I'm starting this thread with the hope that I may get some advise from my fellow Subians! and maybe help someone too. I own an 04 Sti that, unfortunately, has a blown motor. I bought it a few months ago w/ 38000 miles on it. I got mod crazy and the result was a busted ringland in #4. Here are my current mods.... -3" TBE -Unequal length header -Up-pipe -Short ram intake -3" turbo inlet -Utec ECU -Greddy type-s bov It ran strong for a bit, but it shot REALLY big flames that lasted a few seconds at a time. That lasted for about 300 miles, then it started smoking. I was about to have it tuned, but Topspeed recommended a compression test before putting it on the dyno. I felt like I was waiting at a hospital to hear the bad news, lol. #4 showed 60psi :wtc:. I guess the tune was too little too late! I highly recommend getting tuned for EVERY mod, and Topspeed for that matter. They were very friendly given the circumstances.
Im planning on keeping the car so I am going to re-build it much stronger. I really dont want a stock motor again.
After he got the motor out I went over to his shop to lend a hand (learn a little more about my motor) I would have neve guessd that after we tore the motor down, is that the block is actually the size of a shoe box...lol. It's crazy that it can make the hp it does.
I am sure you will hear a variety of recommendations, but from all the research that I have done when I was getting ready to build a block, I would go with boring the cylinders slightly and fitting the block with some good quality oversized pistons that have been bore matched to the exact dimensions of the cylinders after they have been bored over. Connecting rods seem that they can go either way. Balancing the crank pistons and rods can really help with the smoothness of the engine and is relatively inexpensive. Other than that, the crank should be plenty strong. The rods I think are good for more hp than you are likely to make any time soon and forged pistons are always a good option while you have the engine open. Just don't get drop in pistons. I have heard too many bad things about drop in forged pistons.
Thanks for the info..you have discribed much of what I am doing. I have already ordered the majority of the parts that i will be using. -Crower forged H beam rods -JE forged pistons 100mm bore -ARP studs -Exedy clutch (the stock one was just about gone :keke: ) -Power Enterprise timing belt -Cosworth rod/main bearings -Cobb 12mm oil pump
Ooooooo that looks like all sorts of fun. Any plans on a valve train upgrade and spinning that thing to 9k?
I have my eyes on the crower stage 2 cams, springs and retainers but I'm not sure if I'll have the money. I'm definitely doing some port and polishing while it's out. :ddirty: Can anyone recommend a GOOD machine shop? I'm kinda nervous just taking it anywhere.
Even with headwork you still can't spin that block reliablity over 7500 rpms. You gotta get some crank work done and blueprinting/balancing as well.
Ball engines in Lilburn. They do all my work and they have done work for a couple of board members. Skip the cosworth bearings and just get some ACLs. If you need cams, GSC motorsports has cams, they were going to sponsor my STI but since we are going with the 6 cylinder I won't need them. The timing belt is overkill, the factory timing belt is fine, that or you can pick up a gates belt from Napa.
LOL tooo late. The reason I said that about the bearings is I think they are just repackaged ACLs but since you already have them it doesn't matter. Matt
http://axispowerracing.net/stage2valvetrain.html sleeve the block and add this to your list of goodies
Just do a full Ferrea Valvetrain and a 2.2 block that will be way cheaper and you get a better bore to stroke ratio with the smaller bore.
Man this sucks! When it rains it pours. I have been stuck on my bike since my subie died. Someone rear ended me at a light in PTC. They bent my exhaust up a little. I know it dont look like much but that was a $700 titanium exhaust. Oh well, other than that I'm still waiting for parts and more $$$$. BIG thanks to slowwrx for recommending Ball Engines in Lilburn, I am going to be dropping off my motor there probably monday or so. They are going to bore/hone the block, re-surface my flywheel and balance the rotating assembly. Until then keep the tips flowin'.
If you are thinking about pistons for a future build. Cobbs pistons are JE forgings but the way that cobb machines them is way better. They machine them so that the piston has a tighter quench area. Tighter quench area means better more efficent burn. Matt
Correct. Just for refrence my 2.5 with a .039 thickness gasket, the compression ratio was 8.97 with a .059 it 8.84....so head gasket thickness is really only changing the Compression ratio by very little. Its worth having the extra compression to get the tight quench.
Don't worry it will be fine, we didn't use custom pistons in Jeremys bugeye and its making a ton of power.
Ok, I dropped my block and crap off at Ball Engines. Should have everything back by the end of the week :sx: . I hope to start re-assembly next week, depending on when the rest of my parts come in. I have to pick up a complete gasket kit from SOG, anyone know where I can get it cheaper without sacrificing quality? It is going to run me about $300.
I got these in but I have heard that these when combined w/arp's are not reliable. I have the stock Head gaskets that came with my gasket kit but they are not 100mm. Can I use them anyway? Should I order 100mm stock head gaskets? Any info would be appreciated, at this stage in the build it would be easy to change.
Ball Engines did a fantastic job on the bore and balance. I cant wait to get out of the friggin' cold and back in my subie.
stock headgaskets are fine with 100mm pistons. I have been using them on my motor the entire year without any issues.
Hell yeah. Sorry I havent been able to lend a hand..... Work "owns" me. I'll try to be around when I can.
Well, I was waaaay too busy at work to mess with the block much today. I did get the heads torqued down though. Here is Dougs advise in action. More to come!!
Got the motor in!!!!!!!!!!!!!!!!! Soon I will be out of the cold!! :drool: The oil pump finally showed up too.