cylinder leaking oil at head

Just finished rebuilding the 1974 1600DP, and put it back in. Breaking
it in, runs great, save a cracked fuel pump insulator and a couple of
other small problems I had to fix.
Noticed that my oil strainer cover is leaking a bit, I will replace
that. But I also noticed that my cylinders appear to be leaking at the
head joint. Not a whole lot of oil, mind you, just some drops, but
there appears to be some coming out. I appears to be mixed with a bit
of gas, since it is eating some of the tin paint. Is this normal? I
have only put about 50 miles on it so far. Will it seal up on it's own
after a while? Not all of them are leaking, I think it is just #2 and
#4. Please advise.

I hope someone else can back me on this...

First the cyl's should leak anything, anywhere. Are the heads torqued
enough ( something like 24 ft-lbs)?
Also leaking oil from the cyl/head 'seam' would mean your rings are shot.

--
Mel P.

"js" > wrote in message
oups.com...
> Just finished rebuilding the 1974 1600DP, and put it back in. Breaking
> it in, runs great, save a cracked fuel pump insulator and a couple of
> other small problems I had to fix.
> Noticed that my oil strainer cover is leaking a bit, I will replace
> that. But I also noticed that my cylinders appear to be leaking at the
> head joint. Not a whole lot of oil, mind you, just some drops, but
> there appears to be some coming out. I appears to be mixed with a bit
> of gas, since it is eating some of the tin paint. Is this normal? I
> have only put about 50 miles on it so far. Will it seal up on it's own
> after a while? Not all of them are leaking, I think it is just #2 and
> #4. Please advise.
>

I agree. I was just thinking it may be oil passing the rings if they
have not seated fully. The rings, pistons, heads, and cylinders are
new. 18ft lbs for mine, 8mm studs with case savers, at least that is
according to the books. I assume the oil collects there after the
engine shuts off, and leaks (just a bit mind you) after it cools (at
different ratios, aluminum mated to steel). First time I have ever
rebuilt an aircooled engine, so I am naturally worried about every
little thing.
Does not appear to have compression issues or to be passing gas ;-). I
am going to check the compression tonight. I guess I just wonder if
anyone has seen this. It appears to drip a bit onto the pushrod tubes,
and collects in the middle of the tube on the bottom. Not the seals
though. Not enough to make a puddle, just a few drips.

Mel P. wrote:
> I hope someone else can back me on this...
>
> First the cyl's should leak anything, anywhere. Are the heads torqued
> enough ( something like 24 ft-lbs)?
> Also leaking oil from the cyl/head 'seam' would mean your rings are shot.
>
> --
> Mel P.
>
> "js" > wrote in message
> oups.com...
> > Just finished rebuilding the 1974 1600DP, and put it back in. Breaking
> > it in, runs great, save a cracked fuel pump insulator and a couple of
> > other small problems I had to fix.
> > Noticed that my oil strainer cover is leaking a bit, I will replace
> > that. But I also noticed that my cylinders appear to be leaking at the
> > head joint. Not a whole lot of oil, mind you, just some drops, but
> > there appears to be some coming out. I appears to be mixed with a bit
> > of gas, since it is eating some of the tin paint. Is this normal? I
> > have only put about 50 miles on it so far. Will it seal up on it's own
> > after a while? Not all of them are leaking, I think it is just #2 and
> > #4. Please advise.
> >

Maybe you got some leaky push rod tube seals.

js wrote:
> Just finished rebuilding the 1974 1600DP, and put it back in. Breaking
> it in, runs great, save a cracked fuel pump insulator and a couple of
> other small problems I had to fix.
> Noticed that my oil strainer cover is leaking a bit, I will replace
> that. But I also noticed that my cylinders appear to be leaking at the
> head joint. Not a whole lot of oil, mind you, just some drops, but
> there appears to be some coming out. I appears to be mixed with a bit
> of gas, since it is eating some of the tin paint. Is this normal? I
> have only put about 50 miles on it so far. Will it seal up on it's own
> after a while? Not all of them are leaking, I think it is just #2 and
> #4. Please advise.
>


Ok, I've been away from all of Usenet for ages and came over
here to dig for info for my bug_farm... but while I'm here
what da heck.

My first 'take' as an oil leak between the case and barrels.
That would mean a paper gasket was left out.

Then I reset my brain and re-read your article.

My first guess would be that you might have forgotten
to set the gaps in each ring to a different location.
The "Idiot's Book" gives the correct info. I'm happy to
say that this is one I've yet to muckup... but I'm NOT
breaking my arm patting myself on my back. I've got More
Than Enough Bad Muckups to my credit...

