spits out oil mixed air from cylinder and head

After 36 months of construction of my special Fastback Black Knight (is a synthesis of many years Commando from 68 to 75) today was the first start.
It was easy, the bike started the fourth chick, no smoking, plugs perfect, good carburation, idling 1000 rpm.
After the first start the bike is always started to the first shot.
After a while came the bad news.
The engine bleeds between cylinder and head in rear right side, and spits out oil mixed air.
Nothing better after tighten all bolts.
I used the gasket 063844 from  Andover with Wellseal both side; the head  has guides, valves and stem seals all new.
What are the mistakes I made?.
I will remove the head and check.
I would like to disassemble the head leaving the engine in the frame: can i do it easily?.
What should I check?.
I need your sugestions.
Ciao.
Piero

R rear area is where the gasket is thin d/t the oil drain hole, which maybe clogged with sealant or even blown thru as I've had happen 10 miles after new
inferior grade flamering let go almost catching us on fire blasting fuel hose open.
You know you will be put down and ashamed by others here as likely didn't use a torque wrench trying to stifle the leak. Much as I am put down on annealing copper gaskets rather beyond cherry red hot, it definitely get softer yet going into the orange-yellow level of temps before installing. Open up and let us know what ya find. Possible rings ani't well sealed yet even though not smoking but once head weeps and nip up no help back to Commando worship postures and rituals.

I hope the head is perfectly flat.
I had my head surfaced, got a new flame ring from Andover, applied a thin file of hi-temp silicone to the areas around the push rod tunnels and the oil drain hole keeping it away from the hole on the gasket so it didn't squeeze out into the drain hole when tightened.
The first day after installing the head I started it up and let it get to operating temp and then let it sit over night.
I then retorqued it, went for a 20 minute ride going nice and easy and then let it sit over night.
I torqued it again rode it for 500 miles, let it sit and torqued it again the next day.
I then checked the torque for the next 3 rides.
In all I torqued it 6 times and not one leak after 3 years now.
Guido

Guido said:

got a new flame ring from Andover

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Hi Guido,
New flame means new gasket?
The standard one?
Ciao.
Piero

To answer at least one of your questions, yes, the head can be removed with the engine still in frame. The only touchy part is guiding the pushrods up into the cylinder head during both removal and replacement. Other than that, it is not difficult. Just follow the procedure in the service manual.

Ken

Ugh if not for the push rod puzzle with slick fingers and wiggle head being held up, a gasket change with clean up and nip up ready to ride may take less than an hour. I zip tie or wire up head to spine and IIRC the inner intake push rod must go up all the way first then the exht side fight begins for me for up to 45 min before I can clear barrel to extract head or just slip in another gasket. BTW I've had two flamering gaskets on 2 Combats, The 1st had powdery adhesive on both sides and rings were almost piston ring like robust and worked a treat and did not blow out on Peel's 11,000+ event, 2nd one from Anover was cheap looking paper composite with tin foil thick rings just folded around the paper. Anovers blew out oil hole 15 miles from home on mere commute w/o ticket or thrill to work. I asked about new type flame rings but no one had any response so last gasket I got was copper, even though I'd rather a good flamering on my Combats like Norton Intended. If anyone is in the know about flame rings I'm all ears. Of course your flamering may be fine, though they don't stand reuse like copper kind so may be shopping anyway like me.

You talk about "flame"and "a good flamering".
What does it means? I do not understand, sorry.
Ciao.
Piero

The 1st FlameRing I bought somewhere other than Anover was rather robust and lasted-sealed though 3 reuses. That was over a decade ago. The 2nd from 5 yr ago, looked distinctly inferior quality and only lasted 15 miles with oil hole blow out. I was an experienced head and gasket installer by time the 2nd flamering installed so not likely I over looked or did something wrong. I don't know if that's your issue or not but I don't know where to get a better flamering anymore if Anover's is so poor. I guess I'll have to go down my vendor list and order a flamering from a number of them and return the ones that don't look good or all of em if that's all that being produced nowadays. I've had pows pows with world wide vendors on this or that feature and item so maybe they can fill me in what to get or not. I didn't have time to do that prior so put in copper to get going mean time.

