Mineral oil vs Synthetic ?

[Royster]

Hi Guys

I was told that mineral oil is the way to go for breaking in new engines? I did use for about 1hr and thought i'd swicth to good Motul 800T synthetic oil.

Does it really matter if I just run very good syntheic instead? or should I switch back to the mineral oil (which is Castrol Activ 2T)

Also I gather premium unleaded is the way to go as well? ( I use BP Ultimate)

[aviti]

	Quote: Originally Posted by Royster
	Hi Guys I was told that mineral oil is the way to go for breaking in new engines? I did use for about 1hr and thought i'd swicth to good Motul 800T synthetic oil. Does it really matter if I just run very good syntheic instead? or should I switch back to the mineral oil (which is Castrol Activ 2T) Also I gather premium unleaded is the way to go as well? ( I use BP Ultimate)

You're gonna get many very different opinions here. I've followed what DA says breaking in 2 DA 100's and both have run flawlessly. I don't think you can go wrong with the manufacturers recommendations. By the way, DA says 5 gallons with Lawnboy Ashless (mineral) then switch to synthetic (they give several choices on brand). They also recommend lower octane. I run 89 octane.

[Royster]

Thanks Tony

The engine I am running is a SPE40 40cc with a Walbro carb. The manufacturer doesnt suggest ant type of octane fuel.
Bare in mind our fuel here in Australia is not as good as other countries. Old habits die hard, I used to ride 2 stroke Motocross bikes and hence me using 98 octane and the better oil. I figured if its good for a $12,000 dirt bike, its good enough for a basic 2T engine swinging a prop.

I know its customary for DA engines to be run on mineral first. I thinking I might swap back as the the BCMA web site says it prolongs the break-in if you dont use mineral first.

But how many Litres do need to run through the motor before I switch back to syntheic?

[b0Bro']

TD tought me to run my 3W's at idle for 4 hours with castrol as per manual. Then you can swap to mineral.

[adrian]

new generation synthetics - 100% - all the big racing engines run on it - nascar, indy, F1 and the rest

NO QUESTION even from day 1

I run motul 800 in my DA's, 3w's/ zdz' s/ MVVS etc

[Richo]

Royster, If your run about 15 to 20lts of mineral oil mixed fuel, your run in will be fine. You need to use the mineral oil to give the engine a chance to bed in. The Syntheic will prolong the brake in period, and you may not get the best out of your engine until much later.

These engines aren't reving that hard in comparison to a $12k bike. You also wont be swapping the rings out as often as you would of on a 2 stroke MX'er. They are built quite a bit different.

[Royster]

	Quote: Originally Posted by Richo
	Royster, If your run about 15 to 20lts of mineral oil mixed fuel, your run in will be fine. You need to use the mineral oil to give the engine a chance to bed in. The Syntheic will prolong the brake in period, and you may not get the best out of your engine until much later. These engines aren't reving that hard in comparison to a $12k bike. You also wont be swapping the rings out as often as you would of on a 2 stroke MX'er. They are built quite a bit different.

Point taken on the dirt bike. KTM do things a bit different

Now what about fuel? Premium or standard?

[Richo]

	Quote: Originally Posted by adrian
	new generation synthetics - 100% - all the big racing engines run on it - nascar, indy, F1 and the rest NO QUESTION even from day 1 I run motul 800 in my DA's, 3w's/ zdz' s/ MVVS etc

Were talking about 2 total different kinds of engine here. F1, NASCAR and Indy engines are 4 stroke for a start, and the loads those engines are under are way different to a fairly slow reving, built to last for years (not just a race), model aircraft engine.

[adrian]

synthetic oils have been with us for a while now and have proven to be the product of choice for all engines - my dad was in the racing industry for years and an engine builder for years - now he has also been flying models for 40+ years and has never lost an engine - we have many engines 25+years old - this said, he firmly believes that the new generation synthetic oils are so much better than any of the old generation oils that its not even worth getting into a slog - just use it and see!!

[Royster]

The reason I was told to use mineral first was to purley "bed-in" the cylinder sleeve & rings. This will happen with syntheic as well but will take a lot longer due to the better properties of the synthetic oil.

So far 9 out of 10 people have said use mineral first. Mind you they all use DA engines.

At the end of the day synth wont wreck the engine it just means longer breaking in time. Well at least thats what I was told.

I just got an email from Shing Pen (designer of the SPE40 & SPE26 engine) and he says synth oil is always better, but he didnt stipulate breaking in.

[adrian]

what you say is 100% right and many people do this we also did that many times way back - but of late we have just started with the best oil day one and all is well - we mostly run 3w engines now and the factory has told us to certainly use the best synthetic oil you can afford from day one

[Richo]

	Quote: Originally Posted by adrian
	synthetic oils have been with us for a while now and have proven to be the product of choice for all engines - my dad was in the racing industry for years and an engine builder for years - now he has also been flying models for 40+ years and has never lost an engine - we have many engines 25+years old - this said, he firmly believes that the new generation synthetic oils are so much better than any of the old generation oils that its not even worth getting into a slog - just use it and see!!

I'm not trying to get into a sloging match either. Synthetic oil is (in my opinion) better than mineral, no question. I believe Royster is trying to establish if he should run his engine in on Mineral or synthetic. In my opinion the break in period will be shorter with mineral.

The comparison with any high performance racing engines, is like comparing cars with trucks. Aero modeling gassers are under nowhere near the stress levels of a high performance racing engine. I do use synthetic, and have been for many years, in all kinds of applications.