What is the thickest- dimension head gaskets made for panheads and who supplies them?
Here's the issue--I bought a pair of heads from a rip-off artist which, among many other problems, were over-milled. I've since ground down the cylinder spigots ( fire rings) and have the heads torqued properly with new gaskets. All's well, but I'm detecting some light seepage from the front of the front head gasket and I suspect that a thicker gasket would do the trick.
Another q--what about using some form of head gasket sealer in a case like this? I know that it's not rec'd in the manual, but in a case where all else has been done and there is still a slight leak, would there be any harm in this? If not , any recommendations as to type or brand?
Head gasket questions
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Cotten
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Re: Head gasket questions
Doc!
If indeed the heads were flat and the cylinders as well, and the assembly was properly torqued to spec,..
then any seepage at the front, near the exhaust port, would be a sign of overheating.
I wouldn't blame the headgasket.
....Cotten
If indeed the heads were flat and the cylinders as well, and the assembly was properly torqued to spec,..
then any seepage at the front, near the exhaust port, would be a sign of overheating.
I wouldn't blame the headgasket.
....Cotten
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doc308
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Re: Head gasket questions
Cotton--if this were the case, what other signs might I look for? The plug reads pretty normal/ almost perfect --ie it's not reading lean and the oil seems to be circulating through the engine well. The engine isn't broken in yet from a rebuild ( new pistons and rings were installed). Also, if it is overheating, why would it leak---is a head gasket surface beginning to warp?
Hmm--I noticed that the oil appears to be slightly above the gasket . I had assumed that the air flow, while riding, blew the oil in that direction . Could it be that the oil is seeping from the exhaust port? If so, what should I do about it?
Hmm--I noticed that the oil appears to be slightly above the gasket . I had assumed that the air flow, while riding, blew the oil in that direction . Could it be that the oil is seeping from the exhaust port? If so, what should I do about it?
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Cotten
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Re: Head gasket questions
Doc!
Attempting to read plugs with today's fuels is futile.
Three common origins of oil on the front cylinder are from the head gasket, from the port, and from cracks in the head casting intersecting a headbolt insert.
If it is cracks, cleaning and close inspection may reveal them.
If it is from the port, then a valve guide most likely has a channel of damage between it and the head.
If it is indeed heat warpage that has only occurred after assembly, then it would be real interesting to see if a cheap non-contact thermometer can detect the elevated temperatures.
Two preliminary questions that occur to me are:
Were the heads inspected for 'flat' even though they were "over-milled"?
How exactly were the headbolts "properly torqued"?
....Cotten
Attempting to read plugs with today's fuels is futile.
Three common origins of oil on the front cylinder are from the head gasket, from the port, and from cracks in the head casting intersecting a headbolt insert.
If it is cracks, cleaning and close inspection may reveal them.
If it is from the port, then a valve guide most likely has a channel of damage between it and the head.
If it is indeed heat warpage that has only occurred after assembly, then it would be real interesting to see if a cheap non-contact thermometer can detect the elevated temperatures.
Two preliminary questions that occur to me are:
Were the heads inspected for 'flat' even though they were "over-milled"?
How exactly were the headbolts "properly torqued"?
....Cotten
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BigDen
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Re: Head gasket questions
Doc,
I had similar problem with my 54 pan. It looked like it was coming from the exhaust port or the head gasket. I tried three different head gaskets with no success. Bad news is it was a crack in the head that ran from the oil drain hole up towards the exhaust port. Mine was between second and third fin from bottom. Solution was to fix the crack by welding.
BigDen
I had similar problem with my 54 pan. It looked like it was coming from the exhaust port or the head gasket. I tried three different head gaskets with no success. Bad news is it was a crack in the head that ran from the oil drain hole up towards the exhaust port. Mine was between second and third fin from bottom. Solution was to fix the crack by welding.
BigDen
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doc308
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Re: Head gasket questions
Here's a picture of about where the leak is coming from--it seems to be a crack.
When you had your head welded up, did you need to dismantle the valves/seats/etc?
When you had your head welded up, did you need to dismantle the valves/seats/etc?
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Cotten
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Re: Head gasket questions
Doc!
Many Pans have suffered erosion of the casting from the inside of the port.
This weakens it to the point where overkill clamps can easily stress it to the point of cracking.
(If you are lucky, it is not really all oil, but exhaust soot carried by the moisture of combustion. It is the moisture that eventually forms acids that eat the aluminum. If you have significant oil coming out the port, you have other problems to consider.)
Although I know of TIG-men skilled enough to stitch them adequately while installed in the chassis,
severe cases require total diassembly, and total replacement of the spigot as well.
(This can lead to a cascade of collateral expenses, as the exhaust seat will distort.. The worst case scenario is where hardened seats fall out later.)
Honestly, I suggest soaking it out and applying some wicking-grade Loctite.
Even if it must be reapplied occasionally, it buys some time, while the weather is good.
My favorite goober is an aluminum isocyanate urethane water tower primer, which I have even used to seal cracks between cases where raw oil would flow. Unfortunately, it is not an off-the-shelf product, and sadly, Post Office-prohibited hazmat.
