I have a 93 WRX which has done 80000 mls and I had a thread a few days ago about overheating, its not overheating now but its loosing a little bit of water so as I suspected one or both of the head joints must be gone. There is no visible leaks anywhere else.

I have a couple of options, the engine runs fine at the moment with no adverse sounds coming from it and is producing good power so other than the water problem its good. I do have a spare engine thats still in my 95 uk wagon that I can slip in for the time being which I know is good.

I have a few ideas running around in my head as to what to do to the engine that comes out the WRX. Give it a complete overhaul, new bearings, mains and big ends. Depending on the condition of the pistons just a hone and a new set of rings and give the heads a port and manifolds.

Im very new to Scoobys but no stranger to building engines, Im looking for advice on things like what kind of gaskets and parts to use, Ie OE, Subaru or aftermarket. I do have plans for the power output of the engine with 350 bhp being the max. Are std pistons and std compression ratio capable of this? Should I be thinking about forged jobbies? What about uprated bearings or are std fine. I will be fitting new belts and oil pump.

I think thats enough for now to get some replys and opinions in.

 

are there any signs of headgasket failure apart from fluid loss? The scoobs do have weak radiators and the plastic end caps tend to split with age, these can be hard to see as when they have cooled down they contract slightly making it very difficult to see the split. Also when cooler they tend to reseal up again until when hot. The drivers side end tank is the most likely side to fail. Also check the top and bottom rad hose especially on a car of that year (good year same as mine) as if they are originals then they are prone to getting leaks. I have done 2 rads on mine, first one was a quick fix second hand job that lasted about 8 months, then I bought new. I have also replaced both of the hoses as well.

If you go down the stripping of the engine route, then for a better chance of reliability at 350bhp, I personally would use uprated rods and pistons and bearings as I think std internals on a 93wrx (with 80,000 miles) running 350 bhp may be just a little to much. It may be an idea changing the water pump as well as if it is the original it will probably be a little bit tired

 

I was in past the local Subaru dealer today and they did a carbon test on my coolant, I have a reading of 5ppm. Since I managed to get the system bled and stopped it overheating I have only had to put in coolant once which was two days ago. Since then I have lost no coolant at all and thats including several high speed runs one of which was 6500 rpm in 5th for a few mls. The cooant level this morning was the same as last night. Im just going to run it for a while and see what happens. 5ppm is very low, admitedly it should be 0ppm but Im thinking that maybe because the car now has a thermostat in it Im stirring up crap in the system.

Ive been looking at piston and rod combo's. Ive found these on ebay, The comp of 8:5.1 is higher than I want but Im just waiting for a reply to see if they can do them at 8:0.1. Is it ok to take the std block out to 92.5mm and will std head gaskets be ok?

eBay Motors: SUBARU wrx impreza ej20 RACING PISTONS, RINGS, RODS new (item 300062376844 end time Dec-24-06 22:33:59 PST)

 

Whatever you decide, fit a modified/uprated oil pump !!!

Rob