Cylinder to head sealing rings

lownslo Commited Dubber

64 posts · joined Aug 2007 · 8 Aug 2007, 4:51 pm

#605831

So I pulled the 36hp out of my beetle today as there is some oil leaking from somewhere. Whist degreasing I turned the motor over by hand and noticed that between the cylinder and head on one cylinder there was air escaping.

I have never opened one of these motors up before. But checked my book for dummies and noticed there is a sealing ring. I rang up to order some and was told that I don't need the,. Just remove the ring and bolt up the head and re torque it correctly and it will be fine. Does this sounds right that I can leave this copper(?) gasket out and just rebolt the head?

Also I took the cylinders off to check the bores and noticed that there is also no gasket between the cylinder and the block. But again in my book for dummies there is a gasket. Has this one just perished and should actually be replaced with something, or can this one also be bolted up with no gasket?

Also as I am taking the copper rings from one of the heads, should I be doing the other head also, even though it doesn't appear to be leaking. I don't want to rebuild the engine as I really don't have the money so for the time being this isn't going to be an option.

cheers

OZ Towdster Keen to finish some projects

1,921 posts · joined Dec 2003 · 8 Aug 2007, 5:50 pm

#605838

In the few engine builds i have done over the years i have never used the the head to cylinder gaskets but if it has been leaking i would recomend a fly cut to both heads BUT BEFORE SENDING THE HEADS OUT FOR THIS JOB PUCHASE SOME VALVE GRINDING PASTE AND GIVE THE HEAD END OF THE BARRELS A GOOD HAND LAPPING SO AS AFTER YOU REFIT YOUR NEWLY FLY CUT HEADS YOU CAN HE CONFIDENT OF A GOOD SEAL and as you have already read torque them back on correctly while also checking that you also don't have a pulled head stud which is highly possible on an older motor.
In regards to the barrel to case joints i again have not ever used a gasket but only high temp silicon sealant but if it currently has shims between barrell and case these should be refitted to set the correct deck height( this ensures the correct compresion ratio and also ensures that the piston will not hit the head at higher revs )
And in regards to your final question yes i would also pull the other head off and perform all the above also including if money stretchs far enough a new set of rings .

Don't let body work get in the way of real suspension travel

Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion

8,040 posts · joined Jan 2003 · 8 Aug 2007, 7:13 pm

#605858

If it was not sealing, then the head was probably loose.........so are you sure you haven't pulled a head stud?

lownslo Commited Dubber

64 posts · joined Aug 2007 · 8 Aug 2007, 10:32 pm

#605926

Well when undoing them there was a big variation in torque on the head bolts. The two under the rockers were considerably looser than the rest. One stud also looks to protrude further out than the rest. But on this one when undoing the bolt was highly torqued not loose as one would expect if the head stud had pulled.

So how would one check for stud pull as I would like to get the engine back this this weekend.

cheers

[ Edited on 8-8-2007 by lownslo ]

1303Steve Scirocco Rare

8,650 posts · joined Aug 2002 · 8 Aug 2007, 10:48 pm

#605934

Hi

You can check for stud pulling out by roughly reassembling the motor and give it some extra torque, about 35 lbs should do it. The copper sealing shims were only used on the non fresh air motors i.e. 36 hp and early 40 hp to stop exhaust fumes from getting into the heater system, the Germans had some bad experiences along these lines.

Steve

lownslo Commited Dubber

64 posts · joined Aug 2007 · 8 Aug 2007, 10:51 pm

#605936

1303Steve wrote:Hi

You can check for stud pulling out by roughly reassembling the motor and give it some extra torque, about 35 lbs should do it. The copper sealing shims were only used on the non fresh air motors i.e. 36 hp and early 40 hp to stop exhaust fumes from getting into the heater system, the Germans had some bad experiences along these lines.

Steve

Cheers for that, i'll torque em up and see how they go.

Also, I have the generator off the solid post, thus theres an opening into the crank case and with this off when the engine is turned over by hand there is alot of hissing, would this be air passing the rings or would one assume this to be normal. So should I hone the cylinders and chuck on some rings if there not ludicrously expensive.

[ Edited on 8-8-2007 by lownslo ]

Hmm perhaps I should just fork out the $$$ and change to the 1600cc...that way i can actually have a stereo too....

[ Edited on 8-8-2007 by lownslo ]

xornge666x Wolfsburg Wizard

460 posts · joined Sep 2006 · 9 Aug 2007, 6:29 am

#605957

36 and 40hp non fresh air both use head gasket rings.
If they have been leaking, the head seating surface wouldhave been getting hot. Before re-fitting the heads, get them flycut to make sure they are true, and lap the barrels in with valve grinding paste as mentioned above..
or change to a 1600.
36hp is a much nicer built engine imo, just not as quick!