Millennium can replate it and rebore it back to OEM size. 2004-2005 is hard to do because the cylinder block is integral to the top half of the crankcase. Piston skirts will be damaged as well, so you need to replace those with either OEM or JE forged.
scarred cylinder
So I pulled my head because while doing a spark splug change one of the valve cover bolts snapped.. no worries, I had a spare head laying around it was only when I seen that I have some wall scarring going on and it feels pretty deep in some places.. can I save it? Or do I need to go over size bore and if so what needs to happen?
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That's pretty severe. Not sure if plating will be enough to bring back to spec. Wouldn't hurt to check.
Worse case; can always install sleeves.
In either case, new pistons needed.
Also need to figure out what caused that and fix. Otherwise new cylinders and pistons will end up the same.
Worse case; can always install sleeves.
In either case, new pistons needed.
Also need to figure out what caused that and fix. Otherwise new cylinders and pistons will end up the same.
That’s what I was thinking, looks to be pretty severe and it’s like that on 2 cylinders with #3 being the worse. Would it be worth it just doing a big bore kit this go around or would sleeves and going back factory be worth it? I really don’t wanna get into the head if I don’t have to with cams as I know no one to ground the cams or let alone find cams. I guess this will be a major engine build so all help is welcomed. I’ve got no idea where to even start as to see what caused this as I changed the head gasket around 8 months ago and maybe some type of trash got inThat's pretty severe. Not sure if plating will be enough to bring back to spec. Wouldn't hurt to check.
Worse case; can always install sleeves.
In either case, new pistons needed.
Also need to figure out what caused that and fix. Otherwise new cylinders and pistons will end up the same.
The absolute minimum cylinder wall thickness is 3mm or Cometic won't even make you a gasket. On the later year models you can get away with +2mm pistons and have 3mm wall thickness to get a gasket made, and that's only if you sign a waiver.That’s what I was thinking, looks to be pretty severe and it’s like that on 2 cylinders with #3 being the worse. Would it be worth it just doing a big bore kit this go around or would sleeves and going back factory be worth it? I really don’t wanna get into the head if I don’t have to with cams as I know no one to ground the cams or let alone find cams. I guess this will be a major engine build so all help is welcomed. I’ve got no idea where to even start as to see what caused this as I changed the head gasket around 8 months ago and maybe some type of trash got in
If you do go overbore, it will be by 1mm for almost no performance gain, yet cost $800 for overbore/Nikasil plating and $500-700 for a set of overbore pistons. Millennium charges extra for this type of cylinder block mated to the crankcase, because it's more work getting it dialed in on the milling machine.
I would honestly get a new set of crankcases, deglaze the cylinder walls, and rebuild from that. You will save at least $1k over the alternative of trying to salvage the damaged cylinder walls.
I’ve thought about changing the cases out as well but once again I hear so many negative things about that as well due to each case is specifically made for the application and clearances won’t be the same when you change the casings.. I could be wrong not unless you’re talking about changing the whole entire bottom case. What about your thoughts on sleeving the cylinders?The absolute minimum cylinder wall thickness is 3mm or Cometic won't even make you a gasket. On the later year models you can get away with +2mm pistons and have 3mm wall thickness to get a gasket made, and that's only if you sign a waiver.
If you do go overbore, it will be by 1mm for almost no performance gain, yet cost $800 for overbore/Nikasil plating and $500-700 for a set of overbore pistons. Millennium charges extra for this type of cylinder block mated to the crankcase, because it's more work getting it dialed in on the milling machine.
I would honestly get a new set of crankcases, deglaze the cylinder walls, and rebuild from that. You will save at least $1k over the alternative of trying to salvage the damaged cylinder walls.
I will add that I have no issue sending the block out to have them see if it can be replated and then just do factory size JE pistons that are higher in compression if you think that’d be worth trying?The absolute minimum cylinder wall thickness is 3mm or Cometic won't even make you a gasket. On the later year models you can get away with +2mm pistons and have 3mm wall thickness to get a gasket made, and that's only if you sign a waiver.
