Synthetic or not?, What weight oil should be used? Options

[Porschewagon]

Here's the skinny. I have an unmolested 1971 1.7 with original FI. What oil should I be using in this car. Brand, weight, etc.

[ripper911]

Everyone here usually says 20w-50 Brad Penn, or RATs Snake Oil.

I'm about to change mine using Valvoline VR1 20w-50.

[yeahmag]

There are two things you need:

1. High levels of ZDDP
2. 20w-50

Like ripper911 said, there are only one or two oils that have those qualities in known quantities. Brad Penn Racing Oil is one of them.

-Aaron

[p914]

Royal Purple has high ZDDP and 20-50 weight.

[Porschewagon]

Thanks for the input, I don't want to burn my baby up. This is my second teen, first car gernaded. Never got that one put back together.....sad. (IMG:style_emoticons/default/headbang.gif)

[Socalandy]

I've seen this 20/50 conversation before and I'm wondering if this just for high mile engines or new rebuilds too? 20/50 is heavy stuff versus the factory 30w and I would think it would reduce cooling thru the oil cooler. I'm running Mobil 1 10/30 synth with no issues?

go ahead and straighten me out (IMG:style_emoticons/default/chair.gif)

[jcd914]

Multi weight oils were common when our cars were new and are appropriate for them now as well. New cars today are designed to use the very light weight oils that are common and they are better off with the very light oils. In my opinion (I have no secret corporate memos that were suppose to been shredded) it is the government and fuel efficiency requirements that have pushed the manufactures to these light oils. Why would they up their costs to machine to the tolerances required use these thin oils if there was no need to.

Oil viscosity was standardized many years ago by measuring the volume of oil that would flow thru a fixed size orifice over a given time frame at a specific temperature. I don't recall the time, orifice size, temperature but I passed that engineering class anyway. Multi weight oils meet the viscosity index of their lower number at colder temperatures and the higher number at higher temperatures. So a 20/50 oil has the viscosity of a 20 weight oil at say 15 degrees Celsius and a viscosity of a 50 weight oil at say 100 degrees Celsius. So a 20/50 will be slightly thinner cold that a straight 30 weight oil but it will be thicker at operating temperature.

In California with an air cooled car I always use 20/50 and currently I have been using Swepco 306 since I can get that locally and it has the zinc our engines need.

All 3 Porsche dealerships and the independent Porsche shop I worked at used 20/50 in all the air cooled cars. New motors got break-in oil to begin with before they got the 20/50.

Jim

[Porschewagon]

Multi weight oils were common when our cars were new and are appropriate for them now as well. New cars today are designed to use the very light weight oils that are common and they are better off with the very light oils. In my opinion (I have no secret corporate memos that were suppose to been shredded) it is the government and fuel efficiency requirements that have pushed the manufactures to these light oils. Why would they up their costs to machine to the tolerances required use these thin oils if there was no need to.

Oil viscosity was standardized many years ago by measuring the volume of oil that would flow thru a fixed size orifice over a given time frame at a specific temperature. I don't recall the time, orifice size, temperature but I passed that engineering class anyway. Multi weight oils meet the viscosity index of their lower number at colder temperatures and the higher number at higher temperatures. So a 20/50 oil has the viscosity of a 20 weight oil at say 15 degrees Celsius and a viscosity of a 50 weight oil at say 100 degrees Celsius. So a 20/50 will be slightly thinner cold that a straight 30 weight oil but it will be thicker at operating temperature.

In California with an air cooled car I always use 20/50 and currently I have been using Swepco 306 since I can get that locally and it has the zinc our engines need.

All 3 Porsche dealerships and the independent Porsche shop I worked at used 20/50 in all the air cooled cars. New motors got break-in oil to begin with before they got the 20/50.

Jim

Thanks for the info Jim. I never really understood what the numbers meant, but now I have a better idea. Off to find 20/50 royal purple.

[brant]

Like ripper911 said, there are only one or two oils that have those qualities in known quantities. Brad Penn Racing Oil is one of them.
-Aaron

There are actually many many racing and off road oils that have the correct zddp and qualities. just most of those options are either harder to get (mail order) or more expensive.

because they are specialized, most of them are also synthetic.
The truth is that these air cooled motors actually are better on synthetic
the air cooled motors are harder on oil because they don't have the water cooling to regulate the heat the way a modern motor does.

some of the trade offs can be increased leakage on old gaskets or seals


the VR1 is good
I use royal purple which has it
joe gibbs
redline
many many others.

[utah914]

Has anyone tried Mobil 1 0W-40? It's listed with 1100 ppm zinc. Seems like it might be the right stuff for our engines.

I've been running it in my M3 because it's specifically approved by the factory. When I saw the zinc level, I figured I'd try it in my 914. I'll let you know how it works out.

http://www.mobiloil.com/USA-English/MotorO...oduct_Guide.pdf

[brant]

modern cars don't need the zinc
they have things like hydraulic lifters, and roller bearings
modern cars have catalytic converters which get plugged by the zinc and really are the reasons that the oil companies took it out (the manufacturers wanted it out)

the 2nd reason was the phosphorus. Its the combination of additives that protect the bearings and moving parts. But the phosphorus breaks down and requires frequent oil changes (every 3,000 miles). So with the the change in additives (including removing the phosphorus/zinc combo) the car can now go 10 or even 15 thousand miles between oil changes.

look at the the letter rating on the oil
its inside the starburts API certification
for example SM or SJ

if the oil your using has an SM in its API rating it is the BAD stuff

The rating will tell you if the oil is produced to the new formula or old formula (ie: catalytic converter safe = bad, off road or not produced to be used with a catalytic converter = good)

zinc ratings around 1500 are probably the good stuff
1100 is the newer formulas.

one of many articles

[neilca]

I am running a six cylinder and tried to use Mobile 1, Not good, these motors are not designed for modern oils. I now run Rotella 15w40, 95psi ath the end of the straightaway.

