Head porting or not - ***updated with dyno graph***

[Byrdman]

Talk to me about aftermarket cams?

I would think that it would be a relatively small modification job that would yield a decent return?

[R1000]

............I'll have more accurate hard numbers by May, but my 1255 will be making ~200RWHP, and close to 110lb/ft of torque. FWIW, we did NOT decrease the size of the ports.

........

I would chose a turbo kit if the goal was to move into 200 hp territory.

[tomek]

I am by no means the expert here, but the engine guy I use for race cars (that run liter bike engines) tells me that porting on current generation engines is not very cost effective. In other words, the factory doesn't leave alot undone. I'm having a 2002 (yeah, not quite current) GSXR 1000 engine built for my sports racer, and the best bang for the buck in the opinion of the engine builder was to raise the compression with aftermarket pistons, degree the cams and reprogram the stock ECU. I'll have to run 100 octane gas. The engine will be producing about 170 hp at the wheels. This fellow builds engines for race bikes and race cars, and has a good reputation nationally. It's pretty easy to go backwards when people start playing with engines, when you look at the big picture of torque and horsepower. Not many street riders would be happy with a Blackbird that puts out 20 more hp with a peaky torque band. Just something to consider before you let someone work on your engine.

Well,porting on current sportbikes is not really a "porting",it is just basic clean up to better match valve seats to the throat part of the port.Port shape is not really changed.

As far as cost effective,motors on sport bikes are well developed these days,unless you turbo the poor thing it is not effective,honestly,2-3 grand to squize 20 extra hp from liter bike ?

High compression pistons are total waste of money in current era,not to mention something like from Wiseco is much lesser quality then O.E.M.I weighted pistons on my 04 R1 ,all are within 0.1 gram.Try that with aftermarked.

I built YZF 1000 motor with Wiseco 1040 kit,it was a fucking nightmare,pistons as delivered opened squish to 1.7 mil ,had to shave off 1 mil from the block,shave those stupid compression bumps,lay back valve pocket to get good burn,,,,,,,Wiseco sucks,those pistons belong in Cat diesel ,not in lightweight bike motor,,,,,,,,,,,

Formula Extreme factory R6 and Erion cbr600 rr run stock pistons,140+ whp from 600 cc motors,,,,,,,,

Honestly,what compression ratio do you run? You can get 13.5 with stock pistons and cams without touching valve pockets on current literbike,thinner head gasket/shaved block/shaved head,,,,,,,,,,,,,,,,,,,170 whp is nothing to brag on Gixer 1K,,,,the money would be better spent on set of cams,like from Yoshimura,,,,,,

Looking at those ports ( R1000),it is classic www.motoman.com

high velocity port job,parts are actually smaller then on stock head,it looks like it is "light " version,ports are taller then what he recommends.

That yzf 1000 I mentioned, bike received high velocity portjob a la mototman,it pulls like a freight train from 3000 rpms to the redline,there are no steps in powerband whatsoever,,,,,,,,,,

Next couple of weeks,I`m gonna pull out the head from my XX,refresh valve seats,do high velocity port job,etc,

It is normal to use JB Weld on intake ports,it works just fine,,,,,,,,,,,exhaust ports,,,temps are too high,welding it the only way,,,,,,,,

You're right, 170 hp isn't a big number for the GSXR - I just wanted an engine a step above stock that would have a nice tq curve and good longevity. This is what the engine builder recommended for my goals. As far as the pistons, I don't know what he's using, but whatever they are he's had good success with them, as he's been building the motors for a long time. My compression will not be very high, as evidenced by the recommendation for only 100 octane. Cams were an option, but not considered as cost effective as what's being done. He's got a dyno, and knows what the bottom line is for each modification. BTW, I'm spending $2K for this complete engine, not a rebuild on my current engine. I'll finally have a good spare stock engine.....

Replacing pistons for your power target is utter waste of money,honestly,actually the weakest part of gixxer 1k are rods,engine has very long stroke for 1000 motor.( it is basically stroked 750).

Octane numbers are not that important in case high revving superbike motor.Quick burn is.Fuel that workes on turbocharged motor is pretty much useless for this application.You can run close to 14 C/R on pump gas,there is no need for 100 octane,,,,,,

As far as port size,it all depends what is your power target,what kind of usage engine will get.

What works for drag racing will be no good for road racing,so the numbers don`t mean much here,,,,.

Actually intake speed in the ports can be calculated,over the years (of the engine design) figure increased (close to 400 ft/sec in F1 motors),the key is to get good flow numbers without increasing ports size.Huge ports will flow well but velocity is low, so piston will push back the intake charge when is going up past BDC.

