I don't think you have to worry about putting syn oil in a car that always had dino oil in. The one thing that could be a problem with that is the fact that if the car has a lot of deposits inside the valve cover then I do not think that I would use synthetic oil. The syn oil may clean that stuff off inside the engine and get the screen clogged up in the oil pan. But using trans fluid to help clean the engine will do the same thing if anyone has ever tried that. If the motor is fairly clean inside I see no reason not to put in synthetic oil. I have heard stories about it will leak past the seals and all this. If the motor was real dirty inside sure I could see this the syn oil is cleaning out all the crap in the motor. Think about this the 10-30w syn oil is no thinner or thicker than 10-30w dino oil. If you want thinner oil then go with 5-20 weight in any kind of oil and it will be thinner. 10-30w = 10-30w The one thing I like about synthetic oil is it will not burn. I put a torch to this in a thick metal container and all it did was bubble when I got the metal hot. When I did the same thing with dino oil the oil started to smoke and turned black. So synthetic oil can at least take the heat from the motor. Now wouldn't it be nice to know that maybe you didn't cook the bearings in the motor if you had overheated some? The synthetic oil may give this the extra edge it needs if something like overheating happens. This is just my opinion but I think this is logical. Did I convince you? My choice is Mobile 1 oil I have used it for 15 years now and have great confidence in it. They have the super syn out now that is supposed to be good for 15,000 miles. The 15-50w I have read has more of the zddp in that particular oil. I just use 1/2 10-30 and 1/2 of the 15-50w oil and this keeps good pressure up, is not too heavy in viscosity, and has a little more of the zddp. I just had the oil pan off recently and the motor looks like brand new in there and that is after 15 years on a new motor. I have always been a fan of Pennzoil oil when looking for regular oil. I ran the engine hard on that oil too before I ever had the motor rebuilt.
Thanks again for the feedback. this is all good stuff. Sorry I haven't gotten back right away but I ran into a problem during the oil change. I had already drained the oil and was about to fill in the new oil when I realized I bought one bottle of 10w-30 and four bottles of 20w-50. I guess I was in a hurry and not paying attention grabbing the bottles from the rack. Anyway not having a way back to exchange the oil I went ahead and used what I had ou: . Am I going to have problems? Another thing I noticed, this was even before change, at start up the pressure is at 40 psi. but after awhile it drops down to 20 psi at idle. Is this normal for stock 350?.
Those pressures are fine for a bone stock 350, Im assuming from the pressures the oil pump still has the stock relief spring in the pump? Your hot idle oil pressure is excellent Yes, its normal for ANY engine to have less oil pressure when the oil gets up to temp.
Whew! Thanks Mark, that's what I needed to hear. Can't afford any problems on the way to Dallas. How about the oil I got in there. Is that going to be alright as far as the weight is concerned?
You'll be fine for an extended drive. Thick oil hurts more on cold startup, so let the engine idle up to temp before going for a romp. Devon
Can I use a diesel motor oil in a car? The newest CJ-4 formulations are now limited in the amounts of Zn and P allowed, compared to the CI-4 formations most users are familiar with. If the oil says CJ-4 or LE or "Low Emissions", even if it also lists CI-4 or CI-4+, more than likely it conforms to the new, lower levels, and should be avoided unless you have a 2007 and later diesel which requires these oils. The verdict is still out in my opinion on the performance of a CJ-4 oil in our application. If you choose to use a diesel or mixed fleet oil, stick to an a CI-4 rated oil. Nowhere should the oil say for emission system protection or for use in engines equipped with particulate emissions filters. Swepco 306 15w40 is one such example of an extraordinary diesel oil we use in our performance engines. Swepco 306 has a healthy dose of boron and moly also for additional ant-wear response. Although difficult to find, earlier CF-4 or CH-4 rated diesel oils have similarly high levels of Zn and P but are less detergent. Worth noting, CI-4 diesel motor oils tend to have more detergents, and it has been determined in the SAE paper "Oil Development for Nascar" that overly detergent motor oils can block or "clean" the anti-wear films off of engine parts, that is one reason that these oils usually have high levels of anti-wear additives. SAE Technical Paper Series 2007-01-3999, Modern Heavy Duty Engine Oils with Lower TBN Showing Excellent Performance, also show that low detergent packages increase the effectiveness of film formation, just as in racing oils tend to have less aggressive detergent packages, which is another reason many be to consider a racing oil versus a diesel oil for your engine. The new ACEA E9 specification will be for a low Zn and P (ash) oil with low TBN, building upon this relationship to ensure that wear protection is not sacrificed for improved detergency or longer drain intervals. http://www.lnengineering.com/oil.html#Z5
Thanks Devon, I needed to hear that too. How long should I keep it in there. Should I have it changed when I get there, or is it good till the next 3k mile oil change?
Wally World oil...... I use the cheapest/on sale 10W-30 oil I can find. The car runs like a "scalded dog" with over 150,000 original miles, and has never burned or used a drop of oil between regular oil changes every three thousand miles. "Go Fast with Class".... Gotta Love It!
If you're driving it regularly, I wouldn't change it until 6K unless you get into some cold climates before then. Devon
Gee, what you'll worrying about this oil thing. I knew a guy that bought a 1950 Chevy new and changed the oil one time in 25 years of driving. His son was going to do him a favor and change it and took the plug out and could not get anything to run out. Poked around some and gave up and just poured some more in it and let it go. Would have been interesting to see how long it would have ran if the timing gear had not stripped. Who needs any oil changing anyway? Jim N.
in our race motor i use napa or carquest 10-30, which is valveoline rebox. never any problems with the oil. turning it 7500rpm is a different story.:laugh: btw, with the rod bearing at 1.88 and a s/c, we're banging 6500 rpm. which is kind of a no-no. heck, its just an r&d engine anyway.
That's great. I will be driving this car regularly and hopefully not have to worry about cold weather in TX. Thanks again Devon :TU: .
My daily driver is a 91 GMC 2500 and it has 325,000 km on the original engine. I drive 220 km a day right now and that is at 80+ MPH. The Rotella 15W40 protects the engine and does not leak. The engine burns half a Litre of oil every 500 km. When I bought the truck it was using 10w30 and burned 1 litre every 500 km. My point is that my worn out engine prefers the Rotella Deisel oil. Since we are into freezing weather I went to a high quality 10W30 Synthetic oil and leaked a half litre of oil in two days! I changed back to the Rotella, cleaned up the engine and no more oil leaks.
