Engine Oil

[robwright]

OK probably been touched on a million times before but recent posts have brought it to the forefront of my mind. The oil I use is nowt special but I am happy that it does the job OK. I know my car runs a little rich due to aftermarket chips for increased boost, which I am also happy with. I have noticed since staring to wind up my boost (currently 15 psi & 16 when colder) I do notice more blue smoke coming out the kyber!! And yes oil consumption has increased. Is there a better oil I can use for instance Magnatec??? I believe Pete (PSH) said he has had good results from this stuff. Also has anyone got typical values for compression testing of the turbo engine? Are these best done hot or cold? Thanks in advance guys.

 

[Frenchy]

Rob, Mine runs Rich on 18 psi [] i use Magnatec and hAve no problems with it very rare top ups. Still not got round to fitting my Tial DPW too busy sorting the new 220, would not mind some pics of yours in situ if you get some time ? Frenchmeister []

 

[robwright]

Frenchy, Will sort some out as soon as I get the opportunity. Rob

 

[oilman]

If you are considering Magnatec as an upgrade, I'm guessing you are using something fairly basic and mineral based. As the car has been chipped, the oil temperature will have increased a bit and that will help to burn oil. Mineral and semi-synthetic (semi's are all 100% mineral oil based, just modified) oils burn off easier than synthetics as they are a mix of different sized molecules and the smaller ones evaporate and burn. In a synthetic, all the molecules are the same size, so the evaporation rate is a lot less. Have you got any idea what the oil temperatures are in your car? I would probably use a 5w-40 synthetic and you will find those through the link below. [link=http://www.opieoils.co.uk/c-656-5w-40.aspx]http://www.opieoils.co.uk/c-656-5w-40.aspx[/link] Out of those, the best ones are the Silkolene Pro S, Motul 300V, Redline and Gulf Competition. The Motul 8100 X-Cess, Gulf Formula G, Fuchs Supersyn and Mobil Synt S are good, cheaper alternatives. The cheaper ones are mineral based synthetics that have been modified enough to be legally called synthetics. They should burn off at a slower rate than a mineral or semi-synthetic oil though.

 

[sawood12]

The features of Magnatec are nothing to do with oil consumption. Magnatec is an Ester oil which means the oil is effectively statically charged meaning that it never fully drains away from the surfaces it touches - at least the ferrous metal surfaces. This means they remain covered with a very thin film of oil and provides better protection in those first few seconds of the engine turning when you start the engine and improved protection for the first 10mins or so of each journey until your oil has come upto operating temp. This is not a marketting gimick - it is a real and very effective property of Ester oils. I wouldn't use anything else. Even my Focus gets a good Ester oil as my wife does so like her short 60 second journey's down to the shops! Your increased oil consumption since you've increased boost is probably due to one of two thing - either the increase in pressure differential across your turbo oil seals drawing oil though when on boost or more oil being drawn through your air oil seperator (AOS). In terms of compression, the only time my engine was compression tested at around the100k mile mark the results fell within the 'Just Run In' band. I never got the actual results so I can't advise on the actual numbers, my specialist did it as part of the cars first major service after I asked him to give her a damn good looking over to understand what i'd bought. I wish i'd asked him for the results now.

 

[robwright]

Hi Scott the turbo is a recon K60 that I acquired from Lynsey about two months ago so fairly confident it is OK. As for solutions are there any??? Or should I just accept it as an occupational hazard of increased boost?

 

[944Turbo]

Im not sure that magnatec is a proper ester oil, certainly there are better oils available, Tony

 

[sawood12]

Whether or not you accept it is upto you - I wouldn't like to speculate as to what the source is in your case. I'm not sure how you'd go about checking the turbo but i'd not expect a newly reconditioned turbo to pass oil through the seals. I guess it depends on what the oil consumption is. If it is within the handbook guidelines then I guess no harm is being done, but if it is outside then burning excessive oil isn't a good thing. My car used very little oil in normal road driving - I often wouldn't need to top up the level between services - however on the few trackdays I did it did use more oil and I had to top the level up a few times through the day (maye a couple of litres), so I guess it depends on how much driving you do on boost!!

 

[oilman]

Magnatec... It does contain ester of some sort. However this is where castrol are being from a marketing point of view quite clever. In order for ester to be effective in oil ideally you need upto around 20% content, on top of that it works best blended with a pao synthetic base stock. Magnatec has a few % content so they can say its there for sure but does it really do anything..? Plus its blended with a mineral base stock so really not taking full advantage of what the addition of esters in an oil can do. The genuine ester/pao blends cost a lot more and there is a good reason for that. Cheers Guy

 

[Copperman05]

I would also suggest you put in a good quality ester based fully synth oil, probably not magnatec but one of the ones oil man recommends, silkolene pro s for example, more expensive yes but still very cheap compared to how much you would spend on petrol over the same miles. Edd

 

[robwright]

Scott it is just a niggling thing really when you see that puff of blue smoke out the back when burrying your foot hard. What makes it worse is when others make comment but they don't really uinderstand what is going on under my bonnet!!! Even for a modern car to be approaching the 300 BHP mark is no mean thing. Consumption is definately within the factory guidleines although I admit these are quite large lol. I am guessing I will just have to live with it [] Engine wise the car runs like a dream. I will be looking at the suspension when I eventually get the money together (or age forces me into a corner). Would still like to compression test it to ensure I am not passing too much by the rings. I have all the equipment just need to get my hands on figures for what is acceptable.

