On Oct 28, 8:07 am, Bruce in Bangkok wrote:
On Sat, 27 Oct 2007 13:11:25 GMT, Brian Whatcott





wrote:
On Sat, 27 Oct 2007 13:08:19 +0700, Bruce in Bangkok
wrote:

I've only switched in the cars... no problems at all.
According to the local
mechanic, you can mix oil and synth without problems.
-
I've used one quart of Castrol synthetic to 3 quarts of Castrol
mutigrade changed each 4000 mile interval since new,
for over 300 k miles on two festivas, where the engines
work for a living.

Brian Whatcott Altus OK
-
-
Not to be picky, but why a mix of synthetic and multigrade?

Bruce-in-Bangkok

I once witnessed an extreme pressure oil bench-test.
Basically, a ball bearing is pressed hard onto a rotating shaft
and left to run. With mineral oil, there was soon a good flat.
With synthetic, the ball held in there, much longer.

But then, they cut the synth lubricant with mineral, and
the wear life held up at fair dilutions.

So, in view of the cost difference, and knowing they are
designed to be completely miscible, I used the 1:4 cut.

Finally, the makers started marketing a synth mix, but I do
it myself still - its no trouble to do. (The only precaution I take
is to use both types from the same maker - I chose Castrol)

I have read often enough, that synthetic can be searching in old
engines and unclog them or loosen seals and also that they
may not carry crap as well, and staying runny, the oil can
drain from cylinder walls
so it could be hard on startup, but the improved flow at
startup makes that point moot, I'm guessing.

Brian Whatcott Altus OK

Interesting. I had always assumed that synthetic oils were more
durable as they stood up to high temperature better but your test
seems to say that they have a higher lubricity factor.... Or perhaps
it is the resistance to heat. But, for whatever reason it seems that
they provide better lubrication.

So - why not 100% synthetic? Cost?

Bruce-in-Bangkok
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- Show quoted text -

Someone explained to me that the synthetic mocules are all the same
size, like billions of BB's, where as regular oil would be like
billions and billions of BB's all very different sizes. So the load on
Synthetic could be carried easier and more even than regular oil. This
friend has a Cumming's Dodge truck and said he gained almost 10%
better mileage. He said once you switch do not go back or you will get
leak problems, but if you stick with it you will not have any
problems.

Joe

On Sun, 28 Oct 2007 20:07:55 +0700, Bruce in Bangkok
wrote:


...why a mix of synthetic and multigrade?

Bruce-in-Bangkok

...
So, in view of the cost difference, and knowing they are
designed to be completely miscible, I used the 1:4 cut.
-
-
So - why not 100% synthetic? Cost?


Bruce-in-Bangkok

Yep, I'm basically cheap. And the crap suspension issue
with mineral oil gives me some comfort.

Brian W

"Joe" wrote in message
oups.com...
On Oct 28, 8:07 am, Bruce in Bangkok wrote:
On Sat, 27 Oct 2007 13:11:25 GMT, Brian Whatcott





wrote:
On Sat, 27 Oct 2007 13:08:19 +0700, Bruce in Bangkok
wrote:

I've only switched in the cars... no problems at all.
According to the local
mechanic, you can mix oil and synth without problems.
-
I've used one quart of Castrol synthetic to 3 quarts of Castrol
mutigrade changed each 4000 mile interval since new,
for over 300 k miles on two festivas, where the engines
work for a living.

Brian Whatcott Altus OK
-
-
Not to be picky, but why a mix of synthetic and multigrade?

Bruce-in-Bangkok

I once witnessed an extreme pressure oil bench-test.
Basically, a ball bearing is pressed hard onto a rotating shaft
and left to run. With mineral oil, there was soon a good flat.
With synthetic, the ball held in there, much longer.

But then, they cut the synth lubricant with mineral, and
the wear life held up at fair dilutions.

So, in view of the cost difference, and knowing they are
designed to be completely miscible, I used the 1:4 cut.

Finally, the makers started marketing a synth mix, but I do
it myself still - its no trouble to do. (The only precaution I take
is to use both types from the same maker - I chose Castrol)

I have read often enough, that synthetic can be searching in old
engines and unclog them or loosen seals and also that they
may not carry crap as well, and staying runny, the oil can
drain from cylinder walls
so it could be hard on startup, but the improved flow at
startup makes that point moot, I'm guessing.

Brian Whatcott Altus OK

Interesting. I had always assumed that synthetic oils were more
durable as they stood up to high temperature better but your test
seems to say that they have a higher lubricity factor.... Or perhaps
it is the resistance to heat. But, for whatever reason it seems that
they provide better lubrication.

So - why not 100% synthetic? Cost?

Bruce-in-Bangkok
(Note:displayed e-mail
address is a spam trap)- Hide quoted text -

- Show quoted text -

Someone explained to me that the synthetic mocules are all the same
size, like billions of BB's, where as regular oil would be like
billions and billions of BB's all very different sizes. So the load on
Synthetic could be carried easier and more even than regular oil. This
friend has a Cumming's Dodge truck and said he gained almost 10%
better mileage. He said once you switch do not go back or you will get
leak problems, but if you stick with it you will not have any
problems.

