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28 president 8


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I have read the original owners manual frontwards, backwards, and now trying it sideways hoping to find out how much oil a 28-8cyl engine will take to be happy. It says to fill it to the full line. Secondly, Gurus, I would like a recomendation as to what motor oil would keep the big 8 smiling. I dont drive in winter and live in Mass.

Once again, Thanks yal

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When you add oil it is going straight into the crankcase. If your President is like most Studebakers of this era you do not have an oil filter. So, in this case the owner’s manual is correct, you fill it until the oil reaches the full line of the dipstick. As a word of caution, the oil dipstick has two marks on it, full, and empty. Unlike cars of today, in 1929 they did not have an add mark on the dipstick. If I recall correctly our Presidents have a 6 or 8 quart capacity crankcase. Buy 8 quarts and keep checking the dipstick as you add the oil and you should be fine.

I use straight 40 weight detergent oil in my President and it does just fine. However, when I got my President I dropped the oil pan and thoroughly cleaned everything and inspected the oil pump. The oil pump on Studebaker’s of this vintage is made out of pot metal. I never saw an original oil pump come out of a 1920’s Studebaker that was not full of cracks. Do not assume anything. Drop the oil pan and inspect everything, including the oil pump, before you add oil and start the engine.

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Mark is correct about how about finding the oil level in your car . As to the oil you need to be aware that the new oils are all reformulated without the zinc levels we need not to destroy our engines running the flat lifters and old style cams. The zinc prevents wear which will start the minute you use the new formula oils. I have been using an oil developed by a company to take care of that problem for the last few years in both my big president 8's and flat head cadillac motor and they work great. I own nothing in this company just passing this on as I found out about this thru the CCCA . Classic Car Motor Oil 317-225-0040 www.classiccarmotoroil.com Try it it will save your engine.

post-71352-143138508834_thumb.jpg

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Since the President 8 is a "Flat Tappet" design, modern oil chemistry can be a problem for it. Do a search on "ZDDP" in the AACA forum and you will find a lot of data.

The following thread contains good info, only Valvoline Racing Oil at this time contains enough ZDDP for flat tappet engines, but it also lacks other additives best for street driven vehicles. best safety option is seperate ZDDP additive with each oil change.

http://forums.aaca.org/f120/zinc-dialkyl-dithio-phosphate-257307.html

Stude8

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Thank You Mark, I have not pulled the pan, but the motor has been rebuilt about 25 miles ago. Not by me or anyone I know but motor sure does sound good. 6 to 8qt is good enough for me. I just didnot want to come home with 6 and have to go back for more. appreciate your input.

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so assume that I will drive my car in the summer only. Not much at that, so maybe I will have 600 miles tops per season, and will change the oil just for something to do in the winter. How much zddp will I need, and how much will break down in that time? Interesting topic I will have to ponder longer, thanks.

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With regards to zinc dithiophosphate....I thoroughly investigated this and, after reading SAE Publication 2004-01-2986 ("How much ZDP is enough?") and talking to one of the authors who is a lubricant technical specialist at GM Powertrain, I am thoroughly convinced that no harm will come to a flat tappet engine running the newest API rated oils.

Scott

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Stude light ; Sir I hope you are right for your sake ,but I will er on the side of caution as these engines cost way to much to fix. With so little precaution as to pick an oil with more zinc in it seems prudent to me.

Totally agree. I would not use modern oils without adding ZDDP.

Terry

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Okay, so I knew better than to comment on the ZDP/ZDDP issue! But now that I dug my hole and will get the wrath of others, I will have to comment further.

I think one thing we can all agree upon is that for a reciprocating engine and particularly our old engines without oil and air filters, the best thing you can do is to change your oil very often. I have practiced this in every engine I own or operate and have had exceptional results with regards to longevity. Cars, trucks, lawnmowers, tractors , aircraft (many of which still do not have engine oil filters) – frequent oil changes = good practice. And today, oils are usually recycled so you can't feel bad about using a bit more than the average guy. <O:p

My problem, like many others, is that I have limited resources. Constant oil changes with expensive "specialty blends" or additives can get costly so I wanted to make sure I really needed these. I started reading about ZDP but found much of the information was put out by companies wanting to sell additives and specialty oils and had nothing more than a good story. This information was then repeated in many forums.<O:p

I'm a test engineer at GM and am constantly bombarded by opinions and anecdotal stories to which I request the data to back them up. So with the ZDP issue I decided to dig deeper to get the data. I was able to obtain copies of the Society of Automotive Engineers (SAE) publications that have the history of engine oil development, the need for additives, the introduction of ZDP in the 1940's, continued work to balance oil performance with fuel economy /emissions and test results to back up the conclusions. In addition to the paper listed earlier there are many related SAE publications dealing with ZDP and tappet wear (821570, 560017, 852133, 861516 to name a few). These are written by the industry experts that have no ties to selling product, but determine what is appropriate for proper oil performance to ensure that the consumer is protected by the standards set. I have read the papers listed and would gladly post them so people could come to their own conclusions, but the papers are copyrighted by the SAE (you have to purchase them). The oil additive issue is actually rather complex as it is not just about lifter wear but also related to bearing wear, antioxidant (corrosion protection), etc. and ZDP specifically has traits related to both zinc and phosphorus levels that have a level of interaction with the other oil additives which are also improving with time.<O:p

I contacted Mr. Robert Olree, who published several of these SAE papers and served as Chairman of the International Lubricants Standardization and Approval Committee (ILSAC). ILSAC is the governing body which has been empowered with the task of establishing minimum performance standards for the lubricants used in today’s gas engine passenger cars and light duty trucks. I asked him about the ZDP issue and he gave me some information and sent me a summary he had put together which I can post. Mr. Olree worked for GM as a technical expert in the oils group. He was co-author of publication 2004-01-2986 which dealt specifically with understanding how much ZDP is required to prevent wear in modern and older engines. The conclusion in this report, based on extensive research and testing, is that 0.08% phosphorus (in the form of zinc dithiophosphate) was more than enough to protect engines old and new. It also suggested levels of 0.05% phosphorus and even as low as 0.03%, when used with other additives and phosphated cams (for initial break-in) could be acceptable. Keep in mind that these tests are based on the high contact loading of the newer flat tappet engines beginning in the 1950s and particularly from the1960s-1980s. The pre-war engines had much weaker valve springs, lower lifts and much lower contact stresses at the cam/tappet interface and ran with no ZDP oil additives in their day. The current ILSAC GF-5 API SN spec is 0.08% phosphorus maximum. The sequence wear tests were specified to pass at 0.06% phosphorus.

In conclusion - I'm really not buying or selling that you should or shouldn’t use higher levels of ZDP (ZDDP) in your cars - just offering information. The amount of data I reviewed convinced me to spend my money on more frequent oil changes and not worry about ZDP levels causing any damage. If you think it is wise to add ZDP or buy specialty oils with ZDP, I'm fine with that. Just don't add too much ZDP as the testing reported in SAE publication 2004-01-2986 indicates that phosphorus levels of 0.14% increased long term wear and at 0.20% phosphorus, camshaft spalling begins to occur.

<O:pRespectfully submitted,

Scott

Engine Oil Mythology 2-2007.pdf

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