If you do go overbore, it will be by 1mm for almost no performance gain, yet cost $800 for overbore/Nikasil plating and $500-700 for a set of overbore pistons. Millennium charges extra for this type of cylinder block mated to the crankcase, because it's more work getting it dialed in on the milling machine.
I would honestly get a new set of crankcases, deglaze the cylinder walls, and rebuild from that. You will save at least $1k over the alternative of trying to salvage the damaged cylinder walls.
And are we talking about millennium machine shop out in scottsboro/skyline Alabama?
I’m pretty sure he gave you his answer right above your 2 last posts.I’ve thought about changing the cases out as well but once again I hear so many negative things about that as well due to each case is specifically made for the application and clearances won’t be the same when you change the casings.. I could be wrong not unless you’re talking about changing the whole entire bottom case. What about your thoughts on sleeving the cylinders?
Correct. There’s 2 different people with 2 different opinions. So I was asking the one who didn’t initially offer the changing cases and sleeving cylinders his point of view and why.I’m pretty sure he gave you his answer right above your 2 last posts.
Regardless of how you repair the engine, you will want to prevent a repeat of the damage. Being that high up on the cylinder it could be from a broken ring or possibly the piston microwelding to the cylinder and then the rings scraping it off. You might learn more when you finish disassembling the engine. Main thing is to use an oil that has a high film strength and can handle the top end heat, like a top tier ester base oil like Redline, Driven, or Amsoil. I use the Amsoil Signature oil in all my vehicles and it has protected under sever abuse. Also make sure the cooling system is in top condition to pull the heat away efficiently.
I prefer rebuilting myself rather than buying a used engine. Good luck with your rebuild.
I prefer rebuilting myself rather than buying a used engine. Good luck with your rebuild.
Thanks a lot for the info. I’m waiting on millennium to get back with me and if they think they can replate it then I’ll go that route and go back with STD bore JE pistons. Still a little lost as to what needs to be done as I have no issue rebuilding myself but idk if I should mill/port the head as well considering I’d be going with high comp pistons and just do a mild engine build. I definitely think rings are broken considering I’ve been having problems with a little bluish smoke after I roll off throttle. But like you said I’ll learn more after I open it up further. if you’ve got any insight on a plan for a mild motor build I’m all ears. Thanks againRegardless of how you repair the engine, you will want to prevent a repeat of the damage. Being that high up on the cylinder it could be from a broken ring or possibly the piston microwelding to the cylinder and then the rings scraping it off. You might learn more when you finish disassembling the engine. Main thing is to use an oil that has a high film strength and can handle the top end heat, like a top tier ester base oil like Redline, Driven, or Amsoil. I use the Amsoil Signature oil in all my vehicles and it has protected under sever abuse. Also make sure the cooling system is in top condition to pull the heat away efficiently.
I prefer rebuilting myself rather than buying a used engine. Good luck with your rebuild.
Millennium Technologies in Plymouth Wisconsin. I have no experience with iron sleeving on motorcycle engines. Nikasil is the industry standard on just about every sport bike today.
If you go with JE pistons, 13.5 will mandate use of high octane gas. On my build, I had to redo the ignition table to fix pinging on 93 pump gasoline. Power gains from head porting are minimal relative to the cost of having the work done.
If you go with JE pistons, 13.5 will mandate use of high octane gas. On my build, I had to redo the ignition table to fix pinging on 93 pump gasoline. Power gains from head porting are minimal relative to the cost of having the work done.
not worth it. These engines are extremely optimised from factory. You'll need to do complete hot-rod/racing build to get significant gains. Just slap in 12.5:1 pistons and get it tuned for 91 pump gas and call it good.but idk if I should mill/port the head as well considering I’d be going with high comp pistons and just do a mild engine build.
Lots of work to transfer everything to another case. Measuring for bearings, gaskets, etc. Easiest is just another used engine in good shape.
