JP engines
#61
Tech Fanatic
Joined: Mar 2003
Posts: 783
Originally posted by daniz24
Naaahhhh...
I'll just use my standard JP FX T-03 (not this "team" engine) for GQ Cup laahhh...
It's raining everyday
Plan to save it for the upcoming Jakarta Open

How about I give you an offer? A very rare custom JP RRL3 based engine? Wanna try baby?
Naaahhhh...
I'll just use my standard JP FX T-03 (not this "team" engine) for GQ Cup laahhh...
It's raining everyday
Plan to save it for the upcoming Jakarta Open

How about I give you an offer? A very rare custom JP RRL3 based engine? Wanna try baby?
He might want to call you right away.
#63
Originally posted by Ah10
a friend of mine told me when you start pinching the sleeve it will not hold it's shape or size very long!
So are you still suggesting stay away from AAc?
a friend of mine told me when you start pinching the sleeve it will not hold it's shape or size very long!
So are you still suggesting stay away from AAc?
#64
Originally posted by BrainTeased
What do you mean by pinching the sleeve?
What do you mean by pinching the sleeve?
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
#65
Originally posted by DOMOisCOOL
Well, over time, sleeves inside the engine wear out. So if you try to push a piston through the sleeve, it has no pinch (no compression).
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
Well, over time, sleeves inside the engine wear out. So if you try to push a piston through the sleeve, it has no pinch (no compression).
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
#66
Originally posted by DOMOisCOOL
Well, over time, sleeves inside the engine wear out. So if you try to push a piston through the sleeve, it has no pinch (no compression).
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
Well, over time, sleeves inside the engine wear out. So if you try to push a piston through the sleeve, it has no pinch (no compression).
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
#67
Originally posted by daniz24
Do any of you guys spoke French and please tell me what's the meaning of "Moteur rode" on my JP FX box?
Do any of you guys spoke French and please tell me what's the meaning of "Moteur rode" on my JP FX box?
Break in already made. God knows how many tanks...
#69
Originally posted by DOMOisCOOL
Well, over time, sleeves inside the engine wear out. So if you try to push a piston through the sleeve, it has no pinch (no compression).
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
Well, over time, sleeves inside the engine wear out. So if you try to push a piston through the sleeve, it has no pinch (no compression).
Theres a process called pinching and it actually "shrinks" the sleeve almost like it came from the factory. So you'll have more compression. Also, you'll have to re-break-in the engine.
I have used the piston spreading technique before. It expands the piston to give you more compression but it only lasts a short time. I actually watched my dad years back holding a piston in his hand (gripped between his finger and thumb) and spread it with a pair of heavy duty pliers at the trackside. That engine ran for a further 2 months without any problems. Not that I would recommend doing this off course
But I really believe that once an engine starts loosing its compression it is cheaper in the long run to replace the P/S set. While the engine might still run for short periods with little compression it is hurting the conrod, crankpin and bearings due to being able to rev harder.
#70
I'd generally agree with Palmaris Europe.
However, when faced with a X/12 Rody that absolutely flew till it ran out of compression, I figured I'd try the osrocket sleeve pinching service.
What the heck, it was a A$27.00 investment in a A$650.00 engine.
The sleeve to crankcase fit wasn't noticeably different and there was no sign of flaking chrome or anything nasty. I guess we're talking about very small measurements here, so this should not be surprising.
The piston/liners came back with 4mm of top space after pushing the piston up the sleeve as far as possible by hand. To me this seemed rather excessive but I was advised that it would be OK. I ran a couple of tanks through it and became concerned at what I still considered to be excessive piston sticking at near TDC. These Rody cranks are a bit suspect from day one and I didn't want to risk it. I then lapped the piston using a paste type bath cleaner to get the measurement down to 3.3mm, reassembled it and proceeded with the break in. It now felt a lot better and broke in properly. Feel free to laugh at the method, but it worked just fine.
As I say, I agree with Palmaris Europe's thoughts, but this was a pretty cheap experiment with really no down side. Naturally you should not expect to get a new engine back with just a pinched sleeve since the crank pin will be at least somewhat oval, for instance. So, for 27 bucks, if it only lasts one meeting that's not a bad investment.
I also would not recommend doing this.
However, when faced with a X/12 Rody that absolutely flew till it ran out of compression, I figured I'd try the osrocket sleeve pinching service.
What the heck, it was a A$27.00 investment in a A$650.00 engine.
The sleeve to crankcase fit wasn't noticeably different and there was no sign of flaking chrome or anything nasty. I guess we're talking about very small measurements here, so this should not be surprising.
The piston/liners came back with 4mm of top space after pushing the piston up the sleeve as far as possible by hand. To me this seemed rather excessive but I was advised that it would be OK. I ran a couple of tanks through it and became concerned at what I still considered to be excessive piston sticking at near TDC. These Rody cranks are a bit suspect from day one and I didn't want to risk it. I then lapped the piston using a paste type bath cleaner to get the measurement down to 3.3mm, reassembled it and proceeded with the break in. It now felt a lot better and broke in properly. Feel free to laugh at the method, but it worked just fine.
As I say, I agree with Palmaris Europe's thoughts, but this was a pretty cheap experiment with really no down side. Naturally you should not expect to get a new engine back with just a pinched sleeve since the crank pin will be at least somewhat oval, for instance. So, for 27 bucks, if it only lasts one meeting that's not a bad investment.
I also would not recommend doing this.
#71
Tech Adept
Joined: Jan 2002
Posts: 232
From: Puyallup Wa
I also value Palmaris's comments, but I also have used the OS Rocket method on my C-5. HAd it done last year, and still runs strong to this day. In fact, it pulls them all on the track!!
For 27.00, you realy can' go wrong.
Smitty
For 27.00, you realy can' go wrong.
Smitty
#72
JP FX comes with fully hopped-up version...
Black crank case, ceramic bearing, black hardened (and lightened) crankshaft... It cost more than $400, damn the .12 engine get more and more expensive these days
Black crank case, ceramic bearing, black hardened (and lightened) crankshaft... It cost more than $400, damn the .12 engine get more and more expensive these days
#73
Originally posted by daniz24
JP FX comes with fully hopped-up version...
Black crank case, ceramic bearing, black hardened (and lightened) crankshaft... It cost more than $400, damn the .12 engine get more and more expensive these days
JP FX comes with fully hopped-up version...
Black crank case, ceramic bearing, black hardened (and lightened) crankshaft... It cost more than $400, damn the .12 engine get more and more expensive these days



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