I's about to put an engine together this weekend.. THe engine is ported and I'm running an upgrade turbo and will be tuning for 15PSI after the break in period.

Now, my third gen buddy swears up and down that you don't need the outer oil control ring.

I know for a fact that he doesn't have his outer rings in his motor and the car runs great, in fact, its the fastest car i've ever ridden in on the street, it outran a worked Yamaha r-6 last weeken with two of us in the car).

The theory comes from an RX tuner here in PA. Something about when you port the motor, the outer ring is too close to the port area and high boost levels cause problems with the ring and there is less drag on the rotor from the four outer rings, thus the engine revs quicker.

I've built a couple of motors, and the outer rings dont seem to ever have much crap on them when you tear down the motor, but, its there for a reason right (but then again, so is the cat and we all tear those off all the time)

Sooo.. I'm looking for input from people with a lot of engine building experience to decide if i'm going to omit the outer rings when i put it back together or not.

Emissions are not a problem cause my car is a <5k exemption car in PA.

 

I dunno how he pulled it off, but it will normally smokes like a **** missing any of the oil control rings.


-Ted

 

I dunno either, I'm really leary about putting this thing in like that, but i LOOKED in his intake port when we had the LIM off and the only oil control ring on there is the inner..

He's going to talk to the Doctor today, I'll get the report back on if its just a third gen thing or what...

 

How do you tell it's missing an oil control ring just by looking into the intake port?


-Ted

 

LOL, I was about to ask the same thing...Unless it's way overported....

 

UM....so instead of the rotor spinning against the housing with the OCR, the rotor strictly relys on the side and corner seals?

That's so awesome.

So instead of calling it the Oil Control Ring......I'll call it the Oil No-Control Ring. Or ONR proceedure.....Because well, we all know rebuilding (rotors and side housings) are cheap and easy to install.

If you got Oil, there's just simply no reason to "control" it.

 

Mobius... THere are TWO oil control rings on each face of the rotor.. they omitted the larger, outer one and left the smaller, center one in place.

As for how you can see it.. The outer OCR is very close to the intake port, even on a non ported motor, if you out an optic borescope for a rifle in the primary ports you can actually see the edge of the outter OCR (obviously the LIM has to be off), and i looked for about five minutes trying to find it and it aint there!! I even went home a poked my beak in a junk motor i have under the table and i saw the edge of it in that one!!

I have seen some rediculuously overported motors where you could actually see the ring going past the port, but his is a normal street port where you don't cut any deeper towards the center than stock, just elongate the ends of the port.

 

Woops double hit..

However,,,, I think I'm going to put the outer ones in, it will ease my mind regardless of what the Doctor tells my bud today... Hell, I paid that god awefull price for 'em, might as well use 'em.

 

Yea - put it in.
Less drag on the rotor?? It can't be very much. Maybe 1 ft-lb.

 

These people that are porting inwards towards the center should be shot.


-Ted