Suzuki GSX-R Motorcycle Forums Gixxer.com banner

1041 - 1060 of 1104 Posts

·
Registered
Joined
·
313 Posts
Wow - and to think, I had a set of Stage-R, Type-R's in the head and decided to go with some Webs when I got the thing ported. Sounds like I could've used them even in the current set-up. Boy, oh boy!!
 

·
Registered
Joined
·
16 Posts
Can you tell me if there's any power difference between a full exhaust with a moto gp can vs a full length exhaust? Would I lose any low end torque with the shorty pipe?

Its on my L3 1000 I'm setting up to be a drag bike
 

·
Registered
Joined
·
202 Posts
Can you tell me if there's any power difference between a full exhaust with a moto gp can vs a full length exhaust? Would I lose any low end torque with the shorty pipe?

Its on my L3 1000 I'm setting up to be a drag bike
Just do the shorty can and spend your money on something else if it's a drag bike. Weight/clutch/suspension will make a bigger difference then the 2-4 more horse the full length header will make.
 

·
Premium Member
Joined
·
3,489 Posts
Which of these wideband O2 sensors is the best bang for the buck to use with EcuEditor/Woolich (K7-K8 1000 ECU)?
Zeitronix ZT-2 and ZT-3
Innovate Motorsports LC-1
TechEdge
 

·
Premium Member
Joined
·
3,489 Posts
My friend is rebuilding my K5 1000 engine and while it's completely apart. I would like to do some performance mods to it. Engine is for a track bike.

I'm going to use K7-K8 electronics.
Cams: K7 1000 Intake (degreed @105), but not sure which cam for the exhaust side (APE sprockets, APE retainers)
Akrapovic Evolution full system

Some of the mods I was told that could be done.
Shaving 2.2mm off of the stock pistons to gain more compression and same amount off of the block (OEM gasket). Should we also modify valve seats to make sure there won't be clearance issues? (I'm not sure what they are called) :dunno

What else should we do?
 

·
Redneck Rider
Joined
·
1,741 Posts
Shaving off of the piston will lower your compression.... Shaving the head will increase some but not as much as you will loose with shaving down a piston.
 

·
Redneck Rider
Joined
·
1,741 Posts
Pistons are like this.



Point is to make them more like a JE high comp pistons ie. flat.
Yes, but by shaving down the piston to make it a flat top piston, you are removing mass and bringing the top farther away from the head. This will lower compression.

Or are you somehow welding up the face then machining it down?
 

·
Premium Member
Joined
·
2,086 Posts
My friend is rebuilding my K5 1000 engine and while it's completely apart. I would like to do some performance mods to it. Engine is for a track bike.

I'm going to use K7-K8 electronics.
Cams: K7 1000 Intake (degreed @105), but not sure which cam for the exhaust side (APE sprockets, APE retainers)
Akrapovic Evolution full system

Some of the mods I was told that could be done.
Shaving 2.2mm off of the stock pistons to gain more compression and same amount off of the block (OEM gasket). Should we also modify valve seats to make sure there won't be clearance issues? (I'm not sure what they are called) :dunno

What else should we do?

Wait, what??

seriously,

what??

You are milling the pistons 2.2mm shorter, and taking 2.2mm off the deck of the block ?

To gain compression? and/or get more of a flat top piston ?

Are you off a decimal place in your measurements above? ie, .22mm vs 2.2mm ?? Or is this a translation issue and you you mean .022" (thousandths of an inch) instead of 2.2mm or .22mm ??

I'm sorry, I don't mean to sound like an asshole, but I'm completely fucking lost as to whats going on.

I'm just a guy who likes building GSXR1000's for trackdays (roadrace track). Been doing it for a few years, built several engines and have had pretty good luck doing it, and my overall packages keep working better and better and better........ And I like getting rather in depth in terms of building fairly serious motors (regardless of whether I am good enough or not as a rider to even begin to utilize the extra power...).

I have built and run, and am currently running most of this - big bore kits (usu +3mm), near max compression for the fuel available, ported heads, good cams, upgraded aftermarket springs/cotters/retainers, carrillo rods, full Yosh Superbike transmissions, Yosh EM Pro ECU's with full Bazzaz package on top, full Ti race exhausts, bored out throttle bodies w & w/o secondaries, etc etc etc.

