Mike Romain

Ok Bill, just got back from a bush run and read the thread and looked at
all the photos....

Here is my $0.02 for what it is worth. ;-)

Man, that set of photos sure looks like a classic case of gas wash
killing one cylinder dead. Big Time!

The gas washing all the carbon out and cleaning the rings so oil comes
up and gets flash burnt when you change plugs and it fires for a while.
While it's firing that flaky varnish looking crap builds up from the
burning slurry.

Then the build up finally kills the spark.

No spark, so on a normal compression or firing stroke, the cylinder is
in a vacuum mode and the piston needs to be pulled down against that
vacuum rather than the spark firing the piston down.

The vacuum must be released or the engine will up and stop.

'Some' oil will be then sucked up past the rings and sucked down past
the valve guide seals when this is happening, whichever is looser. Hmm,
valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
down from the top, then it mixed with some gas to be thin and ------,
------s across to the spark plug threads. Hmmm....???

Now the poor old crank which sounds like a 10/10 is not used to or
designed to have any piston under suction, the piston is under spark or
intake or exhaust, no vacuum motion involved.

Check on top of the oil filter on the block boss for a letter. If M and
P are there, it is a factory 10/10 crank which is just 10 thousands
under. You can go to 30 or 40 if desperate, 20 is fine. B means
factory 10 thou over piston. C means cam 10 over.

This vacuum in the cylinder because of no spark means the crank slams
down on the bearing and wears the crap out of the center of the bottom
bearing on the cap side. The cap side isn't designed for pulling, just
being in neutral to the push from the piston rod on spark or sucking
from the carb/ TB or blowing out the exhaust which is zip for pressure
point wear like is showing.

If the engine is newly rebuilt like advertised, the vacuum on the
cylinder would be nasty. The compression was way up there, so the
vacuum 'was' up there too...

Bingo, burned out rod cap bearing and likely both main bearings on each
side.

I also would be worried the cap and rod and the crank journal could have
been pounded out of round from this.

I seem to remember a complaint about a timing ping or knock at idle???
Hmm vacuum on a piston starting the crank slapping on the bearing makes
a neat knock. The bearing can wear away and the knock can lessen or get
worse. The first while with the dead cylinder causes the big damage.

Then the cylinder is polished up sweet! Well, carbon under heat with
gas as a solvent has been sliding around those rings for a while, damn
near a diamond polish, eh?

No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
that 'is' what they look like. I come from the carb days and have seen
engines that look like that from short term gas wash. Normally on all
or a half bank though, not like injection that just nails one.

You need to open some other rod and main bearing caps and post the
photos.

If those are not burnt out or worn through then the gas wash theory
holds, if everything is fried, then it was a dud engine someone sold you
or the other person under the 'used' engine tag.

If just gas washed, a hone on the cylinder and some new stock 10 under
bearings should do the trick. You have to buy the whole bearing set and
it is open, so just swap them all.

While it is out, that one piston rod should have the cap torqued on
properly
and be mic'ed out for round. Most engine shops around here charge
$20.00 to over grind a rod end or make it true round again and have a
bearing to fit.

Ok, that was long winded.... Whew... ;-)

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

William Oliveri wrote:
>
> Got the piston out. Just tapped on the rod bolt a couple of times and it
> loosened up. Came right out of the cylinder, no ridge, no problem.
>
> Here are the pics. Any feedback on the condition of this piston or what the
> pic might tell you would be appreciated.
>
> http://members.bigvalley.net/wuji/je.../piston_2a.jpg
> http://members.bigvalley.net/wuji/je.../piston_2b.jpg
> http://members.bigvalley.net/wuji/je...berrings2a.jpg
>
> Thanks,
>
> Bill

Mike Romain

Ok Bill, just got back from a bush run and read the thread and looked at
all the photos....

Here is my $0.02 for what it is worth. ;-)

Man, that set of photos sure looks like a classic case of gas wash
killing one cylinder dead. Big Time!

The gas washing all the carbon out and cleaning the rings so oil comes
up and gets flash burnt when you change plugs and it fires for a while.
While it's firing that flaky varnish looking crap builds up from the
burning slurry.

Then the build up finally kills the spark.

No spark, so on a normal compression or firing stroke, the cylinder is
in a vacuum mode and the piston needs to be pulled down against that
vacuum rather than the spark firing the piston down.

The vacuum must be released or the engine will up and stop.

'Some' oil will be then sucked up past the rings and sucked down past
the valve guide seals when this is happening, whichever is looser. Hmm,
valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
down from the top, then it mixed with some gas to be thin and ------,
------s across to the spark plug threads. Hmmm....???

Now the poor old crank which sounds like a 10/10 is not used to or
designed to have any piston under suction, the piston is under spark or
intake or exhaust, no vacuum motion involved.

