Synthetic, or is it SIN-thetic

[Sandy]

A little fun in the title to kick off an interesting topic. And that is -

Synthetic vs. Normal mineral based oils. A few folks have chimed in from the oil temp thread, but good to keep the info ordered so a new thread was started here.

Some of the reasons that I run synthetic is for potential lower oil operating temps, as well as its ability to withstand more abuse then mineral based due to its elevated temperature capabilities and a much higher load capability acording to the marketing fluf that is floating around on the web. Ton's of good info, but nothing like peoples first hand stories to give some info.

I don't have much scientific to offer except that I am running Royal Purple racing 41 in the 65 Mustang (331cu" 12:1/Solid roller 560+hp@7200). I don't run an oil temp gauge, and I guess wouldn't look at it until the motor stopped working anyway, but I guess that temp in the pan would be a good indication point of how well it may be working vs conventional oils. I have not had the motor apart for anything since I started using the synthetic so can't say how things look. It usually runs in the hot desert climates of willow springs. The broken rocker shaft was before synthetic as well, and on oil changes the oil generall looked cleaner then the conventional counter part.

Another good questions is about brands and why?

I'm running Royal Purple as it is pretty easy to get in the conventional viscosity I used to run (or close to it). Also easy to get via mail order, like AMS, and others I'm guessing. I'm not comfortable running a lower viscosity (or would likely run mobil 1), although some say that this is where you can get some free hp (Nothing is in fact free as far as I can tell) due to less drag.

Have at it!

Sandy

[Jac Mac]

Flat Tappet cam - Mineral Oil, Roller Cam - Synthetic.( Thats on Race Cars )

OHC Late Model Road Cars- Semi Synthetic.
V8 Hi Po Road Flat Tappet-Mineral or Semi Synthetic.
V8 Roller-Semi or Full Synthetic.
Older Stuff with Wide Rings etc -Mineral.

Have had ugly experience's with AMSOIL & Valvoline.( Both Product and Agents).

Jac Mac

[Russ Noble]

Well Jac Mac that's the 'what'. How about the 'why'?

I'm all ears.

Cheers

[Sandy]

Originally Posted by jac mac

Flat Tappet cam - Mineral Oil, Roller Cam - Synthetic.( Thats on Race Cars )

OHC Late Model Road Cars- Semi Synthetic.
V8 Hi Po Road Flat Tappet-Mineral or Semi Synthetic.
V8 Roller-Semi or Full Synthetic.
Older Stuff with Wide Rings etc -Mineral.

Have had ugly experience's with AMSOIL & Valvoline.( Both Product and Agents).

Jac Mac

Yes, you didn't think that you would get off that easy with that Why the different suggestion for flat tappet vs roller?

Sandy

[chuck smith]

flat tappets were not designed for synthetic oils or even modern mineral oils. Oil that has zink in it is the prefered. Shell Rotella T, an oil for diesel engines still has the zink additive and works much better for flat tappet cams and is what I use in my old school motors. Some racing oils (redline racing) has it also but it has been removed for pollution reasons in others.

I do like the idea of thinner synthetics for winter start up in roller cam motors,but I think frequent oil changes are more important the the type of oil in modern motors in general.

[Sandy]

I was going to ask about Zinc, but found this on the web, but can't say if valid or not, but here it is...

Zinc is contained as part of the standard additive package in virtually every major brand of engine oil sold today, varying from a low volume of 0.10 per cent in brands such as Valvoline All Climate and Chevron l5W-50, to a high volume of 0.20 percent in brands such as Valvoline Race and Pennzoil GT Performance. Organic zinc compounds are used as extreme pressure, anti-wear additives, and are therefore found in larger amounts in oils specifically blended for high-revving, turbocharged or racing applications. The zinc in your oil comes into play only when there is actual metal-to-metal contact within your engine, which should never occur under normal operating conditions. Under extreme conditions, the zinc compounds react with the metal to prevent scuffing, particularly between cylinder bores and piston rings. However - and this is the important part to remember - available research shows that more zinc does not give you more protection, it merely prolongs the protection if the rate of metal-to-metal contact is abnormally high or extended...

Do synthetic's use zinc as one of the 'additives'?

Sandy

"Zinc Oxide and you" (A movie quote)

[Scott Calabro]

Hey All !

Ditto's Chuck on the Shell Rotella "T" for flat tappet engines. A recent issue of HOT ROD magazine had a very good in-depth arcticle on the subject of additives REDUCED by our pals at the EPA!

Sandy,
As far as your broken rocker shaft, that happens on Fords with high pressure valve springs, I assume you have stiff springs due to the 7200 rpm you run when you race, try a set of Jesel "Sportsman" shaft rockers and that will be eliminated. I don't know zinc contents in synthectics. For weight of oil to be used, pick the thinnest oil that will maintain 10 psi per 1000 rpm at your running oil temperature (7200 rpm = 72 psi) Also go to cancutter.com and buy the $90 dallar cutter and inspect your oil filter after every race!
S

[Scott Calabro]

Hey I forgot one thing... if you can't find ROTELLA T go to any GM dealer and buy their anti wear oil additive that is loaded with zinc and molybdenum.
S

[chuck smith]

that is correct Scott and highly recommended for cam break in (STP also has high zinc content I believe)
Sandy, I think Red Line racing oil has it in high amounts

[Ron Earp]

Originally Posted by 5150

Sandy,
As far as your broken rocker shaft, that happens on Fords with high pressure valve springs, I assume you have stiff springs due to the 7200 rpm you run when you race, try a set of Jesel "Sportsman" shaft rockers and that will be eliminated.