Big ports work well only over very narrow powerband.

Factory Superstock literbikes on special brews get clost to 180 whp.Stock cams,stock heads less valve seat prep plus whatever cheating they are allowed courtesy of AMA.Superbikes get 200+,so it is little more then 10% gain.

Next time they come to Road America I`m gonna ask Mladins engine guy to allowe me to measure port size on that Gixxer.I`m pretty sure they will be more then happy to help me.

[Northman]

I would chose a turbo kit if the goal was to move into 200 hp territory.

Depends on what your goals are. Turbo is great for drag racing or straight line speed, but too temperamental of a power delivery for street riding, IMO. I don't like lag.

[Northman]

I`ve worked on 3 gen of Yam 5 valve motors,thunderace,99r1,04 r1,they went to smaller ports everytime,,,,,,,

The Genesis was notorious for a weak midrange, so Yamaha's answer was to decrease intake size to build torque. Yamaha's GP bike has been 4-valve since the beginning, and so now are it's street motors. The 5-valve is history.

XX has a weak midrange( 4-7k),high velocity port job should do wonders to our motors,at least for the street use,,,,,,,

Weak compared to what? A Busa? A 14? You're giving up minimum 160cc there, and unless you're raising compression or increasing displacement, you aren't going to gain more than a few lb/ft of torque.

[tripledigits]

I am by no means the expert here, but the engine guy I use for race cars (that run liter bike engines) tells me that porting on current generation engines is not very cost effective. In other words, the factory doesn't leave alot undone. I'm having a 2002 (yeah, not quite current) GSXR 1000 engine built for my sports racer, and the best bang for the buck in the opinion of the engine builder was to raise the compression with aftermarket pistons, degree the cams and reprogram the stock ECU. I'll have to run 100 octane gas. The engine will be producing about 170 hp at the wheels. This fellow builds engines for race bikes and race cars, and has a good reputation nationally. It's pretty easy to go backwards when people start playing with engines, when you look at the big picture of torque and horsepower. Not many street riders would be happy with a Blackbird that puts out 20 more hp with a peaky torque band. Just something to consider before you let someone work on your engine.

Well,porting on current sportbikes is not really a "porting",it is just basic clean up to better match valve seats to the throat part of the port.Port shape is not really changed.

As far as cost effective,motors on sport bikes are well developed these days,unless you turbo the poor thing it is not effective,honestly,2-3 grand to squize 20 extra hp from liter bike ?

High compression pistons are total waste of money in current era,not to mention something like from Wiseco is much lesser quality then O.E.M.I weighted pistons on my 04 R1 ,all are within 0.1 gram.Try that with aftermarked.

I built YZF 1000 motor with Wiseco 1040 kit,it was a fucking nightmare,pistons as delivered opened squish to 1.7 mil ,had to shave off 1 mil from the block,shave those stupid compression bumps,lay back valve pocket to get good burn,,,,,,,Wiseco sucks,those pistons belong in Cat diesel ,not in lightweight bike motor,,,,,,,,,,,

Formula Extreme factory R6 and Erion cbr600 rr run stock pistons,140+ whp from 600 cc motors,,,,,,,,

Honestly,what compression ratio do you run? You can get 13.5 with stock pistons and cams without touching valve pockets on current literbike,thinner head gasket/shaved block/shaved head,,,,,,,,,,,,,,,,,,,170 whp is nothing to brag on Gixer 1K,,,,the money would be better spent on set of cams,like from Yoshimura,,,,,,

Looking at those ports ( R1000),it is classic www.motoman.com

high velocity port job,parts are actually smaller then on stock head,it looks like it is "light " version,ports are taller then what he recommends.

That yzf 1000 I mentioned, bike received high velocity portjob a la mototman,it pulls like a freight train from 3000 rpms to the redline,there are no steps in powerband whatsoever,,,,,,,,,,

Next couple of weeks,I`m gonna pull out the head from my XX,refresh valve seats,do high velocity port job,etc,

It is normal to use JB Weld on intake ports,it works just fine,,,,,,,,,,,exhaust ports,,,temps are too high,welding it the only way,,,,,,,,

You're right, 170 hp isn't a big number for the GSXR - I just wanted an engine a step above stock that would have a nice tq curve and good longevity. This is what the engine builder recommended for my goals. As far as the pistons, I don't know what he's using, but whatever they are he's had good success with them, as he's been building the motors for a long time. My compression will not be very high, as evidenced by the recommendation for only 100 octane. Cams were an option, but not considered as cost effective as what's being done. He's got a dyno, and knows what the bottom line is for each modification. BTW, I'm spending $2K for this complete engine, not a rebuild on my current engine. I'll finally have a good spare stock engine.....

