Subaru Upper Engine Cleaner review...

zephyrus17 · Postby **zephyrus17** » Sat Mar 17, 2012 6:15 pm

Did you let the engine die after the first spray?

I have to say, though, that cleaner didn't do much to my engine. Only a bit of smoke, and that's it. Does it mean my engine's clean? Highly doubt it at 180,000kms, but it might not have just done much

Postby **NitroDann** » Sat Mar 17, 2012 6:24 pm

If you run premium, keep good oil in it, and you dont have blow by its unlikely this stuff will help much.

Dann

Sailor · Postby **Sailor** » Sat Mar 17, 2012 7:50 pm

NitroDann wrote:If you run premium, keep good oil in it, and you dont have blow by its unlikely this stuff will help much.

Dann

Indeed!
Subarus need it and need it often because they are not a particularly good engine design with lots of oily blowby and subsequent fouling of the inlet tract.

Postby **NitroDann** » Sat Mar 17, 2012 7:56 pm

To be fair, they just have a lot more liquid blowby, as opposed to gas blowby due to the heads being so low compared to the sump.

But yeah.

Dann

marty085 · Postby **marty085** » Sat Mar 17, 2012 10:06 pm

NitroDann wrote:If you.. keep good oil in it

Dann, what do you consider "good oil"? Note: I'm not asking what oils ppl use as has been asked many times. Just wondering how i can tell a good oil from a bad oil... Reputable brand? I am intending to simply use good brand dino oil (eg Castrol magnatec or something) in my newly rebuilt engine along with premium fuel.

zephyrus17 · Postby **zephyrus17** » Sat Mar 17, 2012 10:37 pm

NitroDann wrote:If you run premium, keep good oil in it, and you dont have blow by its unlikely this stuff will help much.

Dann

Yeah, I use at least 95RON due to my 14deg timing. Don't think 98RON is going to be any better for me other than the extra lightness in my wallet.

Postby **NitroDann** » Sat Mar 17, 2012 11:05 pm

Oh so wrong, but busy so ill let someone else explain.

Dann

zephyrus17 · Postby **zephyrus17** » Sat Mar 17, 2012 11:35 pm

Well, as far as I know, isn't RON just the resistance to combustion? Running to low will cause pre-ignition, but running too high could also decrease efficiency because some of the fuel isn't ignited

Postby **NitroDann** » Sun Mar 18, 2012 12:16 am

Premium isnt only called premium because the octane is higher.

Dann

zephyrus17 · Postby **zephyrus17** » Sun Mar 18, 2012 12:32 am

Yeah, I know, there's cleaning agents and stuff. But I'm just thinking the difference between 95 and 98, other than the octane, isn't really much. Or at least, I don't think it's much to justify the price increase.

Postby **NitroDann** » Sun Mar 18, 2012 1:09 am

What about the fuel economy increase?

It costs just a few dollars a tank and can save you from many vehicular ailments that cost 80/h minimum just to have looked at.

Dann

Postby **Okibi** » Sun Mar 18, 2012 1:16 am

http://www.miata.net/garage/KnowYourCar/S10_Timing.html

The risk in advancing the timing is that the flame front (the increase in pressure) from the burning air/fuel mix strikes the piston head before, at, or too close to TDC to create the optimum forward rotation of the crank.

If the downward force reaches the top of the piston before the piston is able to react with a downward motion then the force is directly to the crank, rather than to the rotation (a bit like how landing on a stiff leg transmits the jar to the hip).

The ignite and burn time for 98 RON fuel is longer than 92 RON fuel. Lower RON fuels means the flame front hits the piston top sooner than with a high-octane fuel. If the flame front hits the piston too soon the crank angle will not be in the optimum angle range to commence its downward stroke. The result can be pinging cause by premature detonation. That is why higher-octane fuel can be good insurance if the timing is advanced.