The Stovebolt Site Forums The Shop Area General Truck Talk Synthetic motor oil in the old 6.

Do you guys use or recomend using synthetic oil in the origional 6 cyl?. The block in my truck is origional (never been apart)and I was wondering if synthetic would help to better protect it or is conventional oil OK.

Thanks.

I firmly believe that synthetic is superior in all engines, all ages.

Here is a good article regarding modern oils in your old truck.

Lot's of good discussion about this, try a stovebolt search for some good reading. About 100 hits on a search of "synthetic oil"!

That IS a good article.

But, I have read discussions regarding lowered zinc content in modern automotive oils due to emissions equipment. In my 250 inline 6 I have switched to Rotella T oil for diesel engines.

I'm using 15W-40 in my '51 216, same as my big truck gets. It seems to like it.

Same as hotshoe36. Shell Rotella T Multigrade 15W-40

The Shell Rotella T multi-grade 15W-40 oil appears to be non-synthetic (I am noting this because this thread started out with a question about the use of synthetic oils in 216 engines).

I believe in synthetic oil and yes the article linked by Ghostrider is an informative article. It seems the author's primary objection to using synthetic is the cost & tendency to extend oil changes when using synthetic oil. Both are valid concerns but if one is primarily concerned with preventing wear & not cost, I believe synthetic is the way to go.

This one seems to meet the qualifications of being comparable to a 15W-40 eventhough it is listed as a 5W-40 Synthetic.

Link

Anyone ever tried it? Opinions?

Blown up 3 350 chey's in past 4 years using Pennzoil, all flat serface failure, cam flat, hole in rocker 2 dropped valves. I think it was caused by the lack of zink in the oil since 2005. Flat tappet engine owners beware.

Take a HARD look at what Beaver says, especially when you have rebuilt an engine, the zinc compounds in the oil protect the flat surfaces, specifically, zinc is an anti-wear additive for surfaces such as tappets and cams. The zinc has been lower, lowered, gone out of most oils now. As an engine wears, it uses oil, and zinc degrades the catalytic converter performance so big brother required they phase it out. It is still found in Rotella diesel type oils as well as the "high Mileage" blends and in certain additives. Do not take my word on this...do some research on the net, I will post some websites so you can check this out. Anyway, diesels are going to have catalytic converters soon, so the zinc will be gone from them also. The GM EOS assembly lube is a MUST when starting up a new engine, cams usually go flat pretty quick. No more time now, I will leave the info for you to make up your own mind.
http://www.hotrod.com/techarticles/engine/flat_tappet_cam_tech/oil_summary.html

http://www.bobistheoilguy.com/motoroil.html#ZINC

heres the better article:
http://www.hotrod.com/techarticles/engine/flat_tappet_cam_tech/index.html

Quote

The Shell Rotella T multi-grade 15W-40 oil appears to be non-synthetic (I am noting this because this thread started out with a question about the use of synthetic oils in 216 engines).

tclederman is correct. Is the Shell Rotella T SB (Synthetic Blend) getting confused with the Rotella T Multi-Grade or are some of you using one and others another? Not trying to highjack the thread BTW.

Don

I would be leery of switching a high mileage engine to synthetic at that stage in its life. Several years ago, my daughter had a high mileage Fnrd Probe. It had noisy lifters, but used no oil. Mobil 1 quieted the lifters, but it immediately began using high quantities of oil. Returning it to the same oil brought back the lifter noise, but the oil consumption continued. switched to Valvoline MaxLife and the lifter noise lessened as did the oil consumption, but still far from the no oil usage as before.
Ran my rebuilt 292 on 30W Valvoline for about 30 minutes to break in the cam. Switched it for 5-30 valvoline for 300 miles. Switched to 5-30 Mobil 1 at that point and that is what it I've used in it for three years now.

I have been using and selling synthetic oil for over 26 years and have never had a problem in my own collection of engines, (which include everything from single cylinder stationary engines from the 30's to 450+ hp engines from the 60's ), or in any of my customers engines or transmissions, and I have sold thousands of oil changes. There are some simple guidelines on when to use synthetic oils, and if they are followed they are superior to any standard petroleum oil in every way. Firstly, you can't save a sick engine with synthetic oil. You should never use synthetic oil as a break in oil because the rings will not seat because there isn't enough friction. If you don't have a filter on the engine, you should not increase the oil change interval. There are many more, but I have just been called away. I flew fighters and commercial jets for 40 years, and every one of them was serviced with synthetic oil because of its superior characteristics. On the big jets in the company I flew with, the oil was sampled every 100 hours ( approximately once a week ) and the oil could stay in the engine for a considerable period of time. The longest I am personally aware of was 26.000 hours without a change. The reason the oil was changed at that time was because of a hot section component failure that contaminated the oil. There are some synthetics that are better than others, and a major brand name doesn't mean that the oil is the best of the pack.
Bob