Joe



Well, now we've heard all the ways... leaks if you switch to synch, leaks if
you switch back to regular oil, not effective if you combine them. I've done
all three with older car engines with no problems.


--
"j" ganz @@
www.sailnow.com

Thanks to all for the suggestions. I pulled the oil cooler and the
oil pressure valves this weekend and all looks good. The Oil cooler
tubes are almost scary clean. I did change the oil, but the only oil
I can get here is a 15w-40 for diesels from BP. Believe it or not,
that or a 20w-50 is all that I can get here. I am getting about 10-15
psi at idle and about 50 psi at max speed. My manual says that I have
seperate senders for the warning light and the gauge. The time the
pressure really dropped off and the light came on was right after
pushing the engine hard for a while (on plane). After I change the
oil and checked the cooler and such, I cruised around for an hour or
so and the pressure never went below 15 psi.

On Sun, 28 Oct 2007 13:10:50 -0700, hookipa
wrote:

Thanks to all for the suggestions. I pulled the oil cooler and the
oil pressure valves this weekend and all looks good. The Oil cooler
tubes are almost scary clean. I did change the oil, but the only oil
I can get here is a 15w-40 for diesels from BP. Believe it or not,
that or a 20w-50 is all that I can get here. I am getting about 10-15
psi at idle and about 50 psi at max speed. My manual says that I have
seperate senders for the warning light and the gauge. The time the
pressure really dropped off and the light came on was right after
pushing the engine hard for a while (on plane). After I change the
oil and checked the cooler and such, I cruised around for an hour or
so and the pressure never went below 15 psi.

The viscosity numbers mean that when the oil is cold it will flow as
well as 15 weight and when hot won't be any thinner then 50 weight. I
would doubt that is your problem.

You mention that "the pressure dropped off and the light came on"
which implies that both the gage and warning light circuits are
working correctly.

When you say that the oil cooler tubes are "almost scary clean" what
does that mean? The oil side should be full of nasty old engine oil,
it is, isn't it?

You say that you checked the oil pressure valves - plural? If you can
get at the oil pressure relief valve try sticking a washer behind the
spring and see whether that raises either the idle or full throttle
pressure. If it does then either the pump is worn or the spring in the
pressure relief valve is getting weak.


Bruce-in-Bangkok
(Note:displayed e-mail
address is a spam trap)

On Sun, 28 Oct 2007 06:43:35 -0700, Joe
wrote:

On Oct 28, 8:07 am, Bruce in Bangkok wrote:
On Sat, 27 Oct 2007 13:11:25 GMT, Brian Whatcott





wrote:
On Sat, 27 Oct 2007 13:08:19 +0700, Bruce in Bangkok
wrote:

I've only switched in the cars... no problems at all.
According to the local
mechanic, you can mix oil and synth without problems.
-
I've used one quart of Castrol synthetic to 3 quarts of Castrol
mutigrade changed each 4000 mile interval since new,
for over 300 k miles on two festivas, where the engines
work for a living.

Brian Whatcott Altus OK
-
-
Not to be picky, but why a mix of synthetic and multigrade?

Bruce-in-Bangkok

I once witnessed an extreme pressure oil bench-test.
Basically, a ball bearing is pressed hard onto a rotating shaft
and left to run. With mineral oil, there was soon a good flat.
With synthetic, the ball held in there, much longer.

But then, they cut the synth lubricant with mineral, and
the wear life held up at fair dilutions.

So, in view of the cost difference, and knowing they are
designed to be completely miscible, I used the 1:4 cut.

Finally, the makers started marketing a synth mix, but I do
it myself still - its no trouble to do. (The only precaution I take
is to use both types from the same maker - I chose Castrol)

I have read often enough, that synthetic can be searching in old
engines and unclog them or loosen seals and also that they
may not carry crap as well, and staying runny, the oil can
drain from cylinder walls
so it could be hard on startup, but the improved flow at
startup makes that point moot, I'm guessing.

Brian Whatcott Altus OK

Interesting. I had always assumed that synthetic oils were more
durable as they stood up to high temperature better but your test
seems to say that they have a higher lubricity factor.... Or perhaps
it is the resistance to heat. But, for whatever reason it seems that
they provide better lubrication.

So - why not 100% synthetic? Cost?

Bruce-in-Bangkok
(Note:displayed e-mail
address is a spam trap)- Hide quoted text -

- Show quoted text -

Someone explained to me that the synthetic mocules are all the same
size, like billions of BB's, where as regular oil would be like
billions and billions of BB's all very different sizes. So the load on
Synthetic could be carried easier and more even than regular oil. This
friend has a Cumming's Dodge truck and said he gained almost 10%
better mileage. He said once you switch do not go back or you will get
leak problems, but if you stick with it you will not have any
problems.

