I switched over to 20w 50 normal cheapo walmart oil from the 10w 30 I always run (in my "new" used junkyard 1975 chevy 350) It stopped smoking completely, quit burning oil, runs much smoother, idles incredibly better, starts easier, exhaust seems cleaner... overall an insanely big difference The motor needs rebuilt but right now I'm just driving the heck out of it, 57 is my daily driver, probably 50+ miles a day. So will this change hurt anything in the long run? I ran this motor for a few weeks and it ran very, very poorly until I switched oil grades... now its like a completely different motor! I actually like it!
Did the cheapo Walmart oil block all of the passsages in the motor so there is no way for oil to get into the combustion chamber any more? If it works, don't fix it!
Well it is much thicker than the old oil, I adjusted the rocker arms running with the covers off yesterday, definately getting great oil pressure out of everyplace... what a mess it was. Sprayed everywhere. The oil is also very, very clean... runs cooler than it did before It is the cheap stuff in the blue 5 quart bottles at walmart. I have been using it for a while and it seems just as good as "better" stuff for old engines like this. Spark plugs used to be oily, now they aren't at all... too thick to get around the rings maybe? I like it.
to me oil is oil for the most part as long as you change it frequently. by the way never run 10/30 on an old sbc, i run 10/40 on the rebuilt motors and 20/50 on anything with some miles on it.
1) Repackage the walmart oil as "Slick 50" or "Engine Rebuild in a bottle" 2) Make millions 3) Let me have a 10% cut for the idea! Seriously, I'm glad it's working for you!
i was expecting to read that the motor had just completely grenaded itself and stopped running all together!
My old 327 quit smoking. When it snapped the crank and cam at about 30mph... that motor had a hard life though! I kinda suspected the worse when it happened even though it wasn't very hardcore. Just felt like someone had cut the ignition off, no nasty noises, no grinding, no clunking, no ANYTHING Just felt like the ignition switch was shut off. The next day when I went out to look it over I realized the issue when the starter would not turn the motor over because it seemed locked, although I could turn the harmonic balancer over by hand. That old crank just gave up! My 350 is more than a bit more powerful.
Wow, glad to hear that worked. I thought Id be doing my engine a favor by switching to a modern oil with detergents. Sure stuff got cleaned up, but that stuff was making it so my rings wouldnt leak. Now my motor smokes. Oh well, gotta learn somehow.
Straight 40 is my personal favorite, but not too many store got it anymore where I'm at, so I have to settle for straight 30.
Can I ask why? I've been running 10/40 Valvoline in my 327 (which is old as in 1968, not old as in high mileage, if that makes a difference) but I occasionally top off with 10/30 if I can't get the 40. I'm seriously contemplating switching to Rotella diesel oil next time I change it, based on the flat tappet cam article in the latest Hot Rod.
They don't put a lot of additives in modern motor oils that they used to (primarily zinc, it seems) that keep flat tappet cams alive. Roller cams don't require the additives and that's all the OE's use anymore. The additives are hard on catalytic converters, so they've started leaving them out and now people are wiping cam lobes more often on flat tappet cams. According to the article, diesel oil still contains those additives.
Valve guides are probally loose and the thicker oil won't go past them now. Running the 20w50 won't hurt anything. II have been running rotella for years in my race cars and never had a problem.
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