Nick's Motor Rebuild

[WRX06TR]

Thought I would start this rather than further derail the Solo Thread.

I really hope the crank didn't get too damaged. I read that replacing the oil pump is necessary after a bearing failure (?). I also need...

New timing belt with tensioners
New water pump
Cam seals (stockers are leaking)
Gasket kit after splitting block
Headstuds
Clutch (pretty sure my stocker is going)
and the bearings

I can't afford pistons and rods, but I have read that the STi rods are pretty stout. So if they are in good shape I wouldn't mind reusing them. I would hate to have a ringland failure after all this (the car is at 85k) so I was thinking pistons. Still unsure, money is a huge deciding factor. And I want to look at my oil pick up and make sure it isn't looking weak, that would suck to have break after a rebuild.

Anybody with advice chime in, I wasn't planning on doing a motor right now so I hadn't done much research.

[Dean]

How many miles? That determines water pump, timing belt and tensioner replacement. Oil pump should be fine, but oil/water heat exchanger should be swapped. Could go to 11mm oil pump.

Buy a rebuild gasket kit. It will have most everything you need for much less than buying even a fraction of them individually.

ACL Race bearings, Stock or .001 over depending on crank condition and preference.

Why studs? Not necessary IMHO.

Clutch. Buy Mike's 6 puck & flywheel.

Pistons, rods and cylinders can't really be decided until tear down and inspection.

[khail19]

Originally Posted by Dean

How many miles? That determines water pump, timing belt and tensioner replacement.

Originally Posted by WRX06TR

I would hate to have a ringland failure after all this (the car is at 85k) so I was thinking pistons.

I would definitely do the water pump and timing belt/tensioner with 85K.

[WRX06TR]

Thought headstuds were necessary, guess I was wrong. I don't know if I want/need a 6 puck clutch, didn't Mike get rid of it because it was so heavy.

[Dean]

Originally Posted by khail19

I would definitely do the water pump and timing belt/tensioner with 85K.

Agreed, missed that. I'd do all idlers at 85K+

[MPREZIV]

Originally Posted by WRX06TR

... I don't know if I want/need a 6 puck clutch, didn't Mike get rid of it because it was so heavy.

He just didn't like the way it drove, but it doesn't matter anyway, because he sold it, and I put it into a black STi just last week... too late.

[sperry]

You won't need to do rods unless one or more of them are damaged from the spun bearing. I know the last time I lost the bottom end like that, the rod bearing that went ended up welded to the rod. But if the rods are in good shape, they're plenty stout unless you're looking at crazy boost, and then you should also be looking at sleeving the cylinders and other crazy build up stuff.

Forged pistons is a good idea IMO, if you're going through the cost already of pulling the motor apart. Sure you're looking at an extra $500 give or take, but that's the biggest weak link in the stock bottom-end.

Like Dean said, a gasket rebuild kit is going to include all the gaskets/seals you might need. Again, if the motor's apart, might as well replace all that stuff so the motor is good-as-new when it's done. I believe there are kits out there with the water pump, gaskets, and timing idlers as well.

Headstuds aren't really necessary unless you're planning on running a bunch of boost. But they are relatively cheap insurance for the head gaskets, as you probably should be replacing the stock head bolts if you're not doing studs. Just make sure you follow the right torquing procedure for the studs, since it's usually different than the stock bolts.

Also speaking of head gaskets, new OEM gaskets should be fine... no need to spring for Cometics or anything.

[WRX06TR]

Thanks for the advice Scott. Any recommendations for pistons? I was looking at CP. They seem to have a fairly good rep. Cosworth is out of my price range.

[sperry]

Originally Posted by WRX06TR

Thanks for the advice Scott. Any recommendations for pistons? I was looking at CP. They seem to have a fairly good rep. Cosworth is out of my price range.

I had a set of JE pistons on recommendation of Mike at GST. I'm sure Dean will suggest the brand he's been working with, but I'm not sure they're purchasable yet.

[Kevin M]

Originally Posted by sperry

I had a set of JE pistons on recommendation of Mike at GST. I'm sure Dean will suggest the brand he's been working with, but I'm not sure they're purchasable yet.

CP is Crawford-spec JE, so either is a good option.

