transaxle oil and motor oil questions

[lawyerbob]

1) I need to fill the transaxle - I picked up some Valvoline 80/90 gear oil, but figured I better check first - should this be ok? What are others using.

2) I know this has been debated at the Interchange a number of times, but I have a question regarding motor oil. Assuming you change the oil and filter after each race weekend - is there any real value to the extra cost of synthetic? It would seem to me that with the limited run time, a good quality "real" oil would be fine - ?

Thanks

[Bill Bonow]

1) 80/90 gear oil is fine/prefered

2) I change my oil (Redline) and filter once, maybe twice a season. Word of caution, don't get stingy/cheap with your choice of oil. A good low cost alternative is Shell Rotella. Find it at your local auto parts store. Has plenty of zink and all the good stuff we need. It is low cost and high quality. It only comes in gallon containers (at least from what I have found).

[lawyerbob]

A good low cost alternative is Shell Rotella. .

That's what I picked up for the initial run in period (at teh suggestion of the engine builder. I guess that was my point. If I buy a bunhc of gallons of that and change it every weekend, is that protection just as good as the 2-3 times more pricy Mobil 1? I think the answer appears to be yes. Again, assuming it's fresh for every weekend.

THANKS!

[rickjohnson356]

He said he changes oil once or twice a season. Probably runs 10-12 races per year.

You may be chnaging it too often. However, If your oild got really realy hot (like here in SE during July/Aug.), you might want to change it a little more often.

Put that $$ toward entry fee for more races.

[Andrew Stein]

FWIW, I'm no engineer or chemist, but am told there is a lower concentration in modern "road" oils of zinc dialkydithiophosphate (ZDDP) or zinc dithiophosphate, which is said to be important in protecting flat tappet cams in high-performance applications (film strength) This is done to extend catalytic converter life, I believe. In researching this a bit on MSDS sheets, Brad Penn shows 1.4% "zinc compound". Redline shows on their race oil MSDS sheet a 2% concentration of ZDDP. Redline regular oils show between 0.6 and 1.2% ZDDP. Exxon Superflo (cheap street oil) shows "less than 2.5%" - but they don't indicate how much less. Mobil 1 on their 0W-40 oil shows elemental zinc, ZDDP and another phosphate additive. Some Mobil 1 oils don't seem to show any. Some air-cooled Porsche guys who are particularly vigilant about this stuff suggest using diesel oils or 4-stroke motorcycle oil - but that's usually expensive synthetic. My other concern about cheap oils is controlling foaming. In the "old days" I remember Kendall GT-1 racing oil had an anti-foaming agent. Don't know if that's necessary at all in modern formulations, though. Using cheap oil for race engines seems OK only if you can find good specific information on the additive package in the oil you want to use.

[lawyerbob]

Thanks guys - I was going by the advice of an engine builder who instisted that the oil should be changed after each weekend (NOT the builder of my current engine). Maybe the other guy owns Mobil stock. That's really REALLY helpful information - THANKS!

Andrew - I don't think anyone was talking about "cheap" oil, but simply the best value for acceptable oil - ie. the Rotella is supposedly higer in Zink but MUCH less than Mobil 1 (not synthetic either of course).

Thanks!

[Albatross]

C'mon guys stop beating around the bush and look up the phone numbers of your favorite oil company. Some companies make oil for racing applications, many do not. Personally, I use Red Line and have been using it for years. Want good information? Call Redline @ (707) 747-6100 and ask to speak with a technition or engineer-not a salesman. Or, look up the phone number of your favorite racing oil manufacturer on Google, phone and ask questions. Anyone who doesn't use synthetic oil with the zink additive in their race car is still operating in the 20th century, perhaps earlier.

As an aside, in the 1980s we all became enamored with PTFE (teflon) in our oil. Alas, to go faster we bought the story-and were sucked in. To quote from Dupont, the patent holder for teflon," Teflon is not useful as an ingredient in oil additives or oils used for internal combustion engines." Be careful what you buy and know why you're buying [it].

[Matt King]

Zinc. Zink was a manufacturer of FVs.

