stevehf2

iTrader: (12)

I have heard this is not possible for the Subaru is this correct? If so why not as it's fine on other units!

The rookie

iTrader: (1)

It is possible, the trouble is it has a very poor record, all to often swarf gets lodged in the oil ways (they are truly a PITA to clean out effectively) and the rebuilt engine doesn't last long, so most rebuilders reckon its cheaper long term to just fit a new crank!

Simon

jonny_693

iTrader: (5)

Its because the crank is case hardened and when you regrind them you take away this hardness so the crank will last about 5 minutes.

PeeVee

iTrader: (1)

As Simon says, re-grinding a Subaru Crank is possible, just as it would be on any other vehicle. The problem lays in the way that the oil galleries have been sealed one end by non removable ball bearings. This in turn means that it it is vertually impossible to ensure that the swarf is removed by conventional methods of cleaning.. There is of course the technology to effect a guaranteed clensing process but this is expensive and outweighed by the cost a new one.

The very latest cranks by the way have grub screws in the oil ways, so this would make washing them through a much easier and cost effective option.

phill6x6

This might be a stupid one..
But...
If it's a known problem, would it not be possible to fill / plug the oil ways with Vas or similar.
Some of it would wash out during machining, but you could dig out what was left easily enough. If the grinding dust does not get in, you wont have to get it out?

Just a thought..

(franticly searches for Flame suit)

KickboxingCrazy

iTrader: (15)

a good engineering company will be able to do a cleansing process which will clear oil ways of all swarf, alot of people make so much fuss about subaru cranks because they've heard it off there mate.

Jolly Green Monster

iTrader: (4)

Dont! Youll be rebuilding it again sooner than you think

Jay m A

iTrader: (2)

Usual reason for a regrind is a spun bearing so there is stuff in the oilways already before you even start the machining

PeeVee

iTrader: (1)

I assume you are basing your advice on extensive experience gained buy either, rebuilding lots of Subaru engines or having worked in engineering ??

Splitpin

That's a bit of a silly line of reasoning. Sticking your hand in a pond full of goldfish is fine, for example, while doing the same in a pond full of piranha is likely to cause you a problem. What we learn from this is that not all ponds are the same, and the same applies to engines.

The EJ engine design is not "other units". You only have to look at a picture of one and compare it with your typical 16 valve inline four to see that. It's unique, with its own strengths and weaknesses. For the reasons given above, and a couple more besides (the size of the bearings is one), you won't find many reputable engine builders regrinding cranks on these.

Of course there's nothing stopping you acting as a test case for the alternative approach.

Fords, by the sound of things.

merlin24

iTrader: (1)

TheVoices

iTrader: (5)

I wouldn't risk a reground crank but find it odd that Subaru themselves quote tolerances for crank regrinds in the dealer workshop manuals ?

Tends to suggest that they don't regard it as a problem ?

harvey

iTrader: (48)

In the same way that there are competent tuners and mappers along with incompetants then also there must be properly equipped machine shops with ability and those with less competance.
My first reground Subaru crank went in my STi 3 Wagon three or four years ago and well over 20,000 miles. Oil is changed every 4000 miles perhaps less and I only use good oil. The car is never ragged cold and it is now running 400 to 420 bhp on standard pistons subject to the fuel and map in use.
As a result of my pleasant experience on this engine we now have cranks reground from time to time and always with the owner's knowledge. A regrind and ACL race bearings for less than half of the cost of a new crank cannot be sniffed at. When I got my crank done first I was told that if it packed up in the first 12 months for reasons of the regrind/bearings they would buy me a new crank FOC. That's confidence for you and we have had no reasons for concern since but reground cranks are restricted to budget rebuilds that are never going to be high power 500 bhp plus.