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Oil blowing out of cylinder
#795370 01/11/20 11:00 am
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Hope some one can help with my problem of oil blowing out of left cylinder on 1969 T100T Daytona.
I rebuilt the engine from ground up - reground crank new mains bigends pistons rings oil pump valves and valve guides gaskets etc.
Engine runs for 10 miles and oil blows out of left cylinder. Lots of it.
Camshaft breather valve is in and breather pipe is clear.
Another breather fitted at back of crankcase where plug for timing locator is fitted.
I drained the sump after a run- no sign of wet sumping and anyway oil returns to tank nicely.
I disconnected the oil feed to rocker boxes which made no difference so oil is no coming in through the head.
All crank seals are new..
Oil pressure relief valve came with engine
I cleaned out barrel and lapped the plunger. No sign of it sticking.
OPRV spring measures 37 mm while manual specifies 35mm.
Local supplier has both springs in stock so it seems that there are 2 types of OPRV but I cannot find details of them or even which is correct for my engine.
Any ideas on what I should do next are welcome

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Re: Oil blowing out of cylinder
Ian Bailie #795371 01/11/20 11:40 am
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Is it coming out of the exhaust?

If it’s coming down a valve stem or the outside of a valve guide, you should be able to see that by looking into the ports.

Suspect an upside-down or broken piston ring.


Amateur Loctite enthusiast.
Re: Oil blowing out of cylinder
Ian Bailie #795372 01/11/20 12:45 pm
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Are you talking about oil smoke or actual liquid oil blowing out of the exhaust pipe?


79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
Re: Oil blowing out of cylinder
Ian Bailie #795385 01/11/20 5:02 pm
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Originally Posted by Ian Bailie
Hope some one can help with my problem of oil blowing out of left cylinder on 1969 T100T Daytona.
I rebuilt the engine from ground up - reground crank new mains bigends pistons rings oil pump valves and valve guides gaskets etc.
Engine runs for 10 miles and oil blows out of left cylinder. Lots of it.
Camshaft breather valve is in and breather pipe is clear.
Another breather fitted at back of crankcase where plug for timing locator is fitted.
I drained the sump after a run- no sign of wet sumping and anyway oil returns to tank nicely.
I disconnected the oil feed to rocker boxes which made no difference so oil is no coming in through the head.
All crank seals are new..
Oil pressure relief valve came with engine
I cleaned out barrel and lapped the plunger. No sign of it sticking.
OPRV spring measures 37 mm while manual specifies 35mm.
Local supplier has both springs in stock so it seems that there are 2 types of OPRV but I cannot find details of them or even which is correct for my engine.
Any ideas on what I should do next are welcome

Unless the second breather is equipped with a one way valve, it will eff up the whole crankcase ventilation. I've seen similar things all too often.
There are two types of crankcase ventilation

1: The timed breather is a good system, it's designed to pump down crankcase pressure. A one way valve can replace or complement this.
2: Open breathing can be good too, but relies on big holes to work. Imagine no case at all as the ultimate. Triumph used this from 1970.

But here's the thing; combining the former with the latter renders the former ineffective. If a big port is used, you have modified it to an open system.
If not, you have simply screwed up the breathing system.

If you have a one way (PCV type) valve on the second breather already, please disregard this post.

SR

Re: Oil blowing out of cylinder
Ian Bailie #795386 01/11/20 5:21 pm
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Hello; I had plenty of oil coming between the head and the cylinders in a 750 with a rotary oil pump. I removed the head and studs; put balls into the holes and changed all the push rod tubes O rings

Re: Oil blowing out of cylinder
reverb #795393 01/11/20 6:09 pm
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Originally Posted by reverb
Hello; I had plenty of oil coming between the head and the cylinders in a 750 with a rotary oil pump. I removed the head and studs; put balls into the holes and changed all the push rod tubes O rings

Is it oil tight now?

SR

Re: Oil blowing out of cylinder
Ian Bailie #795395 01/11/20 7:07 pm
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¿?
can the re-ground crank interfere with the end feed ?

Re: Oil blowing out of cylinder
Ian Bailie #795417 01/12/20 1:45 am
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...sorry; yes, in that part is oil tight after a few thousands km done.

Re: Oil blowing out of cylinder
Hillbilly bike #795428 01/12/20 7:43 am
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Its oil coming out. Not smoke

Re: Oil blowing out of cylinder
quinten #795429 01/12/20 7:46 am
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Does not seem likely. I am running an oil pressure gauge and the readings are fine. 60psi on start up and 20psi on idle

Re: Oil blowing out of cylinder
Stein Roger #795430 01/12/20 7:48 am
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Sounds right. The added port is 6mm but no oneway valve now. But I will fit 1way anyway and see how it goes

Re: Oil blowing out of cylinder
triton thrasher #795431 01/12/20 7:51 am
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Does not seem likely. I am running an oil pressure gauge and the readings are fine. 60psi on start up and 20psi on idle

Re: Oil blowing out of cylinder
Ian Bailie #795432 01/12/20 9:10 am
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Originally Posted by Ian Bailie
Sounds right. The added port is 6mm but no oneway valve now. But I will fit 1way anyway and see how it goes

Good plan. I'd simply plug it but a valve is OK too. Contrary to what many think, the factory knew how to build these things, stock is good.
I can't say this will solve the oiling issues though.

