Web-Cam sez:

[Doug Zielke]

I just received my set of new Web-Cam 20/21 camshafts. (Superman made me do it! )

They come with installation instructions which include this warning: "Do not use synthetic oils....."

Now, I will send Web-Cam an e-mail asking why, but what do the gurus think of this admonishment?

[pwd72s]

I'm guessing, just guessing mind you...that the admonishment refers to the cam wear-in period only. Either that, or webcam uses a special alloy that disintegrates in synthetic oil?

[TimT]

That instruction is for the break in period for the cams.. Im sure web-cam would frownon any warranty help if you disregard the instructions they provide.

[Doug Zielke]

I thought that, Tim.
Like the usual instructions about breaking in the rest of the motor with dino oil. I'm a strong synthetic oil advocate....after break-in.

[Bill Douglas]

Check what Dick Fleming has to say about oils and cam wear. He's an incredibly knowedgeable guy.

www.pcapotomac.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=2&t=002775

[Wayne 962]

Consumer Reports did a report on Dino vs. Synthetics. Ran them in Taxi cabs for about a year with 150,000 miles or something like that (the exact article date and reference is in 101 Projects). They found no difference in wear between the two.

I have heard that the synthetics offer up less staining than the normal oils. I for one don't use synthetics - I think that they are just too expensive for the lack of proof on their benefits.

Don't use synthetics in older cars - they have a tendency to make them leak. Newer engines that are broken in are okay...

-Wayne

[ChrisBennet]

This is was a port to Rennlist which was pasted from the 928 list some time ago. Note the words in bold.
-Chris
------------------------------------------------------
Subject: synthetic oils
From: "Brian E. Buxton"
Date: Tue, 3 Nov 1998 17:17:55 -0600
X-Message-Number: 69

This was posted on the 929 list and I wanted to get some thoughts on it.

BEB

"Hi All,
Kinda long, sorry ....

I've noticed the recent inquiries and responses to "winterization" questions
for the 928 and thought I'd offer an unsolicited comment. Within the past
week I have been made rudely aware of what *not* to do for engine care
during the winter. It may or may not apply to the 928. Just use it as
additional information to add to your knowledge base. I live near Portland.
Oregon where the winters are not particularly cold, but do tend to be damp,
rainy, and foggy at times.

Here is what happened. I also have an airplane which resides in my garage
with the cars. The garage/hanger is mostly unheated. I fly some during the
winter, but not a lot. I always fly enough to heat the oil when I do go out.
A few years ago, I began using Aeroshell 15W-50 semisynthetic aircraft
engine oil.

Reasons were the usual ones for using synthetic based oils, and I noticed
immediate reduction in cylinder head temp, smoother operation, reduced fuel
consumption, etc. I have all digital engine gauges including fuel flow which
is accurate to 0.1 gph so these improvements were actual, not seat of the
pants feelings. I changed the oil at regular intervals - less than the
recommended time. The Shell semisynthetic is especially formulated to
inhibit corrosion. At least that is what the Shell specs say. Conforms to
FAA specs., Mil-Spec., engine manufacturers approvals, etc., etc.
Supposedly, the best money can buy.

One cylinder was down on compression due to a leaking exhaust valve so I
removed it for repair. What I found was not pretty. Rust pits!! Rust on the
cam. Rust on the can followers. Rust on the piston pins. Rust on the inside
of the cylinders. I have not removed a rod cap to check the crank, but I
fear the worst. These rust pits are through the hardened surface so service
life will be short and the engine must be removed, torn down, and all rusted
corroded parts replaced. The basic engine overhaul cost is estimated at
$14,900. That is with me removing it, and re-installing it. No accessories
like carb, magnetos will be touched for that price. If the crank is bad, add
another $6k to $8k.

The engine shop said, "We see that all the time when people use synthetic
oil and don't use their machine regularly. The synthetic flows off the
internal parts and leaves them open for condensation moisture attack". They
recommended to only use synthetic oil if the engine will used continually.
If it will not be used much during the winter, use regular, non-synthetic,
oil; something that will stay on the surfaces. Here I thought I was doing
all the right stuff to take the best care of the thing and It was not right
at all. Wish I had known then what I know now. |

I guess it doesn't matter much, but wear on the parts, excluding corrosion,
was nil with about 800 hours on the engine. This may not apply to auto
engines or auto engine synthetic oil, but it seems like it shouldn't be too
far off.