[problemchild]

Considering that Bob was a complete FV newbie who ran a season without any engine problems .... I don't see any reason why he should change much. Dropping $25 worth of oil and filter every weekend is cheap insurance for a $4K engine. If he gets cocky, maybe he can try 2 weekends between oil changes

I have had no FST engine issues (wet or dry sump) running Mobile One 5W20 from Walmart. It is cheap and Zinc free. I would do three weekends before changing. Who needs 21st century technology for an early 20th century engine? Bob's 15W40 with zinc can only be better!

[Matt King]

I run Mobil 1 15W50, also from Walmart. Not only is it cleap at around $4/qt, that particular grade has 1200ppm of zinc, the highest of any of the Mobil 1 street grades, and is very close to the zinc content of most racing oils that cost more than twice as much per qt.

[lawyerbob]

Zinc. Zink was a manufacturer of FVs.

so I'm not a chemist either! lol

I appreciate all the input and suggestions.

[Albatross]

I wouldn't use anything that has been improved upon either: won't ride in airplanes that are propeller driven, either jet or I walk; won't drink pasturized/homoginized milk; won't let my kids get the polio vaccine, tetanus, diptheria, whooping cough, penicillin, small pox,etc. Refuse having my teeth cleaned or giving up smoking or floride treatments. Won't have a colonoscopy, prostate exam and hung up about circumcisum-need help with that one.

[problemchild]

I think that you are exaggerating just a bit.

Bob is using a quality synthetic oil with zinc that he can buy locally as he needs it. No pre-ordering, shipping costs, or premium price.

Cheers!

[sracing]

Changing oil (a good oil) every other or every third weekend is more than adequate. (Unless you took the engine temps etc. to extremes.

The FST engine is a flat tappet cam with higher than normal lifts and steep ramp. A zinc is mandatory. Best option is any of the racing oils like Red Line, Royal Purple, Joe Gibbs etc. Or any off the shelf brand name oil labled "For off road use only" etc. is adequate. Mobile, Valvoline and others sell it.

Rotella no longer contains the high zinc levels that it used to in earlier days. You can use it AFTER breakin if you want, but with a new cam and lifters (break-in) you WILL destroy the cam in any high contact pressure valve system.

You don't NEED a synthetic, but if not you are losing HP in the first few laps. And,, risk a failure if temps go to extreme. (and that is not just the temp on your gauge. The temps can be much higher at the bearing points.)

Assuming 3 races on a change, a good race synthetic doesn't add much to the cost of racing and may save you money.

Mobile One was the last of the high zinc streeet oils. However they cut way back several years ago due to government regs.

None of the street oils contain high zinc level now due to the destruction of cats and 02 sensors coating.

BTW, you can buy ZDDP in bottles for adding to your oil. A bottle is about $9-10 and it will treat 2 oil changes in a FV/FST. So you can buy a lower cost street synthetic and add ZDDP and still come at a low price.

While the ACVW is 40+ years old, they originally never did 7000 RPM, never aproach ed 280 deg and didn't have a higher lift cam.

[Matt King]

A good ZDDP supplement is GM Engine Oil Supplement (E.O.S.) I've been using about 1/4 bottle per oil change.

As you can see in the attached chart, not all variants of Mobil 1 have the same zinc content. The 15W50 is the highest of the street oils at 1300ppm, which compares to about 1700-1900 for most racing oils. I'm not sure if that level is high enough on its own, which is why I add the EOS, but that may not really be necessary, especially after break-in.

http://www.mobil.com/USA-English/Mot...duct_Guide.pdf

[budawe]

Oil conversations are like arguing over blonds vs redheads. If you are having oil breaking down after just a few hours and requiring changing, I'd be looking at other brands or checking my engine. If your oil is blackening quickly, it's got too much blowby from the cylinders and you are carbonizing the oil. Think about it, if the oil is getting dirty in just a few hours something is wrong. I generally don't change my oil, just the filter. Granted, I'm into my motors more often for R&D but changing oil really often is not worth it. If your engine is running cleanly, maybe once every 4 weekends.

The real advantage of synthetic oil starts from the first second of use with higher film strength for a given viscosity. Using non sythetic oil in a vee makes no sense. With our ancient oiling systems and heat, the true insurance for a motor is to buy the best synthetic to begin with, not with how often you change it.

Some folks go through a qt. a session, that's like changing your oil every 3 ssessions! Regarding filteration, if you do not have a filter on your motor, get one.