Ok I have looked at everything I could possible get at to find where this tapping noise is coming. I need your guys help on giving me some ideas on what to try to figure where this tapping noise is coming from. I will detail my mods and what I have done to figure where the tapping is coming from, so let’s begin.

I have a 99 Vette LS1 with the following mods.

LG G5X3 cam
Launati Lifters (supposed to be Morel, I paid big bucks for them)
Patriot P LS6 heads
Comp 7.050 pushrods
Patriot P shaft roller rockers ( adjustable)
Comp 918 springs (had the PP gold springs but they made the valvetrain noise much louder so I went with the 918's)
New Jwise timing chain
New ported LS6 oil pump

I notched the piston on the intake and exhaust side. At first I had only notched the intake side since that’s what LG said only needed to be done. But after running the car for its first time since the upgrades I was getting very loud valvetrain noise the sewing machine noise not the tapping. So I pulled it all back apart and noticed the exhaust valves had nicked the pistons only on passenger side. None of the valves were bent but went ahead and replaced them while I had the heads off. Really didn’t nic the pistons that much ever so little. I then notched the exhaust side and clayed after this to be sure all was good and it was.

I had low oil pressure after the upgrade and went back and changed out the new o-ring with another new o-ring just wanted to be sure it wasn’t the cause of the low PSI and tapping noise. I also shimmed the pump spring to give me more pressure

I put everything back together and started it up and than had the tapping noise, tap tap tap. But the oil pressure was good.

I than pulled it all apart again to go through each part to inspect for abnormal wear. I broke down each lifter to clean and inspect no signs of any abnormal wear everything looked good. The pushrods had some where marks around them so I put them in a drill to determine if they were bent, and they wabbled a little bit so that seemed kind of odd. So I had an extra new pushrod and put it in the drill and it also wabbled a little just like the others. So this couldn’t be the problem. Should I have any wear marks down the shaft of the pushrod? The pushrod spins so it looks like a wear mark all the way around the shaft and couple have wear marks on a single side of the shaft.

Rocker arms look good bearings feel smooth. Any known issues with PP shaft rollers making tapping noises?

It can’t be a bearing since it taps only at a certain spot in the rotation of the engine.

Please give some ideas things to try to determine the source of the tapping. Looking for something that I won’t have to pull the heads I had them off 3 times already and don’t want to do it again.

Thanks,

 

Maybe a rocker not adjusted properly?

 

I have tried a .30 preload to a .45 preload still have the tapping.

 

How long have you actually run the motor? I spoke to Chris Straub about the Morels and he told me it will take about 20 minutes for them to pump up since they have a heat sensitive grease internally when they ship and the grease needs to heat up and flow out then the ball check needs to seat. If you haven't run it that long, and your oil pressure is good, you might want to just let it idle for a while. Shoot Chris a PM if this sounds like your issue, he can explain it better than I can.

 

Its been ran probably a combined total of 2 hours. Start stoping the motor, running it around the block. Should been plenty of time. Also I have taken each lifter apart and cleaned them, thinking same thing about the lube they use at factory.

 

Could it be that your pushrods are too short? 7.050 seems really short compared to the stock 7.400.

 

The Patriot shaft rockers change the needed length up a lot. They require shorter pushrods and you also have to elongate the pushrod hole in the heads.

 

I bought me one of those automotive stethoscope, going to have someone crank it over with out it starting to see if I can pinpoint the tapping location.

 

If you have marks on the sides of the pushrods, I'd start there. That's obviously a clearance issue. Also, the best way to check the pushrods is to roll them on a flat piece of glass like a glass countertop. That will give you the best indication if they are bent or not. Sounds to me like you need to elongate the pushrod holes. I'd have somebody crank it over with the valve covers off and look to see how much clearance you have when the valve is full open and closed. You want alittle room here and you can't really have too much clearance there anyways if it's even in doubt.

 

I did the roll to check for any bent pushrods and all looked good. I will check clearance on pushrod holes, I hope thats the problem.

