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!!
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.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
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.Pistons are like this.
Point is to make them more like a JE high comp pistons ie. flat.
you are also making a known weak piston weaker. i have seen them crack across the face of the domeYes, 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.
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?
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. :dunnoyou are also making a known weak piston weaker. i have seen them crack across the face of the dome
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)....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.
There might be some miss-used terms etc.Wait, what??
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.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 ??
No worries, better to say things how they are.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.
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.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)
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.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....
I appreciate your help and sounds like you know what you are saying. :cheersAnyways. 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
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.Thanks, we are really grateful to our grandfathers. :thumbup
It's already snowing here, but summers are really nice here.
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.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!