I like ISR master cylinders for brakes (nice stuff you very very rarely ever see here...), along with Brembo brake rotors. I used to own 4 pairs of magnesium race wheels in 16.5" that I ran at the track, along with, literally, a small bedroom full of tires, wheels, brakes.... haha

Even played with a stroker motor in my K4 while I had it. nothing like a 3x4mm bore/stroke 1143cc bike for a trackday!! haha

I say all of the above just as background for the sort of stuff I've played with.

Anyways, I've had good luck with what I'm doing, but I'm far from a true EXPERT. So maybe you have a friend that knows way more about this than I do and he has some brilliant master plan that's above my head.

But, so far, I just don't understand whats going on.



If I were doing this PERSONALLY, i'd go at this from another direction. i'd figure out where I want to be, and work BACKWARDS from that to determine how to get there. Questions / goals I'd be trying to determine first:

1. What type of racing? Short track sprints? Multiple hour endurance races?

2. Related to #1, how long does the engine need to last between teardowns?

3. Whats your budget?

4. What fuel are you planning to run? how much compression can it support?? If in doubt, I'd always suggest decking a race engine block .002" and the head .002", give or take, esp on a first rebuild, if nothing else just to get a really nice, smooth, consistent surface to make the head gasket last a long long time (basically do a minimum fly cut to clean up the surface)

Figure out what compression you can run, THEN i'd work backwards from that to determine whether you need to cut the head, block, pistons, etc. Personally I'd really like to see the engine end up with a piston to head clearance of .025 - .030"... and, if I had to, i'd rather have the piston to head clearance in that range and sacrifice a bit of compression to get there... that nice tight squish area will help the engine stay alive & run right

5. Run OEM head gasket unless you have NO other choice

6. Get a good valve job. 5 angle / more angles / smooth radius is good, but..... concentricity is even more important. Aim for .001" or less runout

7. Related to #6, make sure the valve guides are not worn out. With a used head the guides are probably not going to be too tight, but if the valves are loose and floppy, it will beat the shit out of the valves.... and may burn oil from the loose valves leaking oil past the valve seals / guides....



Anyways. I'm about to shut up. I think it was Karns above who mentioned not cutting the dome on a K5 piston. I'm heavily inclined to agree with that! I wouldn't cut the dome of a late model 1K GSXR piston unless I had no other option... and / or it was just a tiny, tiny cut. That's the hottest / highest thermal load area of the piston.

And, K5 pistons in particular are known to sometimes crack in the middle when raced hard / long. Not sure exact reason (probably several factors in combination), but its a problem that has occurred enough that its a known possible issue... That area of the piston is already thin enough, taking even a small amount out of it would make it just that much thinner & more likely to have issues.....



btw, sorry if I sounded hard on you, I just don't understand what you are trying to do, OR there is a translation issue.... all of which is possible. I've played with AMA superstock engines, other race engines made by well known shops, and for most of those, a ONE mm cut on the head / block is considered to be fairly extreme....

I see you are from Finland, I love that country!! Always wanted to go there. Much respect for them. Did a great job giving Stalin a black eye & embarrassing that psychopathic, megalomaniac fucking asshole, starting in 1939. Owned a number of M39 rifles. Tikka's, valmet, Sako, etc.

Currently own a Sako TRG42 in .338 Lapua. Finns make great guns :)
 

·
Premium Member
Joined
·
3,489 Posts
you are also making a known weak piston weaker. i have seen them crack across the face of the dome

jason
Thanks, I already ditched this idea. This is just something my friend told that could be done. He said, he did a similar thing to his K4 1000. :dunno
I haven't even seen the engine myself, I'm just going by what I was told. I had the engine shipped to my friend and he is rebuilding it.

I'm just going to use a Cometic 0.018" (0.457mm) hg and should we also shave the head. Everybody says to shave a head when using an Yoshi hg (0.55mm). Looks like 105/106 are good cam timing numbers. Would 105 also work for K7 intake? K7 intake because I'm going to use K7 electronics.
 

