Pumped up valve lifters. Valves will not seat properly

[Wizard]

I had my machine shop replace all my intake valves and got the head back and noticed all the intake valves were not properly seated when all the valvetrain was properly torqued in place. The lifters are pumped up as I previously had the car running before I took head off. There is about a 2mm gap and you can see light coming through where valve should be seated with a flashlight. I took off the valvetrain and removed the lifters and all the valves seat tight like they should when valve is closed. I poured some gas in on the closed valves and confirmed there is no leakage. I put valvetrain and lifters back on head and same thing happens. Lifters pushing valve down to far and opening valve. I kept rotating cam for several days hoping lifters would bleed down as a few mechanics and machinest said they would but it has not happened. I now have head on car and have no compression when trying to start it.

What to do? Should I take lifters out and compress each in a vice to squeeze oil out?

 

Thanks,

 

Wizard

[shoquest2007]

you need to try to bleed the lifters manually. take the lifters back out and there is a little hole you can put like a small paper clip in and press the lifter closed, when the oil pressure his them they will pump themselves back up. If that doesnt work, you can replace them, you can get them from a member on the board "DAD" aka Randy.

[Dad]

you need to try to bleed the lifters manually. take the lifters back out and there is a little hole you can put like a small paper clip in and press the lifter closed, when the oil pressure his them they will pump themselves back up. If that doesnt work, you can replace them, you can get them from a member on the board "DAD" aka Randy.

 

 

 

\Just what he said, the clip will press and relieve the pressure. Did the put the same length valves back in? Did they check the stem height? tip of valve to spring seat? Course you say the lifters are pumped up so I would assume they just need bled off.

 

Dad

[Wizard]

Thanks, I'll give it a try. Is this little hole on the side of lifter or up in through the big hole where oil goes in from the rocker?

 

Wizard

[Dad]

Thanks, I'll give it a try. Is this little hole on the side of lifter or up in through the big hole where oil goes in from the rocker?

 

Wizard

 

 

The big hole.

 

Dad

[Wizard]

Well, I pulled out all the lifters and bleed them. They were pumped up and got oil out of all of them with a paper clip and can now squeeze them to make them smaller. I put them all back in car, torqued valve train to correct torque, hooked up compression gage to spark plug hole and still have no compression. I tried cyclinder 1,3,and 4 with compression gage while turning over car and still no compression at all. What now? Is it possible I bent more valves again with the pumped up lifters as I first turned over car and pushed valves into pistons? When I had the head off and first noticed valves were not seated completely, I would say you could slip maybe 2 pieces of paper thickness through the valve when it was supposed to be completely closed and not on a cam lobe. About 2-3mm gap or could just see a flashlight through gap. Could this be enough for pumped up lifters to extend the valve to far down and damage valves on pistons? I don't have a pressure tester so can't blow air into cylinder to see where it is leaking. Probably by Tuesday I can get one. I did take out lifters again to start to bleed them again but don't seem to be getting anymore oil out of them and unable to get them any smaller. Possible bad new headgasket that didn't seal right?

 

Wizard

[Tim_C.]

No, the valves are not bent. You need a very high lift, wide duration roller cam grind before you run into that problem on these engines.

Well, I would say your compression tester checkvalve is defective (very common on compression testers), or the cam is not timed correctly. It is entirely possible too that the head was not set up properly as Dad eluded to above. Whenever work is performed on any hydraulic head, there is a chance the set up won't work unless other steps are also taken. If they sunk the valves too far into the seats, then the top of the valve can stick out too far and cause your problem. However that isn't so common on these heads as they are set up a little too loose from the factory for me anyway. The valve seats can be cut quite a bit before the valve will stick out too far up top. In other words, the factory lifter proload, when the rocker is positioned on the backside of the cam lobe, makes for about .015 of travel into the lifter, just barely preloading it. Full lifter travel is usually around .125 or so, depending on who made the lifter and when. Around .085 is about as much preload you can have and be safe without worrying that a problem like you are having will occur.

 

How does that help you now? Well, it doesn't really. What you need to do is loosen the rocker shafts and measure the spring height when you know the valve is completely closed. Tighten the rocker assembly again and measure again to confirm the valve is not closing all the way.

 

Plus, if you just put the head on with 'squishy' lifters, and it has not run so the oil pressure can pump it up, then the compression test may not be very accurate, but you will get much more than zero. You should see at least 100 PSI on it.