 

Definitely check the pushrod holes. It sounds like your have the older blue rockers that we sold. It is possible that the the pushrod is making contact with the head and some material needs to be removed form the pushrod hole.

 

I enlarged the holes the last time I took the heads off, but didn't do much enlongating just made them wider. I will revisit this area again and look more into elongating the holes.

 

When I looked into these rockers, someone recommended elongating them by 0.125" to clearance the pushrods. I don't have them though, so I am just passing what I was told.

 

What about the valve covers themselves? Any shiny marks inside where the rockers may be rubbing? Just a thought.

 

I was getting some marks on the valve cover spacers, but I since clearanced them and no longer hitting.

 

I did a test to see if the pushrods were rubbing against any thing and I found that most of the pushrods for the intakes were rubbing the outside of the intake runner. So now I am pulling the heads again and going to open up the pushrod ports more. Test was done cold engine and just cranking it over without starting so rubbing on tape would probably be worse once engine heated up and force is put on pushrod.

 

You shouldn't have any mark(s) on the pushrods except on the ends where it wears.

The shaft mounted rockers that require the "short" pushrods really make for clearance issues.

There is usually only one side of the hole you need to make "bigger".
It will be the top side of the hole that is closest to the pivot of the rocker.

No need to hog out the whole hole.

Also, if you loosen up the pre-load setting this will move the pushrod a bit.

Amazing what a difference a couple of .001's will make.

 

Top and bottom of the hole is fine it's not hiting there. Its hitting on the side, not both sides just against the intake runner. Yeah those PP rollers require some extra work to make work. I have the older ones I guess those require a little extra work.

 

I know what you mean about "extra attention".

The worst angle the pushrod "sees" is when the valve is closed and the rocker is pushing the pushrod towards the hole.

This is where loosening up the preload will move the pushrod away from the edge of the hole.


Welcome to MOD HELL.

 

I think I am in the same boat as you, first combo in a c-5

6.0 iron short block bought a used 224 224 comp cam and had a set of 317 heads angle milled and done up by precision porting used stock rockers tried 2 different sets changed pushrod lengths shorter and longer car had strait pipes and was loud noisy at a stop light or cruising next to a median wall I always blamed it on the fact that I didnt have adjustable rockers and tore car apart before correcting next car:



bought 03 z06 and built a forged stock cube 346 used same heads and cam as previous engine but bought new comp R lifters and comp adjustable rockers and tall covers from nasty perf. same noise this car has lg longtubes X pipe with no cats and B and B bullets and is even louder I can pull covers and adjust rockers until I get rocker tap and then adjust the tap out so I dont think it was that . To give you a idea this car was tuned at wheel to wheel and this noise is so loud they had to tune it with the knock sensors off both cars had stock oil pumps different ones though 2 sets of lifters 2 different short blocks. both engines also had different timing chains the second one beeing a rollmaster, I thought well perhaps through buying a used cam maybe it was a solid roller and when used with hydraulic lifters this would result but I was told if that were the case it would actually be queiter due to the ramps not being as steep on a solid cam. I still never figured it out I have two much money into it it drives me nuts and every one that gets in the car points it out and I 'm sure it wouldnt be long before I pimp slap them!

Tomorow all my new parts come : high volume and pressure oil pump , new MTI Y cam , new comp OEM lifters , chet herberts pushrods to match the comp shaft mount roller rockers, and new ALL PRO heads I will install all this this weekend and get back to this thread with no noise I'm not a parts changer but I am fed up and I am not just picky this is not a acceptable noise I DIDNT MEAN TO STEEL THIS THREAD ITS JUST THAT I HAVE THE SAME ANNOYING ISSUE AND I KNOW YOUR PAIN AND IM NOT A CHEAP *** AND DONT KNOW WHY IM PLAGUED WITH THIS PROBLEM SPENDIN MONEY ON GOOD PARTS ?