Best Oil???
Can anyone tell me what they suggest as the best oil...Brand/Weight for a 427/390. All stock, 9K on rebuild..very tight engine
Thanks,
Bob
(9944)
Thanks,
Bob
(9944)
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Re: Best Oil???
This is sometimes the "dreaded oil question", can get many opinions. That said, most current off the shelf oils are high quality but lack high enough ZDDP for old type engines re: cam wear, etc. I use Brad Penn 10/40 which is made for older type engines and has proper ZDDP levels. Joe Gibbs also has a good muscle car type oil. And, you can buy ZDDP in a bottle to add to an existing off the shelf oil. Just my opinion. -
Re: Best Oil???
Bob,
I would recommend carefully reading Duke's oil article. Here it is, scroll down to page three:
The boutique racing oils may be OK, but they are expensive and the amount of ZDDP is usually unspecified. Too little or too much is not good for your engine. I would do as Duke recommends and go to Wally Mart, buy the cheapest oil that is API CJ-4.
JoeComment
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Re: Best Oil???
Shell Rotella 15W 40 available at Walmart. I use it in my 427/390 and all of my older Corvettes with no issues. I agree with Joe. Any CJ-4 rated oil will work fine. Tough to get a consensus on this subject. Kind of like what wax or polish is best.Comment
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Re: Best Oil???
Learning about the reduction of ZDDP in oil I have used for years and reading the articles in the NCRS Restorer and on the NCRS Discussion board by Duke I switched years ago to diesel oil to continue to protect the original engines in my 68 and 85 Corvettes. I have bought 10W30 Shell Rotella, but for few years have only found 15W40 diesel. I also use it in my 69 Triumph motorcycle. My local NAPA store can order 10W30 Shell Rotella if requested.Comment
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Re: Best Oil???
Thanks.....been hearing a lot about ZSSP as of late!Bob,
I would recommend carefully reading Duke's oil article. Here it is, scroll down to page three:
Been hearing a lot about
The boutique racing oils may be OK, but they are expensive and the amount of ZDDP is usually unspecified. Too little or too much is not good for your engine. I would do as Duke recommends and go to Wally Mart, buy the cheapest oil that is API CJ-4.
JoeComment
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Re: Best Oil???
I have used the valvoline RACING oil since it came out and have been happy with it Especially using it in aircraft engines which require 40 ,50, & 60 weight and use 20/50 in all my cars.
After reading all the articles here I am wondering about my choices. I Don't see CJ-4 on my oil of choice.
I had a conversation with the Penzoil rep back in the 70's when they also had RACING oil and he said that both Penzoil & Valvoline racing oil were ashless disbursent oils the same as aviation oil except that the automotive oils were allowed to progress and use additives for foaming, temp, etc.
Any good reports on the racing oil??
DOMComment
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Re: Best Oil???
"Ashless" oils, which were recommended for racing engines by GM back in the seventies are "ashless" because they have little if any additives. This is why light aircraft engine oils are considered "ashless". It's typically the additives in oil that leave combustion chamber deposits that can lead to preigntion and detonation.
Light aircraft engines could probably benefit from the typical additives in modern automotive oils, but the cost of certifying new oil formulations for engines, including existing engines that were designed in the forties, is cost prohibitive. Who's going to pay for it?
As a result, aircraft engine technology and fluids are virtually unchanged for over 50 years.
As far as modern racing engines are concerned, oils don't need detergent and dispersant additives because it's assumed the oil is changed after every race. Most modern racing engines that use roller everything valvetrains don't need much ZDDP, but NASCAR engines, which are required to use flat tappet cams, do.
It's always a matter of selecting a properly formulated oil for the type of service the engine sees. In the case of light aircraft engines you have to use a properly certified oil to maintain the aircraft's airworthiness certificate.
DukeComment
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Re: Best Oil???
Duke,
A question here about detergent. The rep told me that the detergent in oil actually enhances the oil for better lube.
About the airworthiness certificate.
Part 43:13 of the FAR's (federal Aviation Regulations) basically says "as good or better".
So as a certified mechanic I sat across the desk at the local FAA-FISDO and told them what oil I use in my aircraft.
I also voiced my opinion on the ancient destructive oil being used in the airctaft engines today.
Their reply was that one should stick with the manufacturers recomendations and that I might be operating in a gray area.
Was it legal to use?" Yes, "as good or better", and I defended the additives that were in modern day oils.
The cost you mentioned about certifying new oil seems to be the gray area in my book as the oil companies have the $$ to do so.
I had a long talk (over 1 hr) with Continental motors after red tagging most of their new hydraulic units (lifters) and sending them back to them unairworthy.
In a nut shell the leak down that a hydraulic lifter NEEDS was out of limits and I told them of a modern machine I made to accuratly test them in the areas they needed to be tested in ( operating area).
They understood what, how, & why the lifters were not airworthy. But in conversation they agreed that over 80% of their engine overhauls were due to camshaft & lifter failure (bad oil).
I asked them how they handled the problem and it was a one word answer "denial".
Getting back to the oil, my thoughts are that they sell parts & engines and the TBO (time before overhaul) needed to stay where it was (cash flow), why extend the life of their parts?
Mobile oil spent the $$ and came out with a certified synthetic oil for aircraft engines, they went to far with the change,( synthetic oil) and they replaced
many engines due to a class action.
At the time I believe they would have done it better by upgrading aviation oil to automotive standards.
DOMComment
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Re: Best Oil???
I don't think detergents or dispersants inherently add anything to the lubricating quality of engine oils, although by holding contaminents in suspension they have much less tendency to thicken and create sludge, which reduces lubricity degradation over time. So from the standpoint of degradation over time detergents/dispercents do improve the lubricating qualities.
Detergents/dispersants are known to increase foaming tendency, which is why a good dose of anti-foaming agent is required for high detergent/dispersant oils. Turbochargers are known to exacerbate foaming due to the very high bearing surface velocities, and since nearly all modern diesels have turbos, you can be assured that CJ-4 will not cause excess foaming in a non-turbocharged engine.
Most current aircraft engines were designed in the forties, and the designs are very conservative. Cam lobes have very mild dynamics and with their low rotational speed only need mild valve spring forces, which minimize lifter foot loads. Since SAE J-1899 only allows trace metals in piston engine aircraft oils, there is no ZDDP as far as I know, but I believe there may be other - possibly boron based - anti-wear additives that are probably not as effective as ZDDP.
I agree that modern automotive engine oils would probaby improve the life of reciprocating aircraft engines, but the oil companies have no economic incentive to change oil formulations for light aircraft because the market is so tiny. Any kind of change to incorporate modern technology in light aircraft powerplants is a third rail because of the cost to achieve FAA certification. It's tougher than trying to make changes in NASCAR, though they took a big step this year with port fuel injection.
DukeComment
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