 

What you must confirm is if the valve is closing when the lifter is squishy where you can depress it by hand. If the valve will not close, then the head is not properly set up and it needs more work. Maybe new seats, or shave the valve tip, but I don't think you can shave much more than .030 off of the valve without shaving through the hardening. Maybe less. Dad knows that spec. I forget because I don't do it regularly.

 

Another option if you determine the valves will not close with the lifters un-pumped, is to try a performance camshaft with a reduced base circle. This may loosen it up enough to allow the valves to close.

 

If you determine the valves are closing when the rocker assembly is on, then you need to figure out what is going on elsewhere to cause the problem. Just make sure you check the cam is timed correctly.

[BC_99]

I ran into this problem awhile back on my head on the exhaust side. The seats seemed to be pressed into the head just a touch to far on a couple of the cylinders. I had to take the head back off and send it to Brian at Lower shores performance, and he fixed it up for me. I think he ground the valve tips down just a bit. Are your valve springs new? maybe weak? Just a thought, Good luck with it, as I know how frustrating this problem can be.

 

BC_99

[Wizard]

This engine was running and had 145-150 psi pere cyl hole before I took the head off. I checked the compression gage last night as that was the first and simplest thing I thought it may be broken but it works fine and holds air from a air hose. Gage is also new. All that was done to the head since it was taken off was 4 new intake valves installed. Everything on the head, springs, seals, you name it is new except for stock cam that is in it. I had my machinest come over before we pulled the head and made a degree wheel and checked for correct cam timing. It was right on and only off 1 degree. I marked it with a scribe before I took off cam chain. Cam pin is at TDC is at 11:58 to 12:00 o'clock position.

Going down to look at it again to see if something obvious is set up wrong.

 

Wizard

[Wizard]

I took the valvetrain pressure off the cam and lifters so there was nothing touching valve tips. I hooked up my compression gage to #1 cyl and hand turned the crank around once and achieved about 20lbs of compression on the compression gage. This I guess eliminates head gasket problems and questions if valves are bent or bad seating problems. Points more towards valve seating problems with lifters in. I then put the valvetrain back on except left out #1 intake lifter. Rotated the crank twice by hand and noticed the #1 intake rocker was still pushing down and compressed the spring around the valve. I did not achieve any compression. Wanted to see if it was the exhaust valve causing the problem.

My machinest did not touch any of the exhaust valves when he put in the 4 new intake valves. My question is there anything in height difference that could have changed when he took out the bent intake valves and installed new ones? Valves were exact ones I had in previously from DAD. He did no cutting or grinding on valve seats when machinest took out bent valves and put in new ones. Machinest said he just took out old and put in new. Is there some way the valves have to be set to a certain height or do they just pop in and you snap on the retainers like they were previously and good to go?

 

Wizard

[Dad]

I took the valvetrain pressure off the cam and lifters so there was nothing touching valve tips. I hooked up my compression gage to #1 cyl and hand turned the crank around once and achieved about 20lbs of compression on the compression gage. This I guess eliminates head gasket problems and questions if valves are bent or bad seating problems. Points more towards valve seating problems with lifters in. I then put the valvetrain back on except left out #1 intake lifter. Rotated the crank twice by hand and noticed the #1 intake rocker was still pushing down and compressed the spring around the valve. I did not achieve any compression. Wanted to see if it was the exhaust valve causing the problem.

My machinest did not touch any of the exhaust valves when he put in the 4 new intake valves. My question is there anything in height difference that could have changed when he took out the bent intake valves and installed new ones? Valves were exact ones I had in previously from DAD. He did no cutting or grinding on valve seats when machinest took out bent valves and put in new ones. Machinest said he just took out old and put in new. Is there some way the valves have to be set to a certain height or do they just pop in and you snap on the retainers like they were previously and good to go?

 

Wizard

First off you need to check with himto see if he checked them for seating EG, vacuum test, just because he swapped the valves does not meen that he doesn't have to touch the seats. I have even seen new valves out of the box that don't quite seat right and need to be touched up in the valve grinder.

Second he should have checked the installed stem height and correct it if needed. tip of valve to spring seat area of head with spring seat removed. Intake is 1.690-1.710 and exhaust- just if you want to check- 1.680-1.700. I have also seen valves get bent if the timing of the cam is off.

