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Adding compression

19K views 51 replies 18 participants last post by  sketty20 
#1 ·
Hi, I have an 06 600 that im looking to get the most from within reason.

Im a machinist with access to any type of equipment I'd need, and if I wanted to I could bore the cylinders, deck the head for added compression etc. Im not wanting to go that far right now, but what I am interested in is porting the head(if that even needs to be done) and especially using a thinner gasket for higher compression. What I'd like to know is will using a thinner gasket cause interference between valves/piston/head and require further modification?

Will using a TRE with the added compression lead to detonation or will the ECU be able to retard the timing properly regardless of the compression?

If anyone has any suggestions as to other mods I should do while the engine is apart feel free to educate me, Im new here in the gixxer world.

Thanks!
 
#2 ·
The ECU wont alter the timing. The bike does not have knock sensors. Bumped compression will almost certainly necessitate race fuel use.

Just bumping up compression by itself will not net much in the way of gains. On a small motor like a 600 the gains are cumulative, meaning no one change nets much at all, but if you do a proper build you can gain a decent percentage of power.

In short... get a proper full supersport/superbike build, or leave it alone and do the normal bolt on stuff (pipe, fuel management, custom tune, filter)
 
#4 · (Edited)
Thanks for your reply, it opens up some questions for me. I'd read that these bikes would retard timing if they were knocking but then I have done searching in the manual and more online and seem to be finding that there is no knock sensor so if they are retarding timing it would have to be by some other reading in the engine. While were on timing control, what type of timing control does the stock ECU do? Does it take temperature into account?

Now Ill think out loud here about compression and knocking and see if anyone can add in to make this a coherent and usable thought for me:
-The bore and stroke as listed in the manual is 67x42.5 which sweeps a volume of 149.84cc.
-The stock compression ratio is 12.5:1
-To figure the remaining volume at TDC it would be (149.84+Remaining Volume) /Remaining Volume=12.5/1 Do the math and Remaining Volume is equivalent to 13.029cc

The 08+ 600s are running 12.8-12.9:1, Newer R6's are 13.1:1 so we know the higher ratios up to that point will work. To achieve a 12.8:1 ratio from where I am at would need a gasket difference of .0938mm for 13.1:1 would need .1831mm

So, these are VERY minimal differences in gasket thickness effecting a difference in compression from 2.4-4.8%

As far as detonation occurring, correct me if Im wrong, but there is no amount of spark delay that can stop that from happening since its a property of compression ratio, engine temperature, octane and amount of fuel to air mixture, right? Perhaps a spark after a detonation could help complete or accelerate the burn but bottom line arent you either knocking or not knocking?

Does anyone know how much clearance there is stock between the open valves and the piston at TDC?
 
#3 ·
With these bikes, around what compression ratio is the use of race fuel needed?
Most high compression pistons for the 600s is around 13-13.5:1 that I have seen. Will this ping with premium fuel? In a car I know the 12 area is safe but once you get in to the 13 territory you will either have to use higher grade fuels if altering the timing does not do the job.
 
#5 ·
These are interference motors, meaning there is no clearance. They will hit.

the newer 600s are tuned for premium. Yours is currently tuned for regular gas.

yes, there is an inake air temp sensor that is used for fueling and ignition I am sure.
 
#6 ·
Im a machinist with access to any type of equipment I'd need, and if I wanted to I could bore the cylinders.....
I doubt that. Nikasil bores, not many places can handle that. You may be able to bore the cylinder larger, but I kinda doubt you have the setup to replate and make it actually usable once bored.

Little too much armchair / theoretical machine work going on. What are you going to do If I told you the current piston / valve clearance is 0.22513654 mm? That number is arbitrarily above your numbers, and equally has more pretended accuracy than reality. I mean, down to 0.0001mm? 0.000003"?

IF all you want is a lot of power, get a turbo, nitrous, or a superbike build.
 
#8 ·
I doubt that. Nikasil bores, not many places can handle that. You may be able to bore the cylinder larger, but I kinda doubt you have the setup to replate and make it actually usable once bored.
Nikasil is a just a special name for a pretty average pvd coating. Nothing special. I can get the inside of the cylinders coated with anything I want even more exotic and durable coatings with lower coefficients of friction. I work for a company that makes parts every day to specifications much more strict than any component on any motorcycle. We can control everything from size down to surface finish. Im one of the main production specialists. So in case you had any doubt this is less than garage tinkering to me. Im used to being doubted though since most people dont even know how their food is made.

The reason Im here asking questions is because I have never personally had one of these engines apart, I dont know at what point the ratios will cause pre-ignition, basically anything I asked about I am ignorant to some degree on, at least enough to seek out people who have experience I dont. If I say I can do something I can do it. If I ask a question its because I dont know.

