M104-AMG

iTrader: (8)

If you look at my spreadsheet, I would safely say the best "base oils" are those with zinc around 1000 and above.

If you go below 900, then you'll want to add the GM additive.

:-) neil

Bruceman

iTrader: (5)

Please buy and add as much of this snake-oil as what makes y'all feel secure from the fear that modern oils are bad for old engines.
GM makes an amazing profit from this crap and could sure use the $$$.

spoolage

iTrader: (2)

I just picked up a 6 pack of ZDDPlus, I will let you guys know what my experience is with it once I change my oil this weekend.

Currently, I am running M1 20w40 --- my vacuum at idle is around 19. When I had the car inspected at Gotham Racing it was 97 / 98 (front / rear) rotors.

I will do the oil change with 20w 40 and add the ZDDPlus and do a compression test 1k miles into the oil change and report the compression numbers as well as the vacuum.

moconnor

iTrader: (14)

Compression is dependent on cranking rpm, engine temperature and altitude; idle vacuum depends on rpm and barometric pressure. You can obviously correct for all these things but there are so many variables that introduce error that I think it is going to be hard to see a signal through the noise. I think many people would have to do this and report consistent findings before any conclusions could be drawn.

RX7 RAGE

iTrader: (22)

Damn, I just picked up a 4 oz bottle of the camshaft and prelube for $13 bucks at the Chevy stealership! Those bastards wouldn't match the price of the gmdirectparts website.

Bruceman

iTrader: (5)

The current oil category, SM/GF-4, was introduced in 2004.
http://api.org/certifications/engine...lGuide2006.pdf

Therefore this is very relevant.

M104-AMG

iTrader: (8)

So how does a category introduced in 2004, with a paper published in October 2004, have enough time to gather field data (not just lab tests, but REAL off-the-shelf oils) with SM/GF-4 oils, when the oil companies were just released these new oils ?

It just doesn't mesh. IMHO, lab/controlled data is a poor substitute for field data.

Also, it is the "Energy Conserving" oil that are at issue.

Does the SAE paper take into account the notion that the metallurgy of our FD's is in "harmony" with oils with high-levels of ZDDP ?

Seems to me that that the SM/GF-4 category took into account the metallurgy and emissions equipment that the auto manufactures were using in 2004, and balanced those two with just enough anti-wear to make it through the warranty period of both the powertrain AND the emissions equipment.

:-) neil

M104-AMG

iTrader: (8)

This is from the LN Engineering link and it addresses the 2004 SAE paper titled "How Much ZDP is Enough?":

:-) neil
=====
How did you determine the recommended 0.12% Zn and P level (ZDP, a.k.a. ZDDP)?

There are many excellent SAE technical papers on the subject, but the one I found most interested was from 1977 titled "Cam and Lifter Wear as Affected by Engine Oil ZDP Concentration and Type." There is some background that is needed to shed light on their results. First of all, there are different types of ZDPs. There is an Aryl ZDP which is the most stable form. There is also an Alkyl ZDP which although is not as stable, exhibits the best wear protection.

In various fleet tests, it was determined that the best performance was from oils containting all Alkyl ZDPs or predominantly Alkyl ZDP blends. They also looked at the performance of "ashless" oils (0.03-0.05% Sulfated Ash) vs oils with normal levels (0.11% or higher) and it would appear that oils with lower ash levels needed more ZDP to provide the same level of protection. I bring this up since the newest CJ-4 and SM oils require significantly lower ash levels, less than 0.10%. Across the Indianapolis, Phoenix, and Los Angeles taxi fleets observed, oils with 0.11-0.13% Alkyl ZDP resulted in the lowest combined and average cam wear measured. Levels of wear remained low with oils with Alkyl ZDPs as high as 0.19%.

The oils that had at least 0.07% Alkyl combined with 0.05% Aryl performed just as well as oils with higher Alkyl only ZDP levels, suggesting some sort of synergistic properties of the decomposition products of the Alkyl/Aryl blend. Combined ZDP levels of the Aryl and Alkyl blend were min. 0.12%. Our assumption with choosing a minimum Zn and P levels of 0.12% is on the assumption that the best combo of ZDPs are being used for wear performance, not longer drain intervals.

More recently, in the development of the IIIG sequence, developers went so far as to say that there was no need for the VD and VE sequences for testing of OHV (overhead valve) engines because these engines are not commercially available as new anymore and do not reflect the needs of more modern engines. In a SAE paper titled "How Much ZDP is Enough?" from 2004, the resulting trend of decreasing phosphorus is as a direct result of observations that modern engines, with lower spring pressures and lighter vavletrain, including multiple intake and exhaust valves, seems to require only .03% Ph to prevent wear. It was further documented that by increasing to 180 lbs of spring pressure with a .03% ZDP resulted in 267 mil of wear where with .05% ZDP concentration tests resulted in 26 mil of wear. That same .05% oil with just 205 lbs of pressure resulted in 153 mil of wear, requiring .095% ZDP to reduce wear, resulting in just 16 mil. The ZDP requirements of a motor oil are directly proportional to valvetrain spring pressure. Most older SOHC and pushrod aircooled Porsche engines have significantly more pressure, as a stock street pushrod Porsche 356 or 912 engine exceeds these levels of spring pressure compared to the levels of pressure on modern engines, for which oils are tested for.