Nik, I'm working on pricing out the options for both minimum to get you running, and for all the things discussed here as far as upgrades and such. KB Icon pistons (the guys Dean is working with) will be getting back to me soon, I'll call when I've got all the info ready for you.

[sperry]

Originally Posted by Kevin M

CP is Crawford-spec JE, so either is a good option.

Nik, I'm working on pricing out the options for both minimum to get you running, and for all the things discussed here as far as upgrades and such. KB Icon pistons (the guys Dean is working with) will be getting back to me soon, I'll call when I've got all the info ready for you.

You sure about that? I don't think Crawford Performance = CP.

http://www.cp-carrillo.com/

http://www.crawfordperformance.com/

Unless, Nick meant Crawford Performance, not CP. Either way, I don't know anything about CP, and Crawford got all that bad press on NASIOC a while back, though they seem to still be putting out some mean cars.

[WRX06TR]

That has confused me as well I have seen CP for both companies, I thought CP was Crawford but wasn't 100% sure.

[Kevin M]

I guess Crawford = CP, CP =! Crawford necessarily. Either way, Crawford's pistons are JEs.

[WRXlerate]

If you find that you would like to go factory due to price on machine work and cost of other upgrades, you can find a brand new OEM shortblock for under $2k shipped. Add on a gasket set and other needed goodies and you're all set.

[sperry]

Originally Posted by WRXlerate

If you find that you would like to go factory due to price on machine work and cost of other upgrades, you can find a brand new OEM shortblock for under $2k shipped. Add on a gasket set and other needed goodies and you're all set.

Rebuilding the motor with forged pistons should cost less than a new shortblock. The last time I spun a motor, I went with a new SB only because the block was going to need a new crank and sleeves which finally put the cost over that of a new OEM lump.

[Kevin M]

Yep, the STi is rare among newer cars that rebuilding is usually the better option.

Nick, quote is coming your way via PM.

[WRX06TR]

So I was wondering, since my job requires me to drive around a bit and stop and restart the car frequently, would forged pistons be a bad idea. I read that forged pistons need to hit operating temp before driven, something I don't always have the ability to do.

[sperry]

Originally Posted by WRX06TR

So I was wondering, since my job requires me to drive around a bit and stop and restart the car frequently, would forged pistons be a bad idea. I read that forged pistons need to hit operating temp before driven, something I don't always have the ability to do.

Forged pistons are just a little "looser" than the cast ones, simply because they expand more once they heat up, so they are just a little smaller when cold. All you need to do is stay out of the boost until the oil temps are up... which you should be doing anyway even if you don't have forged pistons.

Ultimately, the only difference is that the motor may be a little noisier when cold with the forged pistons. It's not really a ton different.

Also, if you have to start and stop the car a lot... if the restart is within an hour of the stop, it's not really another cold start. It takes quite some time for an engine to get back down to ambient temps after turning them off.

[WRX06TR]

Cool thanks Scott. I always wait for my car to hit operating temp, which I define as the water temp reaching the middle of the gauge before I hit boost.

[sperry]

Originally Posted by WRX06TR

Cool thanks Scott. I always wait for my car to hit operating temp, which I define as the water temp reaching the middle of the gauge before I hit boost.

That's better than most people... but oil temps lag quite a bit behind the water temps. Probably a good rule of thumb is that boost is okay once the water temps are up... but give it another 10 minutes before actually flooring/flogging the car.

[100_Percent_Juice]

What oil temp do you consider to be in the safe to boost zone?

[sperry]

Originally Posted by 100_Percent_Juice

What oil temp do you consider to be in the safe to boost zone?

Um, 140F?

Really the oil should be over 180F IIRC for it to be in the "hot" viscosity range. But I've gotta think once your over 140 or so it'll get there soon enough. At least if you're not running a huge oil cooler... On cold days it's impossible to get my wrx over 125-130.

[WRX06TR]

Pricey stuff indeed, sucks that this happened long before I planned on building my block. Oh well I guess. Thanks again to Kevin and Cory for all the help. I'm still deciding on pistons, but I don't want to risk the OEM pistons failing (ringlands) after all this. I think I may have to put the clutch on hold, it wasn't slipping on the street but I toasted the hell out of it at AutoX.