 

Dad

[Wizard]

First off you need to check with himto see if he checked them for seating EG, vacuum test, just because he swapped the valves does not meen that he doesn't have to touch the seats. I have even seen new valves out of the box that don't quite seat right and need to be touched up in the valve grinder.

 

I took off the valvetrain and removed the lifters and all the valves seat tight like they should when valve is closed. I poured some gas in on the closed valves and confirmed there is no leakage.

 

 

 

Second he should have checked the installed stem height and correct it if needed. tip of valve to spring seat area of head with spring seat removed. Intake is 1.690-1.710 and exhaust- just if you want to check- 1.680-1.700. I have also seen valves get bent if the timing of the cam is off.

 

 

I had my machinest come over before we pulled the head and made a degree wheel and checked for correct cam timing. It was right on and only off 1 degree. I marked it with a scribe before I took off cam chain. Cam pin is at TDC is at 11:58 to 12:00 o'clock position and #1 cycl intake and exhaust rockers is not riding on the cam lobe. It is on the round part of cam where both intake and exhaust valves would be closed.

 

Dad

[JAinsworth]

Machinest said he just took out old and put in new. Is there some way the valves have to be set to a certain height or do they just pop in and you snap on the retainers like they were previously and good to go?

 

Wizard

 

Second he should have checked the installed stem height and correct it if needed. tip of valve to spring seat area of head with spring seat removed. Intake is 1.690-1.710 and exhaust- just if you want to check- 1.680-1.700. I have also seen valves get bent if the timing of the cam is off.

 

Dad

 

I'm guessing this is the step the machinist missed.

Jimmy

[Wizard]

Don't know. Did not specifically ask him if he measured everything before he took out bent valves and installed new ones with correct measurement. Says he definately did not grind the seats at all. If you don't grind on the seats is there any other way to adjust the valve height when you put in the new valve? I thought they just go in and you put the locks on them and thats it? No other different parts were used in this valve replacement. Just replaced with same type of valve from DADS that I had in previously.

 

Wizard

[JAinsworth]

They need to be measured as Dad said and ground if necessary. They aren't mechanical, they're hydraulic...they will pump up the same regardless of the stem length. The stem length is like the adjustment you could do with mechanical lifters to a point, they must be measured and ground to work properly. If this step was skipped, they may be bent again.

Jimmy

[Dad]

Are you running a stock hydraulic valve train? not roller rockers? Stock valves not 1mm OS?

Dad

[Wizard]

Running stock cam, stock rockers, and new schneider springs and new hydraulic lifters I bought from Dad. Bought 1mm oversize valves from DaD and everything was set up correctly and car ran before I pulled head off again. Motor complete rebuild from oil pan nut to valve cover. Please read previous threads. Valves in #1 can't be bent cause I got 20lbs compression hand cranking with no valve train pressure on cam.

 

Can't get a leak down tester on it till late Tuesday night.

 

Wizard

Edited November 29, 2009 by Wizard

[Dad]

Running stock cam, stock rockers, and new schneider springs and new hydraulic lifters I bought from Dad. Bought 1mm oversize valves from DaD and everything was set up correctly and car ran before I pulled head off again. Motor complete rebuild from oil pan nut to valve cover. Please read previous threads. Valves in #1 can't be bent cause I got 20lbs compression hand cranking with no valve train pressure on cam.

 

Can't get a leak down tester on it till late Tuesday night.

 

Wizard

 

Ok, so you put 1MM OS valves in, did they replace stock size valves or where there already 1mm valves in the head?

I suspect the valve height is off.

 

Dad

[Indiana]

The OS valves won't just go in and work correctly unless the seats are ground out. You might be able to get the motor to run if you just put them in and do nothing but there would be no point in doing that. If that is what you did then the valves aren't coming up as far as they should not that they are coming up too far. Why did they get bent?

 

You can't get any compression at all with the rocker assembly loosened up and you crank the motor, there is no air being sucked in to compress it only compresses what is in there when you loosen the rockers and let the valves all close.

 

It sounds more like your cam timing is just way off and that's also how you can bend valves. Forged pistons can bend valves much easier than stock pistons because of the shape of the piston and the smaller dish, if that's what you got.

 

Get the crank to TDC, get the cam dowel to the top, ignore those plated links on the chain, get the cam gear so that a line extended from the cam gear bolt to the dowel doesn't go past a line that runs from the valve cover bolt holes extended out to the cam gear. If the cam gear goes past the valve cover you are off but if you have a head that was cut down and a block that was cut down it might be even or if cut alot than it might be just past but for stock decks that cam line won't go past the top.

