Steel Sleeve????
- Thread starter jahames7
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Ol'89r
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- Jan 27, 2000
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jahames7 said:
IMO, no.
A steel liner is old technology. The reason is the heat expansion rate between steel and aluminum.
With an aluminum piston and a steel liner, you have to run more piston clearance because the steel liner and the aluminum piston expand at different rates.
With an aluminum cylinder and aluminum piston the expansion rates are much the same and you can run a much tighter clearance. The tighter clearance and the improved cylinder surface on the aluminum cylinder gives you a better seal, more compression and a more efficient engine.
You don't really save that much money by going to a steel sleeve. Just have it repaired and re-plated.
I agree 100% with the above. I will also add that it can be quite difficult to match up the ports in the cylinder to the port openings in a steel sleeve. It's quite unlikely that a sleeved cylinder will have the same porting characteristics of the original plated cylinder.
They are not all steel either. I have seen some advertized as chrome? The platers can even plate over the liners. What for? Send it to Millineum or just send it to Forward Motion. Eric can cut some great prices on the parts you will need. You could be assured of NOT getting some mickey moused Chinese parts. No lie, my sleeved cr250 has 1/2" of liner hanging into the intake track! I used to believe you really had to watch what rings you run on them liners, its just the chrome liners. The cheap price of the liner, is what usually attracts buyers. And any auto shop will slam them in. Not good, IMO. Vintage Bob
SBC383STROKER
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- Feb 28, 2008
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Sleeving cylinders?
NO!
The steel sleeve will only make your engine run hotter. This is due to the lower thermal efficiency (transfer of heat) of the steel compared to aluminum along with the Nikasil plating which hapens to make the engine run even cooler along with other better qualities. I once had a 1989 CR 250 that i had the cylinder re-sleeved and after one trail ride, you could loudly hear the antifreeze boiling. In return, i bought a used stock cylinder (plated) and that made the biggest difference. Conclusion to this?? DON'T sleeve cylinders!
NO!
The steel sleeve will only make your engine run hotter. This is due to the lower thermal efficiency (transfer of heat) of the steel compared to aluminum along with the Nikasil plating which hapens to make the engine run even cooler along with other better qualities. I once had a 1989 CR 250 that i had the cylinder re-sleeved and after one trail ride, you could loudly hear the antifreeze boiling. In return, i bought a used stock cylinder (plated) and that made the biggest difference. Conclusion to this?? DON'T sleeve cylinders!
2strokes4life
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- Apr 1, 2009
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Let me throw this out there. I know it is a little off topic, but I have a Suzuki LT250R 2 stroke quad. Now I agree with you all on the nikasil and I do run factory cylinders on both of my dirt bikes (2002 CR 250 and RM 125). My LT250R quadracer is a 1989. They were not using nikasil at the time. I believe (not totally sure) that if I buy a new cylinder from Suzuki right now that it will be a steel lined cylinder drilled to factory bore. Now why wouldn't they switch the quads to the nikasil also if it was so much better. Anybody I ever talk to about the quads loves the steel so you can bore them time and again. Just wondering. Also as stated before, if I send my cylinder out to be plated now it will just be nikasil over steel. What would be the difference in a 2 stroke quad vs. a dirt of the same engine displacement? They are also all 3 power valve engines and liquid cooled. I also believe that snowmobile engines are steel lined as well. I have never had a quad or snowmobile engine boil antifreeze because of a steel liner.
There is a bit of difference to an iron bore from the factory, and boring out an aluminum bore to accept a steel sleeve.
Yes, you are correct, the ability to cheaply rebore for an oversize piston is one advantage to steel sleeves or iron bore cylinders. Perhaps the only advantage though.
Yes, you are correct, the ability to cheaply rebore for an oversize piston is one advantage to steel sleeves or iron bore cylinders. Perhaps the only advantage though.
Ol'89r
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2strokes4life said:
Must be a quad thing. :whoa: :coocoo:
With a Nikasil cylinder, the bore does not wear out like a iron cylinder does. The piston wears. So, instead of reboring the cylinder, you just replace the piston and rings.
