Ever done this to a cam...??? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

boogerlovers · 02-27-2008, 02:28 PM

alright so last week i found out that i had my retop timing set 180 degrees off

...so i go to fix my timing yesterday and as i pull the cam bearings off i realize that my cam is in two pieces...:hammer:. Anywho i buy a cam from VUTONY (thanx for saving my ass) and i set the timing to what it should be and everthing is cherry right? of course not...i crank and i get nothing...im thinking im not getting fuel, anywho after i run out of things to check, my friend and i decide to do a leakdown test and i have 100% leakage on all four cylinders. i can hear air coming from the exhaust but not from the head or the throttle body, this means its the exhaust valves right??? and not the piston rings right??? eh just thought id share my stupid mistakes....sorry if this doesnt go in tech...if you have any ideas of other things it could be besides the valves please chime in...

DunG HAB SP · 02-27-2008, 02:41 PM

wow not the first time i saw that one. i believe you might still be off of timing perform a leak down test and see what happens maybe valves aren't bent. and how are the journals when you took the cam off were they scored?

Big Bronze Rim · 02-27-2008, 04:13 PM

Did you crank the engine with the broken cam? My guess is bent valves if you did especially since that was the exhaust cam and the sound is coming from the exhaust.

boogerlovers · 02-27-2008, 04:46 PM

Quote:

Originally Posted by Big Bronze Rim

Did you crank the engine with the broken cam? My guess is bent valves if you did especially since that was the exhaust cam and the sound is coming from the exhaust.

yeah i did, with out knowing of course...but yeah im thinking its the valves too, im actually waiting for a lift/hoist right now to unhook my exhaust so i can pull the head...

Def · 02-27-2008, 07:46 PM

Did you follow the torque pattern for the cam bolts in the FSM?

Gjohnson7 · 02-27-2008, 10:03 PM

Wow! And I thought my timing issue was bad. The long block I purchased had the cams off as well, but only about quarter turn in opposite directions. I did a compression check too and had 3 great cylinders and 1 bad one that was leaking through the intake. Pulled the head and all the valves and nothing is bent. I still can't figure out why it was leaking.

slider2828 · 02-27-2008, 10:25 PM

It has been explained. Didn't follow directions, the CAM got pwned and the valve stuck in the open position. You cranked it, the piston slapped the valve and bent the valve. The valve due to deformaty will not recede back into the head fully hence compressure issues. Also you never know i you have cracked the piston as well since you slapped it that hard or at least nicked the crap out of the surface. Standard engine issues.....

Hench also friction on valve seals, the seals are gone now probably. Timing was off and you might have bent all 4 valves. Doesn't know, but what you did is basically what causes engines to blow. Not just a booboo, its full engine pwnage. Sorry full tear down on your way....

johngriff · 02-27-2008, 10:32 PM

No no. I would just re-do the valves and head gasket. Pistons are fine. The valves are not that strong at all.

And yeah, follow the Tightening patern and loosening pattern in the fsm/any sentra repair manual.. even a honda repair manual its the same.

boogerlovers · 02-27-2008, 11:06 PM

Quote:

Originally Posted by johngriff

No no. I would just re-do the valves and head gasket. Pistons are fine. The valves are not that strong at all.

And yeah, follow the Tightening patern and loosening pattern in the fsm/any sentra repair manual.. even a honda repair manual its the same.

yeah turns out none of the valves were bent...and the cam was snapped due to improper torque patterns...the pistons did not have a scratch on them...but i found a little piece of the cam embedded in the cam journal...i fail haha but hey its a learning process right...? it comes with doing your own shit

, i will say this though i wouldnt trade this experience for anything, cuz now i know to quadruple check everything lol, yeah thanx for helpin out and not flaming me guys...

boogerlovers · 02-27-2008, 11:12 PM

O yeah turns out the leaking was from the valves not seating correctly, not cuz they were bent but because they were not cut properly...

anywho problem will be fixed tommorow when i cut and lap the valves myself...

slider2828 · 02-27-2008, 11:54 PM

Replace the valve seals if you have it all out... Might as well if possibl...

