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Author Topic: oil splashing from air passages  (Read 7631 times)

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Offline phi

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oil splashing from air passages
« on: April 05, 2012, 01:46:53 PM »
I have a big bore (67 mm.) with oil everywhere. installed new bottom gasket and new head gasket, and new rubber rings around the base of the cylinders. It is still bleeding oil, but this time i can see it is coming from the air passages between the cylinders.
Is it the rings not being tight enough, or has the machinist hit one of the passages when boring the block? any easy solutions, or do i have to remove the cylinders from the block and weld holes shut? any ideas are welcome. By the way, does any of you have a cut through drawing of the block?
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Offline Bill/BentON Racing

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Re: oil splashing from air passages
« Reply #1 on: April 05, 2012, 03:55:47 PM »
Welcome to the world of Big Bores! ;) ;D Most people used slicone seal....but a better solution would be a Mike Rieck Big Bore Nikasil cylinder,at top of forum page! ;D No Mo Oil leaks!!! 8) Bill
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Offline MRieck

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Re: oil splashing from air passages
« Reply #2 on: April 05, 2012, 04:47:56 PM »
I don't know how you fitted orings at the base of the cylinder sleeves....once you bore the block to accept the new sleeves there is no recess. If you use the Tapered sleeves like CycleX sells there still isn't the correct recess. I use 1194 around the base of the sleeves. Place the cylinder upside down, work in the 1194, wipe off excess and let it dry. It is oil tight. The "windows" that have opened (between air passages 1&2 and 3&4) secondary to sleeve boring will rust if they aren't sealed with silicone or something.
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Offline phi

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Re: oil splashing from air passages
« Reply #3 on: April 06, 2012, 01:36:20 AM »
That sounds great. No long nights trying to tig in tight places. Thank you for a very usefull answer. It is nice to know that I´m not alone in the pursuit of power.
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Offline bear

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Re: oil splashing from air passages
« Reply #4 on: April 06, 2012, 03:23:51 AM »
I still prefer to weld.

Cheers,
Brian
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Offline Sam Green Racing

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Re: oil splashing from air passages
« Reply #5 on: April 06, 2012, 04:31:54 AM »
If anyone requires anything welding, I know a good hospital in Aus that does a fantastic job. ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

Nice to see normal postings from you Brian and not just about your health, a big step in the right dierection mate. 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8)

Sam. ;)
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Offline mick7504

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Re: oil splashing from air passages
« Reply #6 on: April 06, 2012, 04:59:28 AM »
Quote from: SamCR750A on April 06, 2012, 04:31:54 AM
If anyone requires anything welding, I know a good hospital in Aus that does a fantastic job. ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D ;D

Nice to see normal postings from you Brian and not just about your health, a big step in the right dierection mate. 8) 8) 8) 8) 8) 8) 8) 8) 8) 8) 8)

Sam. ;)
Absolutely  8)  ;)
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Offline MCRider

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Re: oil splashing from air passages
« Reply #7 on: April 06, 2012, 07:41:38 AM »
Would sleeves for a 67mm bore (888cc) open the windows in the casting? I don't think mine did. Maybe they did.

Agree with Mike (how could I not) that by boring out the block to accept the oversize sleeves, you lose the groove where the cylinder base ORings go. IF you try to use them, I can foresee a problem.

I ran an 888 on the street for 50,000+ miles and never had a leak.

They can be left out no problem, even on a stocker. Mikes compound goo 1194 sounds like a good procedure.
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Offline mick7504

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Re: oil splashing from air passages
« Reply #8 on: April 06, 2012, 08:45:49 AM »
Quote from: MCRider on April 06, 2012, 07:41:38 AM
Would sleeves for a 67mm bore (888cc) open the windows in the casting? I don't think mine did. Maybe they did.

Agree with Mike (how could I not) that by boring out the block to accept the oversize sleeves, you lose the groove where the cylinder base ORings go. IF you try to use them, I can foresee a problem.

