tomek

WEll,honestly I don`t think carbon build up would be and issue,for couple reasons. Oil consumption is almost zero in XX,so blowby gas is very low on oil. Rotaries inject oil on the face of rotor,they run massive overlap ,in certain rpms fresh charge with oil is pulled into exhaust ports.They don`t have a problem with carbon build up,or cats packing. Run Synthetic oil,it hardly burns anyway or wd40 Two strokes introduce massive amount of oil into exhaust chambers ( I know it is diff. oil ) ,they do build up carbon in exhaust pipes,but you`ll get more then 5 k miles before it needs to be serviced.So I think 5 K miles in case of XX is waaay to low. Carburator cleaner dissolves carbon in heart beat,no need to replace your pipes,,,,,,,,,,,, I`m not inventing anything here, crankcase scavenging systems that use exhaust pulses have been aruond since 5 BC. I think you guys are just too worry and pussy. Anyway,I`ve already piped my R1 like that,XX will be next( once I`m done with not so high quality valves and seats),what do I have to loose ?,pipes clean up,if it works ,cool,if I`m wrong,I`ll just spend quality time cleaning my pipes with very healty carb cleaner,,,,,,,,

I pulled and took my 94 k miles head a part.Valve seats are really in shitty shape,it looks like recommended clearence is too tight,lots of erosion,low spots,etc.They really should be recut and valves replaced.I`m going to aim for more valve clearence.In is street bike,spends small % of its life at redline.I`m O.K. with some extra noise from valve train.

You can use PAIR to help pull blowby gas out of crankcase.Crankcase vent is actually on cylinder head cover.Pull out the guts of selenoid valve so it is alwayes in open position.Connect crankcase vent with selenoid.Plug in couple empty holes in the airbox. That is all ,very simple.Lower the pressure in crankcase,the better=more power. I`ve done this mod on R1,it actually builds negetive pressure in crankcase.If you remove oil filler cap and put piece of paper it gets suck in. Some guys measured the vacum,it is about 1-1.3 psi,not much but better then nothing or some positive pressure. Ram air systems builds positive pressure at speed,in stock form crankcase vent is connected with air box,so it can build positive pressure in crank case. It is very retarded,but Honda has to do it due to emmision regs.

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,,,,,,,,,

Better yet,you can hook up crankcase vent with PAIR.

Yo,R1000,that head gasket,I just yanked out cylinder head ,,,,,you have to leave middle leaf in place,it contains oil flow orifices,pull out top or bottom,,,,,,,,,or you`ll lose some oil pressure and overflow head with oil,,,,,,,,,,,,,, More on my observations later,but intake ports are huge with very poor match between port and seat,,,,,,,,,,,,,,,,no wonder bike has poor midrange power,,,,,,,,,

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,,,,,,,,,,,

No problem with balance if you weight match your pistons, which any competent builder should do. Mine were lightened to match the weight of the stockers, as well as having the bottom end balanced. Yea,I remember pics,guy spent quality time reworking those pistons,"stock" Wiseco and JE are heavy like a brick and piston crown needs work.They are basically starting point and not so good if left unmodified,,,,,. Are we talking about vibration or typical for 4 cyl. buzz ???????

Aftermarket big bore pistons are much heavier then stockers,there will be more vibration,,,,,,,,,,balancers are designed to work with stock pistons,rods, etc.Any weight diff. screws that up. Check adj. on balancers,but some increase is unavoidable.

If I`m not mistaken some Harleys have offset rear wheel or swingarm. So I guess it would work,becouse as we all know all H-D possess superb handling manners,,,,,,,,

