Hello, I am new to the world of motorcycle's but an avid car guy and amateur engine builder. I am trying to find out a couple of things from this "in the Know" group. First off I am using an 03' 600 motor so i am a little behind on the top of the tech as far as these engines go.. but anyway, I am using this motor with a restrictor so I am not planning on making much in the way of horsepower greater than 80 or so. I am trying to find out swappability as far as rods, maybe using a shorter stroke crank in a 1000 or 750 block? I have to stay at or below 600cc's so I am trying to think of the best crank and block offering shortest stroke to up my redline. also lightening of cranks, seems pretty cheap $250 through gixxerzone..any input? and what kind of compression are you guys getting away with? i have been told that some of the biker gearheads are running in excess of 300psi on a compression test! Thanks for any direction or advice. Dan

Well I don't know of any body with experiance in running a restrictor plate and don't know of any body with experiance de-stroking a crank. Also don't deal much with 600's. Big bore stroker 1000's and busa's.
I have not heard of any complaints about ape except they take awhile on crank work some times. Just stay away from falicon for crank work.

cool, good to know. The restrictor doesn't change all that many things, biggest thing is you hit your max power at approx 8500rpm and then you hold that same power all the way to redline. Makes for kind of goofy tuning... but its pretty much the same other than that.. question does anyone know the is there is any difference in length of valves int & exh between the 03 and 04' gsxr 600? Im thinking about seeing if I can't swap in a set and get a little more rpm out of her.. . Thanks DAN

If you have to stay at or below 600cc then you will have to start with a 600 engine. The 600 crank is the shortest of the lot and any increase in bore size would take you over 600cc.
The cranks use different sized and spaced journals too which kind of fucks the idea anyway. You also run into problems using heavier pistons and rod lengths are different too.
Lightening the crank is not always a good thing. Depends what you want to achieve with regards to torque delivery and traction.
On the valve issue, the 04/05 valves will not fit in the earlier heads. The 03 and before use steel valves with a 4mm stem and the titanium stuff from 04 onwards is 4.5mm diameter. You will have to replace the valve guides. Also the valves are different lengths so that screws the spring seat position and more. Oh and don't even get me started on titanium valves cracking ..... Basically, forget it. Good idea, just a lot of hastle for almost no gain.

On the positive side, there are some very clever things you could do to the entire engine within the rules. All you need is access to a dyno, flowbench and lots of time. Its always fun tuning to a rulebook because that shows who the truly clever ones really are.

cool, good to know. The restrictor doesn't change all that many things, biggest thing is you hit your max power at approx 8500rpm and then you hold that same power all the way to redline. Makes for kind of goofy tuning... but its pretty much the same other than that.. question does anyone know the is there is any difference in length of valves int & exh between the 03 and 04' gsxr 600? Im thinking about seeing if I can't swap in a set and get a little more rpm out of her.. . Thanks DAN



Max Power @ 8500 rpm changes everything.

Optimum intake length & cross section, cam timing on both sides, as well as optimum exhaust cross section and length. If you leave it as designed, which is for something above the stock redline, you'll have an engine that doesn't produce the power it could, or nearly the torque at the rpm it will be operating at. Everything needs to get smaller, much smaller. And longer. You won't find the formula's on this board, but they're out there. The Engine Analyzer Pro manual has a bunch of good information. It used to be available to download at www.performancetrends.com. (http://www.performancetrends.com.) You'll also find a lot of good information searching http://speedtalk.com/. It would also be worth reviewing the Engine Masters competition, particularly the teardowns. Every year you can find.

You have more than enough valve spring for 8500 rpm with the heaviest valve you could possibly find. The newer Titanium valves have larger stems than the steel ones. There is no need for the expense.

My opening shot at building a motor with a restrictor plate would be to spend a lot of time figuring out how to minimize the damage. Smoothing the inlet and exit, building as much volume possible downstream by moving it as far upstream as possible.

After that is done, you've pretty much established how much power the motor is going to make. Torque is the product of displacement, compression, combustion efficiency, and volumetric efficiency. Torque * rpm is HP. From the orifice HP and the engine torque determine the rpm to produce that HP.

Now ignore peak HP and build as much torque at as low an rpm as you can while maintaining that target HP. That is how road races are won.

I'd leave the lower end alone, except maybe to apply a thermal barrier coating to the piston crown and a lubricant to the skirts. There is power down there, but not enough to justify the oily spots on the pavement that appear at inoportune times you'll generate finding it.

The head is where you go nuts. 600 heads are really cheap on ebay. Maybe angle mill it to half way through the 30 degree seats on both the intake and exhaust. Trial mount the head and determine the Piston the valve clearance from 15 degrees before TDC to 15 degrees after in 1 degree increments. Ask a cam grinder how much lift rate you can have with a 8500 rpm 600 using stock valve springs. Ask again for a smaller base circle cam, larger diameter tappets, and softer valve springs. With the stock valve size, the lift rates, and a lift to intake valve diameter ratio of ~0.35-0.40, figure out how much duration is required for a Mean Inlet Mach number of 0.55 at 8500 rpm. It'll be much less than stock.