There are other advantages to a Nikasil cylinder including Thermal Efficiency and less power lost through friction.
2strokerfun
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- May 19, 2006
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And I suppose you think they'll also someday make a dirt bike with radiators and water cooling....
my opinion, is mostly cost for performance against proposed maintenance shedule is the negotiating factor,A steel sleeve (actually cast iron) is standard in most engines whether it is your lined aluminum blocked lawn mower, your cast iron blocked Chevy truck, or a replaceable liner in a heavy duty diesel or the quad in question where the standard is to wait until something happens before you fix it. So you wait until you sieze it , until is so worn out you can't start it or keep oil in it because of poor compression and ring seal and then you bore out the damage and fit in a oversized piston.
Now when you are talking about a motocross racing engine when the manufactures figured out they can sell/race an engine that is a lot closer to the max displacement(don't have to worry about displacement with the not normally available oversized pistons), the advent of better heat dissipation/control and uniformity that helps keep a more uniform cylinder roundness ,tempature and clearances to provide a more constant and reliable horsepower platform where the intended use is going to be maintained for maximum power, the plated cylinder is the way to go
Now when you are talking about a motocross racing engine when the manufactures figured out they can sell/race an engine that is a lot closer to the max displacement(don't have to worry about displacement with the not normally available oversized pistons), the advent of better heat dissipation/control and uniformity that helps keep a more uniform cylinder roundness ,tempature and clearances to provide a more constant and reliable horsepower platform where the intended use is going to be maintained for maximum power, the plated cylinder is the way to go
miekmyk
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- Oct 18, 2009
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Im using a Kawasaki KMX 125 an enduro bike which i use for motocross here in the philippines. It resleeved with a steel bore. It's originally nikasil plated or chrome bore. My opinion is the chrome bore revs better.
The thing with using steel bore is using a piston and piston ring that is also designed for steel bores. if you use the same piston that's designed for chrome bore. The steel bore will eat up the rings
the standard piston for my bike AFAIK is 54 mm, i used a piston from a yamaha DT 125 which is 56 mm. now my engine is around 134cc and it kicks 125's ass. some even used 59mm pistons.
you have to have a good machine shop and consider using a thicker base gasket because of the differences when it comes to the piston's length. hope this helps. Steel bore isn't that bad. My bike never overheated during trails or mx
The thing with using steel bore is using a piston and piston ring that is also designed for steel bores. if you use the same piston that's designed for chrome bore. The steel bore will eat up the rings
the standard piston for my bike AFAIK is 54 mm, i used a piston from a yamaha DT 125 which is 56 mm. now my engine is around 134cc and it kicks 125's ass. some even used 59mm pistons.
you have to have a good machine shop and consider using a thicker base gasket because of the differences when it comes to the piston's length. hope this helps. Steel bore isn't that bad. My bike never overheated during trails or mx
2-Strokes 4-ever
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In 98 Suzuki had an issue with their OEM pistons, ours lost a ring locating pin and we sleeved the cylinder, choosing Wiseco from then on. Looking back, I realize that replating is a better choice, and for a $25-50 difference...
But... the steel liner has thousands of trail miles on it, and this bike is very easy on top ends. We can get just as many hours out of that little 125 piston as on my RM250.
Either way, always give a bike warm-up time.
IMO, replating is best, but no bad experiences here with a sleeve either.
But... the steel liner has thousands of trail miles on it, and this bike is very easy on top ends. We can get just as many hours out of that little 125 piston as on my RM250.
Either way, always give a bike warm-up time.
IMO, replating is best, but no bad experiences here with a sleeve either.
Yeah, it's not that sleeving should NOT be considered. It is indeed a good method for repairing a damaged cylinder, and can sometimes be considerably cheaper than re-plating if there is going to be extensive welding involved in the re-plating process. Then you also have the benefit of being able to bore to the next oversize quite cheaply without having to worry about another re-plate.
when possible re-plate, when necessary sleeve.
when possible re-plate, when necessary sleeve.