·
Premium Member
Joined
·
2,086 Posts
Thanks, I already ditched this idea. This is just something my friend told that could be done. He said, he did a similar thing to his K4 1000. :dunno
I haven't even seen the engine myself, I'm just going by what I was told. I had the engine shipped to my friend and he is rebuilding it.

I'm just going to use a Cometic 0.018" (0.457mm) hg and should we also shave the head. Everybody says to shave a head when using an Yoshi hg (0.55mm). Looks like 105/106 are good cam timing numbers. Would 105 also work for K7 intake? K7 intake because I'm going to use K7 electronics.
When I was building my current K8 engine, (1070 bore w/ CP pistons, ported head, web cams, kibblewhite valve springs, yosh cotters, carrillo rods, full on Yosh superbike tranny, etc etc)....

I was really worried about compression ratio. I just run pump premium gas, 92 octane, and with a slightly decked head & block, and with those pistons, the compression ratio was getting high enough I started to worry. I worked with KWS to do the overall setup, design (piston design, cams, etc), and ordered most of the parts through them.

My compression ratio was getting near 14:1... it ended up at about 13.85 to 13.9:1 (when the compression ratio gets that high, the relative volumes of the piston pocket, head, etc get pretty small.... its easy to measure all those volumes 4 or 5 times and have a .1 to .2cc variance each time... at least for me, i'm no pro, hence why I give the compression ratio as a range, not an exact number). This is with the head gasket I ended up running, an OEM gasket that was cut for bigger bore....

Anyways, I thought about running a Cometic head gasket that was slightly thicker, to kill a bit of compression. Something in the range of .005 thicker... get me down more like 13.5:1

KWS wouldn't SELL me a cometic head gasket for my engine. They told me, both Kevin and Mike G, in no uncertain terms, that I should run an OEM headgasket (with a small cut to work with the larger bore size vs OEM).

They told me, more or less "you're a big boy, if you insist on running a cometic head gasket, fine, its your engine, but we wont sell one to you. Order it somewhere else. We've just seen too many engines come to us with leaking / bad cometic head gaskets that we wont mess with them anymore or even sell them"



NOW - TO BE FAIR - I was discussing a 76mm bore engine (3mm overbore on the k1-k4, slightly less overbore on the K5-K8 engines since the stock bore was slightly larger)..... so would they say the same thing about running a cometic with a stock bore engine (and therefore, more distance between the individual bores & anything they could leak into)?? I don't know

Also, I ran Cometic gaskets on my K4 engines, both as 1070 and 1143cc combo and had zero issues. I do run APE head studs though, and the fastener torque is a fair amount higher than stock, and with the finer threads the clamping power between the head/block is surely quite a bit higher, and with a flat enough surface (head/block) and enough clamping force, that takes some load off the head gasket, which might be why it lived (and several engine builders agreed with that reasoning... )

Also, I have heard from a couple more race engine builders that I HIGHLY respect that they only run OEM gaskets, unless they just have no other choice

Personally, with a motor all apart, I'd rather deck the block a bit more and run an OEM gasket vs leaving the block taller & running an aftermarket thinner gasket....

Just remember, decking the head raises compression ratio (and decreases PTV, piston to valve clearance) but does nothing to piston to head clearance (PTH). Decking block raises CR, decreases PTV, but also decreases PTH
 

·
Premium Member
Joined
·
3,489 Posts
Wait, what??

seriously,

what??
There might be some miss-used terms etc. :)

You are milling the pistons 2.2mm shorter, and taking 2.2mm off the deck of the block ?

To gain compression? and/or get more of a flat top piston ?

Are you off a decimal place in your measurements above? ie, .22mm vs 2.2mm ?? Or is this a translation issue and you you mean .022" (thousandths of an inch) instead of 2.2mm or .22mm ??
My friend just told me this on the phone. So I might have missed something. How I understood it is, that he would have shaved the shoulders, not the middle part of the piston. This would allow more shaving on the block -> more comp. I haven't seen the engine, but that's how I thought it would work.

I'm sorry, I don't mean to sound like an asshole, but I'm completely fucking lost as to whats going on.

