Brumby Kid wrote:Engine Blow By/Back. Is this where you can feel air coming out of the air cox instead of sucking?
What can you do? Coz iz I have to split the block for that im gonna be pissed.
No. Blow by is when you can feel positive air pressure coming out from the oil filler when you remove the cap. It can also be blue in colour as it burns a little bit of the crank case oil.
Excessive, oil rings will be shot shortly after this and you'll see that as blue smoke out the back of the car when you start it/drive/use the engine at any time...
Brumby Kid wrote:Yeah ok,
How would you get the pistons out?
Splitting the block sounds easier.
What are the cons of doing so? Im looking at Sam in particular.
Now is there a way to test for the piston rings, as i know it could also have been the head gasket, or an impropely seated valve, or valve seal thingy.
Thoughts Please.
Hex keyholes on the side of the block beside each cylinder, I think Sam's gone into this. Splitting the block is done to change the cam (for a better one, your cam shouldn't be worn out yet), replace main bearings and big end bearings.
A full engine rebuild like this will give you the best stock compression you can get without starting on other mods you'd go for if building a real performance engine. The cam is a big part of this.
If you follow the instructions, have everything measured as instructed and the appropriately sized parts used in the rebuild. Double check tensions are as they should be and that things are clean when you do the rebuild. The other important thing is to make sure you place the bearings in the correct way around if you go the full rebuild.
Brumby Kid wrote:Is there anyway to test to see if there is anything wrong?
So i don't end up like Sam?
Cam, that's a bit harsh. It was Sam's first build and he needed it done. He may have missed one big end bearing not being seated properly or was in the wrong way around - we'll never know. But it was a gutsy move and I hope that he has another go at it soon, just slower and more thorough/attention to detail used.
Brumby Kid wrote:
Apart from gasket issue.
I do have some blow back.
Possible causes...
Head gasket
Valve issue
piston rings
How can i tell which it might be without putting it back together and taking it apart again?
I would like to fix that to get better compression and performance.
Blow by can't result from a head gasket - that's a leaking head gasket and is different to blow by. Blow by is the compression rings no longer holding the burning fuel mixture in the cylinder, the way to find this is by a compression test before you pull it a part or to inspect the bore once you've got the heads off and read up on a guide as to what the bore is telling you. Note: Subaru engines are good at still showing the hone markings at +300K but they're no good anymore for bedding in the rings as this would have occurred ages ago.
revmax wrote:Yes, disturbing the bottom end is creating unessary work and risk.
Dunno about the "unnecessary work and risk" bit. If you're going for mild performance an engine rebuild is the best way to get the most from your engine. Personally if I was going to hold on to this engine for some time I'd be going the whole hog with a mild cam dropped inplace of the stock unit for a bit more pep while driving.
revmax wrote:Steptoe you went of on a tanget as I never mentioned anything about honing only above the rings.
Steptoe was sharing a story of how not to do it. 1) honing is good for new rings to bed in, I wouldn't be pulling the pistons out if you weren't going to hone the bore and throw in new rings. But then again I wouldn't putting an engine back together without having the bore checked out for roundness and straightness (for the want of a better term).
2) You don't ever hone the bore with the piston still installed. Not only can you not hone the whole bore stroke you also can't clean out all the debris created by honing the bore.
ALWAYS wash the block after having honing work/re-bore work done, you'll be surprised how much debris comes out in the wash!
revmax wrote:if there wasen't any blowby before the gasket failure then it is VERY likley the be compression leaking into the case when the gasket failed.
How many K's has it done.
Edit the gaket and cyl photos show a compression leak.
The amount of carbon on the pistons makes me think the oil rings are worn, is there much carbon build up in the exhaust ports and was it using much oil.
Yeah this is always a hard one to say. The engine could have been running rich... or this could be normal carbon build up for a petrol drinking engine with almost 300k km on the clock:
It's hard to tell by photos and without seeing the engine run before it was torn down.
It's always a complex equation as to what you do - if you were just pulling it down due to a leaking head gasket and that's all you want then just do that work.
If you're after some solid reliable performance a complete rebuild will look after you so long as you do it carefully with attention to detail. Find a good build guide and follow that - and ask questions as you go
Cheers
Bennie
I've remembered you take the pistons out before splitting the block so you could change the rings, but if you left it intact while you honed it surely the connecting rods would get in the way? and all the honing fluid/metal dust would get into the crank assembly?
) Rotate the engine until gudgeon pin is visible, use needle nosed pliers to pull the circlip out, use your slider hammer to pull the pin out (they can be bloody difficult to remove) With the slider hammer end you need a long bolt with a step at the end to hook over the end of the gudgeon pin...kinda hard to explain. 