Piero, here is a flame ring gasket. I have had good luck with this type, but no luck with the copper type. The one I used was about half the thickness of the copper head gasket, so it bumps the compression ratio a bit, about half a point. This is a good thing with an 850, it wakes them up.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 1309202932

Glen

worntorn said:

Piero, here is a flame ring gasket. I have had good luck with this type, but no luck with the copper type. The one I used was about half the thickness of the copper head gasket, so it bumps the compression ratio a bit, about half a point. This is a good thing with an 850, it wakes them up.

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 1309202932

Glen

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Hi Glen,
now i mean, thank you.
I just used this original 750 gasket from Andover.
You used your gasket with glue? Which in case?.
May be i need to control the flat!.
Ciao.
Piero

Piero,

since starting to use VHT copper gasket cement on all head gaskets both copper and composite I've had absolutely no leaks
on my Commandos and Triumph triples. I spray a couple of coats both sides and leave for an hour or so before reassembling.
I also use a thin bead of Loctite 574 around the pushrod tunnels and oil drain hole. Works for me.
sam

Piero, my flamering gasket was fitted dry except I put some Permatex Aviation gasket cement on both sides of the gasket around the pushrod tunnels and drain hole.
Adding the VHT sealant as Sam suggests is likely good extra insurance against leaks.

Glen

Piero,

"Flamering", or "flame ring", refers to the thin steel reinforcing ring around the inside of the gasket. I think Norton has always used that design for the Commando engines. There have been aftermarket gaskets available without it in the past, that didn't work well. There have also been aftermarket flame ring gaskets available that were very poor quality, which also didn't work well. I personally recall trying one that had a thin copper ring instead of steel, and one that had a steel ring, but poor quality material for the rest of the gasket. I tried them on a 750 race engine, and they failed almost immediately. I always had good results from using the factory gaskets with 750 engines, but I use copper gaskets on the 920 engines and also have good results from them. I've never used the more recent gaskets from Andover, but I would expect them to be as good as the originals. I would suggest that you check the surface of the cylinder head for flatness while you have it removed. I am assuming you still have the original washers on the head bolts. If not, the bolts might be bottoming out before they are fully tightened. When you remove the head, examine it and the gasket carefully. You should be able to see exactly where the leak is travelling across the gasket, and that might give you a clue to the cause. Good luck with it. The bike is lovely, and you should be able to enjoy it without worrying about head gasket problems.

Ken

lcrken said:

I would suggest that you check the surface of the cylinder head for flatness while you have it removed.
Ken

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Hi Ken,
and thank you.
May i check the cylinder too for flatness?
Ciao.
Piero

pierodn said:

lcrken said:

I would suggest that you check the surface of the cylinder head for flatness while you have it removed.
Ken

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Hi Ken,
and thank you.
May i check the cylinder too for flatness?
Ciao.
Piero

Click to expand...

I would, as long as you are going to have the head off anyway. It's more common for the head to warp, but it can happen with the cylinder too.

Ken

i fink youd better wrench the rods to check the slack , and Shine a Flashlight into the Bowels of the Cases , while your there . Chanting " Oil , Oil , I Will NOT Forget the OIL " .

Lap the Head on a Glass plate with Grinding Paste or Engineers Blue - to Check . And a Wocket frees TWICE as DEMANDING of Fastidiousnous and Meticularity . Scape the Barrel head face V Clean to . a paint scaperll do .

AND Bung a big Rag in the crankcase mouth , so the rods dont bang & the Debri doesnt fall in . oops . He hasnt taken the BARREL OFF . Oh well , may as well - while your at it . why on earth not . :twisted: 8) :wink:

Hi Matt,
I am very happy when I receive feedback from you and from Hobot.
I try with all my strength to translate and understand what you wrote.
It will be easier to become a good mechanic who be able one day to translate your answers.
But I appreciate you and you put me a good mood!
Ciao.
Piero

Hi Piero,

oil at the head gasket normally comes from the head. Mostly it is caused by the pushrod tunnels. But if it spits out oil, the head is probably not flat.

Ralf

Hi Ralph,
I agrre.
The only thing that i can do now is desmount the head and the cylinder!
I am not very happy, but i had to chek the flat before.
Next time i will do it, sure!.
Ciao.
Piero

"I try with all my strength to translate and understand what you wrote."

As do we native english speakers.