Same with the gearbox. I was running Redline MTL. So far I have killed two first gears, rounded off the dog teeth. THe oil is so slick the synchronizers didn't slow down the gear. I have gone back in time and use Kendall 90w

[maf914]

the VR1 is good
I use royal purple which has it
joe gibbs
redline
many many others.

I was browsing Jake's site recently and noticed that he said he was working with Joe Gibbs Racing to produce his Snake Oil.

[brant]

The diesel oils have now also changed formula's to meet emissions and no longer have the zinc/combo package that was good for older motors

[ThinAir]

I've been running Mobil 1 20/50 in my Type 4 2 liter ever since I overhauled it in 2005. I was not aware of the need for zinc in the oil and I've never noticed any abnormal effects. What am I doing to my engine by not having the zinc in the oil? Is there a zinc additive I can use to supplement?

[brant]

There is no noticeable difference in the way things run/sound/feel.

The additives are better at high pressure contact points in metal. The Zinc/phosphoru provide an extra barrier where metal is under higher contact pressure.

A modern cam has hydraulic lifters and roller rockers.
a Type 4 (and nearly all cars built in the 1980's and earlier) have cam lobes that push lifters to actuate the valve train.

At tear down your going to see increased wear and worn out cam's.

A lot of chevy V8 guys are noticing a loss of power at a very early mileage, due to their cam lobes wearing out and then you don't get full lift on your valves (thus the loss of power because a worn out cam is not opening the valves as much)

Its just an increased wear and shorter duration thing
especially in the valve train
my mechanic has a type4 lifter that actually has a HOLE worn through.

His race motors suddenly cut their lifespans in half when the oil changed.

high rpm, high lift, and high powered valve springs are all going to accelerate this. But stock 914's also have the need for the correct oil to save their cams/lifters

all old style vehicles without roller rockers or without hydraulic lifters are needing this barrier of zinc/phosphorus. Modern engines have eliminated all of the internal friction in their valve train (to improve gas mileage) and can get away without as much contact pressure between components

[ThinAir]

Thanks Brant for the education on the topic. I had no idea.

I learned than an additive is available http://www.zddplus.com/, but there are also those who contend that this may not be necessary http://www.valvoline.com/faqs/motor-oil/racing-oil/. I think oil discussions have never been definitive as long as I've been working on cars (IMG:style_emoticons/default/biggrin.gif)

I haven't done the math yet to figure out if Mobil 1 plus ZDDplus would still end up as expensive as the oils that have been mentioned. The last time I priced Royal Purple at my local FLAPs, I practically needed a 2nd mortgage to finance it.

P.S. - another article on the subject http://www.hotrod.com/pitstop/hrdp_0702_pi...tive/index.html
And there is this from the Mobil 1 folks http://www.mobiloil.com/usa-english/motoro...Motor_Oils.aspx (Their chart indicates that their V-Twin or Racing formulas have the right numbers, but their recommendations make it sound like it would be a no-go for our engines)

[underthetire]

Watch the vr1 oil. While it is a good oil, I think it lacks in detergent. I noticed when I ran it the oil got dark pretty quick.

[Bartlett 914]

Watch the vr1 oil. While it is a good oil, I think it lacks in detergent. I noticed when I ran it the oil got dark pretty quick.

Maybe you have that backwards. The dirt is suspended in the oil. That is what the detergent does. The filter is then supposed to filter out the dirt.

[charliew]

Brant is about 95% right. Everything sounds pretty good in laymans terms except the part about the lifters. The new motors have ROLLER lifters and roller rockers sometimes, so the pressure on the lifter scrubbing the cam lobe is not a problem with the crummy non high pressure oils. If the motor has FLAT lifter surfaces like a vw, 914, or sbchev or ford or lawnmower it needs zinc and phosphorus. Actually you can NEVER eliminate all the friction in a mechanical device. The oil guys happlily left out the good stuff without telling anyone as it made the profits go up. I think I remember Jake thought the cam mfg were making crummy cams and he made a dummy motor fixture that would spin the cams against the lifters under spring pressure to break in the cams and lifters and also to make sure they were good before he would use them in his motors. I think it came down to crummy oil in the end. He probably has the tale on his site.

There is a long thread on the web about motor oils, it's motor oil 101. I've posted the link here before but you can google it. It's written by a cardiac doctor that is a car nut and studied oils as a hobby a long time ago.

I worked in a cold forging process fastener huck plant and we tried to save money on the oils we used so some engineers came in with a cheap oil without the high pressure additives. It didn't run long and we had a very pissed off operator as his dies were screwed up and he lost about 8 hours production and blamed my predictive maintenance dept for messing with his production and creating a bunch of extra unneeded work for a new setup.