You can go 13-1 comp ration on modern 4-5 valve on pump gas with no problemo. You factor in squish area of, let`s say 15-20 % of bore area,if you know stock CR and stroke you can calculate new CR pretty accurate.. Milling the head is not the same as milling block/thinner head gasket.I know XX has a 1 piece block and upper crankcase design,so it is lots of work to mill the block,but if stock head gasket is a 3 piece design I would measure squish on stock motor and see if 1 layer could be pulled out. You could safely close squish to 0.75 mm on XX I guess.To measure squish on 4 valve engine place 4 pieces of solder, symetrically on the piston between valve pockets,torgue cylider head,turn motor couple of times,pull cylider head ,measure the smacked solder,average the 4 numbers.Armed with all that you can figure out how thinner head gacket needs to be. In case of XX with stock CR 11.0 and bore of 59, 0.02 thou mill ( 0.5 mm) CR would be about 11.7 Here is math stock stroke is 59 mm and CR =11.0 X is a tickness of cumbustion chamber if it was a slice of cylinder ( I know it is not but it does not matter for this calculation) 59 +X ------------ = 11 X X =5.9 mm If you mill 0.5 mm of you head you removing only about 80 % of the slice ( you are milling squish area also),so it is like only milling 0.4 mm so X1 =5.5 mm 59+5.5 --------=11.7,that is your new CR with 0.02 mill 5.5 If valves are unmasked,CR most likely would be in 11.5 range. Removing 1 layer of gasket (0.2-0.23mm I guess) and milling head 3 thou (0.75mm) would give 12.5 CR,but I would check piston to valve clearance before doing that,there might be problem here.

Just popped in an APE 2 weeks ago. So here's my advice.... The stock unit blows dead goats, but, they are cheap and easy to install. The Ape units will last the life of the bike, are cheap, easy to install, but are hell to initially adjust.(if anyone tells you different their fucking lying to ya, or don't give a fuck if it's adj correctly , or don't have a clue what their talking about) Up to you First,get that thing finger tight,start the engine,try to screw tighter till rpms start to drop,and then back off a little.That it.That is when replacing good O.E.M. tensioner. I know, APE approved method involves removing cam covers,measuring etc,but they are covering their asses,lawsuits,etc,nonsense,,,,,,, If your O.E.M is already dead,it is more complicated,you gotta make sure there is no lash on non tensioner side of cams-crank drive before starting motor or crank can jump a tooth and you are fucked. 50000 miles on APE unit here.

Well,TP in RX7 is not directly mounted on the shaft,there is cam,and push rod deal,so there is mechanical wear involved. Older models of RX7 did not have self calibrating future and FSM calls for periodic adj.On newer as long TP is good there is no need to touch it.They do go bad. Honestly I˛m not TP specialist,just trying to come to some logical conclusion. As far as a part throttle deal,engine wear,valve lash,etc will effect vacum reading.Honestly,I don˛t see how engine would operate properly over its life if relied on TP alone. Plus ,intake charge is not weightless,it takes some to accelerate when you open the throttle. I understand pure car competition motors dont bother with Map sensor,but bikes need more gentle on-off transistion and definiton of TP is not good enough in first couple deg of throttle,,,,,,,,,,, Why are you trying to mass with TP,,,,,,,,,,,,,I would, I guess, attack BARO or intake temperature sensors if I were trying to get across the line leaner or richer mixture.That is pretty much how PC2 works. PC3 modulates lenght of injector pulse.

You bring some valid points. I believe EFI on XX is a typical dual stage system ,it is using MAP sensor for small throttle,and switches to TP everywhere else or combination of both. System based on TP is not confused be pressure pulsation,or back flow in intake ( "double carburation") ports but does not have definition needed for those small throttle openings.Engine would have very poor On/OFF transition.That is why we have a hybrid here. Calibration. I guess you could use MAP readings to calibrate TP,let`s say at given rpms and MAP vacum TP reads X,ECU can compare that with stored data,and calibrate . It has to have some self calibration ability,you know 0.4 to 0.6 volts,it is 50 % gain,,,,,,,,,, Interestingly enough BIG Book does not call for any start up procedure for new TP,so I`m assuming it is selfcalibrating. In case of, let`s say RX7 Turbo,car I know very well,you have to follow certain procedure after TP replacement.After that it self calibrates and adjust for wear.

Just get manual CCT from http://www.aperaceparts.com/. You will never worry about that stupid part again.

The Big Book does not call for adjustment. I guess the system is self calibrating,basically once TP is bolted in ecu will figure out readings for closed and open throttle. Closed would be 0.4-0.6 V Open 4.2-4.8v When openning and closing the throttle readings should smoothly increase/decrease.

