Hi everyone,

I'm getting my engine rebuilt at the moment, and my engine builder has recommended a technique he uses when building engines. It costs a bit more, but he has told me that the benefits are well worth it.

It involves taking a precision tool, and setting the piston rings so that the ring gaps all line up with each other perfectly.

The supposed benefits include

1. more lubrication to the crown of the piston
2. an increase in crank case boost pressure, which means pressurised air goes through the crank case breather tubes, and therefore more boosted air into the intake (sort of like an extra "turbo boost").

This pressurised air is supposedly mixed with highly atomised oil vapour, which provides more lubrication to the turbo. It will allow me to run more boost I'm told, and therefore make more power again.

Its only going to cost me an extra 100 per piston, but as we all know, its the little things you do that add up in the end...and if this is something that'll really make a difference, then its well worth it!!

What do you guys think?

Cheers

ah yeah iv heard about this. Its the new big thing in the states. Theres heaps of threads on nasioc about it, do a search !

They also recommend porting the bores to allow for even better lubrication. I have heard reports of ppl noticing more psi becoz of the better allowances

I've already bought the bore porting kit, cost me 1800 bucks.

What is bore porting anyway?

I think I remember reading about that on nasioc, but my friend who owns an S13 told me it was good and all the top race guys were doing it, so I got it anyway!

Will this work in conjunction with the ring aligning??

Increased crank case pressure cause greater oil blow by.

Doesnt having increased oil vapour in the intake decrease the effective RON of the fuel mixture and increase the risk of detonation? Plus it will coat the inside of your intercooler with a thick layer of oil and carbon reducing the intercoolers ability to cool air?

I dunno about this "process". Sounds a bit risky.

And just because something is good for a race car, doesnt make it good for a street car. Race engines dont need to survive for much longer than a few races.

I dont know, I've read a bit about it and it seems pretty good...

The highly atomised oil vapour doesnt go into the intercooler and engine anyway, it goes into the intake through the breather tubes, and into the turbo...it provides more lubrication for the blades, and allows more boost to be run.

Not to mention extra lube to the piston crowns!!! Surely that has to help make more power.

i'm not sure about the extra boost bit.. but then again i'm no mechanic.

Sounds a bit wierd to me, seeing as the piston rings move around a bit during engine running.

When we rebuild the aircraft engines which are horizontally opposed as well we set the ring gaps at all different positions. Otherwise you will use heaps of oil and have a major blowby problem when the turbo is boosting.

I have pulled cylinders off aircraft engines because the thing is running like a bucket of crap and the only problem is the ring gaps are in line which causes blowby and carbon buildup in the piston ring grooves which makes the rings stick in and give you stuff all compression.

I proly wouldnt do it but i may be wrong and am open to any corrections.

where is this oil blow by being plumbed into the intake? if its before the turbo, then it will make its way to the IC and coat it in crap. If its after the turbo, then its pointless, and should be routed into a oil/air separator.

Hmm interesting.

See, I've heard that blow by can be a problem on turbo cars, but I think its a bit different to ring aligning and bore porting. I think that airplane engines have different requirements to car engines also.

I mean, how could they possibly charge 1800 bucks for a HKS bore porting kit, if it didnt work? I think that JUN knew what they were doing when they designed their ring alignment machine.

Its being plumbed into the intake pipe, before the turbo.

I cant see how oil vapour, which is intended to lubricate the turbocharger, can make its way into the intercooler especially when its not designed to do that!!