synthetic vs mineral oil

[coupe32]

My rebuilt 340 with a flat tappet cam now has about 1500 miles on it now. I am currently using Valvoline VR-1 10W30 oil. I was wondering if I should now switch to a synthetic oil. What are the pros and cons? Never ran synthetic oil before.

[cudabob496]

I have a 600+ hp 496, that I have used 5w-30 Mobile 1 fully synthetic for 12 years. Engine runs cooler, lasts longer, and makes more power due to less friction. Its a no brainer! And it flows a lot quicker to give more protection at startups, which are the cause of 95% of engine wear! Again, no brainer! I also run synthetic tranny fluid and rearend fluid. All good for about 20 more rear-wheel horsepower!

[JVMopar]

I would suggest you read this article. http://www.hughesengines.com/TechArt...ineoils101.php

And if you still want to run synthetic oil with your flat tappet cam, make sure you check the ppm of zinc phosphate. You want a minimum of 1200ppm. There are some synthetics out there that claim to have 1200ppm but it's not off the shelf at walmart stuff.

[aarracer]

My engine builder said NO to synthetics. But what would he know, he only has 4 National Championships, 8 Divisional Championships, and 42 Wally's

[cudabob496]

Originally Posted by aarracer

My engine builder said NO to synthetics. But what would he know, he only has 4 National Championships, 8 Divisional Championships, and 42 Wally's

Why does he say no?

All the participants in the Engine Masters building competition in Hot Rod or Popular Hotrodding use synthetics. Probably every high performance car built in the world, like Ferrari, use synthetics! I suspect all of NASCAR uses synthetics. Even Dodge requires the Viper to use synthetics. Can't imagine an 8000 rpm NASCAR engine running for 5 hours, and the engine builder not wanting synthetic motor oil in it! Synthetics give you more margin against failure.

[JVMopar]

Originally Posted by cudabob496

Why does he say no?

All the participants in the Engine Masters building competition in Hot Rod or Popular Hotrodding use synthetics. Probably every high performance car built in the world, like Ferrari, use synthetics! I suspect all of NASCAR uses synthetics. Even Dodge requires the Viper to use synthetics. Can't imagine an 8000 rpm NASCAR engine running for 5 hours, and the engine builder not wanting synthetic motor oil in it! Synthetics give you more margin against failure.

Lifters. Go read that link I posted.

[340_GTS]

Anything with a flat tappet cam needs Zinc in the oil for lubrication. No modern motor oil made to be used in new cars has the zinc. It really does not matter if the oil is synthetic or dino, just make sure it has enough of the Zinc additive in it. Zinc phosphate. 1200ppm of zinc phosphate minimum. I'm bettng the synthetic stuff the NASCAR guys use has it, because they are forced by the rules to use flat tappets. With roller tappets, which come on 99% of the new cars, you don't need the zinc. And many people retro fit rollers to older engines, so they can get away without the zinc.

[aarracer]

Originally Posted by cudabob496

Why does he say no?

All the participants in the Engine Masters building competition in Hot Rod or Popular Hotrodding use synthetics. Probably every high performance car built in the world, like Ferrari, use synthetics! I suspect all of NASCAR uses synthetics. Even Dodge requires the Viper to use synthetics. Can't imagine an 8000 rpm NASCAR engine running for 5 hours, and the engine builder not wanting synthetic motor oil in it! Synthetics give you more margin against failure.

I would guess, it is better for looser/wider bearing clearances. But I don't ask much other than for the tuneup tips and dyno sheets.

quote (By Reed Grant Class Racer)

re: oil wedge

There is only 3 areas in a motor that you can utilize a wedge---rod bearings, main bearings, and cam bearings. Every place else is on a film. Proper use of the wedge will make it almost friction-less(most synthetics), but a film only lessens the load. This is why synthetics, in this instance, is less friction. The oil molecules are like marbles. Man made synthetics have all marbles the same size. Most mineral base oils have all different size marbles, therefore the crank runs on different size marbles and is point contact loaded (it only rides on the large marbles).

end quote (By Reed Granrt on class racer)

Joe Gibbs Racing formulates their own non synthetic and synthetic oils. I don't know which ones they run in their racecars. But I bet they sell a lot of both. I have used their breakin oil on my older engines. I would not even attempt to compare a Dry sump oiling system engine to a Wet sump oiling system engine as a defence for a particular oil type!

Peter

[John Kunkel]

Originally Posted by cudabob496

Engine runs cooler, lasts longer,

How do you know that? Advertising or actual field comparison of the same engine on both conventional and synthetic?

And it flows a lot quicker to give more protection at startups, which are the cause of 95% of engine wear!

That's the subject of much debate; synthetic fluids do not stick to surfaces like conventional petroleum oil and run off in matter of hours, rather than days as is the case with petroleum oil. Therefore at cold start the surfaces are less protected and therefore MORE wear might occur at cold starts than it would with conventional petroleum oil especially in cars that sit for long periods and aren't driven regularly.

I'm a big fan of synthetics but recognize their shortcomings.

[cudabob496]

Originally Posted by John Kunkel

How do you know that? Advertising or actual field comparison of the same engine on both conventional and synthetic?




That's the subject of much debate; synthetic fluids do not stick to surfaces like conventional petroleum oil and run off in matter of hours, rather than days as is the case with petroleum oil. Therefore at cold start the surfaces are less protected and therefore MORE wear might occur at cold starts than it would with conventional petroleum oil especially in cars that sit for long periods and aren't driven regularly.

I'm a big fan of synthetics but recognize their shortcomings.

