Oil Recommendations

Don't use cork valve cover gaskets, they compress and start leaking so you re-tighten them, only to have them compress again ... and again ... and again ... until they split and need replacement.

There are silicone valve cover gaskets on the market that absolutely seal wonderfully, but they cost about $50 each.

You'll probably want to select something in between those extremes. I normally pick up whatever non-cork gaskets the local auto parts sells, lay a thin bead of RTV sealant on both sides, let the sealant dry completely, then install them being careful not to over tighten the bolts.

The 351C was designed to operate with 20W40 oil, haven't found that on the shelf since the '70s. 20W50 is a good alternative. Its 20 weight oil, just like 20W40, but it has just a bit more viscosity enhancer in it.

In the good ol' days I would have recommended Castrol, but no more. Today we must pay attention to which oils have adequate levels of ZDDP in them, because these old motors were designed to operate with a certain level of that additive in the oil. ZDDP poisons the catalyst in catalytic converters. The US government requires auto manufacturers to warrant their emissions systems for 100,000 miles. So to meet that requirement the manufacturers have built motors that don't require ZDDP, and then they drastically reduced the spec for the amount of ZDDP additive in the oil for the modern engines.

Up until recently Diesel motor oil had ZDDP in it, and we were using that, but for 2008 the ZDDP level in diesel oil was reduced too. So at the moment I'm recommending Valvoline VR1 racing oil. Either 20W50, or if you want the best, straight 30 weight.

Go up & down the aisle of your local oil supplier, and read the labels of each brand, you'll notice that each manufacturer labels their straight 30 weight oil as HD, or heavy duty. For whatever reason, the oil manufacturers use their premium oil stock, with the best, most shear resistant molecules, in their straight 30 weight oils.

Same considerations must be applied to synthetic oils, you'll want to use one that has adequate ZDDP in the formula. Nothing manufactured for modern engines will meet that qualification. Amsoil 20W50 is the only synthetic I can recommend for that reason. An interesting feature of Amsoil 20W50, it has no viscosity enhancer in it, its viscosity is so stable at elevated temperatures that it can achieve a 20W50 rating without enhancers.

So would you use the straight oil or synthetic? I have a friend who races his BMW that swears by the synthetic.

I kind of figured the cork gaskets were no good, that's what on her now. Thanks for your input on this. I used to work on a Super Modified race team and the gaskets we usede were a FeelPro with a metal rib in them for a big block Chevy running on Methenol! Thew were great and would last a whole season. They ran about $90 a side.

While synthetics are great for breakdown from high temperatures, I am not a big fan of "Pure" synthetics. Here's why.

In the 90's Mobil produced a full synthetic for airplanes. Within a short period of time aircraft after aircraft began to have trouble. Engines were not making it to their overhaul interval and propeller governors were failing.

The problem came from the lead in the fuel. Aviation fuel still has lead in it. It was soon found that the FULL synthetic oils could not break down the lead. This lead to very fast sludge build ups which was damaging engines and locking up the propeller governors.

Today we have very clean gas but there is still 2 concerns with full synthetics. First is it can not break down carbons as well as blends and natural oil. This is not to say synthetic is not good oil. It just does not have the ability to break the carbons down as well. They add additives to help this but with each added percent of additive the less percent of oil you have.

Second is the adhesion to bearings is not as great because of its slipperiness. I know some one who tried a full synthetic and first time on the track wiped out a couple bearings. Changed the bearings and the oil back to a blend and has not had another problem in years.

In a corner momentary oil starvation the bearings can glide on a momentary film. With synthetics it slides off faster. BUT again they have additives for this which means...less oil content.

Now we run full synthetics in our jets but they are not exposed to carbon blow by nor interruptions in oil supply of any kind as well as far better filters. 3000hrs latter and these oils are still as clean as baby oil.

My vote is for a good blend.

Thank Comp2!

I'm probably going to follow CFH's recommedations and stay away from the Synthethics. My friend has a small block 4 cly and I was used to a small block 289. I ran 10w 40 in that motor due to the high compression.

Thanks for the advise!

George

quote:

Originally posted by geoshanna:
Thank Comp2!

I'm probably going to follow CFH's recommedations and stay away from the Synthethics. My friend has a small block 4 cly and I was used to a small block 289. I ran 10w 40 in that motor due to the high compression.

Thanks for the advise!

George

Keep in mind the only synthetics I have problems with are the pure synthetics.

Gary

George,
I'm glad you asked this question, I've been pouring over forums trying to figure out what the best option is these days (I too am a new Pantera owner).

That said, prepare for a long answer based on the research I've been doing the last couple of weeks - the Web is a very confusing place.