Check on top of the oil filter on the block boss for a letter. If M and
P are there, it is a factory 10/10 crank which is just 10 thousands
under. You can go to 30 or 40 if desperate, 20 is fine. B means
factory 10 thou over piston. C means cam 10 over.

This vacuum in the cylinder because of no spark means the crank slams
down on the bearing and wears the crap out of the center of the bottom
bearing on the cap side. The cap side isn't designed for pulling, just
being in neutral to the push from the piston rod on spark or sucking
from the carb/ TB or blowing out the exhaust which is zip for pressure
point wear like is showing.

If the engine is newly rebuilt like advertised, the vacuum on the
cylinder would be nasty. The compression was way up there, so the
vacuum 'was' up there too...

Bingo, burned out rod cap bearing and likely both main bearings on each
side.

I also would be worried the cap and rod and the crank journal could have
been pounded out of round from this.

I seem to remember a complaint about a timing ping or knock at idle???
Hmm vacuum on a piston starting the crank slapping on the bearing makes
a neat knock. The bearing can wear away and the knock can lessen or get
worse. The first while with the dead cylinder causes the big damage.

Then the cylinder is polished up sweet! Well, carbon under heat with
gas as a solvent has been sliding around those rings for a while, damn
near a diamond polish, eh?

No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
that 'is' what they look like. I come from the carb days and have seen
engines that look like that from short term gas wash. Normally on all
or a half bank though, not like injection that just nails one.

You need to open some other rod and main bearing caps and post the
photos.

If those are not burnt out or worn through then the gas wash theory
holds, if everything is fried, then it was a dud engine someone sold you
or the other person under the 'used' engine tag.

If just gas washed, a hone on the cylinder and some new stock 10 under
bearings should do the trick. You have to buy the whole bearing set and
it is open, so just swap them all.

While it is out, that one piston rod should have the cap torqued on
properly
and be mic'ed out for round. Most engine shops around here charge
$20.00 to over grind a rod end or make it true round again and have a
bearing to fit.

Ok, that was long winded.... Whew... ;-)

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

William Oliveri wrote:
>
> Got the piston out. Just tapped on the rod bolt a couple of times and it
> loosened up. Came right out of the cylinder, no ridge, no problem.
>
> Here are the pics. Any feedback on the condition of this piston or what the
> pic might tell you would be appreciated.
>
> http://members.bigvalley.net/wuji/je.../piston_2a.jpg
> http://members.bigvalley.net/wuji/je.../piston_2b.jpg
> http://members.bigvalley.net/wuji/je...berrings2a.jpg
>
> Thanks,
>
> Bill

Mike Romain

Ok Bill, just got back from a bush run and read the thread and looked at
all the photos....

Here is my $0.02 for what it is worth. ;-)

Man, that set of photos sure looks like a classic case of gas wash
killing one cylinder dead. Big Time!

The gas washing all the carbon out and cleaning the rings so oil comes
up and gets flash burnt when you change plugs and it fires for a while.
While it's firing that flaky varnish looking crap builds up from the
burning slurry.

Then the build up finally kills the spark.

No spark, so on a normal compression or firing stroke, the cylinder is
in a vacuum mode and the piston needs to be pulled down against that
vacuum rather than the spark firing the piston down.

The vacuum must be released or the engine will up and stop.

'Some' oil will be then sucked up past the rings and sucked down past
the valve guide seals when this is happening, whichever is looser. Hmm,
valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
down from the top, then it mixed with some gas to be thin and ------,
------s across to the spark plug threads. Hmmm....???

Now the poor old crank which sounds like a 10/10 is not used to or
designed to have any piston under suction, the piston is under spark or
intake or exhaust, no vacuum motion involved.

Check on top of the oil filter on the block boss for a letter. If M and
P are there, it is a factory 10/10 crank which is just 10 thousands
under. You can go to 30 or 40 if desperate, 20 is fine. B means
factory 10 thou over piston. C means cam 10 over.

This vacuum in the cylinder because of no spark means the crank slams
down on the bearing and wears the crap out of the center of the bottom
bearing on the cap side. The cap side isn't designed for pulling, just
being in neutral to the push from the piston rod on spark or sucking
from the carb/ TB or blowing out the exhaust which is zip for pressure
point wear like is showing.

If the engine is newly rebuilt like advertised, the vacuum on the
cylinder would be nasty. The compression was way up there, so the
vacuum 'was' up there too...

Bingo, burned out rod cap bearing and likely both main bearings on each
side.

I also would be worried the cap and rod and the crank journal could have
been pounded out of round from this.

I seem to remember a complaint about a timing ping or knock at idle???
Hmm vacuum on a piston starting the crank slapping on the bearing makes
a neat knock. The bearing can wear away and the knock can lessen or get
worse. The first while with the dead cylinder causes the big damage.