 

The lifters after you bled them down, you put them back in to the rocker arms and after you tighten the bolts down you should be able to mash on the rocker arm end and squish the lifters. After you crank the motor over and oil is pumped they are tight again but should be in the correct length to work. If you did that and then later moved the cam gear around well maybe they need bled again.

 

With the crank mark at TDC you can loosen the rockers and put compressed air into cylinder 2 and 3 since those are at the bottom and listen for a major leak but you will hear air leaking as rings do not seal completely. Turn the crank again so the TDC mark is at the bottom then check 1 and 4.

 

What did you do to prep the head and block surfaces before you put this back together? Did you remove completely all traces of old gasket? If not that might be your problem.

[Wizard]

I talked to my machinest today. I asked him what he did before he removed the bent intake valves. He said he measured the stem height of valves before he took them out. He said the exhaust valves were not bent. Then he removed the bent 1mm oversize intake valves and replaced with exact same new 1 mm oversize valves I bought from Dad. He then remeasured stem height and it was exact height before he took out bent valves. And he states no grinding was done by him when he did replacement. I have known this machinest for 3 years and have lots of other work done by him on other motors and so has many racers around here. Machinest is top notch and I have never had a problem with him. Like I say PLEASE READ PREVIOUS POSTS BY ME ON THIS THREAD. I will say it again what this motor has had done to it. Rebuilt less than a year ago. Ran the motor for 1,000 miles with a TEP cam in it. I started playing with the cam timing after the 1,000 miles because it just did not sound right and other people said it sounded like it was not running right either. In another thread on this board we tested everything possible and came down to where I am today and why I bent 4 intake valves. I was "shotgunning" by advancing the cam and swapping cams to get the cam timing right by one tooth at a time. I did not degree the cam when I rebuilt the motor last year on the engine stand. I put the TEP cam with the cam pin in the 12'oclock position. Yes, I should not have been doing this without using a degree wheel. Lets just say lesson learned and then I finally had my machinest come over and I put in the stock hydraulic cam and we made a degree wheel with motor in car and it was only 1 degree off. But the damage was already done cause we could not get it to even fire. We did compression test and no compression. I bent the valves previously with messing around with cam timing. So within almost a month now I had a running car which pulled strong but would idle crappy and miss once in awhile while going thru the gears to now the same head that I can't get the same valves to seal up. This head was sent to Jonboy down in Georgia and some work was done on it when motor was initially rebuilt and I ran it as previously stated for 1,000 miles. New 1mm oversize valves were sent to JonBoy and he vac tested everything when he was done. So, like I say before after my machinest put the new 1mm oversize valves in and I noticed they were not fully seated I took off the valvetrain pressure, valves seated nicely, I then poured gas onto top of valve and no leaks were noticed on all 4. This leaves me and machinest saying it must be lifters or base circle on stock cam is thicker than TEP cam and is pushing rockers down harder on valve tips which is holding valves open. I did notice that with the stock cam in there now and valvetrain torqued down I cannot push down on tip of rocker and squish the lifter any or even move the rocker end that is riding on cam. It is very tight and no movement. With the TEP cam I can move the rockers around and it is looser due to smaller base circle on cam. I haven't looked at my sales receipts yet but I ordered new lifters when I rebuilt this motor. I bought them from Dad. There is only stock lifters right? No other high performance lifters or any other longer size hydraulic lifters out there right? Was thinking maybe I bought high performance for my TEP cam and now that I went back to stock cam I have the wrong lifters in it. These are the only 2 things left my machinest and I can think of that is causing this problem.

 

Fatter base circle on stock conquest hydraulic cam

Have other than stock hydraulic lifter or I need another set of hydraulic lifters due to can't get them to pump

down enough

 

I am temted to put the TEP cam back in, degree it with the wheel and stay with that. I don't really want to do this though.

 

I did prove that I don't have bent valves again as I said in previous posts I achieved 20lbs of compression on cyl#1 so these are the only 2 things left that we can see why this is happening. What do you think?

 

Wizard

[Indiana]

It would have helped if you said OS valves were in before and you were playing with cam timing.

