Mikelly Posted July 4, 2000 Share Posted July 4, 2000 ....After you have driven your car around town or on the road a bit, what is the oil pressure at idle on your 350/383/small block motors? At idle mine is holding about 15-16psi of oil pressure... is this normal? Also, I'm trying to lean it out, am running about 16 degrees of timing at idle and I have leaned out the metering blocks on the carb a bit, but I can still smell gas in the exhaust pipe as it idles... any suggestions? Maybe drop down a jet zise or two? Mike ------------------ "I will not be a spectator in the sport of life!" mjk Quote Link to comment Share on other sites More sharing options...
pparaska Posted July 4, 2000 Share Posted July 4, 2000 Mike, I seem to remember the old rule of thumb being 10psi for each 1000 rpm being a good goal for oil pressure. Anybody know if this is right? Rich idle. Yeah, primary jets could be rich, but what about the power valve. The get blown on backfire. Then they leak fuel all the time. I installed a check valve (Spectre?) in my Holley to help that from not happening. Check a Jegs or Summit catalog. I think Holley makes one now. Quote Link to comment Share on other sites More sharing options...
John Scott Posted July 4, 2000 Share Posted July 4, 2000 Mike, I wouldn't worry about your reading @ idle. About where mine is after it gets hot. Use to bug me, but always have great pressure at speed. I agree with the 10 psi/1000 rule. What kind of oil do you run? I get a little more pressure with the 20-50 racing Vavoline. Got to warm up slow so you don't peg the guage and blow the filter. Also harder on the dist gear I've heard. All the new cars seem to run the 5-30. Looks like water to me! JS Quote Link to comment Share on other sites More sharing options...
DennisK Posted July 4, 2000 Share Posted July 4, 2000 I worked for the Quaker State Corp. from 82' thru 89', ending as a regional mgr. I have had many arguments over the years about oil and oil pressures, & filtering. Most people don't realize that the oil filter was an OPTION for car buyers on some models into the early 60's. "SC" motor oils were pretty basic, and recommended change was at 1000 miles. With each new designation(SE,SF,SH etc.), the lubricant is asked to do more than just lubricate. Suspending contaminents, and protecting the bearings is critical because NO filtering media has been developed that can filter completely and flow fast enough to avoid lube starvation at the bearings. By-pass spin on filters have a valve inside that allows the lube to by-pass the filter at pre set pressure. Pressure settings vary by manufacturer, however are in the 7-12 lb range. This means when your oil pressure is at 15lbs, the lube is bypassing the filter. 99% of engine wear happens at cold temps. The first 5 minutes is critical for lubrication/wear. The tighter the engine, the lighter the lube needs to be to do it's job, cold. In SBCs, tolerances are not as tight as the newer 4cyl engines. 20w50 should not be a problem, and is preferred as long as you don't start racing 2 minutes after start-up! On a 90+ deg day, at idle, with a/c, at a stop, foot on the brake(AT), 15lb oil pressure is expected. Less would be so noisy you'd shut it down anyway! The "5" in 5w30 is the same viscosity as penetrating oil! Not bad for cold starts and tight tolerances. The number after the "W"(which stands for Winter, NOT weight)is the viscosity at operating temp. A 50 will have a resistance to flow more than a 30, therefore better lubrication. Proper warm up will minimize wear, and different brands do have different pour points(room temp pour) even at the same viscosity. QS's 15w40 had a pour point of a 10W, so had easier starts in the cold weather. My recommedation for performance engines, as most have here, is 20W50 synthetic, of a brand you know. They are now proven to lube quicker at cold start, and hold up to hi temp. Synthetics should not be used to break in a new motor. Non syn, (organic) lubes CANNOT break down, as advertised by some. They get contaminents (dirt)which lessen effectivness. Hi vol, Hi pressure oil pumps will make a difference in readings, but slight at hot idle. Hi vol is preffered, but hi press could present a flow problem in racing conditions. Quote Link to comment Share on other sites More sharing options...