Then the cylinder is polished up sweet! Well, carbon under heat with
gas as a solvent has been sliding around those rings for a while, damn
near a diamond polish, eh?

No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
that 'is' what they look like. I come from the carb days and have seen
engines that look like that from short term gas wash. Normally on all
or a half bank though, not like injection that just nails one.

You need to open some other rod and main bearing caps and post the
photos.

If those are not burnt out or worn through then the gas wash theory
holds, if everything is fried, then it was a dud engine someone sold you
or the other person under the 'used' engine tag.

If just gas washed, a hone on the cylinder and some new stock 10 under
bearings should do the trick. You have to buy the whole bearing set and
it is open, so just swap them all.

While it is out, that one piston rod should have the cap torqued on
properly
and be mic'ed out for round. Most engine shops around here charge
$20.00 to over grind a rod end or make it true round again and have a
bearing to fit.

Ok, that was long winded.... Whew... ;-)

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

William Oliveri wrote:
>
> Got the piston out. Just tapped on the rod bolt a couple of times and it
> loosened up. Came right out of the cylinder, no ridge, no problem.
>
> Here are the pics. Any feedback on the condition of this piston or what the
> pic might tell you would be appreciated.
>
> http://members.bigvalley.net/wuji/je.../piston_2a.jpg
> http://members.bigvalley.net/wuji/je.../piston_2b.jpg
> http://members.bigvalley.net/wuji/je...berrings2a.jpg
>
> Thanks,
>
> Bill

SB

Long winded but good. No doubt a bit of experience pushing those words out.
I'm gonna have to get my chilton/service book so that I can have a picture
and I'll read this again!! haha that way I MIGHT have a clue what you just
said!

sb

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4043D9EE.73C5B8B1@sympatico.ca...
> Ok Bill, just got back from a bush run and read the thread and looked at
> all the photos....
>
> Here is my $0.02 for what it is worth. ;-)
>
> Man, that set of photos sure looks like a classic case of gas wash
> killing one cylinder dead. Big Time!
>
> The gas washing all the carbon out and cleaning the rings so oil comes
> up and gets flash burnt when you change plugs and it fires for a while.
> While it's firing that flaky varnish looking crap builds up from the
> burning slurry.
>
> Then the build up finally kills the spark.
>
> No spark, so on a normal compression or firing stroke, the cylinder is
> in a vacuum mode and the piston needs to be pulled down against that
> vacuum rather than the spark firing the piston down.
>
> The vacuum must be released or the engine will up and stop.
>
> 'Some' oil will be then sucked up past the rings and sucked down past
> the valve guide seals when this is happening, whichever is looser. Hmm,
> valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
> down from the top, then it mixed with some gas to be thin and ------,
> ------s across to the spark plug threads. Hmmm....???
>
> Now the poor old crank which sounds like a 10/10 is not used to or
> designed to have any piston under suction, the piston is under spark or
> intake or exhaust, no vacuum motion involved.
>
> Check on top of the oil filter on the block boss for a letter. If M and
> P are there, it is a factory 10/10 crank which is just 10 thousands
> under. You can go to 30 or 40 if desperate, 20 is fine. B means
> factory 10 thou over piston. C means cam 10 over.
>
> This vacuum in the cylinder because of no spark means the crank slams
> down on the bearing and wears the crap out of the center of the bottom
> bearing on the cap side. The cap side isn't designed for pulling, just
> being in neutral to the push from the piston rod on spark or sucking
> from the carb/ TB or blowing out the exhaust which is zip for pressure
> point wear like is showing.
>
> If the engine is newly rebuilt like advertised, the vacuum on the
> cylinder would be nasty. The compression was way up there, so the
> vacuum 'was' up there too...
>
> Bingo, burned out rod cap bearing and likely both main bearings on each
> side.
>
> I also would be worried the cap and rod and the crank journal could have
> been pounded out of round from this.
>
> I seem to remember a complaint about a timing ping or knock at idle???
> Hmm vacuum on a piston starting the crank slapping on the bearing makes
> a neat knock. The bearing can wear away and the knock can lessen or get
> worse. The first while with the dead cylinder causes the big damage.
>
> Then the cylinder is polished up sweet! Well, carbon under heat with
> gas as a solvent has been sliding around those rings for a while, damn
> near a diamond polish, eh?
>
> No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
> that 'is' what they look like. I come from the carb days and have seen
> engines that look like that from short term gas wash. Normally on all
> or a half bank though, not like injection that just nails one.
>
> You need to open some other rod and main bearing caps and post the
> photos.
>
> If those are not burnt out or worn through then the gas wash theory
> holds, if everything is fried, then it was a dud engine someone sold you
> or the other person under the 'used' engine tag.
>
> If just gas washed, a hone on the cylinder and some new stock 10 under
> bearings should do the trick. You have to buy the whole bearing set and
> it is open, so just swap them all.
>
> While it is out, that one piston rod should have the cap torqued on
> properly
> and be mic'ed out for round. Most engine shops around here charge
> $20.00 to over grind a rod end or make it true round again and have a
> bearing to fit.
>
> Ok, that was long winded.... Whew... ;-)
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Got the piston out. Just tapped on the rod bolt a couple of times and
it
> > loosened up. Came right out of the cylinder, no ridge, no problem.
> >
> > Here are the pics. Any feedback on the condition of this piston or what
the
> > pic might tell you would be appreciated.
> >
> > http://members.bigvalley.net/wuji/je.../piston_2a.jpg
> > http://members.bigvalley.net/wuji/je.../piston_2b.jpg
> > http://members.bigvalley.net/wuji/je...berrings2a.jpg
> >
> > Thanks,
> >
> > Bill