Replacing pistons for your power target is utter waste of money,honestly,actually the weakest part of gixxer 1k are rods,engine has very long stroke for 1000 motor.( it is basically stroked 750).

Octane numbers are not that important in case high revving superbike motor.Quick burn is.Fuel that workes on turbocharged motor is pretty much useless for this application.You can run close to 14 C/R on pump gas,there is no need for 100 octane,,,,,,

As far as port size,it all depends what is your power target,what kind of usage engine will get.

What works for drag racing will be no good for road racing,so the numbers don`t mean much here,,,,.

Actually intake speed in the ports can be calculated,over the years (of the engine design) figure increased (close to 400 ft/sec in F1 motors),the key is to get good flow numbers without increasing ports size.Huge ports will flow well but velocity is low, so piston will push back the intake charge when is going up past BDC.

Big ports work well only over very narrow powerband.

Factory Superstock literbikes on special brews get clost to 180 whp.Stock cams,stock heads less valve seat prep plus whatever cheating they are allowed courtesy of AMA.Superbikes get 200+,so it is little more then 10% gain.

Next time they come to Road America I`m gonna ask Mladins engine guy to allowe me to measure port size on that Gixxer.I`m pretty sure they will be more then happy to help me.

I don't get into many details with my engine builder. I ask him what he recommends for what I'm doing with the car, and what I'm looking for in power delivery. The engine needed new pistons anyway, so he chose what he considered to be the best for what I'm doing. We talked about rods, and decided the stock rods were fine for the target power level. He's built a number of 180+hp GSXR engines, but I didn't want to get into spending a substantial amount of money for a diminishing return on horsepower.

I wish I could increase displacement, but that would throw me into a different class where the minimum weight is higher. I run minimum weight now, so wasn't willing to trade weight for hp. Some of the C sport racers run built Hayabusas, but their engines are really expensive and a bit shorter lived than the moderately built liter bike engines. My car has a minimum weight of 1020, with driver, for solo racing. I run a straight pipe with custom header, since the bike header doesn't fit the car.

[Northman]

I wish I could increase displacement, but that would throw me into a different class where the minimum weight is higher. I run minimum weight now, so wasn't willing to trade weight for hp. Some of the C sport racers run built Hayabusas, but their engines are really expensive and a bit shorter lived than the moderately built liter bike engines. My car has a minimum weight of 1020, with driver, for solo racing. I run a straight pipe with custom header, since the bike header doesn't fit the car.

Are you rpm-limited at all?

If not, you'd be a fool not to exploit that.

[R1000]

I would chose a turbo kit if the goal was to move into 200 hp territory.

Depends on what your goals are. Turbo is great for drag racing or straight line speed, but too temperamental of a power delivery for street riding, IMO. I don't like lag.

A 200 hp turbo engine will probably be less temperamental than a traditional 1000 CC engine on the same power level. The difference in characteristic to a stock engine will be like double the displacement, but still with a very soft power delivery. I can't take poison on this statement, but it is what a reputable turbo company in Sweden say, and they have bike speed world record by a turbo GSX R 750. http://www.mc-xpress.com

[tripledigits]

I wish I could increase displacement, but that would throw me into a different class where the minimum weight is higher. I run minimum weight now, so wasn't willing to trade weight for hp. Some of the C sport racers run built Hayabusas, but their engines are really expensive and a bit shorter lived than the moderately built liter bike engines. My car has a minimum weight of 1020, with driver, for solo racing. I run a straight pipe with custom header, since the bike header doesn't fit the car.

Are you rpm-limited at all?

If not, you'd be a fool not to exploit that.

No rpm limits. I think the stock rev limiter is not too restrictive, though. I'm a bit concerned about engine longevity in bumping up the limiter.

[R1000]

- Intake runners are port matched (cone shaped) to intake rubbers

- The short radius is smoothed

- The valve guides are reshaped but not shortened

- Intake dividers are sharpened to an edge like profile

- Any steps or other unwanted irregularities, in ports or port-to-seat transitions are fixed, either by grinding or filling with JB weld

- The valve seats are lapped in and surrounding area is unshrouded to improve low lift flow.

- The valves are cleaned back-cut

- The intake runners are sandblasted

- Combustion chambers and exhaust ports are polished.

Others:

- K/N filter, and possibly RAM air.

- Yoshi full 4-2-1 exhaust with race baffled RS3 carbon can

- Kentcams H018

- One tooth down front

The head is now ready, and in addition to above the head has been milled 0.5 mm and the middle section of the head gasket will be discarded to raise the static compression to about 13 to 1 and to reduce the squish. Plugs will be iridium type and the cam tensioner will be a manual APE.

