lift area I'd consider reasonable too.
On balance, without seeing Crazy's Yosh figures, I'd try the Akunar on 102/104 centers....

[kel]

Interesting - first time I've seen this comparison. Have to say that Kelfords are the only ones close to what I'd consider correct lobe centers. Most of the 600 fours run best around 102/104...
akunar are coming into the lift area I'd consider reasonable too.
On balance, without seeing Crazy's Yosh figures, I'd try the Akunar on 102/104 centers....

Well as I no longer have an FXR the infos all up for general viewing. The centrelines of the Akunars were in part dictated by valve to piston clearance and as the bike made 20hp first run on the dyno there seemed little point in machining the piston to get them closer to where they should have been. Akunar provides zero set up data so it's suck it and see.
YZF600 kit - in 8.8mm 262deg 22/60 109 centre, ex 8mm 250deg 55/15 110 centre - but then its reving to 16k. This and running the akunar numbers through Lotus le software (with exhaust and inlet data) influenced where the akunars were set.

[CHOPPA]

Good information, thanks guys! Is the bore a cast iron thing that I can bore out to oversize or does it need to be sleeved?

[Kickaha]

Good information, thanks guys! Is the bore a cast iron thing that I can bore out to oversize or does it need to be sleeved?

Cast and you can replace the sleeves

[CHOPPA]

What size valves do i need?

Inlet Valve OD	Exhaust Valve OD	Valve Length	Valve Stem Width
24.50mm	22.00mm	82.00mm	4.50mm	AKV24228245
24.50mm	22.00mm	85.00mm	4.50mm	AKV24228545
27.00mm	23.00mm	65.50mm	5.00mm	AKV27236550
28.00mm	24.00mm	65.00mm	5.00mm	AKV28246550
28.00mm	24.00mm	72.00mm	5.00mm	AKV28247250
28.00mm	24.00mm	80.00mm	5.00mm	AKV28248050
30.00mm	26.00mm	65.00mm	5.00mm	AKV30266550
30.00mm	26.00mm	72.00mm	5.00mm	AKV30267250
30.00mm	26.00mm	80.00mm	5.00mm	AKV30268050
31.00mm	26.00mm	72.00mm	5.00mm	AKV31267250
31.00mm	27.00mm	72.00mm	5.00mm	AKV31277250
31.00mm	27.00mm	80.00mm	5.00mm	AKV31278050

[kel]

fxr150 valves
in 2 x 23mm, stem 4.47 mm
ex 2 x 19.75mm, stem 4.45 mm

CRF150 for comparison
in valve 2 x 26 mm
ex valve 2 x 22.5mm
valve timing @1mm lift
IVO 15 BTDC
IVC 48 ABDC 243deg
EVO 50 BBDC
EVC 25 ATDC 255deg
inlet valve centreline 106.5
exhaust valve centreline 102.5

and the ported FXR inlet with 28mm carb is good for 120cfm. I'll miss the old 4 stroke

[CHOPPA]

Whats the most important bit I have to match up when sizin? Length of Valve and Stem size? Then find the suitable valve..

[hmurphy]

My god. Why not just do cams and porting and leave it at that!? Can't have you getting more HP than me mate or I might have to start crashing more... or God forbid spend more feckin money on my bike.

[CHOPPA]

No point taking the head off twice mate