SB

Long winded but good. No doubt a bit of experience pushing those words out.
I'm gonna have to get my chilton/service book so that I can have a picture
and I'll read this again!! haha that way I MIGHT have a clue what you just
said!

sb

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4043D9EE.73C5B8B1@sympatico.ca...
> Ok Bill, just got back from a bush run and read the thread and looked at
> all the photos....
>
> Here is my $0.02 for what it is worth. ;-)
>
> Man, that set of photos sure looks like a classic case of gas wash
> killing one cylinder dead. Big Time!
>
> The gas washing all the carbon out and cleaning the rings so oil comes
> up and gets flash burnt when you change plugs and it fires for a while.
> While it's firing that flaky varnish looking crap builds up from the
> burning slurry.
>
> Then the build up finally kills the spark.
>
> No spark, so on a normal compression or firing stroke, the cylinder is
> in a vacuum mode and the piston needs to be pulled down against that
> vacuum rather than the spark firing the piston down.
>
> The vacuum must be released or the engine will up and stop.
>
> 'Some' oil will be then sucked up past the rings and sucked down past
> the valve guide seals when this is happening, whichever is looser. Hmm,
> valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
> down from the top, then it mixed with some gas to be thin and ------,
> ------s across to the spark plug threads. Hmmm....???
>
> Now the poor old crank which sounds like a 10/10 is not used to or
> designed to have any piston under suction, the piston is under spark or
> intake or exhaust, no vacuum motion involved.
>
> Check on top of the oil filter on the block boss for a letter. If M and
> P are there, it is a factory 10/10 crank which is just 10 thousands
> under. You can go to 30 or 40 if desperate, 20 is fine. B means
> factory 10 thou over piston. C means cam 10 over.
>
> This vacuum in the cylinder because of no spark means the crank slams
> down on the bearing and wears the crap out of the center of the bottom
> bearing on the cap side. The cap side isn't designed for pulling, just
> being in neutral to the push from the piston rod on spark or sucking
> from the carb/ TB or blowing out the exhaust which is zip for pressure
> point wear like is showing.
>
> If the engine is newly rebuilt like advertised, the vacuum on the
> cylinder would be nasty. The compression was way up there, so the
> vacuum 'was' up there too...
>
> Bingo, burned out rod cap bearing and likely both main bearings on each
> side.
>
> I also would be worried the cap and rod and the crank journal could have
> been pounded out of round from this.
>
> I seem to remember a complaint about a timing ping or knock at idle???
> Hmm vacuum on a piston starting the crank slapping on the bearing makes
> a neat knock. The bearing can wear away and the knock can lessen or get
> worse. The first while with the dead cylinder causes the big damage.
>
> Then the cylinder is polished up sweet! Well, carbon under heat with
> gas as a solvent has been sliding around those rings for a while, damn
> near a diamond polish, eh?
>
> No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
> that 'is' what they look like. I come from the carb days and have seen
> engines that look like that from short term gas wash. Normally on all
> or a half bank though, not like injection that just nails one.
>
> You need to open some other rod and main bearing caps and post the
> photos.
>
> If those are not burnt out or worn through then the gas wash theory
> holds, if everything is fried, then it was a dud engine someone sold you
> or the other person under the 'used' engine tag.
>
> If just gas washed, a hone on the cylinder and some new stock 10 under
> bearings should do the trick. You have to buy the whole bearing set and
> it is open, so just swap them all.
>
> While it is out, that one piston rod should have the cap torqued on
> properly
> and be mic'ed out for round. Most engine shops around here charge
> $20.00 to over grind a rod end or make it true round again and have a
> bearing to fit.
>
> Ok, that was long winded.... Whew... ;-)
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Got the piston out. Just tapped on the rod bolt a couple of times and
it
> > loosened up. Came right out of the cylinder, no ridge, no problem.
> >
> > Here are the pics. Any feedback on the condition of this piston or what
the
> > pic might tell you would be appreciated.
> >
> > http://members.bigvalley.net/wuji/je.../piston_2a.jpg
> > http://members.bigvalley.net/wuji/je.../piston_2b.jpg
> > http://members.bigvalley.net/wuji/je...berrings2a.jpg
> >
> > Thanks,
> >
> > Bill