I'm just a guy who likes building GSXR1000's for trackdays (roadrace track). Been doing it for a few years, built several engines and have had pretty good luck doing it, and my overall packages keep working better and better and better........ And I like getting rather in depth in terms of building fairly serious motors (regardless of whether I am good enough or not as a rider to even begin to utilize the extra power...).

I have built and run, and am currently running most of this - big bore kits (usu +3mm), near max compression for the fuel available, ported heads, good cams, upgraded aftermarket springs/cotters/retainers, carrillo rods, full Yosh Superbike transmissions, Yosh EM Pro ECU's with full Bazzaz package on top, full Ti race exhausts, bored out throttle bodies w & w/o secondaries, etc etc etc.

I like ISR master cylinders for brakes (nice stuff you very very rarely ever see here...), along with Brembo brake rotors. I used to own 4 pairs of magnesium race wheels in 16.5" that I ran at the track, along with, literally, a small bedroom full of tires, wheels, brakes.... haha

Even played with a stroker motor in my K4 while I had it. nothing like a 3x4mm bore/stroke 1143cc bike for a trackday!! haha

I say all of the above just as background for the sort of stuff I've played with.

Anyways, I've had good luck with what I'm doing, but I'm far from a true EXPERT. So maybe you have a friend that knows way more about this than I do and he has some brilliant master plan that's above my head.

But, so far, I just don't understand whats going on.
No worries, better to say things how they are.

If I were doing this PERSONALLY, i'd go at this from another direction. i'd figure out where I want to be, and work BACKWARDS from that to determine how to get there. Questions / goals I'd be trying to determine first:

1. What type of racing? Short track sprints? Multiple hour endurance races?

2. Related to #1, how long does the engine need to last between teardowns?

3. Whats your budget?

4. What fuel are you planning to run? how much compression can it support?? If in doubt, I'd always suggest decking a race engine block .002" and the head .002", give or take, esp on a first rebuild, if nothing else just to get a really nice, smooth, consistent surface to make the head gasket last a long long time (basically do a minimum fly cut to clean up the surface)
1. Tracks in Finland have relatively short straights and slowish corners, top speeds for me on my K1 750 are 210-230 km/h. I'm just doing track days and maybe some club races next year.

2. I would prefer a long service interval. :)

3. My friend has access to machines and his "labor" is cheap. The goal is to be cost effective and do things that can be done without hindering engine's reliability. Engine is completely apart now.

4. I use 98RON

Figure out what compression you can run, THEN i'd work backwards from that to determine whether you need to cut the head, block, pistons, etc. Personally I'd really like to see the engine end up with a piston to head clearance of .025 - .030"... and, if I had to, i'd rather have the piston to head clearance in that range and sacrifice a bit of compression to get there... that nice tight squish area will help the engine stay alive & run right

5. Run OEM head gasket unless you have NO other choice

6. Get a good valve job. 5 angle / more angles / smooth radius is good, but..... concentricity is even more important. Aim for .001" or less runout

7. Related to #6, make sure the valve guides are not worn out. With a used head the guides are probably not going to be too tight, but if the valves are loose and floppy, it will beat the shit out of the valves.... and may burn oil from the loose valves leaking oil past the valve seals / guides....
7. The engine was burning some oil, that's why it's being rebuild. I got it cheap and it's probably just valve guide seals. Engine has done 45 000km.

Anyways. I'm about to shut up. I think it was Karns above who mentioned not cutting the dome on a K5 piston. I'm heavily inclined to agree with that! I wouldn't cut the dome of a late model 1K GSXR piston unless I had no other option... and / or it was just a tiny, tiny cut. That's the hottest / highest thermal load area of the piston.

And, K5 pistons in particular are known to sometimes crack in the middle when raced hard / long. Not sure exact reason (probably several factors in combination), but its a problem that has occurred enough that its a known possible issue... That area of the piston is already thin enough, taking even a small amount out of it would make it just that much thinner & more likely to have issues.....



btw, sorry if I sounded hard on you, I just don't understand what you are trying to do, OR there is a translation issue.... all of which is possible. I've played with AMA superstock engines, other race engines made by well known shops, and for most of those, a ONE mm cut on the head / block is considered to be fairly extreme....

