My engine is fighting fit and det free :D Having a plan if it does let go or I decide to go mad is what I am working on. If it will all be a hellish nightmare to rebuild then I am likely not to push it as much. If it did go I would be more philosophical if it had not detted to bits but just went because of the amount of torque if you see what I mean.

Further brake and suspension attention would be on the list. Improving my driving skill too, making some progress there. However, I just love torque. I keep thinking about supercharged 5.7 L V8 engines for some reason ;)

[Edited by john banks - 9/1/2002 9:13:51 PM]

Hello John, (hello Carlos)

I am the german guy with STI VII short block in the MY99.

After a big end I decided to put in the STI engine block because of it's unbeatbale price against other rebuilds.
The block costs me ~2000 EURO against a 5700 EURO rebuild from GGR with Cosworth pistons etc( which can of course handle much more power (but would that do my gearbox to ;-)) )

As Carlos mentioned already the block fits without a problem.

After a dyno run and remapping of the Unichip som days ago we saw a very safe power output around 290PS@6200/380Nm@4300 (@ 1,15bar max. boost til 5700RPM falling donw to 1 bar until 7200RPM ).
CO under full WOT was no more lower than 9,5%.
Torque and Power curves are pretty good and linear and the car runs great from down low until the redline.

Remarkable was the very linear power output of the APS SR-30 turbocharger from 2800RPM 'til the end. The performance is much smoother as with the the VF23 which I had installed before.

From my point of view I can strongly recommend the use of the new STI Block for a rebuild.
For me there is no more value for money available concerning a engine rebuild.

Frank :-)


[Edited by FrankM - 9/2/2002 7:27:35 AM]

If you wanted to rebuild the UK Phase II Impreza engine for reliable big power what/who would you recommend and why? Now there is an uprated gearset on the market it has got me thinking that it might be worth making a big power Impreza. What do really hi-po guys do about the diffs?

Close the deck, uprated pistons, rods etc. What about the big end bearings - what can be done to reduce the risk of them letting go? Other weak spots to consider? Oil cooler, bigger turbo, injectors seem obvious. It is more the engine itself and how to approach it to get strength that I am interested in - like how to run say 2-2.5 bar safely.

Is it worth rebuilding an engine that has let go? Some suggest not as they reckon they are never as good as new, but this may be the results of less capable engine builders?

Is it best to go for Aussie EJ25 monster?

Just looking for a little route map beyond bolt ons :)

bank loan....

Forged pistons tend to be of a better material, more able to withstand a little det (not that you want them to), and most are lighter, which means more reliable running at high rpm. I personally have seen no examples of bent rods through too much torque, but rods a probably a good idea too.

Crank is reputed to be good for 400hp, so leave it on.

If you run more power through high revs means less transmission load, just look at the skylines, their low torque is good for something.

Closing the block can be done, but I have yet to see evidence of an engine that's blown, and it's known to be due to the block. Fitting wills rings ("ringing the block") should help keep the bangs in and water out. I think you would be getting into a can of worms trying to get it closed. I believe I know a company that could do it in the uk, but they would probably need at least 2 to experiment on.

Uprated big end bearings can be had, and are probably worthwhile.

I think the real key is making absolutely sure you don't get any det. THe temps weaken pistons, damage lands, pinch rings, stress the bearings by displacing the oil etc etc etc. I think that much of Andy's success has been through the careful use of WI, proper intercooling and slow progress.

Of course I could be wrong, but there seems to be a number of high power STI 7s running standard internals.

How much money do you want to spend, when will it stop? If you want to go faster on track, make the car handle better, you will be faster on the straights if you do, as you will already have a head start out of the bends. Throw money at tyres and brakes if you want a good start.

Paul

Er, John.

Is there something you are trying to tell us here?

Paul

Well, going to fast for big power - yes lots of det - I had a long learning curve - especially on track ;)

Engine has been fine to date. One thing I would say - use the biggest uprated head bolts you can afford - I thing you can get up to 14mm :eek:

This, and Wills Ringing will reduce the impact of head lift - probably one of the biggest problems and will overcome the need to try for closed deck. Hearsay suggests a good quality - blueprint type build can hold substantial boost - although probably not the 2-2.5 bar you are looking at. At that level I would still try and secure a Phase I closed deck block.

I believe you can use a Phase I block with a Phase II manifold, heads and box - although you lose a couple of studs on the gearbox which helps tortional stiffness. I am sure this can be fixed by putting extra studs in the Phase I block.

Trout :D

Trout, your comment about extra gearbox bolts in interesting. It would be easier to weld some extra fixings than close the deck.

Head bolts shouldn't be an issue at 1.8bar ish, as has been proven by some, and I don't mean Andy.

First rolling road day really made me crave more power.

more

more


HUWAAHAAHAAHAA!

P

A german friend who had a MY00 told me that he got a new STi ver 7 short block. And was able to install it with no problems, he used his Phase II engine heads, and had no problem matching the gearbox with it.
I think that the STi ver. 7 short engine, comes with better rods, forged pistons and a different crankshaft, so it might be worth considering it as an option.

Carlos H.

John

I can do you a 600bhp 5.7V8 for a lot less than a 450bhp scooby motor :)

ps You might need to sit in the back seat if you still want it 4wd :D :D

I haven't seen the STi7 internals, but I doubt you can compare any stock internals, with uprated rods/pistons, and whilst your new engine may be great, 290bhp is hardly circa 400bhp, running 2bar.

Wills ringing won't stop head lift, nor is it recommended for a long term reliable seal. It's designed for competition use, as is Coopers ringing. These engine will do a few hundred miles, and then will be rebuilt.

There are already a few companies offering uprated head stud kits, and I believe ARP are also going to be offering a set. Prodrive also supply them for their competition engines, WHY ?? because there IS a head lift problem on cars running high boost.

The most important thing, is to get the engine built correctly, with EVERY tollerance measured, and adjusted correctly, and of course good quality internals.

As for the actual capacity, well, the bigger you go, the easier it will be to achieve power.

Mark.