ShinodaVette

*** Update: Post #36 on Page 2 has the solution to my problem ***

I have a Comp Cams XR275HR cam and a set of Patriot Gold valve springs in my LS2. I've got a ticking sound in my engine that I just cannot seem to track down. When my Crane Gold 1.8 rocker arms gave up the ghost a couple months ago I thought I had found my ticking noise but now that the engine is back together with just about all new parts, including brand new Crane Gold 1.7 rockers, I still have an annoying ticking sound. It's so loud I can clearly hear it with the air on and the windows up. I also hear it clearly with the top down and no radio on. Needless to say I have to find what the noise is from. My neighbor hears it when I drive by his house!

I've read on a few forums online where people say the Crane Gold Race rockers are noisy. However, I also know people running these that say they are perfectly quiet. What I want to try is pulling the rocker arms off and taking the hardened pushrods out and try out the factory stuff just to see if the ticking noise goes away. My question is whether or not the factory rockers and pushrods can be run with this cam. I'm not going to make any performance passes. I just want to run it for a day or two as my daily driver and see if the noise goes away. If it does, then I've found the culprit and can get different rocker arms.

In my opinion, the noise has to either be the rocker arms, lifters, or noisy fuel injectors but I don't know of a great way to test the lifters or fuel injectors so I figured I'd start with the rocker arms since I know how to test those; just yank them out.

I'm confident the noise is not valve cover contact. I'm confident it isn't PTV contact. I'm positive the oil pump o-ring (brand new) is seated properly with no problems. I'm running stock fuel injectors and stock lifters. I had a few loose header bolts (not very loose) but I tightened them to 18 ft lbs and the noise is still there. I have Kooks headers now and am using the Percy's gasket they included but I didn't have the headers before the engine rebuild and still had the tick then. I'm considering replacing the plug wires and plugs but I don't think they are making the noise. It really seems like it is in the valvetrain.

I know the noise could be a bunch of different things potentially but I'm at the point I think I should try swapping out the rockers and go from there. So, will the stock stuff hold up for a couple of days under normal operation? My guess is yes but I wanted to get opinions.


The cam is a 222/224 .566/.568 lift w/112 LSA.

Amric

I bet it is pushrod length.

ShinodaVette

If that's the case, wouldn't temporarily putting the stock rockers and pushrods back in make the noise go away? I'd be thrilled if that made the noise go away because I'd at least be one step closer to figuring this out.

Amric

No, because due to the size of your cam, they may have used a smaller base circle, requiring a slightly longer than stock pushrod to compensate. I actually called the Comp Cams tech phone line when I had a similar problem, and they told me they frequently use smaller base circle cams, and don't even have a way to tell me what was used. They told me to pull the cam and measure it.

Like I'm gonna do that

oneblackvette

Yes they make 7.425 and 7.450 to replace the stock 7.400

ShinodaVette

Interesting..... I had the tick with these same pushrods on a Crane Cam originally. When I had to do the rebuild from the failed rockers, I went with the Comp Cam. The crane cam and rocker package all originally came from Vinci High Performance. I'd hope the pushrods were correct for the Crane Cam setup in that scenario.

Sounds like I should double check my pushrod length though. They are 7.350 I believe and I think stockers are 7.400 but I could be wrong.

marc8090

My LS3 is stock, but I do have another car with a heavily modified 383 so maybe I can offer a little input. My engine ticks a little as well. I also believe it is valvetrain noise. I also have Crane gold roller rockers, so maybe they are simply a little noisy. My pushrods are definately the right length. I have a hydraulic roller cam, 230/236, lift around .555(can't remember the exact spec). I think when you run a cam, lifter, and rocker like this it's just not going to be as quiet as stock. I too have no clearance issues, and no oil issues. I'd love to get mine quiet as well, but I just don't think it's always possible. Not the answer you're looking for, but maybe it makes you feel a little better. Edit: (I just read your post above) If the pushrods are too short you would get contact between the bottom of the rocker arm and the valvespring retainer, so look there for signs of contact.

