theHIGHLANDER hope this doesn't drive you off the deep end but why would you make 168 passes without changing the oil in your racecar? just wondered.
Depends on the (ab)use the engine is gone get Synth has syntheticly fabricated molecules that stand up better to hard and prolonged use than natural oil molecules made from dinosaur bones. But... If your not running the track with your Jalopy, or are doing 1000mile trips at 100mph averages on a weekly basis, or are squeezing 1000+HP out of an originally 250HP engine with nitrous and meth, you will probably not ruin your engine when you are using the cheapest oil you can get at Wallmart On the other hand, if you spend $250 on some rims, why shy away from the more expensive synthetic oil ???
Regarding oil breakdown.... It's my understanding that multi-viscosity oils are achieved by linking chains of molecules. The larger the spread of the oil (ie 10-30 is a 20w spread) the longer the chain of molecules. Because those are literally chains of linked molecules, and because of the small clearance twisting/shearing action of rotating metal bearings, oil "breakdown" is actually the molecular chains breaking. Hence 10-40 would break down faster than 10-30 because it's longer/larger structure is challenged harder by engine clearances. Dunno if it's true or not, but in the 80s we made a switch on our family cars from 10-40 to 10-30 because the ole man read a technical paper with that reasoning, and it sure seemed like oil life increased. good discussion
I agree, if an engine is worn out enough to benefit from a higher viscosity syn than it would also benefit from a higher visciosty mineral based oil.
On all my old honda stuff the filters were always sideways,I just filled the filter and let it sit, then drained out the little bit that didn't soak in to the element before installation. that element will soak up a lot of oil. better to have it full of oil then dry. with my new remote mount filter setup,the filter is upside down, so the oil always stays in it. no dry starts and easy to change. just a pan to catch the drips.
You're missing the point entirely. Superior cold flow of synthetic allows you to increase the overall viscosity. Best of both worlds. Even if your engine runs best on super thick stuff, it's not good for longevity due to startup/cold flow issues. And when I say cold flow, that includes 70 degree weather. The old loose caddy being used as an example would probably run best (warmed up) with 50W, either conventional or synthetic. But I dare ya to cold start that bitch and instantly rev it to 2500 with conventional 50W. Dare ya! I don't care how good an oil is once you're tooling down the highway, if it puts 500 miles of bearing wear on the car every morning, it's not acceptable. Otherwise people WOULD use 50W. High viscosity straight weights are incredibly durable oils.
good thing to bring up, accusump!! you can set it up with the electric valve wired to the ignition, as soon as you turn the key the valve opens forcing oil into your engine. once you start it up the extra oil goes back into the accusump. if you spend a lot of money rebuilding an engine, well worth it's price.
So your point is that you could run a straight 50weight if you used a syn but not if you used a mineral based oil, is that it? But why would I want to run a straight 50 in an car engine anyway, no matter if it's a syn or a mineral based oil and no matter how wore out the engine is. A 20w50 will do a lot better job and it would not matter if it's a syn or a mineral based oil. Because of the superior cold flow characteristics of a 20weight oil it would reach critical areas faster on start up and would offer a thicker 50weight oil film at operating temperature that would be needed for worn engine parts. If the engine would run best with a 50weight when hot but would suffer damage when cold due to poor flow capability it would be best to use a 20w50 instead of a 50 weight. So Why not use a synthetic 20w50 since it would do the same as the mineral based 20w50 could do, but it would do it just a bit better in every way. It would offer even better cold flow abilities and even better protection when hot. So why use a straight 50 at all?
If you think a 20-50 and a 50 behave the same at elvated temperature, you'd be wrong. Throw 30w in your car instead of 10-30 and check out the difference in hot manners. It'll be significant. What I'm trying to say is if you could get the engine hot to start with, it'd probably run best with something as thick as gear lube. If you're that skeptical of synthetics, just means you haven't given them a serious try. That's OK, people still swear by bias ply tires too. The automotive world is a richly textured place and we all have our niche. Only difference is nobody can see your non-traditional oil......
Me, skeptical of synthetics? You gotta be kidding, I run Amsoil Synthetics in every thing I own. I use it in my hotrod, my daily driver which is a 1954 Chevy pickup with a 350 SBC and my 1957 Harley. My Harley is the only Harley that I've ever worked on that has over 30000 miles on it and never needed the solid lifters readjusted and I run haevy valvesprings and a very big cam. I swear by the stuff. But I do love the biasply's that I run on every thing I own.
save you $$$$$$$ I have used castrol for years and change it often and use a good quality oil filter.
