tephra

iTrader: (6)

H Guys,

Just trying todo a boost leak test, but at about 1bar the 'boost is leaking in the engine' lol... and my little compressor wont push psat 1bar

does anyone know what degrees i need to be at so all the valves are closed?

How can I tell without taking the cam cover off?

Cheers
D.

tephra

iTrader: (6)

ended taking of the throttle body hose, and plugging up the BOV line...

2bar tested

busted my throttle body hose putting it back on thou.... oops too tight :|

evogirl916

i made a little rubber coupler that goes right on the turbo with a end cap/valve stem on the other side. pvc primed and glued everything and use the stock clamp to secure it. holds 30+ psi, but pressure still bleeds from the boost control silenoid...unless you plug it

tephra

iTrader: (6)

yeah thats how I used todo it, but after hearing that the turbo seals leak I thought I would bypass the turbo...

MR. Tim

iTrader: (11)

So you ran the test post turbo? So from the inlet of the UICP? Actually due to location, that is easier than removing a bunch of stuff to plug into the turbo inlet.....

tephra

iTrader: (6)

since I have stock IC piping I just disconnected the expander joint in the UICP and started from there...

chidevildog

iTrader: (7)

have you got the results from the test?

tephra

iTrader: (6)

yeah I got upto 2bar and it held ok..

i am still interested in doing a full test, so if anyone knows how far past TDC all the valves will be closed please let me know

SiC

iTrader: (1)

Lets see, firing order is 1-3-4-2 so that means at TDC:
Cylinder 1 is about to combust (intake valve closed)
Cylinder 2 is about to exhaust (intake valve closed)
Cylinder 3 is about to compress (intake valve about to close)
Cylinder 4 is about to intake (intake valve about to open)

It's hard to say what degree exactly since you have to know the exact cam opening/closing degrees, take in consideration the valve clearance, etc. But by knowing the sequence above, it should be a few degrees after top dead center right when cylinder #3 intake valve is closed. If you go too far ATDC cylinder #4 intake valve will open.

Place the engine in TDC (be sure it's TDC cylinder #1 and not #4 ), apply the compressed air into the intake and rotate the crank clockwise until the leak stops.

SiC

iTrader: (1)

Actually it shouldn't matter, it can be ATDC for any cylinder

But know that I think of it, I wasn't thinking about overlap which occurs between the end of the exhaust stoke and the begining of the intake stroke. This maybe a little harder than the easy thinking above

Easy way, just keep rotating the crank until the leak stop

tephra

iTrader: (6)

yeah i tried trial and error but that didn't work too well

i will start at TDC and go forwards from there..

SiC

iTrader: (1)

When #1 is at TDC #4 should be in the middle of overlap. If you keep rotating the crank clockwise overlap will end and #4 intake valve will open further but at the same time the #4 exhaust valve will fully close. So as long as your cylinder isn't leaking, you should still have a good seal even with the intake open. So this means it should still be some degees ATDC when #4 overlap ends

tephra

iTrader: (6)

yeah ok - thats all that matters - exhaust valves being closed

so you think slightly after #1 is at TDC? so start just before and work forwards..

#1 being closest to timing chain yeh?

SiC

iTrader: (1)

Yeah, slightly after #1 TDC when the #4 exhaust valve closes all the way.

Yes, #1 is timing chain side

vboy425

iTrader: (19)

We have the same issues on our race evo with our race cams. I just take the cams out and be on with the test.