SB

Long winded but good. No doubt a bit of experience pushing those words out.
I'm gonna have to get my chilton/service book so that I can have a picture
and I'll read this again!! haha that way I MIGHT have a clue what you just
said!

sb

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:4043D9EE.73C5B8B1@sympatico.ca...
> Ok Bill, just got back from a bush run and read the thread and looked at
> all the photos....
>
> Here is my $0.02 for what it is worth. ;-)
>
> Man, that set of photos sure looks like a classic case of gas wash
> killing one cylinder dead. Big Time!
>
> The gas washing all the carbon out and cleaning the rings so oil comes
> up and gets flash burnt when you change plugs and it fires for a while.
> While it's firing that flaky varnish looking crap builds up from the
> burning slurry.
>
> Then the build up finally kills the spark.
>
> No spark, so on a normal compression or firing stroke, the cylinder is
> in a vacuum mode and the piston needs to be pulled down against that
> vacuum rather than the spark firing the piston down.
>
> The vacuum must be released or the engine will up and stop.
>
> 'Some' oil will be then sucked up past the rings and sucked down past
> the valve guide seals when this is happening, whichever is looser. Hmm,
> valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
> down from the top, then it mixed with some gas to be thin and ------,
> ------s across to the spark plug threads. Hmmm....???
>
> Now the poor old crank which sounds like a 10/10 is not used to or
> designed to have any piston under suction, the piston is under spark or
> intake or exhaust, no vacuum motion involved.
>
> Check on top of the oil filter on the block boss for a letter. If M and
> P are there, it is a factory 10/10 crank which is just 10 thousands
> under. You can go to 30 or 40 if desperate, 20 is fine. B means
> factory 10 thou over piston. C means cam 10 over.
>
> This vacuum in the cylinder because of no spark means the crank slams
> down on the bearing and wears the crap out of the center of the bottom
> bearing on the cap side. The cap side isn't designed for pulling, just
> being in neutral to the push from the piston rod on spark or sucking
> from the carb/ TB or blowing out the exhaust which is zip for pressure
> point wear like is showing.
>
> If the engine is newly rebuilt like advertised, the vacuum on the
> cylinder would be nasty. The compression was way up there, so the
> vacuum 'was' up there too...
>
> Bingo, burned out rod cap bearing and likely both main bearings on each
> side.
>
> I also would be worried the cap and rod and the crank journal could have
> been pounded out of round from this.
>
> I seem to remember a complaint about a timing ping or knock at idle???
> Hmm vacuum on a piston starting the crank slapping on the bearing makes
> a neat knock. The bearing can wear away and the knock can lessen or get
> worse. The first while with the dead cylinder causes the big damage.
>
> Then the cylinder is polished up sweet! Well, carbon under heat with
> gas as a solvent has been sliding around those rings for a while, damn
> near a diamond polish, eh?
>
> No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
> that 'is' what they look like. I come from the carb days and have seen
> engines that look like that from short term gas wash. Normally on all
> or a half bank though, not like injection that just nails one.
>
> You need to open some other rod and main bearing caps and post the
> photos.
>
> If those are not burnt out or worn through then the gas wash theory
> holds, if everything is fried, then it was a dud engine someone sold you
> or the other person under the 'used' engine tag.
>
> If just gas washed, a hone on the cylinder and some new stock 10 under
> bearings should do the trick. You have to buy the whole bearing set and
> it is open, so just swap them all.
>
> While it is out, that one piston rod should have the cap torqued on
> properly
> and be mic'ed out for round. Most engine shops around here charge
> $20.00 to over grind a rod end or make it true round again and have a
> bearing to fit.
>
> Ok, that was long winded.... Whew... ;-)
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
> >
> > Got the piston out. Just tapped on the rod bolt a couple of times and
it
> > loosened up. Came right out of the cylinder, no ridge, no problem.
> >
> > Here are the pics. Any feedback on the condition of this piston or what
the
> > pic might tell you would be appreciated.
> >
> > http://members.bigvalley.net/wuji/je.../piston_2a.jpg
> > http://members.bigvalley.net/wuji/je.../piston_2b.jpg
> > http://members.bigvalley.net/wuji/je...berrings2a.jpg
> >
> > Thanks,
> >
> > Bill

twaldron

If that amount of suction ruined the rod bearing, and likely the
adjacent mains, wouldn't the crank be out of true?

