a few Q's on potential rebuild

[UP2MTNS]

Hey all, I'm probably looking at a rebuild because of a cracked ring land (most likely, still need to actually pull the engine and verify).


I'm trying to do this one as cheap as possible, and one option is to do as much as possible myself.

If it turns out that it really is just the ring land, is it always 100% necessary to replace the rod bearings? can I pull everything apart, have the block re-honed at a shop, install new pistons/rings, and just not touch the bearings?

Currently have ACL race bearings with about 20K street miles and and 4.5 events.

I need to learn more about all these little engine rebuild details. Well, I guess they're not LITTLE details, but you get my point. thx.

[Joshz400_03]

You probably could get away without replacing the bearings. IMO while its apart its always a good thing to do..Check the tolerances in the bearings and see if there is any play if you don't have the funds to replace them.

[A1337STI]

From the little I know, yes that's possible. someone i race with in reno had his STI motor rebuilt due to bad ring landing and only needed a tiny honing out and was able to re-use a stock piston size (think he went from A to B size)

I think my DD sti has the same issue, but as with you i haven't had it pulled apart yet. i burn up to 1 quart per tank of gas (250 miles)

I've got a 1.8L you could slap in that thing, we could have a grand 1.8 battle royal ! :) ya ya ? free if you want it

[JacksonRally]

Didnt you have forged pistons put in with the last rebuild?

[UP2MTNS]

Didnt you have forged pistons put in with the last rebuild?

yes, they were Supertech pistons. If it really IS a ringland, then 1) I'm not very happy with them and will be putting in something different, but 2) then there's something up with my tune because we were never pushing much more than 270wtq and ANY forged piston should be fine with that.

****, the STOCK piston IS fine with that.


trust me, i'm highly annoyed by the whole thing. But that's rally...

[Rally OBXT]

Jon, it's too bad you are having all these problems with your motor. After seeing what you have been through (and countless others) in regards to aftermarket rebuilds, I am thinking that OEM is the best way to go.

[JacksonRally]

yes, they were Supertech pistons. If it really IS a ringland, then 1) I'm not very happy with them and will be putting in something different, but 2) then there's something up with my tune because we were never pushing much more than 270wtq and ANY forged piston should be fine with that.

****, the STOCK piston IS fine with that.


trust me, i'm highly annoyed by the whole thing. But that's rally...


Gotcha. I went with JE pistons for my rebuild on the battlewagon. I agree that stock should be fine for your numbers. Lame nonetheless.

[UP2MTNS]

Jon, it's too bad you are having all these problems with your motor. After seeing what you have been through (and countless others) in regards to aftermarket rebuilds, I am thinking that OEM is the best way to go.


at the same time, racing is racing and sh1t happens....I'm definitely not easy on the car. HDT, while a 'short' rally, for me was basically 5 miles of either redline in 1st gear or redline in 2nd gear, times 3 stages. So imagine driving for 15 miles at 6500 rpms in 1st gear.

In that respect, I almost think Prescott Rally, while a longer rally, is actually easier on your engine because you don't sit at redline in any gear for any length of time.

Also, I think proper gear ratios will help with the same problem. The WRX stock gears are just too long for rally, and especially for stages like Gorman and HDT, where I get stuck in between gears a lot.


And I'm also looking at the JE pistons...they have a piston for the proper compression for a hybrid build like mine.

[Rally OBXT]

Right you are about racing being SUPER hard on your engine and $hit happening. Me thinks you just have extra bad luck. :-(

About the stock WRX gears sucking ass, yes they do in a BIG way. I have been fooling around with gear ratio calculators online recently and found out some interesting things.

The stock gears in a 2.5RS are super short and very good for rally. Redline in 1st is 30 mph, 2nd is 51 mph, 3rd is 74, 4th is 97 and 5th is something like 130. This is with a stock 4.11 final drive. The only bad thing about the stock tranny in the 2.5RS is that is was never designed to handle the power of a turbo engine. If you swap tranny's, you will blow up the gears.

The good news is you can get aftermarket gears in your WRX that can handle the power but keep the stock 2.5RS ratio's. Now if you are super baller, you will switch your final drive to 4.44 and have even shorter gears!! :love: This basicly means you will only use 1st for launching and that's about it. 2nd would be so short that you would never need to dip into 1st.

So how about it?

[UP2MTNS]

Right you are about racing being SUPER hard on your engine and $hit happening. Me thinks you just have extra bad luck. :-(

About the stock WRX gears sucking ass, yes they do in a BIG way. I have been fooling around with gear ratio calculators online recently and found out some interesting things.

The stock gears in a 2.5RS are super short and very good for rally. Redline in 1st is 30 mph, 2nd is 51 mph, 3rd is 74, 4th is 97 and 5th is something like 130. This is with a stock 4.11 final drive. The only bad thing about the stock tranny in the 2.5RS is that is was never designed to handle the power of a turbo engine. If you swap tranny's, you will blow up the gears.

The good news is you can get aftermarket gears in your WRX that can handle the power but keep the stock 2.5RS ratio's. Now if you are super baller, you will switch your final drive to 4.44 and have even shorter gears!! :love: This basicly means you will only use 1st for launching and that's about it. 2nd would be so short that you would never need to dip into 1st.

So how about it?

that's basically it right there. I'm in the NASIOC For Sale: Drivetrain forum almost daily.

Slightly used PPG totally built trannies can be had for cheap (with shorter gear ratios). The problem is all those street weenies pay the big bux for 'PPG' gears and then go and put the stock WRX open diff in the front (WTF!?). So i'd still have to open it up and get a front LSD in there, but whatever. There was a 5speed PPG dogbox with <1000 miles, billet forks, etc on there last month for only $4500 and ready to bolt up. drooools. Its extra baller. MFactory and RA stuff is even cheaper....usually built and ready to go.

I could also just get a set of brand new RA gears (about $1600 + labor) with close ratios and that would probably do me fine as well. The only issue I have with that is after you get all the seals/bearings, upgraded shift forks, etc, etc....you're pushing +$3K for a tranny that can still break. I'd rather get used PPG something or other.

(smacks self in the head....dude....fix your engine first!!)

Anyway, the new job is starting out well, so we'll see where I'm at for 2011 pretty soon. But I'm still pushing for Prescott this year. Gorman if I'm lucky and can find a cheaper way to do this rebuild.


I'm waiting for KMount to chime in here, where is that guy?

[kurt.]

I have a RA trans in my GC and I've still found a use to stuff it into first on some real technical stuff. Just my .02

-Kurt

Right you are about racing being SUPER hard on your engine and $hit happening. Me thinks you just have extra bad luck. :-(

About the stock WRX gears sucking ass, yes they do in a BIG way. I have been fooling around with gear ratio calculators online recently and found out some interesting things.

The stock gears in a 2.5RS are super short and very good for rally. Redline in 1st is 30 mph, 2nd is 51 mph, 3rd is 74, 4th is 97 and 5th is something like 130. This is with a stock 4.11 final drive. The only bad thing about the stock tranny in the 2.5RS is that is was never designed to handle the power of a turbo engine. If you swap tranny's, you will blow up the gears.

The good news is you can get aftermarket gears in your WRX that can handle the power but keep the stock 2.5RS ratio's. Now if you are super baller, you will switch your final drive to 4.44 and have even shorter gears!! :love: This basicly means you will only use 1st for launching and that's about it. 2nd would be so short that you would never need to dip into 1st.

So how about it?