I see you are from Finland, I love that country!! Always wanted to go there. Much respect for them. Did a great job giving Stalin a black eye & embarrassing that psychopathic, megalomaniac fucking asshole, starting in 1939. Owned a number of M39 rifles. Tikka's, valmet, Sako, etc.

Currently own a Sako TRG42 in .338 Lapua. Finns make great guns :)
I appreciate your help and sounds like you know what you are saying. :cheers

Thanks, we are really grateful to our grandfathers. :thumbup
It's already snowing here, but summers are really nice here. :)
 

·
Premium Member
Joined
·
2,086 Posts
Ah OK, I understand much more whats going on now, thanks for the detail, and not taking offense to my questions / approach

Oh, so many things to say...

1. With straightaway speeds of 130-140 mph on a K1 750, you really are talking short tracks. That's a good thing in a way, in that a 1K engine, even stock, will make MUCHO power for that short of a track. with my built K8 engine, I can't even hit FULL THROTTLE until about 150 mph or so. Even with a nice hot sticky race slick, up to under about 150 mph (approx. 250 kmh), full throttle is just wheelspin or wheelie. And that's -actual speed - with standard speedo error the speedo would probably be reading 160, maybe 165 mph......

The sorta power I run is actually kinda pointless and a waste at the smaller tracks, and almost as pointless at the mid size tracks. But fuck me, oh is it fun! I'm an adrenaline junkie

Regardless, you aren't going to have to go crazy to make your 1K fast on small tracks like that. In fact, at some point, you might even go slower with more power, because its so much harder to control.



2. I understand now what you meant about milling the piston SHOULDERS not the dome. I really don't think that will be necessary though, esp not taking off 2.2mm ... which is about .090"

Really, honestly, I'd aim for a compression ratio of about 13:1, and if you are +/- .5 I wouldn't lose sleep over it if you get the other dimensions / clearances correct (PTH, PTV). Unless you're building some end all, be all, high end race engine the time / money you spend machining, and dealing with the issues caused, is time & money that would be better spent in other areas. Bang for the buck we like to call it here in the US.



3. Instead of worrying so much about compression ratio I'd worry more about the ring seal. OK, the motor has 45,000 KM on it. How are the rings? Would be nice to know what the leakdown numbers were pre-teardown. If the leakdown numbers were really good, and the budget tight, it would have been possible to run the same pistons / rings & not touch the bore surface

But, since the motor is completely disassembled, and I'm guessing the rings have been pulled off the pistons (per the shot shown above with the pistons in a milling fixture), i'd take a good long look at the cylinder walls.

You'll probably need to replace rings, and when you do so you really need to consider how they will fit / wear in with the cylinder walls. if you just stick new rings in and don't do anything with the cyl walls the rings wont fully seat / seal. You'll probably lose compression & burn some oil too.

If this was an older engine with aluminum block and steel/iron cyl liners, it wouldn't be such a big deal, they're easy to hone. But with these engines have all aluminum blocks / cyl walls with a thin coating on them (its either Nikasil, or Suzuki's own corporate version of Nikasil, or something similar...). That coating is so hard it doesn't "wear" much in the usual sense (like getting bigger in diameter at top, making a ridge above where the top ring runs). Theres not necessarily a large amount of -measurable- dimensional change. But, the coating can get scratched, worn through (usually through a piston starting to seize, or when the motor ingests foreign material like dirt, stray parts, etc).

But, even if the coating remains intact w/ no missing sections, it still gets "glazed". Essentially, turned into a smooth surface. The crosshatch is either worn down, or filled in with old oil / other contaminants that are baked on.

new rings need a slightly rough, cross hatched surface to wear in, and also retain a microscopic oil layer (which reduces friction and helps the parts resist seizing together).

