Don, I agree with what your saying. but as an engineer, oil science and test do not agree. How ever that stated, the bumble bee, according to science can't fly either. Over the years I have read every oil test I can get my hands on done by universities. synthetic, and multi grade oils hold viscosity better, longer under extreme conditions. Which leads me to believe that perhaps viscosity is not the correct metric to be judging oils by on high performance - race engines. My opinion, non-scientific, but most cam manufactures and oil producers will agree, is that additives are more important. With all the oil test I have read, the top performing oils, synthetic or petroleum based, were not that far off on viscosity failure rates. Most oils today do not contain the level of zinc, manganese and/or phosphates they once did. It is proven that these additives do reduce ware, especial on break in. The reason they are not present in today's oils is that they damage catalytic converters, and pollute. I like you, as I have stated before, put it together and run it like cops are after me. (sometimes they are). With all my motors, I WILL NOT start a new motor without it having the GM additive EOS, and a good diesel rated oil like Delo or Rotella in the motor. We have never experience a oil related motor failure. The American Engine Rebuilder's Association (AERA) bulletin #TB2333 address this issue of reduced additives. I have spoken with their consulting engineer, and he totally agrees this is a growing issue. My advice to everyone putting together a new motor, is to use Rotella, and EOS. If your motor is close to being put together correctly, you will not experience an issue. If you're a bone head, and the motor is not right, oil will not save you. Valvoline is now offering an "Off Road 20W-50" oil that has the correct level of additives, also Redline. Bottom line, be concerned about additives, stop believing the Mobile 1 slick TV commercials, and like Don says, do what has worked for years. You will be money ahead.... THINK - EOS - Rotella - Delo. Earl -----Original Message----- From: Don Dulmage [mailto:big-d@xxxxxxxxxxxx] Sent: Thursday, June 28, 2007 6:33 AM To: 1962to1965mopars@xxxxxxxxxx Subject: synvrs normal. The advantage of synthetic oils is all the molecules are supoosedly exactly the same size having been made that way. My current belief is in high stress situations maybe that isnt the best. Best way i can explain it is no bounce or no springyness to the oil film. Synthetics stand heat much better for sure but when it comes to race engines which includes hot street set ups I have been disappionted. When we were running the XD 3 diesel oils we had no cam wear. Not even shinyness. It looked just like when we installed it. After a weekend of hard racing on the synthetic the cam was already showing signs of wear and the motor while not blown was obviuosly hurt. I am not prepared to go there again. Partially i think because the oils we had were too thin. and were multi grade which never seemed to me to come even close to the protection single grades give. Bob Gauley who runs my engine (ford 6 tbucket recently racing at Columbus Nostalgia meet.) has run royal purple 40 and 50 wt with success. Now it could be the ford six is an engine that doesnt load the parts like a 440 does, I am not sure about that. The car runs mid tens which is all he needs for his style of racing and the engne is over ten years old although he maintains it religiously. The question is why do we want to use something odd when we know what will work perfectly . As always when we gamble sometimes we lose. I am not a opposed to experiment as most know but I am always prepared before i try for the possibilty it might not work out. Cam manufacturers are very hesitant to recomend synthetics as are the factories. Why do you suppose that is? If the synthetics were a cure all then that is all they would recomment because it would save them millions in warranty claims alone. Obviously that is not the case. Still just for the record i am not opposed to synthetics in general . I use Mobil 1 in my beloved V10 truck and am happy with it. It is a different enviorment than my race engines or 426 MW sees. If all we are talking about is the gentle spinning of a shaft in a bearing then syntheitic can lube beyond temps mineral based can but when we pour in the abuse factor or severe hard Hi rpm use with huge spring pressures etc it doesnt seem to stand up except maybe or the royal purple single grades. Then we must ask ourselves are they better than the race oils or severe service Dg mineral based oil . maybe , I am not totally sure. What i do know is camshafts fail regulariy , everyday on Synthetics so they are not the cure all for cam failure. i think that is a fair conclusion. idling and low speed breakin are the worst thing for a cam and an engine for that matter. When my customers ask how to break in one of my motors I always say "drive it like you stole it." Why , because at high speed the crank is throwing oil everywhere in the engine and everything is bathed in lubricant. At slow speed often parts of the cam are not coated in oil because the only oil they are getting is the small amount leaking out the lifter bores. Very little oil is being thrown of that high up in the engine by the oil which leaks from the crank bearing which is where the cam gets most of it lube at hi rpm. The idea which was once popular and still unfortunately exists that you need to break in a new engine by gentle driving for the first few thousand miles was based on the fact that in the early days of motors we could not fit bearings and pistons as well as we can now and nor did they have the precison sizing they now do. Since about WW2 that is no longer valid. The desired clearance is put in the part when it is built . Solid babbit bearings which wear in are no longer used. The perfect fit is installed now when the engine is built. Rings always benafit from hard driving during the seating process. Babying a motor often leads to oil burnig because of this. Cams rarely fail at speed. Almost (if not always) at idling. In fact crane cams used to claim the vast majority of cam failures occured on the starter before the engine actually got started. . i happen to agree with that. Sometimes we tend to overthink problems. Often the solutions are obvious but appear too simple . Anyway i have said too much on this I am sorry. \ Just be as careful as you can on cam breakin (immediate start up and no idling sre whats needed) and if you are having great success with an oil and a proceedure dont change it. (The proceedure and brand I mean ) The comment that for the same money he could have had a roller set up though is well worth pondering when it comes to the current rate of cam failures which according to a recent hot rod mag article is currently far greater than it ever was in the past for both professional builders and amatuers builders as well. . Don Author of Return to Deutschland (True Adventure) Old Reliable (Mopar) http://altonapublicschool.faithweb.com/ http://seniordragster.bravehost.com/index.html [Non-text portions of this message have been removed] ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html. ---- Please address private mail -- mail of interest to only one person -- directly to that person. I.e., send parts/car transactions and negotiations as well as other personal messages only to the intended recipient, not to the Clubhouse public address. This practice will protect your privacy, reduce the total volume of mail and fine tune the content signal to Mopar topic. Thanks! '62 to '65 Mopar Clubhouse Discussion Guidelines: http://www.1962to1965mopar.ornocar.org/mletiq.html.