Chads996

Bingo.

C.

smlporsche

and which one flows better at start up when 90% of all wear occurs, a 0W-XX oil or a 20W-XX oil ???

Anyone know what weight oil is used in F1 cars?? You'll be suprised.

choinga

I dunno what the weight is - but it's gotta be paper thin.

I think the key is to find a high quality oil that 'sticks' and has you covered during the cold starts.

That's why I went w/ Brad Penn:

smlporsche

A legitimate concern mentioned above was the lower levels of ZDDP found in many oils today.

Mobil 1 has recently come out with a new line of pure racing oils (not intended for street use due to the additives package) that have increase levels of ZDDP and are designed for flat tappett engines

http://www.mobiloil.com/USA-English/...cing_Oils.aspx


Notice the weights...hmmm...I seriously doubt that any of us drive our cars harder than the guys in ALMS etc...

food for thought

DarylJ

That's why I like the synthetics. You can get a nice wide spread.

I was under the impression that they ran single weight oils and warmed them before starting. Regardless, I don't see what that has to do with a street car, even if it sees some track use.

DarylJ

For 944s? Really? Air cooled guys, yeah (even though the ZDDP reduction is offset by other additives that serve the same purpose if you drink the M1 cool-aid). But if ZDDP were really a huge concern on these cars, I'd expect to see a whole lot of "OMG - lifters are galled!" threads. I don't recall ever seeing one.

Check the 911 forums. That's what lack of ZDDP does. I just don't buy it as a concern on a 944.

badcoupe

the lack of certain chemicals as mandated by the government has caused oil to get worse recently. Comp and crane have started selling additives because ofthe increased number of cam failures. In my ex-nextelcup motor I use a zinc additive. A good quality offroad motorcycle oil like belray or motul are great but not sure how well they'd work in a street car. I've been breaking in pushrod motors on belray MC oil. The gibbs stuff is great but expensive. You can also still buy the actual racing formula valvoline from jegs and napa, lots of the midget use it in their motors it still has the good stuff in it.

J Berk

I just bought some valvoline Racing 20W-50 today....it specifically mentions ZDDP among a few other additives.

333pg333

Just a whole lot more misinformation yet again in an oil thread. Our cars are not the same as current day Porsches let alone F1 or ALMS. Flat tappet engines do suffer from excessive wear and that was witnessed by many workshops at least down under. The marketers of M1 came around and mesmerised everyone and they all used the new flashy product until they found that all of a sudden they were getting a lot of wear up top way faster than normal. They switched back to a 20w/50 and hey presto, back to normal. Case closed.

choinga

I'm with you. I don't have first hand knowledge, but why risk it?? When there is plenty of stuff out there with ZDDP that's high quality - is it worth jacking around to save a few bucks a quart?

The new Mobil 1 Racing stuff looks interesting, but I'm sticking with Brad Penn. It's a known good thing, has the ZDDP and is as high a quality oil as you can get right now, IMHO.

badcoupe

also places like gibbs and VP recommend you determine oil viscosity by the amount of clearanceyour given engine has. with todays tighter tolerances the engines can safely run on 0-40 etc compared to our engines that are a little more open due to wear etc.

joonas

If you track your car and you do not have external oil cooler oil temperature will raise over 110 degrees C after two laps. When oil gets really hot only high quality high grade oil can hold oil pressure 10 psi per 1000 rpm.

JET951

Hi Darylj , I own and run a Porsche independent workshop in Sydney Australia and have around 33 years experience in relation to mechanical repairs to Porsche's, and we have lost count to the number of worn cams/lifter faces on 944 8v and 16v engines that we have had to replace , same goes for the 928 16v and 32v engines in relation to the use of engine oils that have in hindsight have had low levels of ZDDP , and naturally these oils tended to be in the viscosity ranges lower than 15w-50( example 5w-40 , 0w-30 ,10-40 etc ) , the reason that I can talk about this phenomenon is that I/we never fell for the hype of switching away from the recommended oil viscosity chart that printed in the owners manual in all Porsche's from last century.
So in other words if we stay within the temp ambient temp confines of what I need for my customers Porsche's and our own we see(in the owners manual) that from minus 10 deg cel to unlimited high ambient temp we see a 20w-50 oil viscosity remembered by the people who built the Porsche in question from last century .
Sub note ; in Porsche owners manuals ,I think around pre 1983 , a 20w-50 was recommended for the ambient temp rangers of minus 15 deg cel to unlimited ambient high temp, so a 20w-50 in reality goes down in the lower temp spectrum a long way.
Now here is what I call the double whammy when it comes to oil viscosity and the 944 /928 range.

A) its now accepted that the majority of the engine oils that have to comply the strict ACEA protocols in regards to emissions for petrol (Gas) cars for this century have to be lower in ZDDP and higher in the replacement AW packages are naturally in the lower viscosity ranges for the petrol (Gas USA) engines which in my opinion have not served to well in the older Porsche's with the flat tappet design(last century) , this also goes for the air cooled 911's that suffer much greater valve guide and rocker / cam wear.It gets even more interesting because we only see thrust bearing wear on Porsche's(928 , 993 turbo) that have been on so called synthetic low viscosity oils(low ZDDP) , where as the same models that have been on a decent quality 20w-50 have had no wear at all
So there is whammy 1

B) We have never lost a 951, 944 , 968, 928. 928s, 928 ,928S4/ GT ,GTS , 911 air cooled (all types) to a blown big end bearing (928 journal 2 & 6) (944 no 2) where the big ends were in good condition to start with .
WHY , because in the case of the 944 (all) no 2 is the first to starve of oil pressure at high RPM , and the hotter the oil the worse it gets .
We have won PCNSW club championships and Super sprint championships with our own 951 and customers 944S2 etc , and with all the flogging = no engine problems .we don't even run dry sump nor even modified sumps , nothing but standard street baffle in the sump .
How = Valvoline Racing GP50 , which is a 25w-60(good ZDDP) , so even at 130 deg oil temp we always get at least 6 bar pressure at high RPM ,
That's whammy 2.

Combine the both what do we get at work , well every summer have had 944's and 928's 964's , 993's that have been on lower viscosity oils than what are recommended by the manual that comes with the car, that drop by our work for the first time with the oil pressure warning light on and some get towed in with a damaged big end / crank (boy racing on the street and bang) all of which was avoidable by sticking with the recommendation in the owners manual .

Regards .BB.

DarylJ

Thank you. That's some real information with credibility.

Based on that, I'll pay more attention to ZDDP content.

Great for racing on a hot track. Not so good for a daily driver in the north east US But point taken on your wear observations. I appreciate such a well thought out response.

Bruno'S2

Thanks a bunch guys. This is really good guidance. I will use it to look for a good 20W-50 for my next DE event.