Ragtop 99

My first thought was a bent pushrod. Sometimes adjusting the preload can reduce noise too.

Neumonic2002

I would say go for it! the stock rockers are excellent and if the pushrod's are the incorrect length that will become a huge factor I would think, I thought a person would only go to the shorter pushrods if you milled your heads? anyway, switch the PR and rockers out and let us know what happens.
Generally the so called "sewing machine" sound increases once you switch to an aftermarket cam due to the ramp rate being so much more aggressive which in turn makes the valve open and close much faster and harder, i have also had people tell me injector noise but I think most of the increased noise comes form the more aggressive cam and if you go with dual valve springs over the 918 beehive style I am told the noise increases there as well.

Keep us posted, good luck!

CMY SIX

the crane rockers come with new push rods proper length according to crane

ShinodaVette

Keep in mind that I bought the rocker/pushrod combo from a guy that had them in his car. He may have had milled heads and just didn't think to tell me. After the original rockers died, I just bought new rocker arms and reused the original pushrods, guideplates, etc.

The sewing machine noise I can live with. That said, I really think there is something additional going on in there making the ticking noise. It isn't just a little louder than stock. It's quite loud and annoying. If I had a descent video camera with a good microphone, I'd get a video of it. But, I don't have one.

I'm going to check the pushrod length and report back. Maybe tonight after work if I can get it to cool down enough before it gets too late. It may have to wait until Saturday.

Nightstalker Medic

I'm running an 07' LS-2 with a (239/247 - .623/.623 LSA 114+4) Cam with
Patriot Extreme Dual Valve Springs w/ Titanium Retainers (.660s) – On stock 243 heads, with 7.400 inch Chromemoly Hardened Pushrods.

I have that sewing machine noise you speak of, but no other engine noise.

I was told that the sewing machine noise would be reduced if I purchased a set of Yella Terra Ultralite Shaft Mount Non-Adjustable Roller Rocker 1.7 Ratio Arms.

I'm going to try it when I get back.

pmj341

I have the Crane Quick lift 1.7 Roller rockers, they come as a kit with pushrods, studs and guide plates, I was told when I bought them from Crane that the pushrod length did not matter that the adjustment would take care of it, I have the same noise!!!
I would have to say that installing the stock rockers with proper length
pushrods(hardened) you would be fine.

vetracer

I read in your post that it was ticking before the headers, but the headers will definitely make it more noticeable. That is the only reason I won't put headers on a street car again.

One Bad Vette

I have had a lot of modded (ie: cammed, h&c, and stroker motor) lt/ls engines and all had sewing machine and a tick noise related to the aftermarket valvetrain. Its hard to say over the internet without hearing it, but sounds like valvetrain noise to me. I wouldnt jump to conclusions thinking somethings wrong and I definitely wouldnt just throw stock pushrods back in it as that will without a doubt cause damage with the cam/valvetrain you have. If you arent able to diagnose yourself, take it to someone who is (not joe blow mechanic round the corner who will say somethings wrong to eat up your $$$)before thinking the worse. I have had everything from bent pushrods to broke valve springs and I promise you, it is much more than a tick.

revo1059

Mine's been making a ticking sound since I had a cam installed and headers put on. Just figured it was normal. Car runs fine.

The Alchemist

Most likely, it's a combination of the stronger valves springs and more agressive camshaft that together makes the valves close quicker and louder. Add to the equation some thin walled high flow headers, and it becomes a loud speaker to amplify the sound.

You can try putting some sound deadener under your fuel rail covers and see if that helps a little.

sheesnaz

Did the installer get those rockers adjusted correctly? They are a little more complicated then any other rocker. I have those on my 416 stroker with no noise issues.

glenB

What's your oil pressure? Does it sound like one lifter towards the back?

Neumonic2002

The idea is a good one for trouble shooting, he wasn't planning on running the car with the stock setup aggressively just switching to see if the noise went away or improved.

Using the factory rockers and pushrods might help him find some answers.