Denmark

iTrader: (2)

Hi All,

I simple need to know if the My99 engineblock can be bored ,if one cylinder has some marks from a defect piston,

I looks to me like there is some kind of hard surface on the walls,(like nikasil)can this just be removed,with out the walls going soft?

I have heard about liners,Is that a very thin,hard pipe that is pushed down the block? and is that in the block as standard.
If so where can liners be fitted?

Sorry for all the dum Q´s

Thanks,
Skassa

S,M,G

The block can be bored, but all four cyl have to be done, no std factory subaru has nikasil coated liners, wrc cars have alloy nikasil liners, to recoat a liner in nikasil is about £80 per cyl.
Steve.

Gidney&Knowlesy

You can have them sleeved and bored and coated, depends what you want to have done and the reason for your decision.

i.e if you want to make it a 2.2 then you need to uprate crank, rods, pistons etc....for the extra power

or if you blew a piston and it has damaged the cylinder....

Either way I can put you in touch with people.............

Denmark

iTrader: (2)

Hmm,

There is no one in Denmark that can bore a subarublock,becourse it´s pure alloy...Nobody has the tools to extrudehone it after the bore..
They will not buy the parts needed to to so,becourse there is not enough work on thise engines in this Carhading country.

Time for a new block with better internals.

Thanks,
Skassa

David_Wallis

wouldnt have thought it was extrude honing.. just honing...

David

Denmark

iTrader: (2)

David,
They say,when it´s all alloy, they need some special honing device to make it like standard????

Skassa

sphazell

Skassa you may allready know but Robin Berado has alot of experience with this.

www.pms.net.au

Pavlo

It's an alloy block, but it does have iron/steel liners.

It can be bored and honed as a normal block.

Paul

Denmark

iTrader: (2)

Poul,
Thanks,
That was i thougt,but when i look at the bores i can´t see the liners...

Where do i get thoose liners???.is that something that is a OE part from Subaru?

Skassa

dowser

I opened out my ej25 to 100mm no problems.

Richard

Denmark

iTrader: (2)

Richard,

Did You fit liners after it has been bored out???

It´s not just been bored out has it?

Skassa

S,M,G

The liners are cast in from the factory, which is why ther is alloy above the liner on the face, most alloy blocks are made this way of late as it asures that the liner will not move.The liners are cast iron, if the liner was steel then a cast iron ring would be used and any thing with reasonable power would brake the rings. I use top flanged liners for the same reason this would be to expensive for production use. The main problem with honing a subaru block is that the main bearing housing is close to the bottom of the cyl bore, the honing stones must leave the top and the bottom of the bore the same amount or a tapper will ocour so some careful setting up is needed. Alloy bores are honed using cork pads and a silicon past and its a pain in the ****. The bore finish for the subaru wants to be about 15/20 ra for the ring profile used thes can be acheived with stones but you want a diamond hone finishing with a plateau brush finishers. If the finish is to fine then it will never bed in and it will be a smoker, same thing can happen if its run in using a synthetic oil or left idling. If the finish is to course then it will rip the rings to bits and have a short life.
Steve.

Denmark

iTrader: (2)

Steve,

Thank you very much for the fine explaning,I now understand how it works.

One more Q.

How thick is the Oe liner,or how kuch can the block be bored out?

Thanks,
Skassa

S,M,G

The o/e liner has a wall thickness of about .150 and could take a rebore of +.060/1.5mm no probs, one thing to be sure of is that the head gasket you use has a bigger fire ring than your finish bore size, you will find that most will have a 93mm hole and std bore is 92mm so your best bet is a finish bore of 92.5mm, this should clean up any wear unless you have a bad mark in the bore. Custom gaskets can be made, and thay are metal shim so the choice is yours.
Steve.