I've read a number of comments from people - many claiming to be engine builders - saying that if the bottle has an API SM rating, then the ZDDP level is about 1/2 to 1/3 of what it was in the '70s. So, armed with that information and I've gone up and down the aisles at auto shops, gas stations and even (gasp) Wally World looking for something without the SM rating. I finally found some Quaker State oil that's being marketed as being designed for high mileage older model cars, and it didn't have the 'SM' designation (I thought I'd finally found the oil I needed), but on further investigation, found a thread somewhere that said QS didn't go through the official channels and pay to use the API SM stamp, so they had to stop putting it on that particular type of oil (so now I don't know if the oil has higher ZDDP, or is just a cheaper modern oil without a stamp on the label).

Then there's the threads that say you don't need the ZDDP in classic engines - if you look, you'll find them and the flame wars back and forth.

Then there are the conflicting threads from companies that market ZDDP additives, and people saying don't put in additives, it's better to use straight oil from a manufacturer who puts together the right balance in the first place.

So, after reading lots of opinions from people on Ford sites, Chev sites, and Mopar sites, I was planning on asking this very question here as I have greater trust in people I know aren't here to market one product over another. Hence, When someone like George P. (KFH) says you need ZDDP, I'm inclined to listen.

Unfortunately, up here in the great white north, I haven't found Amsoil products, so I've been pouring over Used Oil Analysis reports at this Used Oil Forum and looking in particular at the Zinc and Phosphorus numbers (the ZDDP).

The most common advice I've seen from the classic car sites is that you want the zinc to be around 1200ppm in the oil, and the currently available (where I am) oil that is hitting that mark is Shell Rotella T 5W-40 (UOA reports I've found on it regularly report Zinc and Phosphorus well above 1000ppm (often up around 1300 for zinc), while many other modern oils are down around 600-700ppm)

Mobil 1 posts it's Phosphorus & Zinc ppm table here - Mobil 1 Engine Oils - however, most if not all of these are fully synthetic, so based on Comp2's reply, you may want to avoid these.

As for Castrol, if you look at this Q&A on their site (see #2) the author admits that ZDDP is needed, but then when he talks about Castrol's response, he uses the future tense (meaning that they haven't got anything yet).

I'm still digging to try and find a UOA on the Amsoil 20W50 - the 5W30 from Amsoil doesn't appear to be quite as good as the Rotella T based on the numbers I've found, but it seems to still get very respectable results compared to other oils - the Amsoil 20W50 could very well be much better, I just haven't found it yet (and it has the CFH seal of approval, so maybe I need to look harder ) Redline and Brad Penn oils look good too.

One word of advice is to look at the source of everything you read, many forums are backed by oil companies, additive companies, or even sales reps from one or the other (even the one where I'm reading the UOA reports is rumoured to be hosted/sponsored by a rep from a specialty oil company) .

Good luck.

Whew, I hope that helped!
Note: I'm not an oil expert, I'm just a guy like you that wants what's best for my cat and looking to the gurus on this forum to set me straight if anything I've found in my research is flawed.

George, i had the same questions when i first bought 7260. Most of my questions where answered on this web site. THANKS GEORGE PENCE!! For motor oil use Valvoline VR1 racing straight 30 weigth. It has ZDDP. For your ZF trans use Castrol Hypoy C gear oil 80-90 weight. Forget synthetics, those products are for new vehicles. Chuck

Made a couple of quick calls to the Shell and Valvoline product technical support numbers, and here's what they told me about their current forumulations:

Rotella T 15W40 - 1210ppm Zinc and 1110ppm Phosphorus (this is in the New Rotella T Triple Protection (CJ-4 blend oil)
Valvoline VR1 20W50 - 1400ppm Zinc and 1300ppm Phosphorus
Valvoline VR1 Straight 30 - 1400ppm Zinc and 1300ppm Phosphorus (same as the multi-viscosity in this regard)

So, they're loaded up with almost twice as much as today's 'SM' rated oils (which are around 600-800ppm). Most of what I've read says flat tappet engines need 1200ppm of ZDDP, but there are a few writers who say we need as much as 2000 ppm (even higher during break-in of a new cam).

For reference, Rotella T in a 4 liter (approx. 4 quart) bottle is $19.99, as for VR1 20W50 I was able to pick up a case of 12 1L bottles at Napa for $5.79/L on Monday - after taxes and the environmental fee, it was $79.10 for the case (Canadian dollars).
NOTE: I had to negotiate that VR1 price, the first store I was in wanted $7.69/L - I walked out when they kept answering phone calls instead of taking my order - went to the next NAPA store two towns over, smiled and chatted with the clerk, asked for a good price and voila Customer Service!!!

Good info indeed. Here is one of the best oil sites I've found, although it looks like he's now sponsored (or at least getting some ad revenue) by Mobil 1 and others. The site used to look very amateur, but now it has a professional polished look to it:
http://www.bobistheoilguy.com/

My neighbor runs Collectors Choice in his restored XKE
http://www.mossmotors.com/Shop...ID=65895&SortOrder=2
http://www.mossmotors.com/grap...810_220-815_INST.pdf