There was some fuzz getting a used Yoshi system as planned, so a new full Akrapovic 4-2-1 system with a race muffler will be used instead.

Considering the mods above, does anyone have suggestions for the initial jetting. The bike will be dynoed and adjusted at a well reputed company, but I will drive it to them about 150 km's from where I live, and want to get the bike jetted in the right territory from the beginning.

a) The stock jetting is 142/145. What would be good starting values for new main jets?

The bike has stock needles, how much should they be raised?

c) Finally, how many turns should the idle mixture screws be backed out from fully turned in?

The questions are not very easy, but if anyone has done similar mods on the Bird and will share their knowledge, I'm happy to get suggestions .

[tomek]

Typically with tighter squish you get more complete burn,higher % of fuel actually burns,so jetting needs to be little leaner,,,,,,,,,,,so with your other mods jetting might be O.K.,,,,,,,,,

If they are gonna tune the thing anyway, I would not worry about mains right know,adjust the pilot screw for best idle( rpm),if runs O.K. let them work on it later,,,,,,,,,,,

[R1000]

Typically with tighter squish you get more complete burn,higher % of fuel actually burns,so jetting needs to be little leaner,,,,,,,,,,,so with your other mods jetting might be O.K.,,,,,,,,,

If they are gonna tune the thing anyway, I would not worry about mains right know,adjust the pilot screw for best idle( rpm),if runs O.K. let them work on it later,,,,,,,,,,,

Progress report - the head was returned for valve and seat cutting (MIRA). They where not perfect, which is needed to get good power and to make them last.

[tomek]

Typically with tighter squish you get more complete burn,higher % of fuel actually burns,so jetting needs to be little leaner,,,,,,,,,,,so with your other mods jetting might be O.K.,,,,,,,,,

If they are gonna tune the thing anyway, I would not worry about mains right know,adjust the pilot screw for best idle( rpm),if runs O.K. let them work on it later,,,,,,,,,,,

Progress report - the head was returned for valve and seat cutting (MIRA). They where not perfect, which is needed to get good power and to make them last.

Well,I`ve seen my head,now I actually know what it looks like.For serious valve unmasking valves have to be pushed much,much deeper into a head.

In stock form thez stick out way too much into chamber,it hurts charge turbulance and there is no way to realy unmask them..

Lots of work is needed to make this head work.I would cut seats as deep as it is possible when using stock valve shims.You gonna need 16 new valve shims.

I know that for race motors people have to shave the thinnest O.E.M. valve shims.Wonder what is a safe limit as far as thickness of valve shim,,,,,,,,,,,,,

BTW my intake valves and seats are in very good shape,,,,,,,,,,,but exhaust are basically shot,,,,,,,,,lapped them with coarse comp,they start to look ok.

I don˛t like using coarse comp becouse it makes grooves in the seats,lots of lapping with fine and polishing comp is needed to eliminate those,,,,

If I was not a cheap person,and cared about XX more ,I would got fresh 5 angle job from APE and replaced exhaust valves,,,,,,,,,,,

The poor condition of exhaust seats was a surprise,it is high mil. motor,94 k miles,but received valve clearance checks,etc

More on the subject later,,,,,,,,,

[R1000]

The poor condition of exhaust seats was a surprise,it is high mil. motor,94 k miles,but received valve clearance checks,etc

More on the subject later,,,,,,,,,

I too was surprised at how much work had to go into cleaning up my head. I had to replace 4 valves and about 9 of the shims were move pretty far out of whack.

¨

It appears as the seats and valves are not as wear resistant as the rest of the Bird's engine. The used head I got as a porting object is in very good condition, the valve guides are very tight and the camshaft bearing surfaces looks perfectly new. Still, all intake valves have recently been replaced by previous owner, and the seats looks like shit. Maybe the valves and seats needs to be recutted about every 50 000 km's or so to be in top shape.

[XX4me]

I'll have more accurate hard numbers by May, but my 1255 will be making ~200RWHP, and close to 110lb/ft of torque. FWIW, we did NOT decrease the size of the ports.

Fucking COOL!!! :icon_thumbsup:

[R1000]

The ported head with stage 1 cams is installed, one piece of the head gasket was discarded and the head is milled 0.5 mm. Just to get the bit and pieces back for a test run tomorrow

[R1000]

I got the chance to test the bike today with the ported head. I only runned for about 15 minutes before I returned and changed oil. The initial impression is that I have got a completely new bike, the throttle response is far better and when I launched like usual the bike did a long wheelie which it have never done during the same conditions. Will test more the coming weekend but there is no doubt that the porting and other camshafts have done great things to the engine.

