What would cause this?

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johnv
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What would cause this?

Post by johnv »

(that's oil ...) New build, on start up it obviously just pumped oil into the combustion chambers. It did start but it wasn't pleasant! I stripped the head and there's nothing obviously wrong with it
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Re: What would cause this?

Post by timmy201 »

Bad head gasket?
Oil getting through valve stems & seals?
Excess SU damper oil?
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Re: What would cause this?

Post by johnv »

Not the dampers there was no oil in them :) To have a pool of oil in all cylinders kind of excludes the others?
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Re: What would cause this?

Post by timmy201 »

Do you have a PCV system or breather setup?

I remember my friend was particularly enthusiastic filling up the oil once and a lot went out the rocker cover breather
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Re: What would cause this?

Post by johnv »

No .. there are breathers where the petrol pump would have been and on the transfer case but nothing connecting anything atm
No breather on the inlet manifold
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Re: What would cause this?

Post by Jason »

Has the motor been freshly bored, new pistons and rings? Oil could be blowing past the rings from crankcase pressure.
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Re: What would cause this?

Post by johnv »

Jason wrote: Sun Apr 09, 2023 2:56 pm Has the motor been freshly bored, new pistons and rings? Oil could be blowing past the rings from crankcase pressure.
Yes all of the above. Thoughts seem to be that the rings maybe upside down or the cam bearings are in wrong. Checked the one (cam bearing) at the timing chain end and it's fine (they were professionally installed so I suspect they're all fine) Pistons out next.

Edit : it wasn't fine it was installed the wrong way round
Last edited by johnv on Mon Apr 10, 2023 1:06 pm, edited 2 times in total.
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Re: What would cause this?

Post by Oneball »

Incorrectly specified guides/lack of oil seals can cause that. As can rings/bore/pistons.

Looking at the photo no 3 piston looks off in the bore. Did you check bore/piston/ring clearances?
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Re: What would cause this?

Post by johnv »

Oneball wrote: Sun Apr 09, 2023 3:10 pm Incorrectly specified guides/lack of oil seals can cause that. As can rings/bore/pistons.

Looking at the photo no 3 piston looks off in the bore. Did you check bore/piston/ring clearances?
All new oil seals (8) bores were machined to pistons
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Re: What would cause this?

Post by iain1967s »

How long did you run it for when it started? It can take a good few minutes for all the engine assembly lube and oil to get burned off.

Especially if you recently filled the oil above the top of the valve-guide seals quite a bit can leak down the stems while it’s taking time to trickle down the pushrod holes into the gearbox.

For the low price of a head gasket I would clean it up, put it back together, run it for the standard 15 minutes at 2500rpm break-in period, keep an eye on the temperature and oil pressure, and then see after that if there is still a problem.

While it’s running, take the oil filler cap off and look down with a flashlight. You should not be able to see a rising head of liquid oil - if you see it rising up above the valve step seals then 100% the front cam bearing is in backwards - ie slot vs hole location - and getting a continuous rather than a pulsed feed to the head.

Also if you have a compressor you could do a warm leak-down test, or just a regular compression test to see if the rings are sealing.
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Re: What would cause this?

Post by johnv »

I'm being told that this cam bearing is fitted the wrong way round causing oil to be pumped into the rocker cover
FB_IMG_1681054799841.jpg
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Last edited by johnv on Sun Apr 09, 2023 4:47 pm, edited 1 time in total.
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Re: What would cause this?

Post by Exminiman »

johnv wrote: Sun Apr 09, 2023 4:41 pm I'm being told that this cam bearing if fitted the wrong way round causing oil to be pumped into the rocker cover
FB_IMG_1681054799841.jpg
There is another thread about this, it is a thing…sorry i couldn’t find it…

EDIT More by luck than judgement found this. http://mk1-forum.net/viewtopic.php?p=220076#p220076
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Re: What would cause this?

Post by Spider »

I'd say the bores are glazed.
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Re: What would cause this?

Post by iain1967s »

johnv wrote: Sun Apr 09, 2023 4:41 pm I'm being told that this cam bearing is fitted the wrong way round causing oil to be pumped into the rocker cover
FB_IMG_1681054799841.jpg
That has definitely been pressed in backwards. The circular hole should point toward the water pump.
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Re: What would cause this?

Post by johnv »

Spider wrote: Sun Apr 09, 2023 10:49 pm I'd say the bores are glazed.
It was only run for less than .. I'd say 2 minutes total, most of it revving to see if the smoke would clear?
I'm going to take the block back to the machine shop and see what they say .. I built the engine in lockdown so a fair while ago, just decided to put it in TPL to see how it went. I found the receipt though!
I'll check that I've put the rings on correctly then put it back together.
I'm hoping the machine shop will put new cam bearings in (I'll check the orientation :) ) and at least give me a new gasket set ..
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Re: What would cause this?

Post by Spider »

johnv wrote: Mon Apr 10, 2023 5:12 pm
Spider wrote: Sun Apr 09, 2023 10:49 pm I'd say the bores are glazed.
It was only run for less than .. I'd say 2 minutes total, most of it revving to see if the smoke would clear?
,,,,,,
I'm hoping the machine shop will put new cam bearings in (I'll check the orientation :) ) and at least give me a new gasket set ..
That's easily enough time to start glazing them, if that's what's occurred.

Noted the Cam Bearing, but your valve guides would need to be fairly warn and the valve stem seals not doing much to get this much oil in there.
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