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Disappointed dyno results after race int, 0.50 hg

Gen 4: 2011-15 
9K views 35 replies 11 participants last post by  mpp12 
#1 ·
Hello.
So we put the race intake camshaft, decked head 0.04mm, 0.50mm hg and degreed the cams at 112.5 / 105.5
All measurements of cam timing is at 1mm lift of the cams.
The plan was to degree the race int cam to 110 but the ptv clearance was 1mm and we decided to leave it at 112.5 were the ptv clearance is 1.3mm
The exhaust is set at 105.5 were ptv clearance is 1.7mm
The results are the same whp as before with the stock engine.
I am very disappointed.
What do you guys suggest?
 
#2 ·
Its notoriously difficult on G4 to make gains with can timing. G4 you should measure the drop at 0.50 earlier Gens are 0.40. Also the head needs another 0.2 mm shaving 0.6 sounds a lot but that's where the gain is with that head. Cutting the seats back to lower the numbers doesn't work either. Teams here prefer the Kent Cam Kawi 35 as it uses a higher lift to get gains.
 
#3 ·
Take it to a shop that works with those bikes and let them work their magic. KWS Motorsports in Charleston SC, or EDR Performance in Portland OR.
 
#5 ·
common results. decked the head .016? measured int/ex ptv at 10-15 degrees after/before tdc? little surprised ur that snug on int at 110. pita to redegree, but that int clereance is adquate on that engine, tight but ok. dont know if this will help but remember stretched 10r had a customers gen 4 on dyno with identical cam timing and mods as yours. making about 183 and not happy. called and 110/108 cam #'s produced 193. that was his experience, his motor, cant say ur's will do same. just put a 400 lift/longer duration web in a gen 1 zx10, not happy with the tuned results myself, hp a little off and torque curve soft. i degreed my gen 3 race int 4 times before i found the power/et/mph i wanted. originally degreed at 108, only change made was int to 110.5 bike jumped 6 mph in 1/4. picked up little more mph better et at 111, slowed up at 112. kaw race int cams are very sensitive to cam degree, at least on my builds. really seems that way on gen 4 in particular. one conclusion i have come to is be careful with larger/longer duration cams in any 1000cc bike especially the kaws. they have the highest lobe intensity stock of all the brands already.
 
#6 ·
one other culprit worth mentioning imo is the decked head. that gen 4 head is most difficult to mill square and flat as it is angle milled from kaw. i've done the setup before, never took less than two hours with a tool bar chucked up in the mill and dual dial indicators attached to each end. head has to be shimmed where indicators read 0 full length, full width sweep of the head at all points within a thousands or two max when fastened down. get a larger deviation and head bows slightley when torqued down distorting valve seats and valve seal lost on a few valves killing hp. been there, done that and learned from it. leak down test best, but simple 10mm sparkplug compression gauge adapter plumbed to 90-100 psi air source, cyl at tdc wil reveal int/ex valve leakage by air escaping.
 
#7 ·
Gaz your posts are always full of good information.
Head is decked to the right angle.
I didn't want to get extra compression from head so I decked the minimum just to be sure it's cleaned/straight.
I also checked each valve before assembly and none is leaking.
Ptv clearance checked at 10 degrees as kawi race manual suggests.
So you say its safe on this 14k high revving motor to set the intake ptv clearance at 1mm?
I now kawi say minimum 0.7mm but I am a little concerned about my engine life.
The other problem with my motor is that power never ends and still climbing.
It hits rev limiter at 13950 and max power is at 13950rpm.
With this power curve everyone would suggest to lower the exhaust cam numbers not raise them.
 
#11 · (Edited)
we all do mods differentley. congrats on checking all that u did, most do not. i also ck all valves assembled in head for leakage before head installation buti have come to know as perfectley bench shimmed valve clereances can/will change once a head is torqued on the block, valve seats subject to same distortion, especially if head not perfectley flat. ur confident head milled correctley and that's great, just saying checking final assembley valve leakage can be present. yes i think ur safe ptv at .040, that's a minimium for me, my 07 has about .048 with 31mm steel intakes and flashed to 14k, turns a real 13500, 14200 tach indicated in the traps with no contact after pulling head twice and inspecting. has carpenter springs retainers. cam degree #'s are a matter of gathered information, opinion or experience. dont disagree with ex lc ur running, i run a little higher on ex, has worked well for me especially with compression mods. agree with thunder coupe, int lc needs to come down, moreso than ex needs to be raised. 112.5 is out there without big compression supporting it. think u have more power to be made at lower rpm. should increase torque also. one setup makes peak hp at 13950, another makes same hp at 13000, which is real world faster and safer? kinda what cam timing is all about.
 
#13 ·
I was hearing that the Kawi brand cams are very conservative... hence the reason they're like $200. You're mostly trading power in the curve & not really influencing the peaks. You're better off getting with someone like RC Performance for some massive cams and probably a 6-10HP gain. Your low end will take a beating, but if it's all about the numbers then you'll be happy. If it's a race bike and you spend all day above 6K RPM then you'll be even more happy. It's gonna cost you like $150/HP though.
 
