Long story short the crank bearing went out on my 03 wrx. The crank is shot. I want to rebuild it so i don't have to tear the engine apart again. Last year almost to the day I had the exhaust valve on cylinder 3 go out. My options as i see are... Option #1 Keep block and put forged internals in. Option #2 Keep block and put in a 2.2 stroker kit (either cosworth or Brian Crower) with full forged internals. Option #3 Drop in the 2.5 and build off that. any help would be greatly appreciated. Power goals are 300-400whp. I understand the all important saying of.. Cheap, reliable, fast. Pick two because you cant have all 3. I want reliable and fast :biggrin:
Your powerband is the determining factor. Power from 3500-6500rpms or Power from 4500-7500rpms I find nothing bad about the 2.0L. It's a different beast to itself. What I find that dogs it down is that it doesn't have the sweet short gearing that the JDM STi gets, so you don't get to see wassup with the 2.0L playing with stock LONG gears. Get cams so your 2.0L can breath up top and you'll see.
As far as the turbo goes I am planning on getting a 30r. Still not sure what to do though as far as the engine rebuild.
nothing is getting twisted. 2.0L motor runs better at high revs than a 2.5L ever will. I wouldn't spin a 2.5L to 8000rpms like I would a 2.0 or 2.2L. If he wants "torque" then the 2.5L will be fine, just that it won't do high revs so efficiently. I would balance the internals like what I'm doing with mine if he wants some revs on a 2.5L. a 2.1 stroker would be nice of the two. balance that stuff!!! twinscroll is always nice. biggest hotside for 30R at the moment is the .78a/r. single scroll you can go big to like a 1.06a/r
Depends on which transmission he has also. No need to spin 8000rpm if he's using longer gears. :laugh: BTW, which transmission also?
2.5L is the best bang for your bucks. Pick up a 2.5L shortblock from the dealership, grab a set of Mahle standard forged pistons and you are more than set to run a 30R. If you use this car as a daily driver, you would be wise to run with a 2.5L for the torque under the curve. Higher revs are nice if you are drag racing or running around a track with it, but for the meat and potatoes everyday driving, you want torque off the line, and torque under the curve. A 2.0L motor revved to 8k WILL require machine work, balancing, your heads will need porting to flow up there properly, cams, valvetrain....get ready to piss about 10k into your motor. And even with all that work, there's no guarantee you wont oval a piston under heavy stress even with a good tune. Engines have capabilities and they have thresholds. I don't trust a 2.0L block in standard sleeved configuration to tolerate a 30R for an extended period of time. Especially if you are rolling it out to 8000 rpms. There are easy options for reaching your goals, 400whp and 400wtq are entirely achievable on a 2.5L with a 30R. And the extra cylinder pinnings should keep your sleeves in tact for the long haul. You can go with forged rods if you wish, but I've seen plenty of 2.5L's run on just forged pistons with that setup. The Rods would just be insurance. Also, your 2.0L transmission isn't going to like 400whp very much, it is highly likely that even with proper shifting and clutching you will still shred gears with that level of torque. You might want to think about a 6 speed or some sort of hardened gearset.
Thanks readymix. Ya it will be a daily driver. Now when we are talking about getting a 2.5l we are talking about the ej257 correct? any idea what one costs? Also, are we talking about bolting up the 2.5 shortblock to my 2.0 heads? Will this cause any complications? Will the 2.5 bolt up to my 5 spd tranny for the time being? When i decide to put the 30r on i will either go with a 6spd swap or go ppg gears 1-4. To do a complete 6spd swap on that car it seems like it would be a lot of work. Lots of questions lol thanks guys for all the info!!!
Yeah, the EJ257. AWDL can get you one, as stated in his post. And I am currently running exactly what you've described for the motor, an EJ257 with WRX heads, Mahle pistons. The only difference is the valvetrain in mine is different, but mating the heads to the block shouldn't be an issue at all. I believe you can use the stock head gasket, but honestly I'd recommend picking up a Cometic brand one. Just get the STi STD sized one. The transmission should also bolt up just fine. I went with the PPG 1-4 straightcut set, mainly for the reason you posted, it cost less and required less work than a 6speed swap. You buy the gears, put them in the transmission, and that's it. No sourcing wierd JDM 6speeds, no goofing around with the rear axles and hubs, brakes, etc...You will also need a clutch that will hold the torque you intend to make, so keep that in mind. I used the Spec 3+, but you have other options in regards to manufacturers and such.
You could drop a 255 in as well, but yes, everyone here is talking about the 257 (unless otherwise noted). If your going to buy a block you might as well get the sti one. They will bolt up to your stock 2.0 heads, there are several people on here running hybrids like this. You can also search "hybrids" in nasioc for some good info about the pro's and con's. Some people have had issues with knock sensors and/or compression issues. As far as I understand you should not have an issue with bolting your tranny up to the 2.5, hopefully someone else with more experience can chime in on that as well.
About 8.6-8.7:1 You can still run 91 if you'd like, just find someone to tune it properly. It can be done.
Here is a group buy that was posted here before: http://forums.nasioc.com/forums/showthread.php?t=1797093 Readymix's are straight cut, these aren't. I think for a daily driver these are a better buy and the price is right. Depends on how quick you need them. Find someone who will let you ride in a straight cut geared transmission.
Nuke called it. I think when I did the calculations it was about 8.75:1CR They were purchased by a local vendor that is no longer in business for me. I paid what Andrewtech is charging in that link that retreif posted, plus shipping.
