cam install nightmare
Registered User
Joined: Sep 2002
Posts: 464
From: Orlando, FL
OK I am working on this with Rob right now, and I can provide a little more insight...
I can verify that the car started and idled fairly well. Today when we went to pull the valve covers and adjust with the car running, it just won't start at all. We're at a lost. Its got spark, and you can smell fuel, but it reeks of dying opti. It just was working fine before though. We also relashed the valves turning the crank 90 degrees at a time. I think they are pretty much correct.
I can verify that the car started and idled fairly well. Today when we went to pull the valve covers and adjust with the car running, it just won't start at all. We're at a lost. Its got spark, and you can smell fuel, but it reeks of dying opti. It just was working fine before though. We also relashed the valves turning the crank 90 degrees at a time. I think they are pretty much correct.
Registered User
Joined: Jul 2001
Posts: 221
From: Raleigh, NC
Ok, this is how to adjust the rockers if you can't get it to run to do it by ear.
Start at the back of the engine on one side. Turn the engine over by hand until the exhaust valve starts to open on the back cylinder. Tighten the retaining nut on the intake valve until you can no longer spin the push rod with your fingers. Be sure to pull the ratchet off the nut before your try to spin the push rod. Once you can't spin the push rod, tighten the nut another 1/4 turn. Turn the engine over by hand some more until the intake valve starts to open, the adjust the exhaust valve the same way. Repeat this for all 8 cylinders. It's pretty easy, when one valve is poening, the other should be completely closed. You wanna make sure you are adjusting the rockers when the valve is completely closed.
Did I miss anything guys?
Start at the back of the engine on one side. Turn the engine over by hand until the exhaust valve starts to open on the back cylinder. Tighten the retaining nut on the intake valve until you can no longer spin the push rod with your fingers. Be sure to pull the ratchet off the nut before your try to spin the push rod. Once you can't spin the push rod, tighten the nut another 1/4 turn. Turn the engine over by hand some more until the intake valve starts to open, the adjust the exhaust valve the same way. Repeat this for all 8 cylinders. It's pretty easy, when one valve is poening, the other should be completely closed. You wanna make sure you are adjusting the rockers when the valve is completely closed.
Did I miss anything guys?
Registered User
Joined: Sep 2002
Posts: 2,481
From: Arlington, VA
If you went ridiculously tight, you may have bent pushrods now. I mean what did you go by (if anything) as a guide for the adjustment? You have to be careful, a lot of things can happen in a situation like that. For one you can slap a piston with a valve (not good) Two, you can collapse all of your lifters and also the pushrod situation.... 
Edit: not to mention, broken retainers. You also totally screwed your cam break-in period now. Make sure to flush all the oil out once you get it going with a cheap dyno oil. Then flush again at 500 miles and switch back to your normal oil.
Good Luck
Edit: not to mention, broken retainers. You also totally screwed your cam break-in period now. Make sure to flush all the oil out once you get it going with a cheap dyno oil. Then flush again at 500 miles and switch back to your normal oil.
Good Luck
Last edited by scoobysnax83; Sep 27, 2003 at 06:59 AM.
Registered User
Joined: Sep 2002
Posts: 2,481
From: Arlington, VA
Yes, I believe that is true. They do not require break-in periods. But my rule of thumb is every new, moving, friction prone part deserves a proper break in... But thats just personal feelings. I believe you will be fine. Sorry to scare you.... Ws6Envy
Registered User
Joined: Sep 2002
Posts: 464
From: Orlando, FL
I really don't believe we've damaged anything in terms of pushrods or lifters or especially retainers. The retainers are all fine.
I was just thinking that if it was running fine, and now its not running at all, its probably not related to valve lashing. Because it ran somewhat when it was totally off.
I was just thinking that if it was running fine, and now its not running at all, its probably not related to valve lashing. Because it ran somewhat when it was totally off.
Thread Starter
Registered User
Joined: Oct 2000
Posts: 460
From: orlando, fl
new opti on....runs fine when you press gas....wont idle....i remember when i built a carb motor...i didnt put on a carb gasket and would run fine as long as you give it gas...but would not idle...i didnt put on a new TB gasket, could this be a factor?
Registered User
Joined: Mar 2001
Posts: 2,521
From: Costa Mesa, CA
Ok, you need to describe everything in detail now.... From when you put the key in and first crank it until you stop trying to crank and even what happens when the motor is running.
When you are cranking the motor over is it even, or does it sounds like there are some weak cylinders in there? If it's uneven you may have collapsed lifters, bent pushrods, valvetrain damage etc.
Does the motor even try to fire when you are not pushing on the gas? If it does not fire at all or fires very little you may have something blocking the air trying to get into the motor.
When you get it started and your are giving it some gas to keep it running, does it run smooth or rough? If it runs smooth you may be ok if you can find out how to get it to idle. If not you might have messed something up.
Two last thoughts-
1) if you are using a throttle body airfoil TAKE IT OFF. My car would not idle after the heads/cam install with it on there. It blocks too much of the air entering the motor with the throttle blades closed.
2) this has been alluded to before but I'll say it again. If you put the cam in, and then tightened all the rockers at the same time WITHOUT rotating the engine then you probably just messed something up big time. The reason being some of the valves were supposed to be open when you tightened the rockers down, what you did if you tightened those was to basically double the lift on those valves. And trust me it will be more than one or two. Like has been said the valves could have hit the piston(because the valve traveled down twice as far as it should), you could have bent a pushrod from the extra stress of trying to push the valve down further etc.
John
When you are cranking the motor over is it even, or does it sounds like there are some weak cylinders in there? If it's uneven you may have collapsed lifters, bent pushrods, valvetrain damage etc.