Guest RON JONES Posted July 4, 2000 Share Posted July 4, 2000 I would also agree with Pete and John.You should be fine with the 10psi/1000rpm rule.John you should see the ROYAL PURPLE 21 that I started useing,5-30w and it sure does look like purple water when its hot.Dennis,do you know anything about ROYAL PURPLE?I,ve been told that it is the way to go for drag racing. [This message has been edited by RON JONES (edited July 04, 2000).] Quote Link to comment Share on other sites More sharing options...
DennisK Posted July 4, 2000 Share Posted July 4, 2000 I've heard the same. There used to be a product called Royal Triton, it was purple also, and a lot of people swore by it. I am not up on latwst race lubes, but would trust what I see with my own eyes at the track, in or around the garage. Stickers on the car mean nothing. One year at Elkhardt Lake, Wi., the CART cars were running Q.S. 20w50 in all but three cars. We were the only ones who had a distributor close, as the other trucks couldn't get in. At that time, late 80's, Q.S. 20w50 racing oil was the exact same product in the retail bottle as for the pro. No one else did that. Now Pennzoil merged(aquired) Q.S., and I doubt anything is the same. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 4, 2000 Share Posted July 4, 2000 CASTROL 20/50 GTX OR CASTROL SYNTEC!!!!!!!!!! TRUST ME, I WOULD NEVER STEER YA WRONG. ITS THE BEST OF THE BEST , IF YA DONT BELIEVE ME , JUST ASK JOHN FORCE! HE HE HE HE LOL LOL. ------------------ 74 260, sbc 350, 700r4, and a few little HP Mods.just gettin started good. www.speedtechcoatings.com [This message has been edited by takman57 (edited July 04, 2000).] Quote Link to comment Share on other sites More sharing options...
DennisK Posted July 5, 2000 Share Posted July 5, 2000 Castrol is a good product, as are any name brand you readily recognize. [This message has been edited by DennisK (edited July 05, 2000).] Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 5, 2000 Share Posted July 5, 2000 I am no super wrench by any streatch of the imagination,, but I have been using only castrol products for over 30 years in all kinds of motorized toys, and I am still always amazed at how clean the insides of the motors are when ya open them up. I am sure you can get the same results with other products,, I guess I am just a creature of habit, but I'm sold on castrol. Tony ------------------ 74 260, sbc 350, 700r4, and a few little HP Mods.just gettin started good. www.speedtechcoatings.com Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted July 5, 2000 Share Posted July 5, 2000 For a non-synthetic I've always used the Castrol myself but in a motor I care about it's Mobil 1. I suppose if I had the money and easy access to product I'd use RedLine or Royal Purple. I've personally seen the detergent action in Mobil 1 clean the undersides of valve covers and intakes - impressive. No varnish afterwards, just clean! Since it sounds like low oil pressure is okay at idle what sort of pressure shoudl you set a warning light for? On this build I'm actually tempted to run one but don't want it going off all the time. On my old Vege Gt with a worn 350 I'd see oil pressure nearly at zero on hot days - that motor was in pretty bad shape And since we've got a Quaker State perosn on board I have to ask - any truth to the rumors that there was wax of some sort in that oil? I'd been warned to stay away from it years ago and was told that parafin was used for the multi-viscosity. Supposedly it wasn't too hot at lubricating but I never had any real evidence to back up those claims (shrug). Quote Link to comment Share on other sites More sharing options...
DennisK Posted July 6, 2000 Share Posted July 6, 2000 There are 3 basic types of crude-napthatic, mid-contonent and Penngrade. Penngrade comes only from the Pennsylvania region(part of W Va, Ny, Oh)and gives the best yield of lube per gal. Napthatic yields more light end fuels per gal. Penngrade is also known as parraffinic, which refers to the wax in the oil. This wax is used to line food containers like milk cartons(no, they NEVER put my pic on one, that was just a rumor!) Our entire annual company overhead was paid by the wax sold alone! There wasn't a speck left in it, but the competition used to like to say those things. It's all changed now as they are not using penngrade any longer except for special customers(racing!). When I was there we were the only oil company that gave a no charge, lifetime warranty, free to anyone who used QS from their first change. It covered everything the oil touched. We even paid a few claims on the sbc cam problem, and that was Chevy's fault. It truly WAS the best. [This message has been edited by DennisK (edited July 05, 2000).] Quote Link to comment Share on other sites More sharing options...
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