Mike Romain wrote:

> Ok Bill, just got back from a bush run and read the thread and looked at
> all the photos....
>
> Here is my $0.02 for what it is worth. ;-)
>
> Man, that set of photos sure looks like a classic case of gas wash
> killing one cylinder dead. Big Time!
>
> The gas washing all the carbon out and cleaning the rings so oil comes
> up and gets flash burnt when you change plugs and it fires for a while.
> While it's firing that flaky varnish looking crap builds up from the
> burning slurry.
>
> Then the build up finally kills the spark.
>
> No spark, so on a normal compression or firing stroke, the cylinder is
> in a vacuum mode and the piston needs to be pulled down against that
> vacuum rather than the spark firing the piston down.
>
> The vacuum must be released or the engine will up and stop.
>
> 'Some' oil will be then sucked up past the rings and sucked down past
> the valve guide seals when this is happening, whichever is looser. Hmm,
> valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
> down from the top, then it mixed with some gas to be thin and ------,
> ------s across to the spark plug threads. Hmmm....???
>
> Now the poor old crank which sounds like a 10/10 is not used to or
> designed to have any piston under suction, the piston is under spark or
> intake or exhaust, no vacuum motion involved.
>
> Check on top of the oil filter on the block boss for a letter. If M and
> P are there, it is a factory 10/10 crank which is just 10 thousands
> under. You can go to 30 or 40 if desperate, 20 is fine. B means
> factory 10 thou over piston. C means cam 10 over.
>
> This vacuum in the cylinder because of no spark means the crank slams
> down on the bearing and wears the crap out of the center of the bottom
> bearing on the cap side. The cap side isn't designed for pulling, just
> being in neutral to the push from the piston rod on spark or sucking
> from the carb/ TB or blowing out the exhaust which is zip for pressure
> point wear like is showing.
>
> If the engine is newly rebuilt like advertised, the vacuum on the
> cylinder would be nasty. The compression was way up there, so the
> vacuum 'was' up there too...
>
> Bingo, burned out rod cap bearing and likely both main bearings on each
> side.
>
> I also would be worried the cap and rod and the crank journal could have
> been pounded out of round from this.
>
> I seem to remember a complaint about a timing ping or knock at idle???
> Hmm vacuum on a piston starting the crank slapping on the bearing makes
> a neat knock. The bearing can wear away and the knock can lessen or get
> worse. The first while with the dead cylinder causes the big damage.
>
> Then the cylinder is polished up sweet! Well, carbon under heat with
> gas as a solvent has been sliding around those rings for a while, damn
> near a diamond polish, eh?
>
> No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
> that 'is' what they look like. I come from the carb days and have seen
> engines that look like that from short term gas wash. Normally on all
> or a half bank though, not like injection that just nails one.
>
> You need to open some other rod and main bearing caps and post the
> photos.
>
> If those are not burnt out or worn through then the gas wash theory
> holds, if everything is fried, then it was a dud engine someone sold you
> or the other person under the 'used' engine tag.
>
> If just gas washed, a hone on the cylinder and some new stock 10 under
> bearings should do the trick. You have to buy the whole bearing set and
> it is open, so just swap them all.
>
> While it is out, that one piston rod should have the cap torqued on
> properly
> and be mic'ed out for round. Most engine shops around here charge
> $20.00 to over grind a rod end or make it true round again and have a
> bearing to fit.
>
> Ok, that was long winded.... Whew... ;-)
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
>
>>Got the piston out. Just tapped on the rod bolt a couple of times and it
>>loosened up. Came right out of the cylinder, no ridge, no problem.
>>
>>Here are the pics. Any feedback on the condition of this piston or what the
>>pic might tell you would be appreciated.
>>
>>http://members.bigvalley.net/wuji/je.../piston_2a.jpg
>>http://members.bigvalley.net/wuji/je.../piston_2b.jpg
>>http://members.bigvalley.net/wuji/je...berrings2a.jpg
>>
>>Thanks,
>>
>>Bill

--
__________________________________________________ _________
tw

03 TJ Rubicon - Rubicon Express 4.5"
01 XJ Sport

There is a very fine line between "hobby" and "mental illness."
-- Dave Barry

Pronunciation: 'jEp
Function: noun
Date: 1940

Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase')
A small general-purpose motor vehicle with 80-inch wheelbase,
1/4-ton capacity, and four-wheel drive used by the U.S. army in
World War II.

(Please remove the OBVIOUS to reply by email)
__________________________________________________ _________

twaldron

If that amount of suction ruined the rod bearing, and likely the
adjacent mains, wouldn't the crank be out of true?