If you live where condensation is not a problem, ie. dry and usually below
freezing, then this probably wouldn't be a factor. Yes, both the 928s still
have Redline oil in them, but will be used regularly. As always, YMMV. Back
to the garage now to spend my Sunday afternoon removing cooling baffles,
exhaust pipes, and lots of other stuff."

cut and pasted from an E-mail by louis ott to the 928 list

[Superman]

I'm really flattered, Doug. But I can't disagree. These cams are just a blast.

Doug, after doing the research, I chose to use nondetergent oil for breakin like the aircraft guys. For the first couple of oil changes. All the internal parts were coated with assembly lube but some say this is not necessary. I'm still using dino oil. One of the cam thrust plates is still weeping oil so I need to seal that up and then the synthetic oil decision. Synthetic's only value for me is that it retains viscosity at higher temps. So really Dino oil has the same value for me most of the time. But I do intend to track this car, so.... After breakin, I sure don't think synthetic oil could be a bad thing except for the cost.

I recommend Dino oil for a while during breakin. Again, I used single-weight (30) nondetergent oil for breakin. Even in winter, if she sleeps in the garage then this would be an option for you. I think the point is to use an oil that is not too good. I mean, those parts need to duke it out a little...synthetic oil is just too good for breakins, I hear.

The interesting part is bolting the heads onto the cam housing and finding that the cam's bearings leave it free to turn. Wasn't a problem at all. I'm almost envying you the experience.

I tell ya Doug, I grin every day when I drive this thing. If I had to pass emissions, and if the 20/21 cams would not pass, well I'd just change cams twice per year.

[speeder]

I've never crossed over to being convinced to use synthetic oil, and these facts are not helping to do it. I would use it in a newer car that was designed for it, of course, but not in anything I own now.

I run SL grade dino 20W50 in the SC, this is *4* grades higher than the best oil available when the car was new! And ~$1.30 a qt. at Pep Boys or Autozone. It is definitely suitable for racing use in extremely high performance engines. It is true that synth. oil will retain lubrication properties at higher temps, but don't worry, your motor will sieze and aluminum will warp WAY before this benefit kicks in. I have an oil temp guage, and will shut it down long before this damage, (or oil failure), occurs.

[Elombard]

Im am curious... how exactly could a new car/motor be "designed" to work with synthetic oils? I believe the new Porsches come with Mobil 1 for instance. Is it the metals used? Especially looking at the above post from the 928 thing. If the oil runs off the parts, how do you design around that??

[Joeaksa]

One question:

What about Porsche saying that they recommend synthetic oils in their cars? BMW motorcycles has also been recommending this for years and their warranty is for 100,000 miles...

I have used synthetic oils in my old 72 and now in my 85 911, both with high mileage (200,000 + in one and 90,000 in the other) with no oil leaks...

Joe

[Doug Zielke]

Somehow I just knew this would turn into a oil thread!!

[speeder]

Elombard, I was thinking that maybe the seals in new motors are "designed" for synthetic oil, but really not sure. Something has definitely changed when a lot of manufactures are specifying 5W30 oil in ALL climates for their engines. (?)

Also, the 150,000 wear test that Wayne refered to, and countless reports of older/used engines developing immediate leaks after switching to synthetic oil. My 120k miles, 20 yr. old 911 motor just came apart, has only had conventional/dino oil, wear on cams, bearings, cylinders, etc., can only be described as "imperceptible". That's all the proof I need.

[island911]

"The synthetic flows off the
internal parts and leaves them open for condensation moisture attack"

hmmm, I don't think so.
I'm thinking even Wd-40 will stick to the CAMS and other internal parts just fine.
The synthetic oil wets (stick to stuff) just fine.
Spill some on a wrench you rarely use. .. come back 6 months later and that stuff will still be a sticky mess.
' flows off the internal parts' . . .c'mon, if you believe that, then give me some money to rebuild your engine.

[Superman]

The wear on my 182K motor was also nearly imperceptible. I want to hear from Doug, when he gets some figures for us. Piston, cylinder and bearing measurements. I'll be you can't tell his engine from a new one, on the inside.