Alright posted this question before and got zero response so ill keep it shorter and dumb it down this time.

Did timing belt job on car, found that cam timing was off by a tooth. Finished belt install and ensured mechanical timing was correct and back in time. When started lifters sounded like they were going to come out of the valvecover. Before doing tbelt valvetrain was quiet as a mouse and car previously made 360+ and was not in time. Used the cam gears to adjust timing back close to where it was before belt service and valvetrain shut up and went back to normal.

I had a few other things happen as well that was expected when setting the timing back to tdc like vacuum change and a shift in the power band, as well as a significant jump in compression but how does timing effect lifter noise? Just trying to figure it out since neither I nor the mechanic would have thought this to be possible beforehand.

 

I am sure the noise is just from NOT having all the lifters primed.

 

^+1

How long was the car down for and did you swap your cams? I've gone through a couple sets of cams now in my car and the first start always sounds awful until oil pressure builds up in the lifters then all is well.

I doubt being off a degree would add or have any effect on valvetrain noise. As long as the valves didnt hit I don't see how it could make much of a difference in sound...

 

This is not a what caused this sound thread this is a why does cam timing change lifter noise.

It in fact does, at least on my car, change the sound of the lifters when changing cam timing.

It has nothing to do with how long the car was down since it took 5hrs or so to swap timing belts and balance shaft belts. Cams were not removed during the process.

Car was originally off a tooth from jumping time or being timed incorrrctly previous to me owning it. Ran fine and even made 360/357. When timing was done it was put back into correct mechanical time and all of the sudden it had tons of lifter tick. After verifying timing was correct 4 times we decided to set the cam timing back close to where it was using the adjustable cam gears (whereas before belt job the timing was off on the teeth). When we set the timing back close to what it was before lifter noise disappeared.

Nothing else changed and car was down for no more than half a day ehile doing the belt. No cam change or removal and yes changing the cam timing changed the lifter sound... my question is how and why.

 

valves tipping pistons

 

Ya valves hitting pistons at tdc when its in time making noise but when we adjusted cams back out of time to how it was before valves dont hit pistons ...makes sense.... smgdh read before posting or dont post bs at all.

 

you obviously havnt a clue what your doing

 

sure i do. you must have zero knowledge of how a motor works. please enlighten us all on how valves can "tip" the pistons when the motor is in mechanical timing and the cam gears zeroed out.... but when we throw the cam timing off by adjusting the cam gears out the noise (or you say valves hitting pistons) stops. please explain how everyone whos cars is in time how their valves are hitting the pistons, because thats what your saying. If you read the post it says noise WHEN CAR IS IN TIME (lifters ticking) NO NOISE WHEN TIMING IS THROWN OFF A FEW DEGREES.

ill be waiting for your brilliant answer to how my valves are hitting my pistons with the timing dead nuts on and verified 4 times.

 

Do you have stock cams? Some cams are so far off that the cam timing has to be adjusted for proper valve clearance. If they were off you may have a 4G64 block which requires the gears to be off if using standard cam gears even with perfect cams. The noise could be the valves tapping the pistons. I hope that is not the case for you.

 

sounds like dead nuts on alright

 

The cams in the car are hks 272's. when the timing marks are at zero on the cam gears, their is a significant amount of compression gained in the motor. around 25 psi i think it was. The mechanic that did the work has been around 4g63's for years him and his brother both have had 800+ hp 4g63 that they have built themselves, so TIMING IS DEAD NUTS ON since i seen with my two eyes, and he double checked his own work about 4 times. and took pics to verify and show me, and then showed me in person when i picked the car up.

if your trolling get the hell out of my thread if you have no decent input.

I wouldnt think it has a 4g64 block in the car. The previous owner never mentioned any of the sort, and i have every receipt for any work done, and would think that my mechanic would have known. Im also quite sure the hks cams are pretty close to spot on, and do not think that a 4g63 tensioner is the same as a 64 but could be wrong on that.

the only explanation my mechanic offered as it baffled him as well, is that the dynamic force of the combustion is travelling through the valves, into the rockers, and making the lifters louder. he explained that maybe the bump in compression when zeroed out is causing more force to be exerted. I did not believe this, and am still skeptical but its all i have to go on because i have verified timing, and like ive stated 40 times now when the cam gears are set at zero the only difference is super loud ticking (lifters because if valves were hitting it would either a. bend them or b. beat holes in the pistons and not run properly. i may also add i recently changed plugs and looked down into the cylinders and seen NO MARKS on piston tops), a pretty decent change in idle vacuum (expected since one cam is -4) went from about -12 to -5, and a loss in low end power (not a drastic loss but noticeable, and also expected since changing cam timing moves the powerband).

His "Theory" is that when we throw cam timing off the drop in compression lessens the force during combustion leading to much quieter lifters.

I guess the only way to know for sure since no one has an explanation besides my valves are smacking the pistons ( which the car wouldnt run as long as it did that night) is to buy a set of zero tick lifters and install them and zero the cam gears back out and see if the problem goes away.

 

I have the issue as well... ever since I had my engine built I have had a weird lifter tick... it was worse with E85 (due to increased timing). If I let the car warm up for 10 minutes or longer there is very little lifter tick. The tick is present only from 2500-3200 rpm, and can be modulated with throttle input. I have had this issue for the past 5 years, and I have also swapped heads on the car, with completely different head components... still no change... stock lifters, GSC zero ticks, ITMs nothing has changed the issue at all... Kiggly HLA vs stock yielded no change either... I have been baffled by this because I don't know what is causing it and I can't get rid of it... Lowering the timing value in the rom will curtail the issue as awdwordie as mentioned, but at the sacrifice of fuel economy and peppiness in traffic... Before you all assume... I have a 4G64 with stock head and GSC S2s and springs and I use an OEM timing belt, and timing is correct... but man the noise drives me absolutely crazy!

 

I havent touched my rom at all with this issue. My issue is when i adjust the cam gears physically. by taking them and having them both set at tdc and 0,0 i have lifter noise like crazy. but by adjusting them out to anything else besides 0,0 the noise goes away.

 

FWIW, When I was testing out cam timing on my car, I noticed huge differences on the mechanical noise registered by the knock sensor from 2500-3500 RPM under low boost load with only a couple degrees of cam change.

I also noticed a lot of it could be gotten rid of by INCREASING timing advance.

I never heard the difference though, just saw it in the data.

 

1. What valve springs are in the car?
2. Its possible you have a 4g64 block.
3. If the head has been shaved before, that can also be a reason. If you take a significant amount of material off of the head, you have to change cam timing to adjust for the difference in space between the head/ block. It would no longer be able to be set at factory timing