 

This cam gear you have, is it adjustable? If it IS, you can do nothing by using that dowel pin hole and assume where ever the hub is will be correct or even close to it so even just installing it you better be very careful even that first turn of the crank might bend valves.

 

Reground cams have a lower base circle that is the usual way of doing that and are usually mechanical because there simply isn't enough length in the lifters to take up the difference depending on how it is ground AND more important that dowel pin hole is now FUBAR and can't be used again without using a degree wheel. Combine that will cut down block/head and its all a mess and YES you can easily bend valves and you found that out and no you should have never ever did what you did by trying to "listen" for anything that just can't be done what sounds good may run like crap or pull at the bottom and be a whimp up top and that cam you paid for was ground specifically for a set centerline not one you play with, if you play with it you might as well just play with a stock cam its all screwed up. People in this case would have to use longer valves using reground hydraulic cams, the 83-84 valves and their retainers and locks to keep the hydraulic rockers.

 

So you put the gear on, used the stock cam and it was barely off? That tells me your block/head have no work been down to them or VERY little. If this is with the TEP cam that tells me you are off at least one tooth and it just appears you are off only 1 degree but if you setup the plated links again I think you would see that you are off. If you are using an adj. cam gear there is no way in hell to know without using a degree wheel. Its ok because one tooth is about 10 degrees and you may been off that much or more who knows.

 

Point is what do you do now. Depends on if that cam gear is adj. and which cam you use. 107 is the stock cam centerline for the intake, completely forget about looking at the exhaust. If you have NEW rocker shafts and arms or very good ones, lash will be near zero as in not even .001 and that's the first thing to do is set the lash to get the intake duration as advertised for that cam then you can go to what appears to be the highest lift then go back down at least .050 on your dial on either side to find the center in the middle of those two points, you adj. to that THEN double check by looking at the open and close degrees and they better match the advertised numbers exactly off the same if you can't get to within 1 degree on the centerline or you screwed up and are off or the cam card is wrong. To begin you first have to find true TDC and even though that timing mark on the timing cover is there when you put a wheel on it and if its just 1 degree off, and you can not tell if you tried to without using a dial indicator then you are wasting your time you are not be thorough.

 

Since it won't start might I suggest your distributor has been put back in wrong and is likely a half turn off. To verify, turn the crank to tdc and the cam dowel at the top now pull the dist. cap and the rotor tip must be pointing to #1 plug wire tower or you are off and need to restab it or move the plug wires so they are right, which will later just confuse you lol so do that right. You plug the distributor back in to the harness? Hint, while you have the dist. out, leave it plugged in and turn the ignition key "on", now SPIN the dist. drive gear. You should hear the coil fire and ah, do that with all the coil wire removed from the coil or at least place the dist. end of the coil wire on the negative battery cable AND it will also fire your primary injector as you spin the dist. because the ECU now is thinking that the engine is running and you are that engine and it just fires the coil based on how you turn the dist. and same for firing the injector.

[Dad]

There is only one lifter for the car. I still suspect the valves are too high. the spec is.... Intake is 1.690-1.710 and exhaust- - 1.680-1.700. is that what he read the second time?

 

Think about this, if the valve head is bent then the stem height of the valve will not be correct, in fact it will be shorter, The more severe the bend the shorter the reading, so just going by what it read before dissassembly does not mean it's what it's supposed to be.

 

Dad

[Dad]

Any chance they sunk the valves knowing that you had a reground camshaft?

 

Dad

[Wizard]

I will try to take a measurement of valve stem height and put this problem to rest.

 

Wizard

[Wizard]

I just got done measuring the valve stem height. I meausured it with a mechainical dial caliper. Meausured from top stem of valve to bottom of spring washer that sits on the head. Came up with Intake- 1.695 and exhaust was 1.698 meausred all of them and they all varied around .001 to .003 difference. They were all within spec though. I also pulled the stock cam out again and checked the back end of it for the 3rd time. It had the "A" stamped into the end of it. So, what gives? A manufacture flaw somewhere in the cam where the center round is to thick? I don't know. I do know when I button the valvetrain down to the correct torque of 15 ftlbs everything is tight and absolutely no movement or wiggle of any of the rockers or squish of the lifters can be done.

I beleive I am going to get myself a set of mechanical rockers and be done with this problem cause I'm out of ideas. Does this mean I have to get a different stock cam if I go this route? Do I have to get rid of the hydraulic cam?

 

Wizard