Good luck!
....Cotten
Many Pans have suffered erosion of the casting from the inside of the port.
This weakens it to the point where overkill clamps can easily stress it to the point of cracking.
(If you are lucky, it is not really all oil, but exhaust soot carried by the moisture of combustion. It is the moisture that eventually forms acids that eat the aluminum. If you have significant oil coming out the port, you have other problems to consider.)
Although I know of TIG-men skilled enough to stitch them adequately while installed in the chassis,
severe cases require total diassembly, and total replacement of the spigot as well.
(This can lead to a cascade of collateral expenses, as the exhaust seat will distort.. The worst case scenario is where hardened seats fall out later.)
Honestly, I suggest soaking it out and applying some wicking-grade Loctite.
Even if it must be reapplied occasionally, it buys some time, while the weather is good.
My favorite goober is an aluminum isocyanate urethane water tower primer, which I have even used to seal cracks between cases where raw oil would flow. Unfortunately, it is not an off-the-shelf product, and sadly, Post Office-prohibited hazmat.
Good luck!
....Cotten
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BigDen
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Re: Head gasket questions
Doc,
When I had my crack repaired, shop that did the work only asked for rocker arms to be removed. They removed the valves, but didn't do anything with the seats. Shop removed a fin, welded crack, and rebuilt the fin. Attached are photos of my leak and crack for comparison to your situation. Crack that is visible in photo is about 2" back of exhaust port, under the third fin from bottom. Shop also repaired the broken fin above the exhaust port.
BigDen
When I had my crack repaired, shop that did the work only asked for rocker arms to be removed. They removed the valves, but didn't do anything with the seats. Shop removed a fin, welded crack, and rebuilt the fin. Attached are photos of my leak and crack for comparison to your situation. Crack that is visible in photo is about 2" back of exhaust port, under the third fin from bottom. Shop also repaired the broken fin above the exhaust port.
BigDen
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NightShift
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Re: Head gasket questions
Dear Big Den,
Didnt they even measure the seat run-out afterwards?
Seriously,
Didnt they even measure the seat run-out afterwards?
Seriously,
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doc308
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Re: Head gasket questions
Thanks for the tips and pictures!
Cotten--what is "wicking grade" Loctite ? What would you think of J B Weld , if I can get at the crack?
Cotten--what is "wicking grade" Loctite ? What would you think of J B Weld , if I can get at the crack?
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Cotten
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Re: Head gasket questions
Doc!
The bottle is at the shop, but I think the number was 291.
It is extremely thin green stuff, and will flow into cracks by capillary action.
JB-Weld is great stuff, but it is more like mortar mix.
Probably just as good as a band-aid though.
Any goober is a roll of the dice.
....Cotten
The bottle is at the shop, but I think the number was 291.
It is extremely thin green stuff, and will flow into cracks by capillary action.
JB-Weld is great stuff, but it is more like mortar mix.
Probably just as good as a band-aid though.
Any goober is a roll of the dice.
....Cotten
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BigDen
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Re: Head gasket questions
Cotton,
Good question. This shop has been doing Harley head and cylinder work since 1956. I should have said they didn't replace the valve seats, since Doc ask about removing the seats. Head was oily, cracked, and a bit carbonized when it went in, when I picked it up it was welded, clean and reassembled. I'm sure they checked the seats before installing the valves.
BigDen
Good question. This shop has been doing Harley head and cylinder work since 1956. I should have said they didn't replace the valve seats, since Doc ask about removing the seats. Head was oily, cracked, and a bit carbonized when it went in, when I picked it up it was welded, clean and reassembled. I'm sure they checked the seats before installing the valves.
BigDen
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doc308
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Re: Head gasket questions
I think I may give the J B Weld a try. Re: temperature, it states that it's good for up to about 350--400 degrees. What is the typical temp for a warmed- up panhead?
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Cotten
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Re: Head gasket questions
Doc!
I'll bet the exhaust port exceeds that a bit.
That's why I suggested something that would seep in deep; Even if it turns to carbon, it will still have a chance to block the passage.
Anything on the outside will likely peel off after it cooks.
But any band-aid is better than a teardown at the beginning of the riding season.
(Unless you have considerable oil going out the pipe, then there are other concerns!)
....Cotten
I'll bet the exhaust port exceeds that a bit.
That's why I suggested something that would seep in deep; Even if it turns to carbon, it will still have a chance to block the passage.
Anything on the outside will likely peel off after it cooks.
But any band-aid is better than a teardown at the beginning of the riding season.
(Unless you have considerable oil going out the pipe, then there are other concerns!)
....Cotten
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Motorcyclemike
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Re: Head gasket questions
Be sure that the female STUDS around the heads all are slightly recessed.....if they are flat with the heads then thats TROUBLE down the road and it will be a ~~BLOWN HEAD GASKET~~ !
Mine were flat with the gasket surface and some were pulled slightly out and the Harley machinist recommended that they all be milled below the gasket surface.....and yes i had it done to my "Stock Heads".
Good Luck.
MCM