Lots of smoke from my rebuilt 1135 engine

[rphillips]

Interesting, keep us updated and good luck.

[John Kat]

I had the machine shop on the phone and they declared that the cylinder head presented no leak whatsoever.
They did the test by pouring oil on top on the combustion chamber while creating a vacuum in each of the intake and exhaust ports.
The single culprit left will be the piston rings and their match to the cylinder bore...
To be followed!

[GregT]

Is the second ring on that piston fitted upside down ? This can be a source of high oil consumption.

[John Kat]

Is the second ring on that piston fitted upside down ? This can be a source of high oil consumption.

No Greg, I checked that right away.
I did further research on the cylinder N°3 and found two cracks left and right of the bottom of the skirt.
As one can't see them on the outside of the skirt, I dismissed these as the source of the oil consumption?
I'm adding a picture that makes it look worse than in reality. IMG_3438.jpg

[GregT]

If the valves seal - as has been proved by the reconditioners vacuum test - then I'd look for a crack from the cam cavity to the exhaust port on that cylinder.
If you've got the head off, clean out that exhaust port, tilt the head so the exhaust side is lower - and leave some oil or better, petrol - in the head above that port.

Some years ago I was asked to look at a Norton which smoked from one side. Whoever had put new valve guides in it, had cracked the head above that exhaust port.

[John Kat]

If the valves seal - as has been proved by the reconditioners vacuum test - then I'd look for a crack from the cam cavity to the exhaust port on that cylinder.
If you've got the head off, clean out that exhaust port, tilt the head so the exhaust side is lower - and leave some oil or better, petrol - in the head above that port.

Some years ago I was asked to look at a Norton which smoked from one side. Whoever had put new valve guides in it, had cracked the head above that exhaust port.

Great input Greg!
I will look into that asap.
It could maybe also be done by pouring petrol in the exhaust port and watching any leakage around the camshaft cam cavity?
Many thanks

[GregT]

Yes, if the head still has the valves in it, that would be a tidy way to check.

Edit - Do it on the inlet port for that cylinder too.

[John Kat]

As one says: Analysis Paralysis!
As I'm still waiting for the result of some measurements, I was informed that it's possible to examine the cylinder sleeves for cracks with a special paint and UV light?
I'm also worried by the fact that the sleeves on my 1st gen 1135 engine seem pretty thin and might not be reborable to 77 mm for the Wiseco 1229 kit if I had to go this route?

Following further research on the rings, I measured an end gap on the top ring of 10 mm that's within specification but the second ring was also at 10 mm.
The Haynes manual gives no indication for the 1135 on the 2nd ring but the 1100 is given for 11 mm.
I measured the 2nd ring on another piston and it came out at 12 mm!
Clearly there is not enough tension on the second ring in the faulty cylinder...
Could this be the end of my oiling problem???

Update
Bad news, I measured the open gap on my two other pistons and they were at 10 and 11 mm.
No conclusion to be drawn yet I suppose?

[John Kat]

I finaly got the measurements done on my cylinders.
They are all within 1/100 of a mm wherever they are measured.
The problem according to the machine shop expert comes from the rings.
According to him, he's had an experience with a Kawasaki engine that was totally rebuilt and that smoked like crazy.
The rings were changed and the smoke was gone!
According to him, if the cylinders were rehoned the rings have to be changed.
This is my case...
Now will I be able to find new GS 1135 +.5 rings is not garanteed else I'm good for a Wiseco big bore kit.

[John Kat]

As no obvious reason was found for the oil smoke coming out of cylinder N°3, I decided to bite the bullet and bought a Wiseco K1229 big bore kit.
Interestingly enough when the sleeves were rebored from 74.5 to 77 mm we discovered that there was severe corrosion on cylinder N°2 as you can see on the pictures.
Sleeve N°3 was OK but it might have been corroded as well but not as deep???
I'll change the defective sleeve and hope for the best...

IMG_3460.jpg

[zed1015]

I presume that pic is before honing ?

[John Kat]

Yes, we will only hone when the new sleeve is installed.
BTW the LA Sleeve PN is KA750-1 but I wonder if the Wiseco branded sleeve KA750 SL would do?
It's apparently obsolete but can be found on ebay.
Do you have the specs?

[John Kat]

LA sleeve said that the OEM like sleeve for the GS 1150 is the FL872.
The issue is that they have none in stock and the lead time is around two months...
I've sent a mail to rapidray to see if he has any usable sleeve in stock?
If anyone else can help, I would be grateful!