suix
Expert Class
Posts: 122
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posted September 23, 2009 12:39 AM
 Edited By: suix on 23 Sep 2009 08:51
Problem is . . . . I cant find the problem. HELP ME!!
My stock motor was giving me blow-by and thus sparked off this 1051 project.
After the rebuild, I faced a very major problem . .. . . the blowby did not go away. Engine oil will rush out of my breather once I hit 10k rpm. Yes it rushed out like it was off the tap. I have less than 2000 km on it and was still in the break-in phase. Suspecting this to be a case of cylinder head blow-by. I went on to get another head and still the problem persists.
Here are some of the actions I've taken:
I measured the oil pressure at 4k rpm (as per service manual) and found that I was having 420 Kpa where the norm should be between 150-230 kpa @ 4k rpm.
The oil pan was down and inspected the oil pressure relief valve. It is kinda tight and strip it out for a good wash. Put the valve back in and the reading drop down to 320 kpa . . . still too high but at least we're heading the right direction.
I decided to switch back to use the OEM oil filter instead of the K&P. Reading dropped another 20 kpa to 300kpa.
Next step, i took the motor apart to check for oil passage chokage. The cylinder wall and conrod look healthy. No sign of burnt. No blockage to be found.
Upon removing the conrods from the crank, I found that the wear on the conrod bushing seem to be a little to much for a motor with less than 2000 km.
Is this an indication that pressure is too high for sufficient oil volume to lubricate the bushing thus resulting in the pre-mature wear?
Here is a breakdown on the bike setup.
1) +2mm JE pistion
2) Crankcase (1 pcs block and upper crankcase) job by APE (bore and Nikasil)
3) Total seal piston ring
4) Crank job (lighten and balanced)
5) Kawi Kit intake cam
6) Secondary plate and shaft removed
What else could I have overlooked in troubleshoot this. I appreciate your kind input.
  
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tcchin
Zone Head
Posts: 867
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posted September 23, 2009 01:23 PM
Which bike is this? Have you checked the cylinders for roundness and taper? Are the rings gapped, fitted and installed properly on the piston?
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Texas12R
Zone Head
Posts: 545
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posted September 23, 2009 01:43 PM
a leak-down test would have been a good place to start.......
higher than needed oil pressure is just parasitic drag ,but I wouldnt expect it to cause
abnormal wear......but as always I reserve the right to be wrong
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dougmeyer
Needs a job
moderated
Posts: 2713
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posted September 23, 2009 04:35 PM
This is a ZX-10 I presume?
Oil flow/pressure not relevant. You have a cylinder sealing problem, which should have been diagnosed with a leak down and compression check. Send us photos of the piston skirts, rings and cylinder walls. What is your cylinder to piston clearance and how was it measured?
You state use of Total Seal rings. I'm suspect of this. What is "secondary plate and shaft"? (Been a long tims since I've looked at 10 parts)
Doug
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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suix
Expert Class
Posts: 122
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posted September 23, 2009 04:59 PM
Edited By: suix on 24 Sep 2009 01:08
The bike is a 06' ZX-10R.
Before big bore
Leak down has been conducted prior to the big bore and reading is within that of the service manual. The issue persisted and hence stripped the motor down and found burnt mark on the conrod.
After big bore
No leak down conducted yet. Taking into consideration that pistons, rings, bushing and conrods are new. Cylinder boring and plating and parts are all from APE.
Stripped the motor down and did not find visual sign of burnt . Only noticeable is the wear on conrod bushing.
The 06' ZX-10R has secondary throttle plates (some called them butterflies valves). The shaft that I'm referring to is the shaft holding these plates. Removing the shaft also disable the auto-choke function.
The motor was assemblied back last night. Going to start it up and do the leak test and oil pressure check. I will post the finding here after the tests.
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dougmeyer
Needs a job
moderated
Posts: 2713
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posted September 23, 2009 08:20 PM
Okaay.....
We're here to help. keep us posted.
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It's not that I think you're dumb, it's just that so much of what you know isn't true....
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