From Sandy's gallery. Believe that is a Jesel Sportsman rocker there, broken. Same as I have on my motor, not broken yet.

http://www.gt40s.com/gallery/file.php?n=32&w=o

Oil debates/discussions are great and pop up on every auto board, sooner or later. I don't think I've ever seen a conclusive discussion but I can say this - I haven't seen failures from types of oil (I don't get out as much as some of you guys) but I have seen failures due to no oil, I've had pretty good luck keeping it full of something slippery.

[Sandy]

Originally Posted by 5150

Hey All !

Ditto's Chuck on the Shell Rotella "T" for flat tappet engines. A recent issue of HOT ROD magazine had a very good in-depth arcticle on the subject of additives REDUCED by our pals at the EPA!

Sandy,
As far as your broken rocker shaft, that happens on Fords with high pressure valve springs, I assume you have stiff springs due to the 7200 rpm you run when you race, try a set of Jesel "Sportsman" shaft rockers and that will be eliminated. I don't know zinc contents in synthectics. For weight of oil to be used, pick the thinnest oil that will maintain 10 psi per 1000 rpm at your running oil temperature (7200 rpm = 72 psi) Also go to cancutter.com and buy the $90 dallar cutter and inspect your oil filter after every race!
S

Thanks Scott, the shaft broke because an allen head broke that held one end of the shaft to the base, I think due to thread failure in the aluminum base. The shaft rocker set were hand made so to speak by a fellow in Ohio, and he re-made the aluminum bases and made them out of 4130, sent studs to replace the allen heads, and it has been fine with much more abuse then before . I went with a set of Jessel's on the Keith Craft motor in the RCR40, but I also got a set of T&D's in case these were scrapped. I will say that anything is better then the old stud mount rockers.

I saved 90 bucks by using an external oil filter! I have a remote canton-mecca filter and easy to look at without too much trouble. Good idea to keep an eye on it as the motor gets more hours on it.

As for additives for cam break in, sure, done a few Big Block Chevy's solid lifter motors, never used them (additive, but plenty of molypaste), but I don't think that I would use them for regual racing use, don't know enough about them to make a conclusive judgement, pretty much the same for synthetic vs. mineral.

I'm guessing that the difference between the regular synthetics and the 'Race' Versions are the additives, but they are often hidden in the secret formula's given to us as some mumbo jumbo trade name, like Royal Purples "proprietary Synerlec" additives amongs others. It's almost a joke trying to find good info on the web due to the many BS web sites that sell synthetic oil (Like AMSOil, RoyalPurple, web dealers have) and published loads marketing hype.

No comments about Mobil1, NEO, others?

Sandy

[Scott Calabro]

I use and abuse Mobil 1 15w 50 @ (when I can actually get it this high) 230 deg F. I change it every 750 miles, I know, I know, its expensive and overkill, but I figure for the $9K motor I have its cheap insurance. After 5500 hard street miles there is nothing on my mag. drain plug, and my filters are absolutely spotless.
S

[Lynn]

Scott, Mobil 1 15w50 is my oil of choice as well (after dino break in) in my street cars, including the GT40.

I haven't tracked a car, so my comments are for street only. But, in general, the tolerances of the engine will dictate the trade off of oil pressure vs viscosity, IMHO. Personally, I'd opt for a thinner oil with higher pressures to make certain metal doesn't meet metal while inducing the minimum drag between bearings and journals. I lean towards synthetics because the hydrocarbon chains are longer and more consistent than in Dino oil (and they stay that way.) That said, I think that 0w and 10w oils aren't called for below the mason-dixon line: 15w is plenty thin to get up in the engine a temps in the teens and above. Synthetics have a great advantage in maintaining an oil film on opposing parts after shutdown and if you are that worried about dry starting an engine, I'd suggest an Accusump for preoiling.

AMSOIL- haven't really looked at their motor oils, but when I did a bit of an indepth on gear oils for Porsche transaxles, I was very underwhelmed by the AMSOIL's technology. Royal Purple evidently has a great marketing department. That is not to say that their products aren't quality, but I just couldn't find that much history to go along with the claims. Redline, on the other hand has both claims and enough empirical evidence for me to be very comfortable with their products. One note of interest, for older Porsche transaxles with old school synchros, Dino oil was recommended because synthetics are to slippery for the synchos to function properly.

Valvoline - The only time I ever used Valvoline was when I used 70w racing oil in my '53 Harley panhead that was put together loose as a goose. It was the only oil that was thick enough to keep bearings and journals apart ;-)

[Mark Worthington]

Ron's right, every forum has discussions on oil. I've read a few and, based on the input from some very knowledgeable people (chemical engineers, racers, powerplant engineers) I put Mobil 1 in the cars I care for. As for transaxle oil, the hard-core guys on the Audi forums swear by Neo, so that's what I'm using in the gearbox.

[Paul]

What about Prolong the adverts show them running a car across America with no oil. I have used it as an addative and it does seem to reduce friction as the engine revs do increase on tickover after the addition. I would not use it in a new engine though.
Merceedes only use Mobil 1 in all of their engines and one would think that they know what they are doing.

Regards

[Lynn]

Paul,

Prolong, Slick 50 and other PTFE addatives will not make an engine break. When Slick 50 was STCed for aviation use, I knew that it was OK to use from that point of view. There is one issue with the use of these products however: rings will not seat if used in a new engine or if the engine is rebuilt, it makes honing cylinders a major pain in the butt. As long as someone else is doing the overhaul, I guess there is no issue, but because of this, it isn't used much in racing engines that undergo more frequent rebuilds than road cars.

Regards,
Lynn

[40 Bud]

I have used Mobile 1, 15-50 since completing the first 1500miles. I now have 13,000 plus and am still happy with it. Check Wal-Mart for the big bottles at about $28.00. They usually have the 15-50 on the shelf. A lot of those miles are open track miles.