Mike Romain wrote:

> Ok Bill, just got back from a bush run and read the thread and looked at
> all the photos....
>
> Here is my $0.02 for what it is worth. ;-)
>
> Man, that set of photos sure looks like a classic case of gas wash
> killing one cylinder dead. Big Time!
>
> The gas washing all the carbon out and cleaning the rings so oil comes
> up and gets flash burnt when you change plugs and it fires for a while.
> While it's firing that flaky varnish looking crap builds up from the
> burning slurry.
>
> Then the build up finally kills the spark.
>
> No spark, so on a normal compression or firing stroke, the cylinder is
> in a vacuum mode and the piston needs to be pulled down against that
> vacuum rather than the spark firing the piston down.
>
> The vacuum must be released or the engine will up and stop.
>
> 'Some' oil will be then sucked up past the rings and sucked down past
> the valve guide seals when this is happening, whichever is looser. Hmm,
> valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
> down from the top, then it mixed with some gas to be thin and ------,
> ------s across to the spark plug threads. Hmmm....???
>
> Now the poor old crank which sounds like a 10/10 is not used to or
> designed to have any piston under suction, the piston is under spark or
> intake or exhaust, no vacuum motion involved.
>
> Check on top of the oil filter on the block boss for a letter. If M and
> P are there, it is a factory 10/10 crank which is just 10 thousands
> under. You can go to 30 or 40 if desperate, 20 is fine. B means
> factory 10 thou over piston. C means cam 10 over.
>
> This vacuum in the cylinder because of no spark means the crank slams
> down on the bearing and wears the crap out of the center of the bottom
> bearing on the cap side. The cap side isn't designed for pulling, just
> being in neutral to the push from the piston rod on spark or sucking
> from the carb/ TB or blowing out the exhaust which is zip for pressure
> point wear like is showing.
>
> If the engine is newly rebuilt like advertised, the vacuum on the
> cylinder would be nasty. The compression was way up there, so the
> vacuum 'was' up there too...
>
> Bingo, burned out rod cap bearing and likely both main bearings on each
> side.
>
> I also would be worried the cap and rod and the crank journal could have
> been pounded out of round from this.
>
> I seem to remember a complaint about a timing ping or knock at idle???
> Hmm vacuum on a piston starting the crank slapping on the bearing makes
> a neat knock. The bearing can wear away and the knock can lessen or get
> worse. The first while with the dead cylinder causes the big damage.
>
> Then the cylinder is polished up sweet! Well, carbon under heat with
> gas as a solvent has been sliding around those rings for a while, damn
> near a diamond polish, eh?
>
> No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
> that 'is' what they look like. I come from the carb days and have seen
> engines that look like that from short term gas wash. Normally on all
> or a half bank though, not like injection that just nails one.
>
> You need to open some other rod and main bearing caps and post the
> photos.
>
> If those are not burnt out or worn through then the gas wash theory
> holds, if everything is fried, then it was a dud engine someone sold you
> or the other person under the 'used' engine tag.
>
> If just gas washed, a hone on the cylinder and some new stock 10 under
> bearings should do the trick. You have to buy the whole bearing set and
> it is open, so just swap them all.
>
> While it is out, that one piston rod should have the cap torqued on
> properly
> and be mic'ed out for round. Most engine shops around here charge
> $20.00 to over grind a rod end or make it true round again and have a
> bearing to fit.
>
> Ok, that was long winded.... Whew... ;-)
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
>
>>Got the piston out. Just tapped on the rod bolt a couple of times and it
>>loosened up. Came right out of the cylinder, no ridge, no problem.
>>
>>Here are the pics. Any feedback on the condition of this piston or what the
>>pic might tell you would be appreciated.
>>
>>http://members.bigvalley.net/wuji/je.../piston_2a.jpg
>>http://members.bigvalley.net/wuji/je.../piston_2b.jpg
>>http://members.bigvalley.net/wuji/je...berrings2a.jpg
>>
>>Thanks,
>>
>>Bill

--
__________________________________________________ _________
tw

03 TJ Rubicon - Rubicon Express 4.5"
01 XJ Sport

There is a very fine line between "hobby" and "mental illness."
-- Dave Barry

Pronunciation: 'jEp
Function: noun
Date: 1940

Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase')
A small general-purpose motor vehicle with 80-inch wheelbase,
1/4-ton capacity, and four-wheel drive used by the U.S. army in
World War II.

(Please remove the OBVIOUS to reply by email)
__________________________________________________ _________

twaldron

If that amount of suction ruined the rod bearing, and likely the
adjacent mains, wouldn't the crank be out of true?