That’s what I’m considering. to much of a headache for what it’s worth, Decisions decisions.. it’s still ridiculous these engines are 18-19 years old And still running 3k for a decent one. Thanks for all infonot worth it. These engines are extremely optimised from factory. You'll need to do complete hot-rod/racing build to get significant gains. Just slap in 12.5:1 pistons and get it tuned for 91 pump gas and call it good.
Lots of work to transfer everything to another case. Measuring for bearings, gaskets, etc. Easiest is just another used engine in good shape.
$3k is a lot cheaper than any type of motor rebuild involving piston and bore work. It's $1500 minimum for parts and machine work in your situation. If you can find a motor for $3k thats guaranteed in good condition, then buy it.
It is, money isn’t really the issue it’s just the 3k motor for a 5K bike with a definite no power increase. I was just quoted 1055.95 for millennium on a replanting and then I’d be looking at 5-600 for pistons/rings. I gotta do some thinking on a good route to take. probably just gonna drop another engine in it and call it a day. I’ll keep you updated.$3k is a lot cheaper than any type of motor rebuild involving piston and bore work. It's $1500 minimum for parts and machine work in your situation. If you can find a motor for $3k thats guaranteed in good condition, then buy it.
Millennium does offer a lifetime warranty on the coating, so if it goes bad it's free. Used motors are a gamble, and there is no way to know if it's got hidden issues unless you tear it down for inspection.
Well if millennium is offering a lifetime warranty then that’ll be the route to go. I just bought this motor last summer so I know all about the hidden issues unfortunately. But if they’re offering warranties like that I don’t think I could pass it up. Game plan is 12:5 pistons/rings on a std bore. While I have the engine open is there anything else that can be done maybe like regrinding cams or is it even worth it? Also should I have it resurfaced as well and send the head in to be resurfaced or is that going to cause clearance issues?Millennium does offer a lifetime warranty on the coating, so if it goes bad it's free. Used motors are a gamble, and there is no way to know if it's got hidden issues unless you tear it down for inspection.
Like with electrical issues, you want to measure and let the numbers dictate next course of action.
1. measure head & deck flatness
2. compare to specs in manual
3. only resurface one or both just barely enough to get within flatness spec.
Shaving head & deck will change cam-timing. So you'd have to get adjustable cam-gear and dyno-test to set at optimum settings again.
Remember, it's like Craftman's lifetime warranty vs. Snap-on. Best not to have to use warranty in 1st place. Even if they re-do block for free, you still have to handle disassembling, shipping, waiting and re-assembling engine when it comes back... each and every time... For stock performance!
Again, engine-build is something you'd do for all out hot-rod/racing bike. Really only time benefits are worth it. If your paycheque to feed family depends upon you finishing that lap 0.15s faster to get 2nd instead of 3rd place in some pro race.
1. measure head & deck flatness
2. compare to specs in manual
3. only resurface one or both just barely enough to get within flatness spec.
Shaving head & deck will change cam-timing. So you'd have to get adjustable cam-gear and dyno-test to set at optimum settings again.
Remember, it's like Craftman's lifetime warranty vs. Snap-on. Best not to have to use warranty in 1st place. Even if they re-do block for free, you still have to handle disassembling, shipping, waiting and re-assembling engine when it comes back... each and every time... For stock performance!
Again, engine-build is something you'd do for all out hot-rod/racing bike. Really only time benefits are worth it. If your paycheque to feed family depends upon you finishing that lap 0.15s faster to get 2nd instead of 3rd place in some pro race.
The as-cast head ports are pretty good. If you have a die grinder, as I do, then just some basic blue printing is all I would do. Remove any casting flash and edges, leave the intakes with a smooth fine sanding roll finish, do not polish. For the exhaust ports you can use an abrasive rubber cone as a final polish. Unless you have several heads to experiment with and a flow bench then don't mess with the Honda engineers design. 
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