What type of oil

Just wondering what weight of oil to use in my 68 cougar with 302. And also looking to see what repair manuel is best Chilton or haynes. Thanks

Oh my, here I am a newbie, and the controversial and many times emotional issue of what oil to use comes up. After many years on other TDBs and as a newbie, I will tread lightly. I have always used a CJ-4 rated oil, like Shell Rotella T 15W40 or the equivalent Motorcraft, which ever is cheaper. Sometimes I have used WalMart brand too, just as long as it was CJ-4 rated. I have used them since I worked for 30+ years for an oil company, and as an old car mechanic/restorer, and the value of a CJ-4 oil has been proven many times for old school engines with flat tappets in my experience. It contains a high amount of zinc and phosphorous, which is very beneficial for old school engines, and it is cheap too. However, if you have roller rockers, and a new school type engine, or want to race frequently, use a synthetic, IMO.

I prefer Chilton’s.

I use Shell Rotella T 15W40 in my 390. Seeing that you are new to here. Welcome to the Classic Cougar Community.

Thank you, I feel welcome already. You would not believe what a bad reaction I got to that recommendation at Scott’s 428CobraJet.org forum a few years ago.

I’m using Joe Gibbs oil now because of the high zinc it offers. Does Rotella offer the high zinc.

When I picked up my engine at Keith Craft I was told to use a high zinc oil like Joe Gibbs racing oil. He said that they have had numerous cam failures lately throughout the industry because of the epa continually robbing our oils of the good stuff.

So if I have a cam and new heads I should use a synthetic?

I used the 15W40 for years in all my old cars until they changed the formulation and lowered the zinc content (6 or 7 years ago?)…so now I use Valvoline VR1 racing oil, either the 30W or the 20W50. And I’m a real looser and sometimes mix the viscosities myself, to thin the oil in the wintertime. The guys over on the FE Forum do that and it seems to have worked for them, and it works for me, too. The VR1 has been analyzed to show that it has an acceptable zinc content–but only the 30W and the 20W50 seem to contain enough.

High zinc content is the way to go. A friend of mine with a flat tappet lasted maybe a 1,000 miles using the regular stuff before his cam ruined his motor.

Are there zinc additive products that you can add separately?

Yes, you can buy ZDDP in little bottles, I have used it for break-in of new and newly rebuilt engines with flat tappets to supplement CJ-4 oil. There are synthetics that have the same high levels if Zn and P that CJ-4 oils have, but they are expensive and there is no need for an old school engine with flat tappets. We have had this question numerous times on many boards, but the Corvette group has it the most often I think Here is a great reference article by our oil guru at Corvette (see page 3), it answers most all the questions, and CJ-4 rated oils still have more than enough Zn and P amounts for flat tappets, the hasn’t changed:


Yes, if you have a roller cam and lifters. No if it is a flat tappet system.

ZDDPlus is good stuff. I should have not bought a bunch more recently as I (also recently) have begun work on a 408C full roller build. I’d sell 5 or more bottles of what I have at a discount if anyone is interested.

My engine builder also insisted on Joe Gibbs oil. Currently in the break-in stage, but I’ll probably use the same brand after the first change. Probably will have to be a special-order type of thing.

What about weight? It probably depends on the car, and the weather, but what oil weights do you guys recommend?

This is an interesting discussion, and one I have seen on other sites from time to time. It has been many years since I have owned a pre-1970 car and I would probably have put the usual Castrol Syntec 5-50wt in my '67 GT. This is what I run in my '87 Grand Nationals, all with no failures or problems. I wonder if it would make sense to add the zddp addative to a good quality synthetic? Would that work? I’ve heard nothing but good things about JG oil but have never used it.

In my old '79 Chevy pickup with 350 I have had for over 30 years, and over 200k miles, I run Castrol non-synthetic 20-50wt in the summer and 10-40wt in the winter. When my dad bought his '67 cougar with a 289 he was a traveling salesman. I inherited that car in 1974 and drove it for two more years. When I traded it in in 1976 it had over 230k miles and never had any major engine work. Both my dad and I ran Quaker State 30wt oil year 'round.

Valvoline VR1 Racing Oil is what I use and I send it through a Ford Racing oil filter to keep it clean. I only have 1,071 miles on my 289 since the rebuild and 671 miles on the first oil change. The first 164,000 miles of it’s life was mostly Valvoline oil (switched from Penzoil back in the early '80s). I swear by Valvoline in all my cars and trucks.

On the topic of viscosity, I was told many years ago that not only temperature (summer weather) and bearing clearances played a factor in what grade you should be using. Is it possible that some of todays engines use a tighter clearance and use thinner oils in comparison to older engines? Back in the day, you didn’t think twice on running 20w50 and the engine liked it, but today you see recommended viscosity from the manufacturer, set in the range of 5w30 for some and 10w30 for others. If this is true, depending on the bearing clearances even our older engines could run thinner oils.
What are your thoughts on this?

Yes, newer engines run tighter clearances, but this includes the pistons too (hypereutectic) and this is the reason for the thinner oil to my knowledge. The last idea you mention would work except for the piston clearance but because of this it will not.

There is an argument against synthetics in engines with older gaskets and seals. I have put synthetic in an older engine and instantly developed leaks EVERYWHERE. I switched back and the leaks stopped. Synthetic seems to not be compatible with older gaskets and seals or it simply flows to all the places the old gaskets can’t keep in.

-Ray Bischoff

Yes. I’m back.

Welcome back Ray!

I looked into getting some oil custom mixed specifically for muscle cars. (My father in law used to work for the Sun refinery in Tulsa where they did custom blends for many different brands). Basically what I learned was that the best oil for us would be fairly high in ZDDP but not too high as it becomes aggressively corrosive in too high a ratio, but also low in paraffin (wax). In cars that are not driven much, or stored for long periods the parraffin tends to get sticky and gum things up like the intake screen on the oil pump, and the excess ZDDP starts to etch the cylinder walls, or other non hardened polished iron surfaces. As a side note, if you start the car about once a week, get it up to operating temperature, and then let it run long enough to heat up the exhaust system to dry out the moisture, you can eliminate a lot of things that cause any kind of oil to lose effectiveness.

This is the ZDDP additive I have been using: http://zddplus.com/ There is a somewhat cheaper product on ebay (they both can be found on ebay) that the ZDDP folks do not like, say is not as good (lower ZDDP, etc.) but then again the other product is undercutting them on price so I don’t know how much creed to give the mud slinging. In any case, I have had no problems with the cam in my 351C using ZDDPlus.

Sorta off topic but… It has been said that 50% of engine wear occurs during the first five minutes after start up. This is due to not having full oil pressure and all parts bathed in oil. To combat this one company makes a preluber that pumps oil around and builds oil pressure before you start the engine. If you drive your car a lot and really want to extend the life of your engine this would be worth looking at.