Koenig-Specials 928

Yes, another here we go again oil story. In my defense, I saw it for the first time today on FChat
So if this is old news or offensive (incorrect info) please move on.

https://www.youtube.com/watch?v=TWuK...s#action=share

khalloudy

I am using the Havoline Formula 20w-50 and its running very well with the proper zinc level. Porsche Classic oil spec’d for the 928 from Porsche direct is 10W-50 though...

ramcram

Well i'm wondering what oil to use in my stroker after it's first 1000km.

It's not really a Porsche classic anymore with Carrillo rods and a Moldex crank. So anyone 'brave' enough to offer informed info???

Wisconsin Joe

Well, the heads & cams are the same, so the ZDDP requirements won't have changed.

Did any of the bearing clearances change with the different crank?

Modern engines are really tight. That's why they run viscosity so much lower than older cars.

0w-20 is great for a new Honda. Not so much for an old Porsche.

Unless you've made radical changes to the crank or rod bearing clearances, I'd still run 15w-50 with proper levels of ZDDP.

928NOOBIE

Royal Purple HPS 20W50. Always good results and has extra ingredients for our flat tappet cars.

Hyper Lube is a nice additive I like; it runs smoother...O'Reilly's has it....it's about 20 bucks a bottle, they don't give it away.

Koenig-Specials 928

+1
This is exactly what I use. 20W50 harder to find now though.

928NOOBIE

I usually get mine on Amazon, just as good a price as everyone else...

Also maybe check your auto parts stores; today I was able to score it at O'Reilly auto parts...they had it in their warehouse and got it to the store for me to pick up after noon..a pleasant surprise for a Friday.

ramcram

I agree and I think I'll be going with Penrite 5W-40.

jcorenman

Buy 'em books, send them to school... And what do they do??

Rob Edwards

I think I'd ask the guy who designed the crank, rods and pistons.

drooman

Kroil - for stuck rings
My final answer

Hilton

I was about to suggest them. I like the fact that they openly publish the specs of each of their oils including zinc, phosphorous, boron etc.

I'd be looking at the Racing 15W50 - I think you may run into low oil pressure issues with a 5W40 in WA with AC turned on. Has a good amount of Zinc, and is a truly synthetic oil.

https://www.penriteoil.com.au/assets...&%20ESTER).pdf

hanick

Yes Kroil the oil that seeps!
Amazing stuff!

fossberry

+1 on Penrite. Because the winter temps get down to single digits degrees C in winter here in NZ and high 20s in Summer I use the 10W-40 racing oil in my 91S4. Runs a tick under 2.3 bar at idle and 5 bar at cruising rpm. The specs suit our vintage engines too.

FredR

FYI there is a reason why oils are called "Racing oils" and it because they are intended to be used in motor racing wherein they expect oils to be changed pretty much each race.Street use oils stay in the engine far longer and thus have more detergents in them to keep microscopic particulate matter that gets through the filter in suspension. Racing oils used in street applications can end up with sludge in the bottom of the sump and wherever else it chooses to go. To be fair that is more likely to happen in cooler climates.

To be clear, not saying racing oils will harm your motor- just be aware of the difference and ensure you know that what you are doing will work. As per Porsche specs 20W50 oil on the 928 motor is good down to minus 10C- there is overlap with lighter oils. I would not deviate from 20W50 unless I was somewhere really cold. 20W50 was the stock lube oil in the UK back in the 70's and 80's and motors were designed for such. Thinner oils were not used because they did not have the requisite film strength. Modern technology has upped that game and even mineral oils that are thinner can get good film strengths these days but our motors are not designed for such. Flow a thinner oil through the system and invariably more oil will go to some places and given the oil pumps are positive displacement that means less oil will flow elsewhere. My educated "guess" is that more oil will flow through the mains/big ends - if so it should be obvious where less oil will flow. Cam lobe wear is usually associated with ZDDP content- I have a sneaking feling that it may be more to do with lower viscosity oils being used