Got some info on oil for you guys

[turbotoaster]

Since i used to work for fuchs/silkolene i know a fair bit about oils, though when it came to what to run in a rotary i wasnt 100% sure, most of the tuners i spoke to had different opinions.

WGT said he would never run fully synth on any engine, even race ones, 20b, 26b etc

Reworx said use the best oil you can and dont worry, never had problems running fully on there engines.


So i thought, well im friends with the guys who actually design the oils so i may aswell ask them.

So i emailed a guy i used to work with at silkolene, nice chap who works in the labs to see what he thought.

here it is below, if you wanna ask any questions i can forward them on to him as he only lives up the road from me and my mum is his boss so hes always happy to help.

ME

Ok thanks very much.

Now im running a rotary engine at the moment, the engine has just reached its first 1000miles, this has been run on 15w50 mineral oil to bed everything in.

Now i understand the benefits of synthetic oils over mineral oils in a normal piston engine all to well.

The issue i have is that the rotary sprays through a pump some of the engine oil into the combustion chamber to lubricate the seals, bit like a 2 stroke bike

Mazda tests fully syn back in the early 90s and found that full syn did not burn cleanly and eventually left deposits in the engine.

Obviously oil technology has progresses since then and in an ideal world id block off the pump, run full syth in the engine and mix full syn 2stroke oil in with my petrol to lubricate.

Now thats 2 much of a pain really as it means ill always have to have oil in my car for that.

So im wondering what modern fully syn are like, i know bike ones are ashless but are car ones? id imagine the temps in the customer chamber are going to be much higher than the flash point on tech sheets ive seen

Lee




JOHN



Dear Lee,
               All ‘synthetics’ are very definitely not the same, so which type of fully syn did Mazda test in the 90s? I bet even they don’t know!
    2-stroke oils are either low ash or (rarely) ashless, meaning that they do not contain large amounts of substances containing calcium and zinc to make the oil last for 10,000 miles…..not really necessary in a 2-stroke. All 4-stroke oils are high ash, but this normally doesn’t matter because 4-strokes don’t burn much oil, so they do not accumulate zinc oxide and calcium oxide (lime) deposits in their combustion chambers. (These cause pre-ignition.)
     Early rotaries such as the Norton (and the related Mid-West Aviation aero engines) ran very well on our ashless ‘Comp-2’ synthetic ester 2-stroke oil, but the Norton engine was also tested and found to be OK on high-ash monograde mineral diesel engine oil. (Much cheaper.) My feeling is that rotaries are OK with high-ash 4-stroke oils because of the high ‘G’ forces generated by the rotor; any heavy combustion-chamber deposits will be flung of by very high centrifugal forces. Of course, the road Mazda RX8 uses standard 4-stroke oil, so I am told.
     All rotaries run high rotor temperatures, so any combustion chamber oil deposits should burn off easily, even with heat-resistant ester and PAO synthetics. I’d go for Pro-S 5W/30, a heat-resistant high-ester full synthetic which is less likely to form coke on the inside of the rotor and ruin the needle roller bearings.
     Don’t worry about flash point. (All to do with safety in storage.)  Engines have been running combustion chamber temps way above oil flash points since about 1890. (Seriously!) Flash point is the temperature at which the oil vapour rising off a static pool of oil can be ignited in air when exposed to a flame. It is NOT the same thing as spontaneous ignition temperature, which for all oils is around 400-450C.
                                                                    Yours sincerely,  JR


Now i havent mentioned to him about the use of my car: ie big boost, big power etc so im gonna come onto that next with him.

My car now has 15w50 pro r fully syth running through it, due to the expected high heat it will have to deal with and the chance of fuel blowby into the oil.

[m1tch]

Just put the OMP adaptor plate in and run a tank of marine 2 stroke into the engine, then run the engine on fully synthetic...job done

[SmbFD3S]

Good information although i\'ve never really took much notice of the "great oil debate"
 
When i bought my RX it had 56 thousand miles on it (UK Car). Since it\'s first oil change in 1993, (i have the entire history) it was then run on fully synthetic 5w-30 and has been ever since. When i ripped it open to do a refresh at 61 thousand there was hardly any carbon build up at all, hardly any wear on the apex or side seals and were infact still within tolerance of the Mazda spec\'s so i\'ve continued after the rebuild using Fully synth 5w-30.....
 
Will be interesting to see what he says about the big power and fuel mixing, although if you\'re running huge ports then you\'d change the oil a lot more regular anyway. 15w50 is a thick oil to be honest, especially when cold and especially when using the standard OMP lines as the pressure will be very very high.....

[nuki]

can you pre-mix a standard rx7. even though the omp is still working and using mineral oil.

[SmbFD3S]

You dont want to really, or if you do it should be a "light" mix or you\'ll be reducing the octane of the fuel too much

[trotter]

yep, you can - \'belts and braces\' approach really. But doing so will increase the chances of your engine surviving a failed OMP on the move.

good idea to reduce concentration though.

