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Has anyone tried adapting something or making some custom set of piston oil squirters up for the rb30 hybrids to help reduce piston temps? No, not trying to pick up the main gallery and bolting squirters to the block where they are in the other RB's if someone suggests that its too difficult to do. I have read and been told this before.

I havent seen anyone having any major dramas yet with piston temps or det/knocking because of a lack of piston cooling, but that doesnt mean it hasnt happened. I know that the forged pistons that most people use in their hybrid builds are pretty good at handling the increased temps as induced from increased power. But is splash feed enough to cool the piston as well as lubricate the bore and wrist pin? or splash directed from conrod bearing skirt grooves? Could the latter have a similiar effect on piston cooling, comparable to straight squirters or doesnt it have enough direct pressure to reach and flood the underneath of the piston?

I had this thought when i was thinking about blocking the internal oil returns today. I have a roughish idea of what could work for piston oil squirters, but i imagine someone else would have already done something or tried something before as rb30 hybrids have been around for quite a while now.

Any ideas or knowledge are welcome.

Michael.

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Hey Michael,

I think a better idea is to have the piston crown ceramic coated. Gary has also suggested and tried this I believe.

There is a shite load of oil being spalshed around inside an engine at 7000 plus rpm, so lubrication shouldnt be an issue.

I will be going the ceramic way with my new engine, as I will be running a higher comp and dont want any detonation issues.

interesting...I have heard about it before....but then there was the argument that it can create hotspots by localising heat in areas where the coating isnt the same thickness or whatever...blah blah...But I guess if Gary has used it and its been proven it must be feasable. So ceramic is another option then. Cheers Brad!

I was having a chat to an engineering shop about this.

The thickness of the ceramic coating can be varied, with a thinner coating being less susceptible to the hot spot issue but if it's coated correctly then you won't have this problem (according to them).

Something else I was thinking about is the power loss the piston oil squirters produce. Surely at 7000rpm with 100PSI of oil pressure shooting the underside of the piston as it tries to move down the bore would be power robbing in some way?

  • 2 weeks later...

I have done the piston oil squirters into an rb30det (26/30). We used std nissan rb20 oil squirters. It took alot of mods and a crank grind to make sure they cleared. If anyone would like more info PM me and ill make a topic on my build.

Im doing them but im in NSW...$30 per piston and $30 to get skirts teflon coated or $55 for both

Awesome, that is alot cheaper than I was expecting.

Is the teflon skirt coating the same as that oil retention coating that sydneykid talks about?

the best coating i've seen is the HKS step 3 pistons. from memory it goes ceramic coated crown, titanium coated ring lands (and top ring) and moly coated skirts. it's like the neapolitan ice cream of the piston world.

The oil serves two purposes on the under side of the piston. Yes one is purely to cool the piston from the high temps.

The other is that cooler pistons mean a cooler burn which means better emissions. (Even some crappy old NA motors have oil jets). The bonus for performance is that a cooler piston creates a bigger difference in heat from intake stroke to exhaust stroke, leading to higher hp.

So oil jets can cool the pistons, but you can take advantage of the cooler piston by running more timing or boost to make more power, which actually cancels out the cooling of the piston for reliability.

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