The coating used is too hard for normal honing stones / brushes. I hear it takes a diamond coated brush (or some other crazy hard material on a brush designed for nikasil like bores) to break the surface glaze enough to allow the new rings to seat. I've even heard of people using scotchbrite or similar pads and working them by hand to break the oil glaze / lightly scuff the surface

Honestly, I can't advice you on what exactly to do with the cylinder walls. Every time I've had a set of bores / rings worn that far, I've just ended up sending the block off and having it overbored / replated & putting in a bigger set of pistons

I have a feeling at some point, when the leakdown numbers on my K8 engine fall down far enough, I will face this issue. I don't want to overbore it, since its already a 1070. Probably what I'll do is take a good look at the bores, and if in doubt I'll send it to Millenium and have them check it out, and if it needs just a real light honing to clean up (and then a set of new rings of course) I'll do that.

Or, if it needs to be stripped and replated, I'll do that. With over 5K in the engine alone, a few hundred $ to ensure the best ring seal possible is simply worth it to me

But, I'm not on a tight budget, AND, being in the USA & shipping to a company inside the USA is easy for me and costs little. I know for a lot of overseas people the access to such services is either almost impossible or just crazy expensive.

Either way, if you replace rings, do something with the bores. Ask around here on gixxer.com, you can get some better advice than me on this matter

I do know though that if you don't have a good ring seal, you're just pissing away power....


And, like I said, with tracks as short as you're talking about, you wont need much power..... I'd focus on durability, reliability.........
 

·
Premium Member
Joined
·
2,086 Posts
Thanks, we are really grateful to our grandfathers. :thumbup
It's already snowing here, but summers are really nice here. :)
Sorry for the double post, but you guys did have some bad ass grandfathers. The tactics used (and often created by) them in the Winter War, the Continuation wars, etc were brilliant. Sun Tzu, who wrote "The Art of War", would have been proud.

I love their reply to the Russian air force general (Molotov) in charge of the Russian air force, who said "we are not invading Finland.... we are just here to help... Those aren't bombs we are dropping from our planes, we are dropping picnic baskets of food for the Finnish people". Your grandfathers said, "well, if they give us picnic baskets, we shall give them a cocktail in return".... hence the Molotov cocktail firebomb. hehehehe

Course, I'm a long ways from Finland, and I certainly wasn't around to see it with my own eyes, but from what I've read and heard..... they were some bad-ass dudes in their day. Tough, but smart. They seemed to understand that much could be done with simple things, if they were used in the right way

Finland is about the only free country bordering Russia that didn't become part of the USSR / CCCP after WW2.... because even Stalin at the height of his power / megalomania, even he didn't want to tangle with you folks again. Even he sat back and said "I don't need this shit in my life!!!!" haha

Cheers to you and your ancestors! :)
 

·
Premium Member
Joined
·
1,993 Posts
IridiumRed!!! I'M GLAD YOUR ass is BACK. Good thing I called you 10x/day with texts for a month to get you out of your cryo state.
 

·
Premium Member
Joined
·
3,489 Posts
Sorry for the double post, but you guys did have some bad ass grandfathers. The tactics used (and often created by) them in the Winter War, the Continuation wars, etc were brilliant. Sun Tzu, who wrote "The Art of War", would have been proud.

I love their reply to the Russian air force general (Molotov) in charge of the Russian air force, who said "we are not invading Finland.... we are just here to help... Those aren't bombs we are dropping from our planes, we are dropping picnic baskets of food for the Finnish people". Your grandfathers said, "well, if they give us picnic baskets, we shall give them a cocktail in return".... hence the Molotov cocktail firebomb. hehehehe

Course, I'm a long ways from Finland, and I certainly wasn't around to see it with my own eyes, but from what I've read and heard..... they were some bad-ass dudes in their day. Tough, but smart. They seemed to understand that much could be done with simple things, if they were used in the right way

Finland is about the only free country bordering Russia that didn't become part of the USSR / CCCP after WW2.... because even Stalin at the height of his power / megalomania, even he didn't want to tangle with you folks again. Even he sat back and said "I don't need this shit in my life!!!!" haha

Cheers to you and your ancestors! :)
Thanks, I need to look into those things. I don't think he did a leakdown test, but he said that pistons&rings/cylinders are in good condition.

Yeah, it's said that: "1 Finn equals 10 Russians" :thumbup
 
1041 - 1060 of 1104 Posts
Top