Oil Weight for Bored 302?

My Grandfather did the boring.. I have no clue as to what the specs are as he passed away but I want to say at least .30 over. Any suggestions? I'm thinking 10-30 or 10-40..

 

Either of the one's you mention should work just fine. I use 10*30 in my car year round.

 

You will be just fine with a 10/30 provided the engine is tight/has good oil pressure. But...Unless you have a roller cam...I strongly recommend an oil with zinc in it like Brad penn for example...Short of Rotella 15/40 . Virtually nothing has zinc in it anymore, and rotellas zinc level has dropped due to tighter emissions standars for diesel engines..

 

Nope ALL oils have zinc, it's just been reduced by approx 25-30%... I believe the upper limit for a SN xW-30 is 849 ppm, this limitation doesn't effect xW-40 oils but most seen to have approx same as the 20 & 30 weights... Mostly this eliminated zinc rumor was started by the boutique oil companies with a solution searching for a problem...

Mobil 1 0W-40 has a good shot of zinc as well as their high mileage 5W-30(It's SL rated)... Also the Rotella T5 10W-30 has additional zinc(it's in my Comet)...

Lots of choices if you like 15W-40...

http://www.pqiamerica.com/June 2014/consolidated HDEO 2015.html

 

any "racing oil" will have more % of zinc. which is of course why they're called "racing oils" in the first place. I like VR1 and it's much cheaper than the boutique oils if you find a sale locally. They also have synthetic version too. 10-40 synthetic will be thinner than a conventional despite having the same viscosity rating. If you have a flat tappet cam?.. I would probably avoid 10-30's in the peak summer months.

as for specific weight requirements for any particular engine?.. while thicker oil can help minimize piston slap at startup.. the bearing clearances have much greater impact on viscosity requirements. The pressure gauge will give you more info on what the motor prefers and you can adjust weights accordingly. Not many motors need more than 70 psi of peak oil pressure once they're all warmed up and ready to rock. Anything more just makes life harder for the cam/distributor gear and robs power.

 

Yeah I should have mentioned VR1, was past my bed time...

 

Why not 10-30 in the summertime? I'm not out drag racing or anything but I'll admit, like anybody, I do crack into it from time to time but not 24/7.. Would rather not do a synthetic as I heard these old engines/gaskets weren't made for that. Thinking of straight Motorcraft 10-30. Don't drive it in winter that much and spring is almost here! Any more suggestions??

 

It was simply a general recommendation tossed in mainly because you're running a flat tappet cam and also have no idea of the internal clearances built into the motor. Other than looking at the oiling system psi.. no real solid way to know how the engine was built. Even that is misleading because there are many areas of an engine that can add restriction/increase pressure to mislead you about overall clearances used. And other areas that can blow off some gauge pressure even though it was built fairly tight elsewhere, rod side clearances for example.

Hell.. if it's on the tighter side, you could potentially run premium 0/20 weight if the motor is currently running very high oil pressures(75 psi or more) as it sits with 10/30 in the crankcase. Thinner oils can and do improve power and reduce crankcase windage giving better oil control/less packed charge contamination(synthetics give less cylinder wall "burn off" to help keep rings and ring lands cleaner too). BUT.. and it's a big but.. even with heavier sacrificial additive packages(like zinc/phosphorus) being added, there comes a point during viscosity reduction that shear strength of the film becomes dangerously thin with added rpm and higher valve spring rates needed with aftermarket flat tappets cams.
Plus, it's a well known fact that thinner oils rely less on shear strength and are forced to expend their "sacrificial" additive packages more quickly to achieve that same level of protection as thicker oils even having the same exact proportion of protective additives. Which means that thinner oils used for performance gains will typically need to be changed more often as a result of that increased sacrifice/higher depletion rate. Should read up on oils.. this is "oil 101" type stuff. As with anything, there's always a trade-off hiding somewhere.

I'm assuming that your car no longer contains very many original OEM engine parts so you will have absolutely no problems whatsoever with gaskets and seals. And even if it was bone stock original.. I never had problems running any synthetics on any old musclecars years ago. Just stay away from "high mileage" oils because they are the ones with seal conditioner packages for swelling gaskets to prevent/reduce leaks. I could be wrong here, but I also doubt they'd be worth a damn for use with flat tappets anyways.

Wasn't trying to complicate or confuse(although my wife calls it "one of my gifts", I still think she's just too damned easily confused, is all).. simply passing what I've learned through personal experience and from hardcore gearheads with much much longer coattails than I will ever have. I myself like to tighten up moderately powered engines used for the street.. and loosen things up from there as power and rpm go up. For pure race.. looser motors make more power so long as you control the oil well enough but need to be refreshed more often. See.. there's another damned trade-off all over again. LOL Hope that helps clarify things a bit better for you.

 

As any oil co about their high milage oils, they'll state they are perfectly safe for seals in any engine new or old... Of course most now have reduced zinc so aren't a good choice... Mobil 1 5W-30 HM is one of the last hold outs...

As I stated earlier I'm using the 10W-30 Rotella in my Comet with flat tappet cam, I'll let y'all know if there is a problem...