Joe


That sounds logical as regular oil is actually a mixture and the
viscosity is measured by how fast it flows. You could have a mix of
100 wt. and gasoline that would be rated at 10 wt., for example.

The Synthetic, being man made would undoubtedly be a more constant
molecular size.


Bruce-in-Bangkok
(Note:displayed e-mail
address is a spam trap)

On Sun, 28 Oct 2007 12:22:02 -0600, Brian Whatcott
wrote:

On Sun, 28 Oct 2007 20:07:55 +0700, Bruce in Bangkok
wrote:


...why a mix of synthetic and multigrade?

Bruce-in-Bangkok

...
So, in view of the cost difference, and knowing they are
designed to be completely miscible, I used the 1:4 cut.
-
-
So - why not 100% synthetic? Cost?


Bruce-in-Bangkok

Yep, I'm basically cheap. And the crap suspension issue
with mineral oil gives me some comfort.

Brian W


Do you mean that synthetic does not hold the gunk in suspension as
well as mineral oil? Probably not the oil for my old diesel pickup
then.


Bruce-in-Bangkok
(Note:displayed e-mail
address is a spam trap)

On Mon, 29 Oct 2007 09:17:38 +0700, Bruce in Bangkok
wrote:


Do you mean that synthetic does not hold the gunk in suspension as
well as mineral oil? Probably not the oil for my old diesel pickup
then.


Bruce-in-Bangkok

That's what I meant - but it's little more than hearsay. I don't have
solid evidence for the difference.

Brian Whatcott Altus OK

The viscosity numbers mean that when the oil is cold it will flow as
well as 15 weight and when hot won't be any thinner then 50 weight. I
would doubt that is your problem.

You mention that "the pressure dropped off and the light came on"
which implies that both the gage and warning light circuits are
working correctly.

When you say that the oil cooler tubes are "almost scary clean" what
does that mean? The oil side should be full of nasty old engine oil,
it is, isn't it?

You say that you checked the oil pressure valves - plural? If you can
get at the oil pressure relief valve try sticking a washer behind the
spring and see whether that raises either the idle or full throttle
pressure. If it does then either the pump is worn or the spring in the
pressure relief valve is getting weak.

I am with you on the gauge and warning lights being correct. There is
actually seperate senders for both. I was looking to get a mechanical
gauge sent out here, but I am in no rush to do that right now.

I must admit that I never looked at the oil side of the cooler (stupid
move). I was focused on the water side as a friend had 50% of his
tubes clogged. I guess I hoped my cooler looked like his, so I
blanked out on looking at the oil side when I sas it was so clean.
Now if the oil side was gummed up wouldn't my pressure be higher? Or,
would the cooler just get bypassed and overheat the oil?

There are two pressure relief circuits for this engine according to
the manual, one is for piston cooling oil and the other for engine
cooling oil.

If the washer raises the oil pressure, should I leave it there until I
can get parts? Or, do I need the parts right away if the pressure is
acceptable?

Kurt

On Mon, 29 Oct 2007 01:35:46 -0700, hookipa
wrote:

The viscosity numbers mean that when the oil is cold it will flow as
well as 15 weight and when hot won't be any thinner then 50 weight. I
would doubt that is your problem.

You mention that "the pressure dropped off and the light came on"
which implies that both the gage and warning light circuits are
working correctly.

When you say that the oil cooler tubes are "almost scary clean" what
does that mean? The oil side should be full of nasty old engine oil,
it is, isn't it?

You say that you checked the oil pressure valves - plural? If you can
get at the oil pressure relief valve try sticking a washer behind the
spring and see whether that raises either the idle or full throttle
pressure. If it does then either the pump is worn or the spring in the
pressure relief valve is getting weak.

I am with you on the gauge and warning lights being correct. There is
actually seperate senders for both. I was looking to get a mechanical
gauge sent out here, but I am in no rush to do that right now.

I must admit that I never looked at the oil side of the cooler (stupid
move). I was focused on the water side as a friend had 50% of his
tubes clogged. I guess I hoped my cooler looked like his, so I
blanked out on looking at the oil side when I sas it was so clean.
Now if the oil side was gummed up wouldn't my pressure be higher? Or,
would the cooler just get bypassed and overheat the oil?

There are two pressure relief circuits for this engine according to
the manual, one is for piston cooling oil and the other for engine
cooling oil.

If the washer raises the oil pressure, should I leave it there until I
can get parts? Or, do I need the parts right away if the pressure is
acceptable?

Kurt
Probably if the oil side was gunked up the pressure would be higher as
the oil cooler is usually between the pump and the engine.

Frankly, the engine will probably not blow up just because the oil
pressure is a bit low. I think someone said that idle oil pressure was
about 20 psi and you have nearly that.

I have no experience with your engine but usually there is a single
pressure relief valve located at the pump outlet, but if you have two,
and they are accessible I'd put a washer behind the spring on both and
see what happens. If the pressure is in the ballpark and oil
consumption does not go up then I'd leave it alone - at least for now.


Bruce-in-Bangkok
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address is a spam trap)