stevie turbo

iTrader: (12)

Any one got a ring grinder tool i need one as i need to gap my new rings on my ej257 engine build

Don Clark

Make your own

stevie turbo

iTrader: (12)

Hi don thanks managed to do my ring gaps!!
Mahle 2618 piston pack supplied,done the ring gaps per the tech sheet i have been told by two very good sources they seem to large for application.

On the tech sheet mahle recommend over 15 psi of post math Is 3.927 x 70 = 27" on top and middle ring.
Emailed them to confirm this and there adament this is correct, anyone had any experience of this,car is a 2011 sti ej257 street car no track days etc looking for 400 +

Don Clark

Subaru OEM supplied values

MOTORS S GT

iTrader: (2)

You need to work on 0.1016mm per 25mm dia of bore for your use of the engine, if you gap as Mahle suggest you will have a smoky old high blowby engine.

stevie turbo

iTrader: (12)

So if im right if i x 0.1016 x 4 = 100mm - 0.25mm gives me 0.016"for a 99.75 mm bore.correct me if I'm wrong I'm bad at maths, is that both top and middle ring i thought 2nd should be bigger than top ring. 🤔 did i say im crap at maths lol

MOTORS S GT

iTrader: (2)

Top ring gap 0.406mm or 0.016", 2nd ring 0.406mm minus 0 plus 0.0508mm or 0.002", oil pack are usually ok, but at least 0.508mm as a minimum, for your build this is more than enough.

stevie turbo

iTrader: (12)

Thank you motors gt i appreciate your help,

so with 2618 pistons on a 99.75mm bore..
top 16"
middle ring 18"
oil rings as per tech sheet min 15"
i think they measured 20" plus.
and i shouldn't get any problems with gap closing and excessive blowbye, can i ask if you may know why mahle have excessive 27" gap on both rings as i think its misleading as ive now got to buy another set of rings from america £150 plus and its a misleading expensive mistake.

MOTORS S GT

iTrader: (2)

The 2nd ring I would set to 0.016" as long as its no smaller than the top ring, as for Mahle's settings, they have to cover all possibilities, & will side with caution, so go bigger, they think everybody uses 2 bar of boost & nitrous injection, even there settings for piston to bore clearance is baggy, if you went by there settings you would have a very noisy engine.

stevie turbo

iTrader: (12)

thanks again new rings are due soon and need to do gaps again, what best option,
1) top 10" middle 16"
2) top 14" middle 16"
3) top 16" middle 18"
4) mahle turbo over 15 psi 27" 🙈


My gut feeling is to stick to option two, but I've had so many numbers put out there i need 2 numbers that puts me in the sweet spot please