Well after many post and lots of parts. I still have this tap that comes and goes as it pleases. Car had about 7k on it after the cam swap. The stock lifters started taping. I replaced them with ls7 lifters along with ls2 trays and had the heads freshened up. Measured for pushrod length and came up with 7.350. I poured a bottle of Lucas engine break in with the zinc in it and that seems to have helped more than anything. I have tryed preloads on the lifters from 63 which is where it is now all the way to .100. The lifters are very noisy but sometimes one just starts taping very loud then goes away. Does it most between 1500 rpm-2000 rpm. Stops if I let it idle for a few minutes.

After much research the only thing that's the same on all the ones doing it are the ls7 lifters. I got them from texasspeed . They came in ac delco boxes They are the noisiest set of lifters I ever heard. An oldtymer was askin if I had a solid cam in it.

The machine shop says it cam bearing issue causing an oiling problem to the lifters? Anyone have a opinion on that . Car has 79k on it 10k with the eps cam.

At this point I'm ready to pull all this crap out again.

Here's a video of it when it first started.

 

Did you install the lifters or a shop?

That is a really loud tap, almost sounds like an exhaust leak. I know when I installed my LS7 lifters, I soaked them in oil (With Mobil 1 until all the air bubbles surfaced) prior to installing them.

Hopefully someone will chime in and offer a solution. I would think a cam bearing would cause your pressure reading on the dash to seem lower than normal.

Good luck!

 

I am a shop. Lol. I also soaked them. That was when the noise started on ls1 factory lifters. I have more videos of it. But just in gerneral the lifters are noisy and I can drive it all day and all of a sudden it gets loud. Just one single tap. One second it sounds like its coming from the drivers front. Then Tomarrow it sounds like the passenger in the middle. Idk wtf. It's driving me nuts.

 

Lol, that would drive me crazy as well man.

Like I said hopefully someone who has had this issue will share some insight. I know these valvetrain's make some noise, but damn, I would lose my mind listening to that.

 

Yea. Like I said. Sometimes it's normal( still noisy). Then outta no where tap tap tap. The let it idle and it slowly quiets back down. Might do it in two minutes. Might do it two days from now idk wtf.

 

Here's the car this morning when I pulled up to work.
Here it is now as I speak.

The machine shop is sticking to cam bearing problem. I'm thinking I got a crap set of lifters that are no better than the first set. WTF. Any opinions on the subject

 

that "machine shop" is wrong because the only thing that gets oil after the cam bearings is the crank and rod bearings. The lifters get oil in parallel with the cam bearings.

I'm running "LS7" lifters from TSP set at 0.045" preload and they are quiet as church mice. I don't think that's your problem unless you have a defective lifter.

What rockers are you running? have you checked rocker bearings and pushords? you may have a bent pushrod or a rocker that spit out some bearings.

is your shortblock stock?

 

Stock shortblock. Milled 241 .015. Stock rockers with comp trunion upgrade. I've tryed every thing from 7.350 which is about .060 preload to 7.425. The length changes the way the noise sounds but doesn't make it stop. The cam and springs are in my sig. The 7.350 pushrods are less than a week old. The noise was their before I changed them.

Thanks for pointing that out about the machine shop. I had a feeling they were BSin me Just dident sound right. At this point I'm thinking lifters I got are just garbage. I may just go with some good link bars this time around and might go with a stouter cam . Time to save some coin. Lol

 

i work for a performance shop as well, ive read a lot regarding LS7 lifters and such and have read/heard tapping/tick/sewing machine described noises coming from factory lifters. others may say they are fine. the reason we hear a lot about it is because LS7 lifters are a common "upgrade" but in my strong opionion and im pulling this right out of this forum, that LS7 lifters are a factory lifter designed for factory cams/engines. i agree that going with a link bar style lifter is really the way to go.

 

Are you sure you don't have some air getting into the oil at oring on the pump? A small amount of air will do the same thing and you will chase your tail looking for bad lifters. I've run into this many times on LS1 engines with low miles that sat alot, oring shrinks from sitting and the lifters will tap. Then it will go away then come back etc. I've had good results using a few qts of high mileage oil to swell the oring back to size.

I found that every engine that tapped at idle would tap less or have it stop tapping as I raised the rpms building oil pressure higher forcing the air out of the lifters. Sometimes I had to let the engine idle for quite a while to get a lifter to quiet down. But this would happen over and over till you just can't figure out what the hell is going on.

Every LS1 I worked on that had lifter tap that would tap then stop then tap again over and over the high mileage oil stopped the problem by swelling the oring. Its not going to fix a ripped oring or damaged oring. I just throwing this out there because its very common and over looked alot.

Another thing to look for is a oil pressure gauge that jumps around a bit.

The bird brain engineer that put that oring in that position was looking for warranty work. Its the worst design application using a oring I've ever seen. It should be a metal to metal contact connection or at least some type of seal with some room for misalignment.

I'll bet that oring is responsible for most ALL LS1 bearing and lifter failures! Even a small amount of air in the oil will ruin bearings quickly under high loads. Start spinning the cam at high rpm with air in the lifters and you will have broken lifters FAST. If I was building a fresh LS1 that connection would be brazed!

 

I will look into the oring as soon I as get the chance. Hell. I may even buy a new oil pump this time around. Thanks for the info. Any more suggestions. I'm all ears at this point.

 

My lifters are only set at about .020" preload (1/4 turn) and are pretty quiet...some like less, some like more.

 

I could not agree with you more. OP if it was me I would spend the extra cash and get some 5206 Morel lifters. It would be money well spent.

 

Which oil pump would you guys get for a mostly street driven car? It might see the track every now and then. Not to often though. I'm gonna tear it down next week and check this oring out. Might as well replace the pump. I also have a new ls2 chain to throw on it.

 

maybe the LS6 ported oil pump, but i personally went with the melling high volume oil pump. mine will be street driven

 

Update


I finally got to pull it down. The oil pump oring was hard. Smaller than it should be and cracked I'm starting to see the light. Next day or two it should be back together and ill know for sure.

 

Just a thought when i rebuilt my engine, I went with all new ls7 lifters and had the exact same sound on my first start up. Called the machine shop who helped me build the motor and they told me it sounds like one of the lifters did not pump up. So i pulled the valve covers and pushed down on the rocker towards the lifter, they all seemed fine except one I was able to push down.

I was able to locate a single ls7 lifter local and the next day i pulled the head and changed it, fired it up and it the noise was gone. Pulling the valve covers to check is a pretty easy job so it may be worth a try.

 

I hear ya.

I did the cam swap at 65k. I dident change lifters or pull the oil pump. The car sat in the driveway for about 3-4 years. After the cam swap about 8 k later I have this noise that comes and goes. Like a lifter that looses its prime after I only rev up above 1500rpm. If I keep it lower it doesn't make it. So I changed lifters and all kinda stuff to have the same problem. I never did really find anything wrong with any of the parts I changed on the car. This is the first thing I have found wrong yet. I will post up results after I get her back together to see if it has quieted up. I've been chasing this noise a long time so we will see shortly.

 

Oil might make a difference too. Tolerances on oe lifters are awful and a thicker oil may help the tapper...of course it could make the others worse.

The suggestion above about pulling the cover is a good one. Just pull up on the nose of any rocker that isnt pushing down a valve. Rotate the motor and repeat on the rest. A bad check valve or collapsed lifter will be soft and or show daylight.

Btw soaking can cause roblems with setting preload. Thick cold oil in a good lifter will leak slowly and can make you think you have less preload than you actually do.

 

Best advice I have been give yet.