Newer oils will continue this trend, leaving older engines with fewer and fewer choices for motor oils compliant with the requirements of these older valvetrain, hence our recommendations for using oils with higher levels of ZDDPs as substantiated by earlier testing sequences and the results on engines similar to our older aircooled Porsches.
What motor oils had the 0.12% levels of zinc and phosphorus recommended?

The current API standard is SM, and calls for 0.06-0.08% Zn and P.

Here are the running averages for all the oils tested thus far, listed by their API rating:
API P (ppm) Zn (ppm) B (ppm) Mo (ppm) Ca (ppm) Mg (ppm) Na (ppm) Total Detergents
SE-SJ 1301 1280 151 357 1936 293 214 2443
CI-4 1150 1374 83 80 2642 199 2840
SL 994 1182 133 273 2347 109 22 2479
CJ-4 819 1014 26 2075 7 2082
SM 770 939 127 122 2135 13 139 2287

I do not recommend the use of any SM or CJ-4 motor oils in any aircooled Porsche, or any vehicle that can benefit from the added anti-wear additives such as pre-ODBII vehicles. If your vehicle is designed to use these newer oils or if your vehicle requires a manufacturer approved oil and is still under warranty, always follow your manufacturer's recommendations!

Azcamel

iTrader: (1)

how about royal purple? im running either 15/40 or 20/50 depending on the temp.. these oils are still cool right? i also premix, about 2ounces per half a tank.

alexdimen

iTrader: (13)

So this idea has gone from crotchety old hot rodders to rotary enthusiasts. I first heard ancient valvetrain components were the only thing it screws up, now it's supposedly detrimental to modern rotary engines. Sounds like paranoia to me.

If that logic helps you guys sleep at night, far be it from me.

spoolage

iTrader: (2)

Well I will take a baseline reading before the oil change. I will take it at 20 different times through out this week and get my set variance.

After that once I do the oil change, I will take a reading every day that I drive up to 1k miles (engine warming and engine about to shut down). I figure if I do this I can get at least 50 readings through out the month.

While I know this in no way a legitimate scientific research model, it will still give some light as to if anything is going on with the engine.

(The compression I will test 4 times this month) @ 250 mile intervals

moconnor

iTrader: (14)

Hard core. Wasn't trying to knock your idea - just suggesting that it will probably take quite a few people doing over a year or more to reach any sort of conclusion. Despite a deep skepticism of additives, I'll probably throw in a bottle for the next few oil changes to see what happens. With 50k+ miles my engine definitely should not naturally gain compression.

Sukai94

I am surprised no one has mentioned idemitsu oil.

Mahjik

iTrader: (1)

Royal Purple is fine. However, the additives which are in most x/40 weight oils are usually not good for the FD. This is way you typically see x/30 and x/50 weights recommended and not 40's.

David0ff

iTrader: (6)

damn , there is so much info out there that picking an oil for MY FD has gotten more complicated than me rebuilding my engine ...
i am using Castrol GTX 20/50 ... is that ok ? , what should i use in the 10/30 range?
damn i r confused

Azcamel

iTrader: (1)

really? so 10/30 or 20/50 but 15/40 is different? weird!

j9fd3s

iTrader: (3)

this is a question, not a flame.

since 2006ish ive seen a HUGE increase in main bearing wear, on teardown of a rotary engine. before 2004, we used to hardly see any wear at all in the bearings. now every engine is showing major wear, with some down past the copper.

why?

dhays

iTrader: (1)

What about running EOS in the oil instead of the GM prelube? Anyone the difference? Pro/con etc... EOS lists for about $25 for 16oz.

RX7 RAGE

iTrader: (22)

How many miles did these engines have with bearing wear?

alexdimen

iTrader: (13)

Great... Now it's going to be bearings too...

My brake lining wore out. It must be because of lower ZDDP. You know, even though there are other additives to take it's place.

Six Rotors

iTrader: (17)

Based on my experience with several rebuilt 13B,13BT and a new RX8 motor,it is quite normal the compression to continue rising upto and occasionally beyond 10k miles.I had always assumed that this was due to better sealing as the apex and side seals wore in to match the housing surfaces.
My RX-8 was fed 10W40 Castrol GTX(2006/7).

2007 ZX-10

their pre-mix rotary lube is a great product

RiceFx306

iTrader: (7)

I run Amsoil Series 2000 20w50....now I'm going to have to do a lot more reading on it, but from my understanding since it is a "racing oil" that it would not fall into the API stamped category and would thus have have the higher ZN and P levels due to non restriction. It also doesn't recommend any additives to it's product so I'm thinking that it would already have ZDP up and above par. Haha I have more homework now.

Sukai94

what about their oil though?

j9fd3s

iTrader: (3)

average engine from 97-2003 is about 100-120k miles.

from 2005-now is about 80k.

average motor in both cases is previously unrebuilt.

all cases 97-03 bearings look really nice, didnt change a single one.

all cases 2005-now bearings are about half borderline and half just plain bad.

engines torn down, range from rx2/rx3 to 1st gen 12a's to fc 13b's to the fc/fd turbo engines