Moto_Joe said:
These are interference motors, meaning there is no clearance. They will hit.
Interference as in there is zero clearance? Meaning literally any carbon buildup or anything in between the piston and valve will cause the mechanical system to have to deflect to make up the difference? Mechanical systems like these dont last long unless there is a spring mechanism designed to absorb the deflection safely. It seems the would be at least a papers thickness of clearance.

Moto_Joe said:
the newer 600s are tuned for premium. Yours is currently tuned for regular gas.
So this means if all I run in my bike is premium which is all I run to start with I should be able to run higher compression safely, correct?

I did a little more reading and found that cam timing has a lot to do with compression ratios and being able to avoid pre-ignition, thats probably a little beyond the scope of a general discussion though to understand even though I'd like to learn more about it.

Thanks for the helpful responses.
 
#9 ·
You asked about open valves. But yes closed and at TDC of compression there is very very little clearence. So little that a blue printed motor will just "kiss" the head with the pistons. That is a tight built race engine though. Stock engine there is a teeny tiny bit of clearence. Carbon buildup can be a problem. yes. In some areas of the head. When there is any buildup on the surface of the valves it usually is in a small recess on the face though which is not as tight.

I honestly feel like you are trying really hard to get in over your head. This isnt a tecumsa or honda lawnmower engine :p. It is already a high performance engine, that you are trying to squeeze more performance out of.

Leave it to the pros. ;)
 
#10 ·
Leave it to the pros. ;)
I was born pro Joe ;) No way for me to get in over my head here. All I need is to figure out which way north is and ill be able to use my roadmap.

I think I have all the torque specs and procedures from the service manual. I have all the tools and years of mechanical experience with which to guide them. If you're one of the pros feel free to tell me what I need to know. I've more than put my time in when it comes to learning the ins and outs of tedious, critical mechanical work, I just haven't specifically done it working on bikes. I know its hard to respect a new person on the scene when you've been there for years and years, but I'm here now and I have a lot behind me.

So with that said, anyone who can answer the questions I ask I will be appreciative toward. And Ill let you know how it goes so if I fail and you want to rub it in you can do that too. Remember, I never said I wanted to bore the cylinders or mill the head, I just said that I could. Mainly I just want to polish up the intake and exhaust ports if they arent already and then install a thinner head gasket if thats even possible without causing interference. If it isnt, Ill probably just skip that whole part until the day comes when I want to increase my displacement and compression in the machine shop.

As I said in the first post, I want to get the most out of my 600 within reason, and that means without removing chips from my engine if possible. Anything like a turbo that would affect my fuel economy or decrease the life of the engine is out also. I dont want anything I cant have available all the time either like nitrous.
 
#11 ·
Wow. :rolleyes :wacko

Ill be done with this after this post. You seem to already have all the answers :lmao. There are guys with decades of motorcycle specific engine building experience who I assume can learn from the likes of you :wacko :lmao

Anything you do, short of power adders, race fuel, or a full supersport build will be mostly pissing in the wind. Especially for street use.

You can put a thinner head gasket, but may need race fuel to do so. The gasket by itself MIGHT give you a hp or three... you wont really even notice it.

The money you spend on the other things would see better results spooning in a 750 or 1k motor ;)

For street use, and even for your average racer, the "normal" mods give more than plenty. Like I said, buy a pipe, a fuel management system, and an air filter. Get a cutsom tune, and ride the damn thing. Thinner gasket will likely net you near nothing other than requiring you to run higher octane fuel all the time. You wont really even feel the difference.

So "the most" out of your 600 "within reason" is as I said. Above that the next step really is a full supersport build to be worthwhile. Anything less is mostly half assing it and pissing away money. The results of each piece of a build dont gain much. But all together they become significant.
 
#13 ·
Wow is right
I believe someone said something about the necessity for a cumulative effect for building horsepower in these 600s earlier. To me those two simple things I wanted to do were part of that accumulation.

I dont care exactly what horsepower it will give me, I do know it will help. The fuel management, exhaust, and intake mods are an obvious given that Im already working on.

I never said I was going to gain 50hp from a thinner gasket. Maybe I just want a thinner gasket because I like the idea of having a thinner gasket, all I really want to know on that front is will my valves crash into the pistons but apparently nobody can conclusively answer that question here.

I ask a simple question and it turns into this thing of how I cant possibly cut it working on my own engine. I try to reassure everyone that I could build the engine from chunks of raw material if I wanted to just so we could get past that and back onto the first couple questions I asked and its like "whoa crazy man, Im done with you ha-ha-ha-ha...."

Internet professors are just absurd. Thanks at least for trying to help in your own way.

When I say I want to do something and ask will this or that happen if I try and you don't know, then say you don't know if you want to comment because I dont care if you think its a bad idea without having the evidence to support that its a bad idea.