Remember, the orifice and your work arounds determine the peak HP. All that is left is to build as much torque over as large an rpm range as possible. Short duration cams are the best compromise for this type of situation.

Obert is a good reference for combustion efficiency. There is one central concept in the book that will keep you from stupidity on compression.

As far as winning the race, it starts with the driver and getting them as much seat time as possible. I'd dummy the car together ASAP with a mule motor and get on with the training. If you can find someone with any racing experience of any type at all they'll have the rest of you covered. This is 90% of the game.

Next work on the suspension. Cornering is cool, but the real key is the drive off the corners. You'd better have more brake than the driver really has the hair to use on one of those cars. Make sure they retract cleanly, but still give good pedal. Never mind the theory, what ever makes the driver happy is what wins. This is 9% of the game.

The peak engine power is the remainder. The other engine characteristics that contribute to the first two are what separate the engine masters from the wannabe's. Basically, you want a broad torque curve that falls slightly at a pretty much constant rate to peak HP, which is 10% before redline. And absolutely linear throttle response. An engine like this makes it easy to tease the edge of traction. It is also important to recognize that none of this can be calculated to the degree required to win, or even to go into production. Trial and error is required. A lot of trial and error. Identifying the variables that you'll expend you're limited resources on and when to go to the next most important variable is why the select few are paid the big bucks.

The bad news is races won by 0.1% margins are rare and boring.

They didn't have fun games like this when I was in engineering school. If they did, I wouldn't have had the time or money anyway.

Max Power @ 8500 rpm changes everything.



I agree that it does make for a far different engine than that of stock, but there are a couple of things I disagree with you about and or questions I have for you.

1st with the statement on shrink everything-- I totally agree -- more velocity = more torque = sooner= better powerband. I figure that once I find my max power I will scael everything to the specs of that i.e. runners plenum volume and exhaust lenght/primary dia..

I may be misunderstanding you, but are you saying build the engine to run maximum power at 8500 and therefore scale the cams down to turn a max speed of up to maybe 9-9500? that doesn't make sense to me.. I f I can make 65 horse at 8500 and also 12500 i will do that rather than scale down the rpms and cams to make torque sooner and will ultimately have to stick taller gears in it to get the same speed on the car.

If I can build 65 horsepower, which is simply torque over time, and then hold this same power, even though yes my torque drops, I am making up for with more cycles(RPM) I see it that if I can make this same power for almost 4 thousand RPM's(8.5-12) I am doing really well because of 2 reasons: 1 I can use an overall higher gear( numerically) or simply put more torque multiplication because of the higher available operating speed of engine and
. well I forgot the other reason....
I


Optimum intake length & cross section, cam timing on both sides, as well as optimum exhaust cross section and length. If you leave it as designed, which is for something above the stock redline, you'll have an engine that doesn't produce the power it could, or nearly the torque at the rpm it will be operating at. Everything needs to get smaller, much smaller. And longer. You won't find the formula's on this board, but they're out there. The Engine Analyzer Pro manual has a bunch of good information. It used to be available to download at www.performancetrends.com. (http://www.performancetrends.com.) You'll also find a lot of good information searching http://speedtalk.com/. It would also be worth reviewing the Engine Masters competition, particularly the teardowns. Every year you can find.

dually noted! thank you!




Now ignore peak HP and build as much torque at as low an rpm as you can while maintaining that target HP. That is how road races are won.

I totally agree but most engines continually build horsepower or, torque, but this engine is not the same -willl email you a graph to better show you.. .

Roger that. good point.

[QUOTE]
The head is where you go nuts. 600 heads are really cheap on ebay. Maybe angle mill it to half way through the 30 degree seats on both the intake and exhaust. Trial mount the head and determine the Piston the valve clearance from 15 degrees before TDC to 15 degrees after in 1 degree increments. Ask a cam grinder how much lift rate you can have with a 8500 rpm 600 using stock valve springs. Ask again for a smaller base circle cam, larger diameter tappets, and softer valve springs. With the stock valve size, the lift rates, and a lift to intake valve diameter ratio of ~0.35-0.40

, Roger


figure out how much duration is required for a Mean Inlet Mach number of 0.55 at 8500 rpm.

Mean inlet mach #? Huh? I got some research to do!



They didn't have fun games like this when I was in engineering school. If they did, I wouldn't have had the time or money anyway.

5 years in the military and one trrip to the sandbox has helped me save the $$$ to do this while in college..


Thank you greatly for a lot of good info and references,
Dan

O.k. Thanks for the info.. Looks like i'll just have to get the whole newer engine if I want the lighter valvetrain...... Thanks again for the info.