Thanks for the info. That was one thing i didn't know about the difference between different types of cylinders. I have the 85 cr250r (the last year before they changed from steel to something else in 86 when they also added the powervalve in the cylinder. What type of cylinder is the 86-89? I want to get a newer cylinder for my bike because i know it will work(my crankcase is an 89 with an 85cylinder and clutch cover) and i'd rather have the powervalve than the sub-chamber. I'd also like to have better compression and heat transfer. Can i get my cylinder plated or what can i do other than getting a newer cylinder? Mine is getting bored right now .050 over so i'm in no hurry just wondering what i can do
So your bottom end is equipped for a power valve, but it's just not in use because the 85 cylinder does not have a power valve? I take it that's why you needed the 85 clutch cover...
The power valves do make a huge difference in the low end power. If I was in that position, I'd be looking for one.
The power valves do make a huge difference in the low end power. If I was in that position, I'd be looking for one.
Real world, IF the liner was precisely installed, no extra "porting", the heat trapped difference is minimal, it is water cooled, the worst thing is the faster ring/piston wear. You can get the sleeve plated. BUT, I do not know if its even possible to perfectly align the sleeve. And the who done it thing, there was an op that had a sleeve installed and they did not even cut the excess off the top! You have the distinct issue of clobbering different year engine parts together? Be very careful! What little I gathered, I would be looking for a newer bottom end to match the jug, or a better jug to match what you have. A crappy exhaust valve set up is better than none, in most cases, imo. Vintage Bob
Yes thats exactly why i have the 85 clutch cover. To match up with the actuator rod that runs up to the cylider to operate the sub chamber. 89 crankcase, trans,clutch,kick spindle with 85 cylinder and clutch cover. I tore the engine down and replaced all bearings except for the shifter cuz it dont spin fast only moves when shifting.
I paid a lot of attention to everything as i put it back together and made sure everything will operate correctly. I switched the rear studs for the cylinder cuz the 89 are longer and i swapped the actuator rod and the dowel(which holds it at the right height). I then put it together without the piston or clutch cover and with the sub-chamber. When i push on the actuator lever by the water pump, the butterfly in the sub-chamber seems to work fine. All being said i would still like to get the right cylinder for the crankcase. if i got a cylinder for the 89 then i could take the 85 cylinder and put it back on the 85 crankcase and have an extra engine. The only reason i took the cylinder off the 85 and put on the 89 is cuz the 85 was left uncovered without the top end on it for five years and had a lot of rust and a hole in the case by the chain
I paid a lot of attention to everything as i put it back together and made sure everything will operate correctly. I switched the rear studs for the cylinder cuz the 89 are longer and i swapped the actuator rod and the dowel(which holds it at the right height). I then put it together without the piston or clutch cover and with the sub-chamber. When i push on the actuator lever by the water pump, the butterfly in the sub-chamber seems to work fine. All being said i would still like to get the right cylinder for the crankcase. if i got a cylinder for the 89 then i could take the 85 cylinder and put it back on the 85 crankcase and have an extra engine. The only reason i took the cylinder off the 85 and put on the 89 is cuz the 85 was left uncovered without the top end on it for five years and had a lot of rust and a hole in the case by the chain
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The cases are still good. Them main bearings are about as fubared as they could get, short of falling apart at 7,000 rpm. Vintage Bob
Could have used a farther pic also, a little hard to see the big picture. BUT, its enough to say it needs replaced. Chain maintenance$ If you are jumping from 85 to 89, 87 would be my target, and there are lots of decent used parts for sale. Vintage Bob
sorry the pic is pretty close but that is the extent of the damage and it is even worse than it looks, JB weld below the hole is really hard to see cuz the color matches the case.
I have the 89 motor minus cylinder piston and clutch cover to match it . oh and the exhaust too.
I have the 89 motor minus cylinder piston and clutch cover to match it . oh and the exhaust too.