[m1tch]

I know when prof took his engine apart that has been running with the 2 stroke OMP adaptor is was nice and clean

[the hat]

Just put the OMP adaptor plate in and run a tank of marine 2 stroke into the engine, then run the engine on fully synthetic...job done

 
any chance you could take some pics and a little guide of how to do it mitch

[m1tch]

any chance you could take some pics and a little guide of how to do it mitch

You would need to as either pete or prof about it, but its basically a sandwich plate that has a hose attachment that goes to a 2 stroke tank and it basically bypasses the oil intake from the sump and lets the OMP take in 2 stroke instead

Here is the thread:

http://www.mazdarotaryclub.com/forums/showthread.php?t=49480&highlight=2+stroke

[TRex]

Seems like your man knows his apples.... :Thumbs-up

 My take on this is simple, the Internal combustion engine is not designed to burn oil, or to put it another way, Oil is not designed to be burned..... It\'s primary purpose is to lubricate and then aid in heat transfer.

 By injecting Oil (normal lubricating oil wether mineral or syn) in your engine cannot be a good thing as it is not designed to burn in this way, this to me is basics, basic common sense.
All it will do is coke the engine internals and cause carbon build up because it will not burn through!

 Now 2 stroke oil, this in it\'s nature is designed/engineered to burn, it is designed to mate/mix with gasoline to lubricate and to burn.

 So to me it\'s simple.....
Pre mix or bust!
 

[m1tch]

Its also best to use marine 2 stroke as marine engines are at high rpm for extended periods of time, so their 2 stroke they use is ment for high temp/high rpm engines.

I will change to the premix system at some point, I will probably get my WI in sooner so that I can steam clean the rotors out as well

[turbotoaster]

Good information although i\'ve never really took much notice of the "great oil debate"
 
When i bought my RX it had 56 thousand miles on it (UK Car). Since it\'s first oil change in 1993, (i have the entire history) it was then run on fully synthetic 5w-30 and has been ever since. When i ripped it open to do a refresh at 61 thousand there was hardly any carbon build up at all, hardly any wear on the apex or side seals and were infact still within tolerance of the Mazda spec\'s so i\'ve continued after the rebuild using Fully synth 5w-30.....
 
Will be interesting to see what he says about the big power and fuel mixing, although if you\'re running huge ports then you\'d change the oil a lot more regular anyway. 15w50 is a thick oil to be honest, especially when cold and especially when using the standard OMP lines as the pressure will be very very high.....

im gonna send him an email in a min for him to read tomorow about high boost and fuel mix etc.

i do remember reading that mixing fuel in will reduce the viscosity.

Article on the r35 gtr claims that they have alot of blowby as stock and before an oil change the oil drops from 15w-50 to as low as 0-20w when it was analysed so you can imagine what its like for us.

The oil pressure isnt that high when cold, it has a release valve at 6bar so never goes above that even with reving when cold.

id say 5w30 is ok for stock ports driving normally, but for very heavy use(heat) or big ports id go thicker to take into consideration the fuel mixing

[turbotoaster]

Just sent him this email so ill let you know what he thinks etc, if you have anything you want to ask let me know as hes the guy who designs the oils for silkolene from scratch, maybe get him to design an oil specially for rotarys lol


hey john.

Thanks for getting back to me with the useful information.

Well since i havent mentioned what the car is being designed for i would also agree with you in terms of the viscosity that you mention, pretty much what mazda says themselves.

Now the engine has been built to run massive power, the stock car is 255bhp, im preparing the car to produce 700-750bhp.

With that increase comes alot of issues, there are 2 big ones that should be obvious.

First is increased heat, the turbocharger will be running 30psi of boost pressure and will create alot of heat, because its only oil cooled compared to the stock water/oil cooled standard turbos that means it will put more pressure on the oil system. Also because you are pushing around 100lbs of air a minute into the engine compared to 40lbs on a stock car you will have more heat created by combustion, ill be running a spark amplifier to increase the spark to burn all the fuel/air and water that is sprayed in to prevent detonation.

The engine will have to rev harder, from 7.5krpm to 9krpm to make use of the turbo and give a decent powerband so that needs to be taken into affect.

the second is blowby, just like blowing fuel/air past the piston rings on a normal engine you get the same with a rotary, ill end up with fuel mixing into my oil which will lower the viscosity, this is because of the extreme pressure the engine will be made to hold and also the bigger than stock ports on the engine that i have put in.

Article on the nissan r35 gtr claims that they have alot of blowby as stock and before an oil change the oil drops from 15w-50 to as low as 0-20w when it was analysed.

Alot of guys in america who run big power rotarys find that alot of time on the rolling road tuning the car causes the oil pressure to drop due to the engine being so hot, they run a 20w/50 which they claim fixes alot of the problems.

Ive now got pro r 15w-50 in it as i felt this was best before i heard back from you.


Also the reason for the massive power is im building the car to take the european rotary top speed record and break 200mph within 1.7miles on an airfield, hence i really want the engine to hold together and ill be throwing around 6000cc of fuel per minute through the engine wanted the best oil for the job.

what do you think, is a higher weight a better option when dealling with massive heat and fuel mixing in?