I didnt start this thread to tell people what I know but since I was immediately drawn into question I told you what I did know. Question is still out there: will the valves crash into the pistons with a thinner gasket, or, how much thinner can I go before the valves crash. And Im not so worried about the knocking now but if you actually know what will happen Im all ears to learn.
 
#15 ·
#16 ·
I already told you. You can run a thinner head gasket. To do so you will likely need higher octane race fuel (not all race fuel is high octane) on the street to do so. So it is rather pointless, especially since other than the addition of race fuel the thinner gasket will net you almost no gains that are noticeable.

If the gains will be almost none from any one given modification... unless you do MANY of them at once (as in a full engine build) then it is pretty pointless to do so.

But do as you wish. You are the guy who thinks he could build a billet engine better than suzuki :lmao

One last time. There are basically three levels here. Maybe four. One is normal mods (as I outlined). Two is supersport engine build. Three would be super bike engine build. And four would be power adders (which you said you dont want).

Anything that falls BETWEEN those levels, are mostly wasted time, effort, and money that will net almost no noticeable gains. What they will require is a bunch of wasted money replacing gaskets and such, and time to do things, that net you nothing by themselves but if you do them all at once will gain you what you want.

What you are wanting to do falls between the normal mods, and a supersport build. They will gain you almost nothing.

If you still dont get what I am saying, so be it.

Your bike. Do as you wish.
 
#19 · (Edited)
It is a common mod, and Yoshimura even sells the damned gasket :facepalm

Fuck engineers make things far more difficult than they need to be.

When I said it was an interference engine was when you were asking about OPEN valves and timing changes iirc. . Your fault if you spoke incorrectly.

When I said near zero, I mentioned blueprinted engines as well. Stock they are damn close, but not so close as to not be able to use a thinner gasket. But AGAIN I say it will almost certainly require high octane fuel (not just premium) if you get one. For street use it is a ridiculous mod to make on its own since it will gain nearly nothing honestly.

Dude. You are one dense motherfucker.

Let me guess. Engineer? Some of the most dense fuckers I have ever dealt with are almost always engineers. Dumbest smart people on the planet.

That is not to say all engineers are dumb. Just most of the people I deal with who THINK they are smart, but really arent, turn out to be engineers.

I dont claim to be an engineer, a machinest, or a master mechanic

what I am is a guy who has a bunch of years working on them, riding them, tuning them, and being involved in them.

I know what people do, what can be done, what it takes to do it for the most mart, what is worth the money and time to do so, and what is not.

Do I know the finer points of high end engine building? Nope. That is what I pay Livengood Motorsports to do.

But I DO know that the shit you want to do is pointless unless you do it in conjunction with a heap of other things to be able to realize any gains, and not mostly loses in other ways

Have fun.
 
#20 ·
Interference engine definition for you ..... so you know what I am talking about when you ask about when the valves are OPEN

An interference engine is a type of 4-stroke internal combustion piston engine. Depending on the design of an engine, piston and valve paths may "interfere" with one another as a result of incorrect timing in their movements. (Such designs are also called "interference head" or "non-freewheeling", and include virtually all diesel engines. Conversely, non-interfering engines, such as the Mazda B engine or Fiat F.I.R.E. engine, are called "free-wheeling" or "non-interference" engines.)
 
#21 · (Edited)
No Im not an engineer, started out to be one but I got out of it because they are dumb like you say. Phd's out there building things that dont have a clue what the difference is between a ball bearing and a roller bearing....

When I was talking about interference in terms of parts colliding you were talking about interference timing? I dont guess either of us were on the same page there but you said:
Moto_Joe said:
These are interference motors, meaning there is no clearance. They will hit.
...right after I asked the question about clearance. Seemed pretty cut and dried to me what you meant. I mean if we were singing from a different sheet of music that's fine but don't try to say I was dense for misunderstanding such a simple statement as that.

Interference timing included its still a question of clearance. Either the mod will work or it wont work. Youre telling me it will, that its a common off the shelf thing. All you had to do from the beginning was just tell me "no, you will not have to do any additional mods when changing to a thinner gasket" since thats explicitly what I asked in the first post. If I wanted to break my engine down to laser engrave my name on the top of the pistons it doesnt matter if its worth the time or money, its what I want to do. So thanks, like I already said, for trying to help out by telling me it was a waste of your time and money. To your credit you said too that its my bike, do what I want so thumbs up to you :thumbup for that

I respect you for what you seem to know its just silly how off the topic that all got. Davidhar on the other hand seems like he just wants to argue about things I never said. At least I learned from you that these were interference engines without knock sensors!

EDIT FOR Davidhar: Btw David, if you want to send me your pistons my company actually does offer custom laser engraving so I could put your name or your favorite ball team or whatever you like on there.
 