I'm not sure about the 600, but with the 750 and 1Ks the head will physically bolt on to the old block. The frame mounting points change, but this doesn't matter for your application. The throttle bodies need to go with the head because the intake port spacing changed. This in turn may require swapping the injectors and TPS's.

Another approach would be to put the valve guides from the newer head into the old head. I wouldn't use Suzuki parts, call Jay at APE about installing an ampco set. The 750 / 1K valves are the same length in Titanium or Steel. Hint - It's pretty cheap to buy just one part from Ron Ayers (the link is at the top of the page). 600 stuff is also pretty damn cheap on Fleabay.

I can't see a way to make more power with the newer valves in your application though. I'd probably be going the other way and looking at older engines. There are weight issues and finding decent specimens can be tough though.

The approach I'm advocating is a fast opening short duration camshaft. Generally, this is a good way to make both good peak power and enjoy it over a wide rpm range. You have to be careful with this approach if you also want rpm. Which you don't. The limits on lift rate are cam to follower contact pressures (when combined with spring rate and preload), spring surge (when combined with rpm, spring rate, & valvetrain weight), and follower diameter (when combined with lift, base circle diameter, and lobe to follower alignment). You have more than enough spring, in fact the springs in that motor are very sophisticated in how they suppress surge. You probably have more tappet diameter than you need, but Hayabusa tappets are 2mm larger. Reducing the cam base circle is often done on high performance cams to allow jacking up both the lift and lift rates. Hardfaced cams allow higher contact pressures. You can also cash in the street milage durability allowance. I doubt I'm the first one to dream this up, and if you ask nicely there is probably a wealth of information at Megacycle and Web cam tech support. I'd be suprised if they don't have a FSAE grind somewhere in their inventory.

The Mean Inlet Mach Number is basically an area-time concept. It's been observed that when you integrate the cam lift - valve periphery - flow coefficient product over the duration and divide it into the volumetric flow, the resulting velocity is usually around Mach 0.55 at the hp peak. This is a camshaft / valve diameter / flow coefficient relationship. It's actually a limit. There are other relationships for the port cross section. I'm suggesting that you abuse the MIMN concept to figure out how little cam duration you can get away with after you run up the lift rate.

More reading material SAE PT-53 (ISBN 1-56091-601-X), SAE PT-100 (ISBN 0-7680-1298-8).

Do you want peak power to be at 8500 rpm?

My .02c worth....... You need compression to make this work, the more the merrier. Look at what Corona Suzuki did in 2003 with the restricted 1000, according to magazine articles (for what they're worth) they went up to 15.8 : 1 (16.4 : 1 in testing). Of course the WSBK restrictors were huge compared to the fsae one but I believe its still a valid concept. Smaller short duration cams will then give you more dynamic compression due to less or no overlap and will help with the piston to valve situation as well. Of course the fuel you can use will have a large bearing on this. If you have to run 92 octane pump gas, well.............. http://www.gixxer.com/forums/images/graemlins/dunno.gif

Just my opinion, I'm sure that Mr MW will correct me if I'm talking rubbish. http://www.gixxer.com/forums/images/graemlins/wink.gif

I think we're on the same page with this.

The location of peak power is going to be set by the restrictor, and lower than the stock 600. 8500 rpm was thrown out as a typical number for these engines.

The only caveats about compression are it stops helping when 1 - the detonation limit is reached, or 2 - the piston dome starts pushing all the mixture towards the edge of the cylinder and away from the spark plug.

The importance of the mixture location in the chamber is the theme that everybody who's serious about performance reads the Obert book for. The title of the book is "Internal Combustion Engines and Air Polution", so you wonder why the hell it's listed right after Ricardo as a high performance must read. The ideal case would be a sphere ignited in the middle with all the mixture rushing inward. The worst case would be an expanding donut. A 1K makes it much simpler to avoid the donut situation because of the long stroke. It still has a dish in the piston at 14.5:1

There is also a pretty good article on getting away with more compression by Vizard in the Popular Hot Rodding archives. The TFX website has graphs and commentary that make this some of this clearer as well. Recardo has a bunch of other stuff on detonation supression.

MrMW, I think you have nailed it on the head with the cams... . dropping them in profiles as much as possible while still maintaining the RPM I need. induction will still be a testing "trial and error" As far as compression, I will have to study oberts for better combustion characteristics. but I think I will also be limited with cam specs-- i.e. drop my duration too much and I won't be able to run as much static compression.. We are allowed to run 100 Octane so I am not too worried about this.. I'm not sure if i'll even be able to make enough compression to use this slow burning gas.. Oh, by the way my redline is still stock at 12,500 to 13k. just makes the same pwer for the last 4- 4500 rpm's. THE remaining power lies in restrictor design and compression. THanks again for the great bouncing of ideas and references
Dan