I ran an 888 on the street for 50,000+ miles and never had a leak.

They can be left out no problem, even on a stocker. Mikes compound goo 1194 sounds like a good procedure.
Curious too as to why 900 sleeves would produce an air gap in the block.
I can't say that I've seen that happen before.
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Offline MCRider

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Re: oil splashing from air passages
« Reply #9 on: April 06, 2012, 08:48:21 AM »
Quote from: mick7504 on April 06, 2012, 08:45:49 AM
Quote from: MCRider on April 06, 2012, 07:41:38 AM
Would sleeves for a 67mm bore (888cc) open the windows in the casting? I don't think mine did. Maybe they did.

Agree with Mike (how could I not) that by boring out the block to accept the oversize sleeves, you lose the groove where the cylinder base ORings go. IF you try to use them, I can foresee a problem.

I ran an 888 on the street for 50,000+ miles and never had a leak.

They can be left out no problem, even on a stocker. Mikes compound goo 1194 sounds like a good procedure.
Curious too as to why 900 sleeves would produce an air gap in the block.
I can't say that I've seen that happen before.
If they did, then they did. I suppose that perhaps sleeves for a bigger bore were used and only bored to 67mm.
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Offline 754

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Re: oil splashing from air passages
« Reply #10 on: April 06, 2012, 09:17:47 AM »
 They could be fatter sleeves, I think they can be welded inside, but you have to do it from where the sleeve sits, Before finish boring. IE bore 50 though under, do your weelding, then grind the weld down and finish the hole that sleeve fits in.
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Offline mick7504

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Re: oil splashing from air passages
« Reply #11 on: April 06, 2012, 09:27:43 AM »
Quote from: MCRider on April 06, 2012, 08:48:21 AM
Quote from: mick7504 on April 06, 2012, 08:45:49 AM
Quote from: MCRider on April 06, 2012, 07:41:38 AM
Would sleeves for a 67mm bore (888cc) open the windows in the casting? I don't think mine did. Maybe they did.

Agree with Mike (how could I not) that by boring out the block to accept the oversize sleeves, you lose the groove where the cylinder base ORings go. IF you try to use them, I can foresee a problem.

I ran an 888 on the street for 50,000+ miles and never had a leak.

They can be left out no problem, even on a stocker. Mikes compound goo 1194 sounds like a good procedure.
Curious too as to why 900 sleeves would produce an air gap in the block.
I can't say that I've seen that happen before.
If they did, then they did. I suppose that perhaps sleeves for a bigger bore were used and only bored to 67mm.
From what I've seen is that larger OD sleeves have a larger ID which was beyond 67mm (for the 750) and which was when a breakthrough occurred.
Possibly could be sleeves from another application???
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Offline voxonda

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Re: oil splashing from air passages
« Reply #12 on: April 06, 2012, 09:30:05 AM »
Back in the day, the 950 and even 970 Japauto's used to weld the block before boring to oversize sleeves.
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Offline phi

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Re: oil splashing from air passages
« Reply #13 on: April 06, 2012, 01:06:47 PM »
Guessing is the road to hell, so here is what I actually know: the cylinders is apparently part of a APE set. It reads "900R" in the place where it usually says "738 cc". I got it this way, and i have never removed the sleeves, so I do not know how it looks on the inside, I can just assume from the oil comming out that it has to do with the size of the blocks bore. I have installed the o-rings in the groove between the block and the sleeves, not knowing there was supposed to be a recess there. the groove is around 2 mm wide all the way round.
I can weld the holes shut, but I am worried that the block might get twisted or uneven in the process.
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Offline scottly

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Re: oil splashing from air passages
« Reply #14 on: April 06, 2012, 07:41:21 PM »
Just how much oil are we talking about? The sleeves are a shrink fit into the block, and any oil leaking between the sleeve and block should be more of a weep, not a splash. I've heard of oil dripping in the air passages caused by sealing problems in the cylinder head; cam pucks, or O-rings??
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Offline phi

