Re: synthetic in older HP engines?
[Re: 63stabamatic]
#1191878
03/06/12 11:07 AM
03/06/12 11:07 AM
|
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
|
Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
|
the "myth" as I understand it and where it comes from...is that synthetics tend to be thinner, and flow better. the side effect is that seals and gaskets that are getting hard and brittle, now allow the thinner oil to seep though them and cause external leaks. I suppose this could apply to valve seals and worn out rings as well, causing the engine to burn more oil.
Another belief, is that the synthetics do a much better job at washing the inside of the engine, and they wash any built up sludge on the non-moving surfaces, again, allowing the thinner oil to reach the worn out gaskets.
take your pick, but there must be some truth to the myth, surely it can't be coincidental that so many old engines started leaking miraculously right after switching to synthetics?
**Photobucket sucks**
|
|
|
Re: synthetic in older HP engines?
[Re: 70Cuda383]
#1191882
03/06/12 03:37 PM
03/06/12 03:37 PM
|
Joined: Jul 2011
Posts: 817
Eugene, Oregon
Secret Chimp
super stock
|
super stock
Joined: Jul 2011
Posts: 817
Eugene, Oregon
|
Quote:
the "myth" as I understand it and where it comes from...is that synthetics tend to be thinner, and flow better. the side effect is that seals and gaskets that are getting hard and brittle, now allow the thinner oil to seep though them and cause external leaks. I suppose this could apply to valve seals and worn out rings as well, causing the engine to burn more oil.
Another belief, is that the synthetics do a much better job at washing the inside of the engine, and they wash any built up sludge on the non-moving surfaces, again, allowing the thinner oil to reach the worn out gaskets.
take your pick, but there must be some truth to the myth, surely it can't be coincidental that so many old engines started leaking miraculously right after switching to synthetics?
Synthetics are thinner when cold. The oil film on some synthetics is actually thicker compared to other oils of the same weight (i.e. Redline).
1967 Dodge Coronet Deluxe station wagon
1.03" T-bars, QA1 arms/rods, Cordoba/GM Metric/Volare brake & knuckle, XHDs, Hellwig rear sway, 318 Magnum w/ air gap, 727, 3.23s
|
|
|
Re: synthetic in older HP engines?
[Re: BDW]
#1191884
03/06/12 09:19 PM
03/06/12 09:19 PM
|
Joined: Jan 2007
Posts: 1,032
Ohio
dobie
super stock
|
super stock
Joined: Jan 2007
Posts: 1,032
Ohio
|
I bought my current motor back in 2008. We freshened it up a bit and did some top end work, but that was it. Since ive had it i run Mobil 1 15-50 plus a bottle of comp cams break in additive. No issues at all and no leaks. I also havent changed the oil since 2010, but thats partly due to not driving it the last 2 years.
1968 Plymouth Road Runner
383 4 speed
|
|
|
Re: synthetic in older HP engines?
[Re: screamindriver]
#1191886
03/07/12 06:43 PM
03/07/12 06:43 PM
|
Joined: Apr 2008
Posts: 1,285
Pacific NW USA
CompSyn
pro stock
|
pro stock
Joined: Apr 2008
Posts: 1,285
Pacific NW USA
|
Quote:
You know I've read a bunch of these threads on here and beyond the usual  from the guys that make a living on this stuff.. The real issue was'nt the leaky seals, or the undisputed fact it does lubricate better...The issue with a straight synthetic was the prolonged storage/dry start conditions that's created by the syn oil sheeting off the parts leaving virtually no protection like the dino based oils that clung to the parts....And so the reason for the warning to all collector car guys that have cars sitting around for extended periods of time stating it's probably not the best oil for that scenario.. 
Oh boy! Another popular myth, the "cling" myth.
Folks, a vast majority of fully synthetic motor oil found on the market today IS DINO BASED; pumped from within the earth and highly refined. Do a Google search for Group III base stocks to learn more.
The other synthetics, those commonly referred to as true synthetics or PAO/Esters, when formulated properly have no issue with cling because they generally have a fair dose of ester oil in the range of 5-to-25%. Ester oil has a high polarity to be positively attracted to the metal surface. PAO alone not so much.
Oh! And not a guy that makes a living selling oil.
For more info, below are a hand full of articles from Thomas Schaefer, Retired VP Sales, Hatco Corp.
Synthetic Lubricants - link
Esters In Syntehtic Lubricants - link
What's In Your Motor Oil - link
Fuel Economy and Synthetics - link
|
|
|
Re: synthetic in older HP engines?
[Re: CompSyn]
#1191887
03/07/12 06:56 PM
03/07/12 06:56 PM
|
Joined: Jan 2006
Posts: 1,220
toronto canada
69chargeryeehaa
pro stock
|
pro stock
Joined: Jan 2006
Posts: 1,220
toronto canada
|
have you ever taken one apart? i have seen the "cling" issue on synthetics on a tranny i took apart (honda 5-spd), literally drove it, and within 5 hours it was apart and laid out on cardboard, and virtually no oil, parts almost dry (mobil 1 10W30 synthetic), vs pulling a spare trans that was almost empty sitting for years, and oil was on everything, i just needed one part (shift fork from the donor trans with reg oil), and it completely soaked the cardboard for a week!!! so I'm not really convinced, seeing that made me 
|
|
|
Re: synthetic in older HP engines?
[Re: 69chargeryeehaa]
#1191888
03/07/12 07:26 PM
03/07/12 07:26 PM
|
Joined: Apr 2008
Posts: 1,285
Pacific NW USA
CompSyn
pro stock
|
pro stock
Joined: Apr 2008
Posts: 1,285
Pacific NW USA
|
Quote:
have you ever taken one apart?
i have seen the "cling" issue on synthetics on a tranny i took apart (honda 5-spd), literally drove it, and within 5 hours it was apart and laid out on cardboard, and virtually no oil, parts almost dry (mobil 1 10W30 synthetic), vs pulling a spare trans that was almost empty sitting for years, and oil was on everything, i just needed one part (shift fork from the donor trans with reg oil), and it completely soaked the cardboard for a week!!!
so I'm not really convinced, seeing that made me
Are you talking about fresh oil in a freshly rebuilt transmission verses sludge, varnish and moisture contaminated build-up in an old transmission that sat around for years? Wouldn't one have to compare two freshly rebuilt transmissions, one with good, clean dino juice versus one with good, clean synthetic to have a relevant comparison?
Don't get me wrong, there are lots of very competent and talented mechanics out there, but when one thinks they see something with only one snap shot in time, the assumptions fly and the myths abound.
|
|
|
|
|