Mike Romain wrote:

> Ok Bill, just got back from a bush run and read the thread and looked at
> all the photos....
>
> Here is my $0.02 for what it is worth. ;-)
>
> Man, that set of photos sure looks like a classic case of gas wash
> killing one cylinder dead. Big Time!
>
> The gas washing all the carbon out and cleaning the rings so oil comes
> up and gets flash burnt when you change plugs and it fires for a while.
> While it's firing that flaky varnish looking crap builds up from the
> burning slurry.
>
> Then the build up finally kills the spark.
>
> No spark, so on a normal compression or firing stroke, the cylinder is
> in a vacuum mode and the piston needs to be pulled down against that
> vacuum rather than the spark firing the piston down.
>
> The vacuum must be released or the engine will up and stop.
>
> 'Some' oil will be then sucked up past the rings and sucked down past
> the valve guide seals when this is happening, whichever is looser. Hmm,
> valve guide seals maybe eh? So when it shuts off, the vacuum sucks oil
> down from the top, then it mixed with some gas to be thin and ------,
> ------s across to the spark plug threads. Hmmm....???
>
> Now the poor old crank which sounds like a 10/10 is not used to or
> designed to have any piston under suction, the piston is under spark or
> intake or exhaust, no vacuum motion involved.
>
> Check on top of the oil filter on the block boss for a letter. If M and
> P are there, it is a factory 10/10 crank which is just 10 thousands
> under. You can go to 30 or 40 if desperate, 20 is fine. B means
> factory 10 thou over piston. C means cam 10 over.
>
> This vacuum in the cylinder because of no spark means the crank slams
> down on the bearing and wears the crap out of the center of the bottom
> bearing on the cap side. The cap side isn't designed for pulling, just
> being in neutral to the push from the piston rod on spark or sucking
> from the carb/ TB or blowing out the exhaust which is zip for pressure
> point wear like is showing.
>
> If the engine is newly rebuilt like advertised, the vacuum on the
> cylinder would be nasty. The compression was way up there, so the
> vacuum 'was' up there too...
>
> Bingo, burned out rod cap bearing and likely both main bearings on each
> side.
>
> I also would be worried the cap and rod and the crank journal could have
> been pounded out of round from this.
>
> I seem to remember a complaint about a timing ping or knock at idle???
> Hmm vacuum on a piston starting the crank slapping on the bearing makes
> a neat knock. The bearing can wear away and the knock can lessen or get
> worse. The first while with the dead cylinder causes the big damage.
>
> Then the cylinder is polished up sweet! Well, carbon under heat with
> gas as a solvent has been sliding around those rings for a while, damn
> near a diamond polish, eh?
>
> No lip, so it 'sure' isn't burnt worn, it is gas washed or gas polished,
> that 'is' what they look like. I come from the carb days and have seen
> engines that look like that from short term gas wash. Normally on all
> or a half bank though, not like injection that just nails one.
>
> You need to open some other rod and main bearing caps and post the
> photos.
>
> If those are not burnt out or worn through then the gas wash theory
> holds, if everything is fried, then it was a dud engine someone sold you
> or the other person under the 'used' engine tag.
>
> If just gas washed, a hone on the cylinder and some new stock 10 under
> bearings should do the trick. You have to buy the whole bearing set and
> it is open, so just swap them all.
>
> While it is out, that one piston rod should have the cap torqued on
> properly
> and be mic'ed out for round. Most engine shops around here charge
> $20.00 to over grind a rod end or make it true round again and have a
> bearing to fit.
>
> Ok, that was long winded.... Whew... ;-)
>
> Mike
> 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> 88 Cherokee 235 BFG AT's
>
> William Oliveri wrote:
>
>>Got the piston out. Just tapped on the rod bolt a couple of times and it
>>loosened up. Came right out of the cylinder, no ridge, no problem.
>>
>>Here are the pics. Any feedback on the condition of this piston or what the
>>pic might tell you would be appreciated.
>>
>>http://members.bigvalley.net/wuji/je.../piston_2a.jpg
>>http://members.bigvalley.net/wuji/je.../piston_2b.jpg
>>http://members.bigvalley.net/wuji/je...berrings2a.jpg
>>
>>Thanks,
>>
>>Bill

--
__________________________________________________ _________
tw

03 TJ Rubicon - Rubicon Express 4.5"
01 XJ Sport

There is a very fine line between "hobby" and "mental illness."
-- Dave Barry

Pronunciation: 'jEp
Function: noun
Date: 1940

Etymology: from g. p. (G= 'Government' P= '80 inch wheelbase')
A small general-purpose motor vehicle with 80-inch wheelbase,
1/4-ton capacity, and four-wheel drive used by the U.S. army in
World War II.

(Please remove the OBVIOUS to reply by email)
__________________________________________________ _________

L.W.(=?iso-8859-1?Q?=DFill?=) Hughes III

That puppy's just got a lot of miles on it, at least two hundred
thousand miles, since it was rebuilt, probably came from a passenger car
before the work order showed it was purchased used to install along with
a that shop's rebuilt head. If no other bearing are worst than what
we've seen Bill, just could throw in a set of inserts and rings and it
would be good to go, for another two hundred thousand.
God Bless America, ßill O|||||||O
mailto:-------------------- http://www.----------.com/

twaldron wrote:
>
> If that amount of suction ruined the rod bearing, and likely the
> adjacent mains, wouldn't the crank be out of true?