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Re: oil splashing from air passages
« Reply #15 on: April 07, 2012, 01:36:05 AM »
I checked orings and pucks when disassembling, and was weary carefull when installing the new ones. there is no signs of oil from the top, but just by revving to streetspeeds, there is oil coming from the airgaps in amounts that sprays my pants, my engine, my carps and battery tray. It is quite a large amount. I will take it apart next week, and will then be able to provide pictures of the gap and the airpassages.
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Offline 754

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Re: oil splashing from air passages
« Reply #16 on: April 07, 2012, 08:10:57 AM »
 I suspect the sleeves may be loose, be hard to weld if already bored. If everything was carefully cleaned you may be able to seal it up with epoxy or similar filler..
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Offline MCRider

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Re: oil splashing from air passages
« Reply #17 on: April 07, 2012, 08:12:30 AM »
Quote from: phi on April 07, 2012, 01:36:05 AM
I checked orings and pucks when disassembling, and was weary carefull when installing the new ones. there is no signs of oil from the top, but just by revving to streetspeeds, there is oil coming from the airgaps in amounts that sprays my pants, my engine, my carps and battery tray. It is quite a large amount. I will take it apart next week, and will then be able to provide pictures of the gap and the airpassages.
WOW!

I'll be following this with interest.

754 has a good speculation, loose sleeves.
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Offline MRieck

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Re: oil splashing from air passages
« Reply #18 on: April 07, 2012, 08:44:59 AM »
Yeah...something isn't right. Crankcase pressure blowing oil out like that. ???
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Offline Jerry Rxman Griffin aka MuthaF'er

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Re: oil splashing from air passages
« Reply #19 on: April 07, 2012, 11:04:18 AM »
Michael,

Big Jay did my 900 and it came back with the taper. I fit CB900 o-rings.

Phi,

Get in touch with Big Jay at APE. He's a proud sponsor of ours and would be glad to help out I'm sure.
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Offline phi

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Re: oil splashing from air passages
« Reply #20 on: April 07, 2012, 12:53:19 PM »
Took a deep breath, and got to it today. Despite crappy cam, you can clearly see the 2 mm. groove around the sleeves. No loose pucks, and dry gaskets. The sleeves are rock solid. Tomorrow, I will remove them, and hopefully get an answer.
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Offline phi

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Re: oil splashing from air passages
« Reply #21 on: April 08, 2012, 12:07:35 AM »
It has been a very long night here in DK, but it was worth it. Look what the sleeves hid. I´m pretty sure fixing this will make my oil nightmare go away.
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Offline mick7504

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Re: oil splashing from air passages
« Reply #22 on: April 08, 2012, 05:20:02 AM »
Welding and reboring the block might take it too far for your old sleeves.
Just something to consider and also the cost of doing that as against another block and 900 sleeves that won't break open the walls.
Can you measure the ID & OD of the sleeves that were removed?
I'm quite curious about this.
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Offline thrutheframe

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Re: oil splashing from air passages
« Reply #23 on: April 08, 2012, 05:43:25 AM »
Quote from: phi on April 08, 2012, 12:07:35 AM
It has been a very long night here in DK, but it was worth it. Look what the sleeves hid. I´m pretty sure fixing this will make my oil nightmare go away.

  OK fellas I know very little about this end of things I have a question or two if I may.

Is this a stock set of 750 cylinders that were bored to fit sleeves for a 900r?

The problem here is the break outs in the cylinder walls and oil was getting behind the sleeves?

Once the sleeves are in place (if it were stock) O-rings would go in the grooves formed by the sleeve and the L-shaped groove?

Forgive the barrage of questions but I have two 750 engines one of which I want to rebuild myself so I've been poking threads pertaining to engine internals and asking questions.

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Offline MRieck

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Re: oil splashing from air passages
« Reply #24 on: April 08, 2012, 05:45:32 AM »
I would use an early cylinder that doesn't have the oil return hole recesses.
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