 

lol.. of course they will, Tom. Petrol cost is down but oil is still like liquid gold due to sheer quantity. eerrr.. based on gallon price maybe that would be Milk? How much is a 50 gallon drum of milk going for these days? LOL

Generally speaking, I realize you're right for the most part and I'm sure many have and will continue to use those additive packages without near term issues. What I really base my opinion off of is the results from having used some of those cheap "pour in gasket sealers" many years ago when I still believed in magic pills. The affect on different materials was startling to say the least. Cork valve cover gaskets swelled up so much it actually looked like someone grabbed the corner and pulled it out despite being cranked down well enough. Any and all inside edges of excess gasket material not being pinched by the valve cover rail were actually so swelled up and wavy that they couldn't even be put back on after I removed the gasket. Looked like curly fries that swelled up about 10% bigger than their original size. Admittedly, I was young and stupid using too much in one single application.. could have been like 50-100 oil changes with the newest formulas all at once. But the trend and affect was obvious enough to learn something about chemicals and cork/rubber expansion characteristics.

After that experience, I once bought a motor that very well likely had that same crap mixed along with motor honey/gear oil to stop timing chain slap and noisy lifters. Didn't fully realize what was going on until I put fresh oil in it. Looked like gear oil draining out during the change and about 10 different leaks all over the place incuding the tops of 2 header pipes. Needless to say.. I got some decent money back on that deal to cover the necessary repairs.

Also consider that the really good transmission and HVAC guys will also warn you away from seal conditioners as well. As I understand it, this is mainly because they only condition in one direction before deciding they've reached their peak level of impact before they begin going in the opposite direction. Different chemical mechanisms at play, but think about what happens to a heavily swelled rubber seal exposed to ethanol over a period of time and then allowed to sit dry. Re-exposing them to ethanol won;t fix it.. irreparable damage was already done during expansion and contraction..seal will eventually fail. Some manufacturers will even void your warranty after using these types of "fix alls" too.

Main point is this. There is no magic bullet to fix this kind of stuff when something is not sealing properly. Almost always best to figure out the issues involved to actually fix the root of the problem. Gives you plenty more time before any band-aids will ever be needed down the road.

Respectfully,

Greg

 

Well the HM oils have worked fine in 4.6s I've owned, stopped a rear main seal drip on one I sold almost six years ago... In my '98 Grand Marquis Mobil 1 5W-30 HM has lowered consumption from 2500 mi qt to 4500 mi... Problem was(is) from a couple leaking valve stem seals, two intake ports in head were wet with oil, this was found when the POS plastic intake busted and I had a friend's son who was out of work replace it... To that point I didn't know why it was using oil, figured it was worth a shot...

 

I hear ya, Tom.

My overall guess is this. Cheaper non-oem type cookie cutter builder stuff has it worse with these types of chemicals vs anything even remotely newer and improved OEM designs. Nitrile/viton/hybrid rubbers/urethanes and much better MLS or o-ringed gasket designs do better than ever before to give manufacturers and consumers 10 years or more of protection.

If the industry wasn't dealing with accumulation for all sorts of minor failures turning into more major ones at TODAYS currently inflated shop rates?.. the market wouldn't even exist for these chemicals to ever be utilized. IMO, it seems that too many people reading the advertising act like they're playing scratch off tickets and just keep playing/pouring the next big thing into their engines in hopes they'll eventually win. Not saying there isn't a legitimate amount of good products and oil formulations being put out these days, because aside from todays more stringent chemical and VOC laws, we have more chemical technology being leveraged today than ever before. Best ones are pricey and its just kinda tough to find them in the sea of snake oil being released to loosen up your wallet, is all. And there are some real bastards out there who mark their products up near the premium products just to psych the average consumer into trying it even just once. At this point I'm more inclined to look at the little "snake oil" salesman pulling his wagon from town to town over the big conglomerates who own and control an industry and its entire price point structure. I know it's just capitalism in full glory but cool pictures of racy or exotic cars on boxes and displays and brochures with pictures of hot women surrounded by palm trees only makes me look.. but I rarely ever buy the product.

But.... that sounds near like talking politics.. and I should be working on engines.. not just talking about them. later guys

 

I have used major oil brands Motorcraft, Pennzoil, Valvoline and the like in my mild modified flat tappet cam since I got the car July 2009 w/o any issues. The car is a mostly weekend cruiser, optioned w/ pwr steer and AC; it has made several rode trips. So far, not had any engine issues. I change oil once a year "average 1500-2000" miles a year.
I say - oil up - enjoy the spring/summer season.

 

I am going to run Mobil 1 Delvac 15w 40 in my flat tappet racing engine.I have been driving 18 wheelers for almost 25yrs & had my own for 8 of those yrs.This oil is THE ONLY ONE I ever ran that I didn`t have to add a gallon between 12000 mile oil changes(Rigs hold 12 gal. of oil).My racing eng will also get a bottle of zinc additive.I own a 2002 Dodge Ram 2500 cummins diesel p/u which has a solid lift cam in it,needless to say it gets the same oil.It has 230,000 miles on it and uses no oil,I`m not going to say the expensive synthetics aren`t better.However,if you can find something better,BUY IT.

 

Appreciate the suggestions! Okay, so I talked to a gearhead that I did some work for last summer, he suggested 10-30 or even 20-50! I seriously doubt I'll go that far but he said he runs the 20-50Royal Purple in his 54' Chevy.. He also mentioned, as did you guys, about a zinc addidive.. So definately going to add zinc no matter what. Also, my old man said he'd go with Penzoil over Motorcraft (we're a Ford family btw) since he seems to think it's more "high performance" oil. One more thing.. Has anyone ever put ATF to flush/clean the oil system before changing the oil??? Either way, I'm not doing the change for another week or two, so keep the thoughts coming!