On Oct 25, 8:04 am, Brian Whatcott wrote:
On Thu, 25 Oct 2007 11:05:13 +0100, "Alec"
wrote:

...

Try a heavier grade of oil, not one of the modern wide range synthetic or
semi synthetics multigrades.
Alec

I'm not arguing with this general advice. But the sentence I
quoted shows a mindset that may not tie to reality.

A synthetic almost as thin as water when cold, can STILL be thicker
than a thick mineral oil when really hot. Its viscosity vs
temperature slope is that much flatter. That's why they are rated
multi-grade. The synthetic doesn't burn off and has better high
pressure film strength.

Brian W

Stay away from switching to synthetic on an older engine, they tend to
develop oil leaks.

John

On Thu, 25 Oct 2007 08:55:27 -0700, Capt John
wrote:


Stay away from switching to synthetic on an older engine, they tend to
develop oil leaks.

John

Yep!

Brian W

On Oct 25, 8:45 pm, Brian Whatcott wrote:
On Thu, 25 Oct 2007 08:55:27 -0700, Capt John
wrote:

Stay away from switching to synthetic on an older engine, they tend to
develop oil leaks.

John

Yep!

Brian W

I heard that if you switch and do not switch back you will not have
leaks.

Anyone switch to synthetics and stay switched?

Joe

On Fri, 26 Oct 2007 05:05:53 -0700, Joe
wrote:

I heard that if you switch and do not switch back you will not have
leaks.

Anyone switch to synthetics and stay switched?

I did it with an older sailboat diesel once. It was a disaster. The
engine developed a major oil leak around the main bearing seal in no
time at all. I've never used synthetics since then.

"Joe" wrote in message
ups.com...
On Oct 25, 8:45 pm, Brian Whatcott wrote:
On Thu, 25 Oct 2007 08:55:27 -0700, Capt John
wrote:

Stay away from switching to synthetic on an older engine, they tend to
develop oil leaks.

John

Yep!

Brian W

I heard that if you switch and do not switch back you will not have
leaks.

Anyone switch to synthetics and stay switched?

Joe

I've only switched in the cars... no problems at all. According to the local
mechanic, you can mix oil and synth without problems.

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

On Fri, 26 Oct 2007 09:47:29 -0700, "Capt. JG"
wrote:


Anyone switch to synthetics and stay switched?

Joe

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

On Sat, 27 Oct 2007 00:16:42 GMT, Brian Whatcott
wrote:

On Fri, 26 Oct 2007 09:47:29 -0700, "Capt. JG"
wrote:


Anyone switch to synthetics and stay switched?

Joe

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

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