The bike will be dynoed next Monday. So far it has shown up to be much stronger than last year. I was staying behind a car this morning out on a very narrow corner on first gear, and planned to be there so I geared up to second at a low rpm and just cruised. Then I changed and twisted the throttle on second gear and was quite surprised, the front lifted 45 degrees and the bike felt terribly strong. I backed of softly and engaged the third gear just after touch down and once more gave full throttle. The bike lifted the front noticeably this time to, which was easier since it was a throttle off/on situation and the clutch was used. Anyway, this is a complete different behavior than last year and it would be wise to watch up until I have got used to the temperamental engine.

[R1000]

The Bird was dynoed today. It gave 153 rwhp on a dyno that reads about 10 % less than a Dynojet 250. Even if that was said to be verified on several engines, it’s hard to believe that it would read 153*1.1= 168 rwhp on a 250 dyno. The bike is terribly strong though; it raises the front wheel some from ground on third gear The recent power is the thin upper grey line, blue line is stock and red line is Yamaha YZF R1 -07 from www.sportrider.com dyno graph.

Dyno_Blackbird.pdf

[davesXX01]

Sweet! Keep posting more how-to info on this and what cams did you use? Web?

[R1000]

Sweet! Keep posting more how-to info on this and what cams did you use? Web?

I think everything that is done is covered earlier in this thread. The headwork is a piece of art, as the MIRA cutted seats. The comp ratio is just above 12 to 1, not 13 to 1 as I stated earlier. And the cams are quite mild Stage 1, the Kent Cams HO18 reworked street cams. They are in good shape but used once during a race with a sidecar racer that pulled well until the engine went into pieces. The bike runs very well, it is just about as strong as my GSX R1000 –03 with Yosh slipon and PC, which was the strongest stock sportbike in –03 and still is very competitive at track days. The power figure is better on the Bird, but there is more weight to carry. Still, the dyno report such high figures for the Blackbird that I must have a second check at another dyno. The person who dynoed the bike stated that the bike would read about 10% more on a Dynojet bench, I have to see that before I'm convinced. I guess I've been lucky and have got a combination that works nicely. Next step will be the RAM air addition since the FI model air ducts bolts on to carb models and builds usable pressure already from 100 mph. That will add 5+ horses.

[tomek]

Nice job.

[mikesail]

R1000,what lobe centers are you running ?

The reason I`m asking,it seems that motor peaks very early,if Im` reading that graph right,at 9400 rpm,at the same time there is a soft 5-6000 rpm spot.

It seems you are running large overlap,exhaust opens late ,intake opens early.I would try to retard intake cam couple deg.,it might improve 5-6000 rpm and give you even more power on the top.

Of course it is lots of work,engine needs to be dropped,etc,

Anyway,nice work,good luck with tunning carb bike for Ram Air.

Is it not possible to index cams while the motor is in the bike?

[tomek]

R1000,what lobe centers are you running ?

The reason I`m asking,it seems that motor peaks very early,if Im` reading that graph right,at 9400 rpm,at the same time there is a soft 5-6000 rpm spot.

It seems you are running large overlap,exhaust opens late ,intake opens early.I would try to retard intake cam couple deg.,it might improve 5-6000 rpm and give you even more power on the top.

Of course it is lots of work,engine needs to be dropped,etc,

Anyway,nice work,good luck with tunning carb bike for Ram Air.

Is it not possible to index cams while the motor is in the bike?

Well,I was looking at the wrong line, ,so I`ve edited my comments .Modded motor pulls very well on the topend.

Can you degree cams with engine in place ?.Not really,frame is blocking the access.Engine needs to be dropped,leave rear lower bolt in place,just lower the front of the motor.It is still big job...............

[R1000]

Yes it's easy to miss the upper line, especially since the stock curve is just marked Bird -97 and one will focuse on that. I think I have got the camshafts exactly where I want. The are just checked to be in the right position, not fine adjusted at all since the engine delivers well at all rpm. The power increase at 3 to 4 k is 20 % up which improves cruising drivability significantly. The top end is up almost 30 hp at 11 000 rpm which means a lot for max acceleration and the power peak is also much wider than before.

[R1000]

The Bird was dynoed on a Dynojet bench today. The purpose was to see if the previous 153 hp reading was 10% low vs. Dynojet readings as claimed. Today’s reading is very much the same, 151.99 hp and 111.77 Nm torque at +28.5 deg C, 1032 mBars and 22% humidity. That is also how the bike feels, very strong and responsive but not completely wild that it should have been with the claimed Dynojet 165 rwhp.