#17 ·
So with all this talk about power curves, what about raising the rev limit to the level that allows for some semblance of an overrev. I think I read somewhere that KRT machines rev over 15k rpms. GRANDED....they have the money/time/resources to burn up motors every other weekend, but isn't there something we can do to run a 14.5k limit? Like a trackbike/racebike only type of thing.
 
#18 ·
This is a 2015 head skimmed down too the max 0.8mm you can just make out where the tooling clipped the valve seats, that's the darker streaking on the face. 0.6mm allows for a distortion when torquing down.
 

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#20 ·
thundercoupe9 and gaz
If it was easy in this bike to change timing I would do the same thing.
Generally it's better to change the lc on one cam check the power curve and then think what to do with the other cam.
In a week or 2 I will take the engine off and try the 110/108 timing that Gaz suggested.
At least this timing worked for someone.
If it works for me too then I will tune per cylinder and if there are any gains.
 
#22 · (Edited)
those listed lift checking points, .040 and .050, are a standard for measuring duration, do not affect degreeing or lobe center. degree setup correct will be same lc at either lift measured. impressed, paying attention to detail. degreeing cams practically requires i pull the engine to get a accurate setup, know what ur saying. lot of work to redo especially after being discouraged. if interested, pm me ur shipping info, send u complete set .016 valve spring shims that go under spring bases. adds about 400 rpm to float factor increasing spring pressure without coil bind. .030 too close. every little bit helps.
 
#23 ·
In the next days I will pull the engine to degree the cams.
In order to put the spring shims I will have to pull the head off, pull the valve seals and put new ones (again) but engine safety comes first.
The 0.16 shims you mentioned will let me run the rev limiter to 14400 or lower?
How much is the safe free distance between the measured height of spring at full cam lift and the fully pressed spring?
 
#24 · (Edited)
if they are metal jacketed seals as stock, u can gentley pull them back off with a pair of needle nose pliers and reinstall. no damage done. . tried shimming stk springs .030, felt coilbind turning the cam sprockets adjusting valves at full lift each cyl. .030 considered safe, can run tighter, i do. hopefully redegree will strengthen and lower powerband to more reasonable rpm limits. ur already damaging valve keeper grooves, like it or not gonna have to shift lower and u shouldnt have to turn it that tight. just picked up a gen 1 zx14 from dyno, made 198/117 ft lb torque on pump gas. power peak at 10400, started hugging that peak at 9600 and hp curve tabletop flat all the way to 11500 with flashed ecu limiter. torque curve peaked at 7800, still at 105 at 10500, dropped like a rock next 1000 rpm down to 90 ft lbs at 11500. when torque goes to hell ur basically thru with hard accleration. need torque to rip thru gears. best to consider both these curves when choosing shift points. this bike wll be its fastest shifted around 10500 where hp is peaked, torque still abundant.sounds/feels fast screaming a engine, most times ur going slower.
 
#25 ·
That's exactly what I think.
There is no reason to put extra shims in this head at all.
With the timing you suggested the peak power will be around 13000-13300 so there is no reason to go further 14000.
I usually check my shift points at strip with the time and km gain from 1/8 to 1/4.
 
#28 ·
So after a year ,two months and 2 or 3 cam redegrees I decided to finally pull the head of and do the right deck in order to gain some power.
Just to remind you I am at 0.05mm deck and .50mm hg...
Thinking to deck another 0.45 and put a stock 0.65mm hg. (0.25mm deck more or 0.45mm deck from stock)
What's your opinion?
 
#30 ·
realize that compression gains from a thin hg are more than same amount decked from a head as entire bore is reduced from thin hg, deck only affects combustion chamber which is smaller area affected. loosen that squish with thicker hg will definatley lose power/torque everywhere. always keep squish as tight as possible. milling head more to .015-.020 will make more power/torque thru entire powerband but as mentioned these are very trickey heads to mill perfectley flat to the factory angle across the entire head. last one took me three hours just to set up on milling machine. just saying u can lose more than gained if head is not perfectley milled due to valve seat distortion/valve leakage when head torqued down on engine. valve seal is critical to make strong power. as far as piston to valve, anything over .030 good with these motors, get everything right u dont have to rev hell out of it, power will be there within designed limits.
 
#32 ·
I milled the head 0.25mm and I and will use an 0.50mm hg as before.
I trust my machinery shop, he does very precise work on my parts and I believe the head is milled correctly (Gaz ,he also said that it took him 1.5 hour to set it up correctly)
The big question is cam timing now.
My thoughts are to degree my stock cams to 110/110.
Also what are best psi that should read on my gauge after cam degree?
Is it correct to be around 210-220 psi in order to have good mid power and also strong top end?
 
#35 ·
on my stk piston big engine street/strip builds i generally see 210-225 lbs cranking compression after cams degreed and engine refired and heat cycled a couple of times. those numbers are a strong indicator of big power and torque after tuning. were talking gen 2 1340 busas and gen 1 1352/gen 2 1441 zx14rs. i commonly deck these heads .020-.025, the busa allows a thin hg for piston to head along with the deck, the 14's require stk head gaskets to avoid piston to head contact. these motors respond best to moderate degree numbers, as in 105-106 zx14 series, 106-107 busa. i dont see that high of a cranking compression on the smaller 1000 engines due to thier current top end hp design. lobe centers, cam durations are higher reducing cranking compression. 190+ is good, 200+ will make strong hp.
 
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