Synthetic oil vs. conventional

[MVZ944T]

As a few of you may have heard, I blew the engine on my new car up at Infineon last October. Now, this may have been coincidental, but maybe not. On my yellow car, when we rebuilt the engine a couple of years back, it has somewhere around 18-20k race miles on it, most of that was run with 16-21lbs of boost. The engine was virtually perfect inside, even the bearing were still good. It had run Mobil 1 since day one and nearly always had the oil replaced after each event and filter every two. I missed many shifts and over revved that engine on many occasions. No damage.

When I purchased my new car I installed Mobil 1 (not sure what kind of oil the original owner used). I had a few leaks I could not get rid of so I switched to Castrol GTX. Sure enough the leaks stopped. Sure enough, the first time I over revved the engine, it blew.

Moral of ths story, I will never again use conventional oils in a racing engine. And most likely, I will never use anything other than Mobil 1.

[Otto]

Mike:

I hear you loud and clear. I have been using Mobil 1 15-50W in my 1986 944T for years now and so far (knock on wood) have not had any problems. Back in 2002, as a preventive measure, Black Forest installed new connecting rod bearings and a baffled oil pan, but other than that and a new head gasket, the engine has never been overhauled, 21 years and counting. Of course, I run no more than about 14 psi of boost. What grade of oil do you use?

[Dan Chambers]

Very Interesting. When I bought my 944 it had over 180K miles on it. I switched to synthetic oils, and suffered the minors oozing and leaks from older gaskets, but drove that engine pretty hard up to the 239K when I sold it. Never had any major issues with the engine, and she's still running strong.

Now I face an older car (1983) with more aged seals that already weep a little, and was debating syn or not for my first oil change. I think for the sake of safety, I'll go with the syn, and keep an oil drip pan under the car in the garage. An occasional wiping of the engine, and a couple of drops of oil is a lot easier to cost out than a thrown rod or sucked valve.

Mike, sorry to hear of your loss at Infineon, but every cloud ..... Thanks for the post on oils. My considerations have been resolved.

[MVZ944T]

I use 10-40,or 5-50 when I can find it. What ever Walley Mart (only time I shop there, honest) has in stock, and then I buy a bunch. Every so often I have to settle for 10-30. I remember reading an artilce on Mobil 1 in the Panorama a few years back. some of the factory mechanics recomended 5-50 or 10-40 but also said it really did not matter the viscosity so much, just stick with Mobil 1. Should have heeded their advice!!

[Otto]

Mike:

Believe you should make the extra effort and find 15-50 W Mobil 1 oil as that level of viscosity provides better protection at the high end of oil temperatures which you will easely and more often encounter during racing conditions. At one point I spoke about this with Steve Grosekemper and he agreed that for turbo motors it is the safer way to go. Try Target, they normally have it at a reasonable price.

[ttweed]

Moral of ths story, I will never again use conventional oils in a racing engine. And most likely, I will never use anything other than Mobil 1.

There has been a lot of discussion on various auto and motorcycle forums about the recent re-formulation of oils, specifically the reduction in additives in order to prolong catalytic converter life. Here is an excerpt from one message:

Is your motor oil destroying your engine?

Recently I became aware of an alarming situation with motor oils. The reduction of Zinc Dithiophosphate (ZDDP) in certain oils along with manganese and or other phosphates. These oils carry API approval and are very suspect in being able to provide the proper high pressure (EP) friction protection our engines need. The reason for all this is that trace amounts can damage catalytic converters and increase pollutants.

In reading several articles I have learned that many major auto part and rebuilders are aware of the problem, and are providing oil package additives to prevent camshaft failures on initial break-in. While several oil companies have confirmed the reduction of these additives, Castrol for one. The AERA (American Engine Rebuilder’s Association) has issued a tech bulletin #TB2333 to directly address the situation. GM is even adding an oil fortifier to oil in its cars. I must stress that all of the above statements are based on articles I have read and discussions from other high performance engine builders.

Here is an article by one Porsche engine builder to further confuse the issue and make your eyes glaze over: http://www.lnengineering.com/oil.html
The major issue seems to be cam wear on break-in of a new motor. Don't know if this applies to your situation or not, Mike. Higher heat resistance of a synthetic oil may make more of a difference in a turbo/racing application than the additive package, since it seems that Castrol GTX still has adequate zinc and phosphorus, according to their test results.

TT

[GeorgeB]

If I switch to synth do I use the model oil filter ive been using with dinasour oil - Mahle 0c52 on the 911-

George

[ttweed]

If I switch to synth do I use the model oil filter ive been using with dinasour oil - Mahle 0c52 on the 911

Synthetic oil does not require any special filter, AFAIK.

TT