SR

Last edited by Stein Roger; 01/12/20 9:19 am.
Re: Oil blowing out of cylinder
Ian Bailie #795457 01/12/20 5:21 pm
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where is all this oil coming out? head gasket ? exhaust pipe?


59 Bonne (in high school!)--67 TR6c (building)--68 Bonne(building)--69 Bonne (sold!)- 70 TR6r (sold!)-79 TR7v custom (building) - CRF 250x & XR 400 dual sport w/ SM wheels (super fun!) & just bought two Honda CT-90 trail bikes in rough shape!
Re: Oil blowing out of cylinder
Bob Fletcher #795459 01/12/20 5:35 pm
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Blows out of exhaust port on left cylinder. No signs of leaking from head or base gasket

Re: Oil blowing out of cylinder
Ian Bailie #795462 01/12/20 5:58 pm
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Follow TT's post then, if its not coming out of the exhaust guide then it can only be rings or inlet guide (check that by taking the carb off and looking for oil on the inlet valve).

Re: Oil blowing out of cylinder
Ian Bailie #795463 01/12/20 6:06 pm
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Or this at the worst, a friend's bike had oil blowing out the exhaust pipe...It was a lot of oil...Fresh rebuild as you can see

[Linked Image from i.imgur.com]





79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
Re: Oil blowing out of cylinder
Ian Bailie #795606 01/14/20 7:36 pm
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way back when I had my 59 Bonnie it blew heavy smoke out the left exhaust pipe after running it about 4 miles-- back then I didn't know about wet sumping so I redid the top end over and over and of course it never fixed it-- If I had know about wet sumping I'd probably still have that beauty! --now I like to vacuum test ( 20" hg?) the sump pick up pipe and measure sump quantity ( 200 cc's?) to check if my oil return system works properly-- I follow the Glen's Triumph manual instructions. it's a interesting problem, hope you find the issue.


59 Bonne (in high school!)--67 TR6c (building)--68 Bonne(building)--69 Bonne (sold!)- 70 TR6r (sold!)-79 TR7v custom (building) - CRF 250x & XR 400 dual sport w/ SM wheels (super fun!) & just bought two Honda CT-90 trail bikes in rough shape!
Re: Oil blowing out of cylinder
Hillbilly bike #795662 01/15/20 7:37 am
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Originally Posted by Hillbilly bike
Or this at the worst, a friend's bike had oil blowing out the exhaust pipe...It was a lot of oil...Fresh rebuild as you can see

[Linked Image from i.imgur.com]





Chit, stop scaring me. Looks like a fresh rebuild alright! So, what happened and why? I'm almost done. I just put the jug on today. Is that a 750 bore kit? Too lean? fuel issue? Sorry, I'm very curious.


1970 Triumph tiger owner
Re: Oil blowing out of cylinder
splash #795665 01/15/20 11:03 am
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Originally Posted by splash






Chit, stop scaring me. Looks like a fresh rebuild alright! So, what happened and why? I'm almost done. I just put the jug on today. Is that a 750 bore kit? Too lean? fuel issue? Sorry, I'm very curious.

The bike sat for a year with fuel in the tank after running about 25 miles on the fresh engine..The owner then decided to take it for a ride with a passanger,with the old gas...Stale fuel, heavy load, classic preignition damage..According to experts, pre ignition, unlike detonation, gives no warning other than doing dumb stuff to cause it


79 T140D, 96 900M Ducati ,61 A10 .On a bike you can out run the demons..
“But I don't want to go among mad people,” Alice remarked. “Oh, you can't help that,” said the Cat: “we're all mad here. I'm mad. You're mad.
Re: Oil blowing out of cylinder
Ian Bailie #795727 01/16/20 3:35 am
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Has the head had any 'work' done on it? Has it been flowed? I've seen where the valve pocket breaks into the exhaust port...just a pinhole, but black greasy oil was dripping out of the bike as well as lots of blue smoke on that side.

Re: Oil blowing out of cylinder
tridentt150v #795849 01/17/20 10:15 am
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No work done on the head but that is definitely worth a look thanks

Re: Oil blowing out of cylinder
Ian Bailie #796438 01/24/20 1:15 am
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Ian-- where you at on this? I'm really interested in your finding the problem-- I talked to KC and he ( like me) had similar problem caused by wet sumping after a total top end rebuild.

Last edited by Bob Fletcher; 01/24/20 1:16 am.

59 Bonne (in high school!)--67 TR6c (building)--68 Bonne(building)--69 Bonne (sold!)- 70 TR6r (sold!)-79 TR7v custom (building) - CRF 250x & XR 400 dual sport w/ SM wheels (super fun!) & just bought two Honda CT-90 trail bikes in rough shape!
Re: Oil blowing out of cylinder
Bob Fletcher #796527 01/25/20 8:22 am
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I am ready to test after fitting PCV valve onto crankcase breather pipe . Pissing down here at moment so I may only run it next week. If that doesnt work then will vacuum test the scavenge pipe in crankcase.


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