Hi guys i am from cronulla area and have a project gen 3 1994 mr2 turbo, it has loads done to it, 3" exhaust bilstien coilovers, turbo smart boost management, drilled and slotted brakes, stinger computer it had areal forged pistons and ran a ton of boost with the TDO5 greddy turbo and intercooler but ended up cracking a cylinder wall. Apparently the gen 3 block has thinner cylinder walls to allow better cooling. 
 
Financially i couldnt afford to get it fixed and i didnt know it was the block cracked until i stripped it down and saw it was not the head gasket, it was the block. rather then sell the car for parts i jumped straight in and removed the engine
 
I purchased a gen 2 block on ebay for 500 bucks, the forged pistons and crank would not fit so i just installed the gen 2 block with the stock pistons as it was with everything else gen 3. i had to run pipes in a different way for the oil cooler and iron out a couple things that were different but i got the whole thing together and back up in the car. it was a mission to say the least.
 
I went away for over a year and have returned and had pretty much forgotten where all of my parts go, i had to install the turbo, dizzy, coil pretty much everything other than the engine, gearbox and intake manifold, which i had installed before i left.
 
Now, i have everything together and the car starts and runs. Here is my problem.
 
First problem, when i filled the engine up with water it ran streaming out of a hole in the side of the water pump i understand that means the water pump is almost screwed? or is screwed. I plugged it up for now as a i want to get the car driving to iron out any other issues.
 
Second and biggest problem, when i start and run the car a belt was screeching i thought it would fix itself after it runs for a while but it turns out it was the timing belt running off into the block! the timing belt is now half the thickness and the side of the engine of full of belt fibres. I was pretty devo because that timing belt and water pump are hard to reach while the engine is in there.
 
This is the first contact i have made with anyone who knows anything about the mr2 so anything you know about what i have done so far and what to do next would be greatly appreciated
 
Mike

Which timing belt did you use? The gen2 belt has one less tooth on it (slightly shorter than the gen 3)
If you are using a gen 2 block with a gen 2 oil pump, i'm pretty sure that's when you use the shorter timing belt (oil pump pulley is smaller in diameter)
Hopefully someone on here will jump in and confirm.

Your comment about the hole in the water pump concerns me.  If it's the opening I'm visualising then yes, your pump has gone to meet its maker and SHOULD NOT BE USED.  Cooling issues are the bane of an MR2's existence, and having a non-pumping pump is the best way to trash what ever you have left.
 
Your timing belt issue could be related.  If the pump is worn, then its pulley may be running off centre, this could cause the belt to slip down the pulley and up against the block.  I'm going to assume that you matched up the timing belts and have used the correct one, so look to the pulleys for an answer.

Hey thanks for the reply guys, i used the gen 3 oil pump pulley and timing belt. i understand they could be related. 
 
But surely this cant be the result of a failed water pump, the belt running off into the block and grinding away, has this happened to anyone before?
 
when under load the belt schreeches so yeah something is not right.
 
does anyone know how much a decent mechenic would do the work for? like double checking the vacuum lines then water pump and timing belt?
 
It looks like i will have to just pull my finger out and replace the two idler pulleys, water pump, and timing belt. After i get the belt on i will turn the engine over a bunch of times to make sure the belt is running straight, but if i do all that work and the belt runs off into the block after i get it back together i will die
 

Just to update you, i have stripped it down the water pump was rooted and the oil pump pulley was a bit loose on the shaft.
 
all the parts should be here in a couple day except for the oil pump pulley
 
Does anyone have a Gen 2 oil pump pulley or know where i can find one? 
 
toyota is telling me three weeks to order one in and i dont have that much time

Try Gatesy on the forums. he works at toyota and has some in stock I think.

Have you got the 'timing belt guide' installed on the crank?  Although I guess this would only prevent outward movement.

I have replaced everything, the timing belt, the whole oil pump, the entire water pump unit (including the back part) Just got it all back together and running again yesterday..
 
the belt runs true now, engine is looking pretty schmick aswell since i pretty much took the whole thing apart to do all this work i repolished and tidied up the components.
 
Its funny you mention the timing belt guide on the crankshaft, i got the whole thing back together and realized i had left that out, so i took it all apart again and put it in... i have now taken this car apart and put it back together that many times i am getting pretty good at it! 
 
i am really glad i did the work myself and didnt go to a mechenic.
 
Ill upload some photos for you guys soon, my phone is el cheapo the camera sux

I have pics to upload where should i do it?
 

Photobucket. Then paste the [img] links. Maybe best to start your own showroom thread since this now appears to be resolved.