#23 ·
Haha! I like you Joe, you know I think before this is all over we're going to become good friends.

I actually did say exactly what you said I didnt say in the very first post just like I said I said a second ago:
Kydan said:
What I'd like to know is will using a thinner gasket cause interference between valves/piston/head and require further modification?
Now when you go back and check that I actually did say that and didnt edit it in know that when a machinist says the word "interference" he means it in the same sense as "interference fit" as in a press fit that holds itself together. I wasnt thinking about timing, rather I was thinking position, when I wrote about TDC but you know TDC is just that...timing, so really were coming at the same thing from different angles.

Moto_Joe said:
Again I say you claim to want to "get the most out of your 600" without "power adders" there is only a few ways to do it that fit that description "the most"
Just for information's sake, I am actually working on a list of upgrades, some minor, some major which as you mentioned before are trivial on their own but add to mean something together. The list is up to 11 things, fuel mapping, intake and exhaust are on that list. Like I mentioned already, I never said I was going to be done in one mod with a huge horsepower increase like with the gasket by itself. Anyway, the term "the most" is purely subjective. Apparently Im thinking efficiency for size and you're thinking dyno curves. Its fine either way.

Btw heres that gasket, a 12.8:1 vs 12.5stock. This is what I want so long as it doesnt mean that I have to use different pistons. http://www.yoshimura-rd.com/p-4309-cylinder-head-gasket.aspx
 
#25 ·
a machinist says the word "interference" he means it in the same sense as "interference fit" as in a press fit that holds itself together.
That is funny, because I am pretty sure we are talking about building engines, not press fiting stuff together ;)

Jargon only works in its industry. You cant take it always and apply it to a different industry ;)

Anyway, the term "the most" is purely subjective. Apparently Im thinking efficiency for size and you're thinking dyno curves. Its fine either way.
Again, you are trying to speak a different lanquage then.

When it comes to tuning an engine there is only one way most anyone will read "the most" and that is HORSEPOWER. And with the modifications you were asking about, it is easy to assume horsepower was your goal. These engines are already damn efficient
http://www.yoshimura-rd.com/p-4309-cylinder-head-gasket.aspx
Even if you didnt actually become an engineer, you are clearly cut from the same mold :facepalm.
 
#27 ·
Makes perfect sense if thats your goal;I was disappointed after dumping tons of money into a 1st Gen 750 and learned an expensive lesson. Ive been spoiled with built big-bore engines ever since :)
 
#29 ·
Bye Joe, dont run off hurt because I want to be your friend. I want you to comment on all the rest of my threads after you've read the first post entirely!

Seriously Im not trying to make trouble, I laughed over this. But you know I was on target from the start you don't have to admit it, but you know! haha.

Take care
 
#30 ·
One last thing. Someone PM me when dude blows up his shit fucking with shit he knows nothin about :lmao

i want the engine cases if they are still good :punk
 
#31 ·
Nah, they might be toast...coz he may wanna run a thin gasket on them too :lmao


Efficiency brah, if he can make the bikes engine a fraction narrower and keep the weight inboard more...then...I dunno, aliens or something
 
#32 ·
OldGixxer said:
Makes perfect sense if thats your goal;I was disappointed after dumping tons of money into a 1st Gen 750 and learned an expensive lesson. Ive been spoiled with built big-bore engines ever since
The single most expensive thing with no substitute other than another similarly priced system is going to be the Bazzaz system. Ill be making my own exhaust from headers to muffler. Those things are pretty much a given. The rest of the things are going to be fairly cheap.

I'll probably post a build before and after all the mods with dyno readings. I'm with you, I wish I had a 1000 too but there are reasons I went with the 600.
 
#33 ·
Ill be making my own exhaust from headers to muffler.
Hey quick Joe, come back! This shits getting hilarious again!

:lol



In my short time here I have seen one other person try to make their own full system. Didn't hear anything from them again. Also saw some guy with some kind of weird spiral idea for the internals of the headers, real spaced out shit.
If you think you can do better than Yoshimura or Akrapovic and their massive R&D departments, start getting them GP and F1 contracts mate :thumbup
 
#40 ·
I'm with Joe he's probably a engineer. You can make a paper asshole but you can't make it shit. I would take the advice of avid racers / long time riders. It's easy to over think things getting lost in thoughts of head gasket grandeur but the smart folks always start with the simple things. I'm a simple person so a pipe, a BMC and in my case a CCMHUNT carb set up will do me just fine.
 
#44 ·
Building a 600 = baaadd idea....you'll need boost, and that's not a fun road to go down, trust me. You really have no idea what you're headed for.(it starts with holed pistons, and ends with picking the rest out of your oil pan)

Then after all the money you dumped into it, you realized you could have just bought a FZ1 or whatever the fuck.

Just buy a second or third bike, like a sane person!
 
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