Does the motor even try to fire when you are not pushing on the gas? If it does not fire at all or fires very little you may have something blocking the air trying to get into the motor.
When you get it started and your are giving it some gas to keep it running, does it run smooth or rough? If it runs smooth you may be ok if you can find out how to get it to idle. If not you might have messed something up.
Two last thoughts-
1) if you are using a throttle body airfoil TAKE IT OFF. My car would not idle after the heads/cam install with it on there. It blocks too much of the air entering the motor with the throttle blades closed.
2) this has been alluded to before but I'll say it again. If you put the cam in, and then tightened all the rockers at the same time WITHOUT rotating the engine then you probably just messed something up big time. The reason being some of the valves were supposed to be open when you tightened the rockers down, what you did if you tightened those was to basically double the lift on those valves. And trust me it will be more than one or two. Like has been said the valves could have hit the piston(because the valve traveled down twice as far as it should), you could have bent a pushrod from the extra stress of trying to push the valve down further etc.
John
Registered User
Joined: Sep 2002
Posts: 464
From: Orlando, FL
OK, here is what I know of the situation:
We need to set the valves again. We did them as correct as I could manage by guestimating when both pushrods were down (closed) and turning the crank 90 degrees at a time in the firing order. I still believe them to be slightly too tight, but we obviously suck at this valve lash thing. I've been told "R" lifters want to run very little past zero lash, so we are going to set the rockers with the motor running.
The motor runs ok, just won't idle, meaning, it wants to die out at idle. As far as I know when you give it a little gas, it runs like it should. Keep in mind this car as no programming and is running on stock manifolds. I think we can get the idle improved once we work out all the kinks and make sure we have no vacuum leaks anywhere (like the TB gasket we rigged) and so on. I believe the valves to be set slightly too tight, but not overly. We were fairly conservative when setting everything.
I do not believe we've done any nightmare scenarios like bent pushrods or bent valves or etc. I guess its possible that we might have collapsed a lifter or two, but I really highly doubt it. Guys, I'm not an idiot, its not like I just cranked down the nut until I was satisfied. With both valves closed, I went until the pushrod had resistance to being spun, and then a quarter turn. I did this as accurately as I could.
The whole reason it wouldn't fire before is because one of us (me) forgot to tighten down fully the left hand 3 water pump bolts, and the resulting deluge killed the Opti.
We need to set the valves again. We did them as correct as I could manage by guestimating when both pushrods were down (closed) and turning the crank 90 degrees at a time in the firing order. I still believe them to be slightly too tight, but we obviously suck at this valve lash thing. I've been told "R" lifters want to run very little past zero lash, so we are going to set the rockers with the motor running.
The motor runs ok, just won't idle, meaning, it wants to die out at idle. As far as I know when you give it a little gas, it runs like it should. Keep in mind this car as no programming and is running on stock manifolds. I think we can get the idle improved once we work out all the kinks and make sure we have no vacuum leaks anywhere (like the TB gasket we rigged) and so on. I believe the valves to be set slightly too tight, but not overly. We were fairly conservative when setting everything.
I do not believe we've done any nightmare scenarios like bent pushrods or bent valves or etc. I guess its possible that we might have collapsed a lifter or two, but I really highly doubt it. Guys, I'm not an idiot, its not like I just cranked down the nut until I was satisfied. With both valves closed, I went until the pushrod had resistance to being spun, and then a quarter turn. I did this as accurately as I could.
The whole reason it wouldn't fire before is because one of us (me) forgot to tighten down fully the left hand 3 water pump bolts, and the resulting deluge killed the Opti.
Last edited by TheHeadFL; Sep 29, 2003 at 11:43 PM.
Registered User
Joined: Sep 2002
Posts: 464
From: Orlando, FL
Originally posted by FastZinTennessee
2) this has been alluded to before but I'll say it again. If you put the cam in, and then tightened all the rockers at the same time WITHOUT rotating the engine then you probably just messed something up big time. The reason being some of the valves were supposed to be open when you tightened the rockers down, what you did if you tightened those was to basically double the lift on those valves. And trust me it will be more than one or two. Like has been said the valves could have hit the piston(because the valve traveled down twice as far as it should), you could have bent a pushrod from the extra stress of trying to push the valve down further etc.
John
2) this has been alluded to before but I'll say it again. If you put the cam in, and then tightened all the rockers at the same time WITHOUT rotating the engine then you probably just messed something up big time. The reason being some of the valves were supposed to be open when you tightened the rockers down, what you did if you tightened those was to basically double the lift on those valves. And trust me it will be more than one or two. Like has been said the valves could have hit the piston(because the valve traveled down twice as far as it should), you could have bent a pushrod from the extra stress of trying to push the valve down further etc.
John
Registered User
Joined: Sep 2002
Posts: 2,481
From: Arlington, VA
Originally posted by TheHeadFL
There is no way that those valves are opening TWICE the lift that was intended. I mean, at the *MOST* I am 1/4 or 1/2 turn past where I need to be. But even if you wrenched that nut all the way on there you're not doubling the lift. Additionally, people install cams a whole tooth off sometimes and don't crash valves into pistons. I watched all the valvesprings while I was helping him lash everything and none of them were at solid height (bind). Those springs will bind before they hit a piston I'd think.
There is no way that those valves are opening TWICE the lift that was intended. I mean, at the *MOST* I am 1/4 or 1/2 turn past where I need to be. But even if you wrenched that nut all the way on there you're not doubling the lift. Additionally, people install cams a whole tooth off sometimes and don't crash valves into pistons. I watched all the valvesprings while I was helping him lash everything and none of them were at solid height (bind). Those springs will bind before they hit a piston I'd think.