The car was using a qt of conv oil every 20 or so rounds. Not a hateful amount considering the use (load). Once the Amsoil went in it stopped using oil. I gained 2MPH and ET dropped .05, and that was every weather and track condition that the improvement was showing, as in good/bad air ( I kept a log book). Not only did it stop using and run better, oil pressure was more consistant. Liking what I was seeing I kept going. The oil always looked new. I will add that as unusual as it may seem in a bracket racer I had a filtered crankcase system instaed of just a plain breather and kept a small degree of vacuum in the case as well. So I had a clean environment, superior control at the rings, oil that looked and even smelled new all the time (no race fuel smell to it), so I experimented I guess. I did do a filter (Wix) and 1 qt at about 100 or so passes in, I also used an oversized pan but 1 qt less to keep it off the crank, so 6 instead of 7. I didn't hurt it any so...
First off, I am an independent dealer of Amsoil synthetic lubricants. And I became a dealer after I had used their products enough to realize what good stuff they sold. I use it in everything I own with an internal combustion engine, from my weed eater to my '03 Chev. Silverado with Duramax diesel. The weed eater uses a 2 cycle oil formulated for 2 cycle air cooled engines, the lawnmower has an oil intended for small 4 cycle air cooled engines, as does the auxilliary generator. My '94 Lincoln MKviii with the 32 valve, 4 cam hi-tech engine uses Amsoil 0W-30 and Amsoil's nano fiber filter, and goes 35,000 miles or 1 year between changes, and has 110,000 miles. My '03 Duramax diesel has a remote dual filter setup with 1 large full flow filter and a huge bypass filter, and both are Amsoil nano-fiber. Once a year I draw a sample of oil and send it off to get a lab test, and usually get 2 years or more out of the oil with new full flow filter every year and every 2 years on the bypass filter. The oil is Amsoil 5W-30 specially for pre-07 engines. They have another oil with less ZDDP for the newer diesels which have a sort of catalytic converter that also is the reason for the new ultra-low sulfur fuel. Amsoil also sells both racing oils with high ZDDP and oils targeted for pre cat engines with a heavy load of ZDDP in street use as a daily driver. The racing oil and the "premium protection" oil both have the high ZDDP, but different additive packages to best suit the intended use of the engine. I intend to use the "Premium Protection" synthetic in SBC in the roadster I'm building. Amsoil says in their literature not to use synthetics for engine break in, so I may go with something likle Brad Penn or Joe Gibbs for the first 500 miles or so, with added ZDDP additive from ZDDP plus. Dave
I bought the 1990 chevy new that my son has now. I drove it 87,000 miles on the factory dino oil and filter. Started changing the oil some at this point. Drove the truck to 200,000 miles it still ran great when we pulled the engine and installed a crate. My brother in law smoked the engine in his T/A, so we pulled the heads off the old 350 to clean out the water and put the heads back on. The engine ran for about 18 months in his car before he bought his crate... Ran good no oil consumption when it came out. Gave the engine to a guy to put in his 56 Chevy,,, I will let you know how it does when he gets it running... IMO, Synthetic is not really needed....
Any one with "real world" experience with extreme load & heat conditions and recommendations for the best gear lube to use? Please NO "dealer" replies ... just real users!
I run Mobil 1 10-30 in all my stuff, lawnmower snowblower hotrod with 327 chevy. never had a problem. Took a power transmission class and the instructor said to put a can of regular oil and a can of Mobil 1 in your freezer over night and see which one pours out best that changed my thinking on synthetic oil.
To reply to Grandaddy-O specifically first and then this resurrected thread second. http://www.bobistheoilguy.com/effects-of-shearing/ This is the #1 thing about oil and lube. This is it's job. If you read the link there is an exhaustive discussion about it. Here's the quick answer. The difference between XXW-YY needs to be as small as possible. The greater the difference between the first number and the second is more viscosity improvers added to the lubricant, which don't act as a lubricant. Ideally, if your gears are rated for 90W, straight 90 is what you would use. However. 80W-90 would flow better at cold (atmospheric) temp than straight 90 and 75W-90 would flow even better. At operating temp, they would all act as 90. Since gears are not motors and things like axles can go straight from cold to a hard pull immediately without warming up, there is the problem. There is a trade off and I personally would want my gear lube to flow at cold temps when needed to stay on parts as hot spots are generated from shear. This is where synthetic beats dino oil. Synthetic flows better at cold temps than dino and it's smaller particle size pulls heat away faster. It's splitting hairs but in extreme conditions, I would use synthetic 75W-90 just because that initial shear force in the cold is going to need to get lubed fast and pull heat fast to get to temp. Also, synthetic resists oxidation caused by use much better so will be a good lubricant longer. (Too long, didn't read...) Synthetic flows better in the cold, resists oxidation better at temp and above. Keep the difference between cold and hot weights as small as possible to minimize VI improvers unless low temp flow (like gear lube) is important. The cost of it may negate more frequent oil changes. Unless it's a daily that will see 15K miles a year, it's probably not worth it.
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