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 agree, In case the engine provides a weak midrange, the intake runner floors will be raised. That is a fairly easy action compared to the other work that is to be done anyway to get rid of production imperfections. It looks like like XX has a "old way" ports,when bigger was better,newer bikes have actually smaller ports.Zx10 makes the most power from the current crop of liter bikes,yet it has the smallest ports,,,,,,,,, I`ve worked on 3 gen of Yam 5 valve motors,thunderace,99r1,04 r1,they went to smaller ports everytime,,,,,,, XX has a weak midrange( 4-7k),high velocity port job should do wonders to our motors,at least for the street use,,,,,,,

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,,,,,,,,

Well,since you can afford to ruin the old one,it is not dif. ,just use small flat head screwdriver to drive the seal out,stick it between the schaft and the seal and pull it out. You may have to attack it couple of times from dif, angles, Clean everything very well,oil the new seal , tap it gently with the hammer,once it starts going in you can use old seal to drive new one,,,,,

Sounds like you've had this done, may we ask where and how much? Any more info? Dave A replacement head is now on porting. I'll post pictures afterhand, to start with a pic showing steps and other restrictions on the stock head. Some parts can not just be worked by grinding, filling with chemical metal is also needed to keep up the gas velocity. The earlier mentioned price is not valid any more. I have bought a head and porting as a package. Anyone having a Stage 1 head in good shape FS? This is picture of stock combustion chambers,right? I`ll pull out my head in couple of weeks once I`m done with my R1 and RX7. Just courious,what is stock squish on XX ? How thick is stock gasket,2 layer or three layer ? Couple of years ago I`ve built 1040 motor for yzf 1000,I did high velocity port job ala motoman from www.mototuneusa.com ,tractor like powerband and with 0.7 mil squish awesome crusing fuel economy,like 50 mpg at 85-90 mph.It feels like lost couple of hp on top end,but it is road bike anyway. I`m gonna do the same thing to XX,I don`t care about couple peak hp but like to have fat midrange. BTW Honda`s prices for internal engine part are from the moon,60 bucks for pair of intake and exhaust valves ( 480 for complete head),,,,,,,,,,, gimme a brake.I can get 20 valves for Yamaha for less then 200 bucks.They most likely come from the same source anyway,,,,, Cylinder head gasket is about 60-70 bucks,,,,,,,14 bucks for 04 R1. No wonder no priveteers are racing Hondas in AMA,their prices are ridicoulous,,,,,,,,,,,,,, High flow numbers are almost meaningless unless intake velocity is kept high,on normally aspirated motor anyway,,,,,,,,,,

Just don`t heat wrap titanium pipes ( they run cool anyway), or they will turn into yellow powder. This subject ( overheating) has been covered to the death,just do the search. Basically the worst offenders are stock F.I. bikes,digital or analog gauges,it does not matter.Some owners reported coolant boiling and dripping.I don`t think Honda did "fine" job with cooling system.It is bearly adequate,and sometimes not, in stop and go urban traffic in the middle of summer. Bikes with full system and rejetted/mapped run cooler for two reasons. One- ritcher mixture at small throttle Two- with less restrictive exhaust less heat is being transfered to the cylinder head thru exhaust ports. I don`t see heat wrap helping much with coolant temperature. One more thing,XX has one ( not two ) radiator fan stupidly placed in the middle.The hot air pulled by the fan has nowhere to go .It is not rocket science,really,just look at some other bikes. Normally, with 2 fan system when they kick in temps drop really fast. I don`t know,maybe Honda figured out bike did not have enough juice to run two fan system on 98-97 bikes( low alternator output) and it just stayed that way. BTW I think someone on this forum installed two radiator fans,but I don`t remember details.

Have you had a personal experiance with bent wheel fixing? Well,MCwheel will not charge you if they feel they can not get better then new specs. I`ve sent them two rims,rear had a lip ,no biggie,but front had a lip and was out of the true at the same time.When they came back it was impossible to tell where the damage was,even the paint was intact. They know their craft.

I`ve used MCwheel before,it is in vendor review section.

Small one ,works on valves up to 5 mm dim. ,or any modern sport bike.XX are 5 mm both,intake and exhaust.