02-27-2008, 02:28 PM	#1
boogerlovers Zilvia FREAK! Join Date: Jun 2007 Location: Palmdale Age: 37 Posts: 1,082 Trader Rating: (8) Feedback Score: 8 reviews	Ever done this to a cam...??? alright so last week i found out that i had my retop timing set 180 degrees off ...so i go to fix my timing yesterday and as i pull the cam bearings off i realize that my cam is in two pieces...:hammer:. Anywho i buy a cam from VUTONY (thanx for saving my ass) and i set the timing to what it should be and everthing is cherry right? of course not...i crank and i get nothing...im thinking im not getting fuel, anywho after i run out of things to check, my friend and i decide to do a leakdown test and i have 100% leakage on all four cylinders. i can hear air coming from the exhaust but not from the head or the throttle body, this means its the exhaust valves right??? and not the piston rings right??? eh just thought id share my stupid mistakes....sorry if this doesnt go in tech...if you have any ideas of other things it could be besides the valves please chime in... __________________

02-27-2008, 04:13 PM	#3
Big Bronze Rim Zilvia Member Join Date: Jan 2006 Location: San Antonio, Texas Age: 46 Posts: 173 Trader Rating: (0) Feedback Score: 0 reviews	Did you crank the engine with the broken cam? My guess is bent valves if you did especially since that was the exhaust cam and the sound is coming from the exhaust. __________________ "Genius may have its limitations, but stupidity is not similarly handicapped."

02-27-2008, 10:03 PM	#6
Gjohnson7 Zilvia Addict Join Date: Mar 2004 Location: Broken Arrow, OK Age: 44 Posts: 980 Trader Rating: (7) Feedback Score: 7 reviews	Wow! And I thought my timing issue was bad. The long block I purchased had the cams off as well, but only about quarter turn in opposite directions. I did a compression check too and had 3 great cylinders and 1 bad one that was leaking through the intake. Pulled the head and all the valves and nothing is bent. I still can't figure out why it was leaking. __________________ LSX Kouki Project, swap completed in Dec 09

02-27-2008, 10:25 PM	#7
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	It has been explained. Didn't follow directions, the CAM got pwned and the valve stuck in the open position. You cranked it, the piston slapped the valve and bent the valve. The valve due to deformaty will not recede back into the head fully hence compressure issues. Also you never know i you have cracked the piston as well since you slapped it that hard or at least nicked the crap out of the surface. Standard engine issues..... Hench also friction on valve seals, the seals are gone now probably. Timing was off and you might have bent all 4 valves. Doesn't know, but what you did is basically what causes engines to blow. Not just a booboo, its full engine pwnage. Sorry full tear down on your way.... __________________ Turn and Burn!

02-27-2008, 10:32 PM	#8
johngriff Post Whore! Join Date: Jun 2004 Location: Long Beach, CA Posts: 4,103 Trader Rating: (4) Rides Gallery: johngriff Feedback Score: 4 reviews	No no. I would just re-do the valves and head gasket. Pistons are fine. The valves are not that strong at all. And yeah, follow the Tightening patern and loosening pattern in the fsm/any sentra repair manual.. even a honda repair manual its the same. __________________ [email protected]

02-27-2008, 02:41 PM	#2
DunG HAB SP Join Date: Dec 2006 Location: NV Age: 47 Posts: 37 Trader Rating: (0) Feedback Score: 0 reviews	wow not the first time i saw that one. i believe you might still be off of timing perform a leak down test and see what happens maybe valves aren't bent. and how are the journals when you took the cam off were they scored?

02-27-2008, 07:46 PM	#5
Def Post Whore! Join Date: Apr 2004 Location: Houston, TX Posts: 2,701 Trader Rating: (16) Feedback Score: 16 reviews	Did you follow the torque pattern for the cam bolts in the FSM?

02-27-2008, 11:12 PM	#10
boogerlovers Zilvia FREAK! Join Date: Jun 2007 Location: Palmdale Age: 37 Posts: 1,082 Trader Rating: (8) Feedback Score: 8 reviews	O yeah turns out the leaking was from the valves not seating correctly, not cuz they were bent but because they were not cut properly... anywho problem will be fixed tommorow when i cut and lap the valves myself... __________________

02-27-2008, 11:54 PM	#11
slider2828 Post Whore! Join Date: Oct 2004 Location: San Francisco, CA Posts: 6,040 Trader Rating: (13) Feedback Score: 13 reviews	Replace the valve seals if you have it all out... Might as well if possibl... __________________ Turn and Burn!