 

[robwright]

Guy, Could you email me a price list for your oils to see how they stack up to my local factor please mate. I think I might go for the Silkolene. It seems to come highly reccomended. When I make the change I take it that is adviseable to do the filter also? I noramlly would be looking at filter every 12 and oil dropped every 6. Current filter has been in around 3 months. Cheers, Rob

 

[edh]

Rob - I'd try the Silkolene 15w50 synth from Opie - it's about the best I've used Bear in mind a compression test will only tell you about the state of the top ring - the other rings may still be the cause of the problem (neads a leakdown test to diagnose?) You could try fitting a catch tank (not much space to put it with the airbox in place) and see what gets pullled through. I'm sure I read that PSH used (and rated) the Ametech treatment - it still sounds like snake oil to me but might be worth getting his opinion on how it worked with his car.

 

[robwright]

You are quite correct Ed but I also know from my work on locomotive engines that bad compression rings can allow excessive wind into the crankcase and lead to excessive pressure and ultimately more vapour escaping from it. In a loco engine's case this is safely vented into the exhaust/turbo stack via a seperator screen. Where does the crankcase vent to on our cars? Is it back into the air intake system? I think Scott mentioned there is an air/oil seperator isn't there?

 

[TTM]

Using anything thinner than 10W40 in a well-used 944 engine is playing with russian roulette, especially in a 944 turbo engine. I switched from Castrol RS 10W60 to Motul 300V 15W50 following advice from the workshop where I had my (Alusil) block prepared. They put it in about any engine that goes through their hands, ranging from Porsche 935 to Velocette KTT.

 

[edh]

The AOS breather connects to the rubber J-boot in front of the turbo intake. The metal pipework is connected to the Cycling valve pipes (you can see them disconnected in this pic as the CV is now bypassed) If your turbo intake is very oily then that's a sign your blowing a lot of oil out of the crankcase. here's mine with a catch can fitted (connects to the J-pipe after the MAF) I've removed it now. You can get them on ebay for about £30-40 I think

 

[333pg333]

Curious how significant the supposed charged particles in Magnatec cling to our Alusil cylinders? I'm in agreement with Thom. I wouldn't put a 10w/40 anywhere near my engine let alone a 5w/40. Remember that the Porsche manual recommends a mineral based Multigrade oil of 20w/50 down to below freezing temps (-10oC)...and this was on cars as recent as some 996 models. For those of you that really care about what you put in your engine, here is a most excellent and detailed thread that is relevant to our 'flat tappet' motors. One of the main contributors on this topic, Charles Navarro is a leading expert in this field. I have saved this thread and return to it semi regularly. [link=http://forums.pelicanparts.com/porsche-911-technical-forum/367300-ultimate-motor-oil-thread-why-we-hate-cj4-sm-oils.html]http://forums.pelicanparts.com/porsche-911-technical-forum/367300-ultimate-motor-oil-thread-why-we-hate-cj4-sm-oils.html[/link] http://tinyurl.com/yzrxn2t

 

[Copperman05]

Here we go again, a common misconception regarding oil vicosity it seems, I would say 10W60 is probably much more damaging to these engines as it wont be thin enough to lubricate it properly at working temperature. The porsche manual 1989 Turbo and 944 also recommends 'all season' fully synth or hydro cracked oils such as a 5W-40 and actually calls it a high performance oil. We have all been here before, one should not automatically put extra thick oils in these engines, you may be doing more harm than good. Edd

 

[333pg333]

When you say high performance oil you of course mean "Fuel economy oil"...and yes, here we go again. As far as lubrication goes, I'd rather my oil be on my camshafts, tappets etc when I start it up as opposed to low visc oils that drain down into the sump overnight. Also as far as protection to the bottom end of my motor goes, I'd also rather an oil that is going to stand up to the rigors of not only spirited hwy driving but also the track. Low visc oils like a synthetic 5w/40 become like hot water under those circumstances and do not provide a protective barrier that a higher visc mineral based multigrade oil does. A 5w/40 would probably be sufficient if you just wanted to potter about the local village of course.

 

[Copperman05]

Yes thats the table I was talking about, thanks. At the bottom Porsche recommends, yes thats right 'Recommends', using 5W-40 oil for all season use, it lists it as a fuel economy oil as it is a synthetic oil which provides less drag and therefore improves fuel economy slightly. This oil is superior to mineral oil, and is a 'high performance oil' porsches words not mine. 5W-40 is the same viscosity as 10w-40 15W-40 20W-40 at working temperature, so it is not like water as you suggest but exactly the same viscosity at working temp as the other oils, the only difference is the cold weather temperature viscosity. Your assumption that thick oil is better becasue it doesnt drain down into the sump is incorrect and this it not how oils are designed to be used. Thin oils are BETTER at start up because they are thin, thick oils are less effective at low temps, this is common fact. A thin oil is able to be pumped around the engine much quicker at low temps lubricating the engine, a thick oil takes much longer to circulate and therefore more wear occurs. Notice on the graph you have posted that as temperatures get lower the recommended oil viscosities also get lower, I'm not just making this up... Edd