Now then, IF you have clear recollection of doing
that to the rings, then take a hard look at the head
cover where it joins the head. In fact, pop the clamp and
take a good look at the gasket on it. It should be Clear of
All Oil on both sides where it was clampped to the head by
the cover. It it's got a slick of oil on it from the inside
to out, that's probably the leak.

That too is a Been Thar item.

AR

"AR Ogden" > wrote in message
news:J4Vzg.7157$j9.4178@trnddc02...
> js wrote:
>
>
> Ok, I've been away from all of Usenet for ages and came over
> here to dig for info for my bug_farm... but while I'm here
> what da heck.
>
> My first 'take' as an oil leak between the case and barrels.
> That would mean a paper gasket was left out.
>
> Then I reset my brain and re-read your article.
>
> My first guess would be that you might have forgotten
> to set the gaps in each ring to a different location.
> The "Idiot's Book" gives the correct info. I'm happy to
> say that this is one I've yet to muckup... but I'm NOT
> breaking my arm patting myself on my back. I've got More
> Than Enough Bad Muckups to my credit...
>
> Now then, IF you have clear recollection of doing
> that to the rings, then take a hard look at the head
> cover where it joins the head. In fact, pop the clamp and
> take a good look at the gasket on it. It should be Clear of
> All Oil on both sides where it was clampped to the head by
> the cover. It it's got a slick of oil on it from the inside
> to out, that's probably the leak.
>
> That too is a Been Thar item.
>
> AR
>

i think there was no sealer put on the headside of the washers under the
head nuts....that'd be my bet...

Hey, thanks for the replies. I actually did use some high tack
underneath the washers (I think), but I will check again when I pull
the engine to retorque the heads. The leaks appears to have stopped, so
I THINK I/you may have been right about the oil passing the rings.
I had originally arranged the rings inside of the top 180' of the
cylinder, but I had to pull them back off due to a construction
malfunction, and may have gotten them moved around enough to cause a
leak. I think that now that I have put more miles on it, the rings have
sealed up, might just be residue inside from the initial break-in.
The engine seems to make a lot of "noise", and not just the leaking
exhaust donuts ;-). It seems to be very tight sounding, if that makes
sense. I assume this is a good thing, and I have checked my pushrods
again and again, so I am assuming it is just the new cam and lifters.
(anyone know a good way to make the donuts seal, save flanging the
heat-exchanger/muffler connection?)

"js" > wrote in message
oups.com...
> Hey, thanks for the replies. I actually did use some high tack
> underneath the washers (I think), but I will check again when I pull
> the engine to retorque the heads. The leaks appears to have stopped, so
> I THINK I/you may have been right about the oil passing the rings.

if the oil made it past the rings that is bad.....if it made it past the
rings *then* leaked out at the cylinder to head sealing surface, that is
even worse...that means your heads are loose and the sealing surface can
take a hell of a burning due to this.....this can trash a set of heads
pretty quickly...

Ok, finally had the chance to check the compression.
#1 137psi
#2 138psi
#3 140psi
#4 140psi

Still a little bit of oil leaking down from around the barrels on #1
and #4.
Retourqed the lower head bolts. I wonder if it is coming from above the
barrels some how? Intake? Oil cooler? I am stumped. Very little oil,
just enough to make a shiny coating in a few spots, on top of the tin.
Nothing appears to be leaking from the pushrod tubes. The oil is very
black, like it is burned or picking up the black paint of my cylinders.
If my compression is good does that mean I can rule out leaking head to
jug joints?
Makes no funny sqeaking, just a nice smooth whistle going down the
road, tail pipes I guess.
Covering the pipe when the engine is cold will not stall the motor,
however, so I think I do have a pretty good exhaust leak at the heatbox
joints.

Is there oil directly above where the cylinders join the case?
Compression figures look good to me, but maybe leaking when the engine
cools down, then resealing when it heats up and expands. I would clean
it all off and check it when you start it up when oil pressure is high,
then when it's warmed up and finally after about hour after a run.

--Steve

js wrote:
> Ok, finally had the chance to check the compression.
> #1 137psi
> #2 138psi
> #3 140psi
> #4 140psi
>
> Still a little bit of oil leaking down from around the barrels on #1
> and #4.
> Retourqed the lower head bolts. I wonder if it is coming from above the
> barrels some how? Intake? Oil cooler? I am stumped. Very little oil,
> just enough to make a shiny coating in a few spots, on top of the tin.
> Nothing appears to be leaking from the pushrod tubes. The oil is very
> black, like it is burned or picking up the black paint of my cylinders.
> If my compression is good does that mean I can rule out leaking head to
> jug joints?
> Makes no funny sqeaking, just a nice smooth whistle going down the
> road, tail pipes I guess.
> Covering the pipe when the engine is cold will not stall the motor,
> however, so I think I do have a pretty good exhaust leak at the heatbox
> joints.
>


--

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