Synthetics not sticking, and not providing adequate protection at startup, is a myth, from what I've read. Do you have any documentation or proof?

[cudabob496]

Originally Posted by JVMopar

Lifters. Go read that link I posted.

I read it. Written in 2006. I conclude its saying "Ensure enough zinc additive if use any oil with high performance
flat tappet cams (synthetic or non synthetic oil)."


Found this on web:

AMSOIL Z-ROD Synthetic Motor Oil (ZRT, ZRF) features high-quality synthetic base stocks and a proprietary additive package tailored to perform on the street and protect during storage. AMSOIL Z-ROD Synthetic Motor Oil is formulated with high levels of ZDDP to protect flat-tappet cams, lifters, rockers and other areas susceptible to wear. Its high-zinc, high-phosphorus formulation provides the extra wear protection these critical splash-lubricated components require.

Also, "Royal Purple HPS is fortified with advanced additive technology - zinc/phosphorus anti-wear additives and Synerlec - to surpass many other oils."

Here's some zinc additives for sale:
http://www.nextag.com/zinc-oil-additive/shop-html

[John Kunkel]

Originally Posted by cudabob496

Synthetics not sticking, and not providing adequate protection at startup, is a myth, from what I've read. Do you have any documentation or proof?

The first I became aware of this was when Mobile introduced their AV-1 full synthetic aviation oil. They withdrew it after a couple of years because certain engines with high-mounted camshafts (Lycoming) suffered premature cam/lifter failures that were attributed to oil draining from the cam surfaces during long periods of inactivity (common in GA aircraft). The conclusion was drawn both by the engine manufacturer and independent rebuild facilities.

This was the subject of several nasty lawsuits and lab tests verified the drainoff difference between synth and dino oils.

[coupe32]

And I thought EVERYONE was going to tell me to switch to synthetic.

[cudabob496]

Originally Posted by John Kunkel

The first I became aware of this was when Mobile introduced their AV-1 full synthetic aviation oil. They withdrew it after a couple of years because certain engines with high-mounted camshafts (Lycoming) suffered premature cam/lifter failures that were attributed to oil draining from the cam surfaces during long periods of inactivity (common in GA aircraft). The conclusion was drawn both by the engine manufacturer and independent rebuild facilities.

This was the subject of several nasty lawsuits and lab tests verified the drainoff difference between synth and dino oils.

Interesting aviation issue, however, the subject, as of late, does not seem to be of much interest in the car/engine community, since 99% of the auto performance community seems to be ok with synthetics. Maybe all the more reason to use synthetics, since at startup they flow to the engine oiling areas much quicker than conventional oil. By the way, I have a Snapper lawnmower, and was told when I got it, use straight 30w conventional oil. Instead I went to 5w-30 synthetic, and just change the oil once a year. Be interesting to see how long it lasts. Had it for 17 years so far.

[cudabob496]

Originally Posted by coupe32

And I thought EVERYONE was going to tell me to switch to synthetic.

Well, welcome to America. You've listened to the opinions, and you get to make your own free choice. At least Obama hasn't dictated whether we gotta use synthetic or not, YET!

[coupe32]

Not yet anyway.

[Rich Kinsley]

I just switched to Mobil One on the advice of my machinist/racer. He runs about .002" clearance and 2wt Mobil One in his 9800rpm 312ci Mopar racer.

I do add the zppd additive as I have a 318 poly w/solids. I am turning in the 7500rpm range now and it loves the synthetic. I ran it in '76 when it was new and had very good luck. I did see a noticeable operating temp drop and increased mileage. I must say my engine is running extremely cool. It rarely opens the t-stat even in 100+ weather. I am impressed.

[Rich Kinsley]

I ran it in '76 when it was new and had very good luck. [/QUOTE]

I meant when synthetic oil was new. Not my "64 Dodge :-)

[aarracer]

Rich

Ah, yes. Do we see a dry sump system on that Competition engine. Not a fair comparison to a wet sump engine.

[Rich Kinsley]

Originally Posted by aarracer

Rich

Ah, yes. Do we see a dry sump system on that Competition engine. Not a fair comparison to a wet sump engine.

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Yeah on the 312 race engine but I even have a stock oil pan and pump on my poly. Some oiling mods were done which included drilling an extra oil hole in all the mains and blocking the valley area over the cam. I just had some serious headwork and a new cam installed which dropped my 4000 pound 4dr from 9.75 to 9.15 in the 1/8th. I also gained 7mph. It sure runs better with the proper set-up for my 2X4's. Stock heads and the smaller cam couldn't really use the extra carb. But it was great at cruise night :-)

I have not yet changed the tune from the original with the stock heads, etc.. I should be into the 8's with some tuning and trials. I'm having fun!

[cudabob496]

Just seeing the oil pressure guage move up much quicker at startup
is good enough for me!

[John Kunkel]

Originally Posted by cudabob496

Interesting aviation issue, however, the subject, as of late, does not seem to be of much interest in the car/engine community, since 99% of the auto performance community seems to be ok with synthetics.

And 500 years ago 99% thought the world was flat. I'm among the 99% that's OK with synthetics, just stating what's been found regarding drain off.

Maybe all the more reason to use synthetics, since at startup they flow to the engine oiling areas much quicker than conventional oil.

Their ability to flow better fits in with the "runs off easier"

[cudabob496]

[QUOTE=Their ability to flow better fits in with the "runs off easier"[/QUOTE]


Perhaps, but ability to flow (viscosity), and adhesion to metal surfaces, are two different issues.

[crisser]

I will use Valvoline VR1 for break in, and then will switch to this;

http://royalpurpleconsumer.com/produ...!hps-motor-oil