rob20rx7

Just finished putting together what was quite the mod list including a set of LSX heads that were purchased from a fellow forum member.

Im having to deal with this ticking sound that does not quite sound like the rockers. in fact it sounds more like its coming from right under the Fast intake. sounds like a clicking but with a bit deeper sound that the conventional rocker out of adjustment sound. The rockers are Crower solid shaft rockers and I left them adjusted while hot (est 150degrees) to 1/4 turn after zero lash.

I remember before I did the head work listening to what seemed to be a bit of rocker sound from the car. but really didnt pay mind to it being that the engine only had 7000 miles.

Im thinking now that since the lifters are the only thing left from the original set up there may be some that are sounding or perhaps failing.

Also i noticed that while adjusting the lash last week. the lifters (appx 3 of them would loose presure and i would have to crank the engine over to get them hard again.

I dont know if my explination makes sence but hope someone can shed some light on this sound.

rob20rx7

here is a list and description of the heads i put on

GMPP-LSX 6 Bolt Heads,
Crower Shaft Roller Rockers, Del West Ti intake valves, Ferrea Turbo SS exhaust Valves, Manley Nextek Polished Finish Springs, Ti Retainers, bronze guides, All head work was done by Richard at WCCH.

I also went with a Katech Torquer 116 Cam, FAST 102 intake with 102 TB

left the OEM lifters and used OEM Head Gaskets

djfury05

What oil? There have been cases of LS7 lifters failing new straight out of the box so that may very well be the case even with 7000 miles.

Z06_1

On my old LS6, after an oil change, I had one bleed down, air pocket developed and it was loud as hell under idle for a good 10 minutes. It refused to go away but I pretty much knew what was going on, I wasn't about to pull the heads off for a bled-down lifter.. Finally I got desperate and just decided to bite the bullet and drive the car down the street to see what would happen.. The extra rpms and time cleared the issue in about a mile, and it never happened again.

'06 Quicksilver Z06

ZedNought6

I had a ton of noise after I did my first round of mods. It included the torquer 116, Pfadt headers and heads by WCCH. What it did not include was new Pushrods and thus had the incorrect preload. I found out about the preload when I had the engine redone. However I replaced the Torquer with an EPS cam and the lifters with slow leakdown lifters that I got from Brian Tooley Racing. The sound is much diminished. The EPS cam has different lobes, the Torquer cams use XER lobes which, from what I have read, have fast ramp rates and snap the valves open and closed rapidly. Some people swear by the LS7 lifters, just as many say they suck. Easiest thing is to recheck preload I would think. After that you have to decide weather or not you want to yank off the heads and change lifters or yank out the cam for something friendlier to the VT. I did both. Also, I read that the FAST will also increase the amount of noise, as will headers. Its a total PIA.

Others will tell you to turn up the radio....

Zip Corvettes

What length push rods did you use. Even though you have the shaft mount rocker arms you still have to have the right length push rods.
I can't remember is the LS7 is the same length as the LS1-3 which is 7.400. You may need a 7.100 etc, you need to get a push rod length checker and see what it needs. The LS7 lifter is a good lifter. They do make a GM high rev lifter that is even better with less bleed off.

Mark2009

Did you put the same lifter back on the same lobe with the wheel turning in the same direction? (x 16?)

Dirty Howie

Well you know the headwork was good

I was advised to use new lifters when I had my heads done .....


DH

rob20rx7

Im using Mobile 1 5w-30w Before the mods and after

I put the same lifters and guide trays back in but did not look to place them in their same positions and roller direction as to before they were removed.

I had to measure for new push-rods and went with Comp-Cams Magnum 7.950 in addition to 1 spacer under the rocker bracket to get the geometry right in the middle of the valves.

I asked about changing the lifters before the re-install but i was told it was not nessasary because of the motors low mialage and that those lifters are great for my application. I did however at the time forget to mention that slight ticking sound the car had before the tear down

I'm positive the head work is good. I even had my local builder go through them before before i installed them. He found that at the time they didnt have Bronze guides so i had those installed at the time and everything else checked out.

If the ticking is to be accepted then so be it. Im just concerned about going to the dyno like that to make power. just want to make sure everything is good before.

double06

I think LS7 lifter needs like .80 or .100 preload not sure if a 1/4 turn is enough. On the LS7 it is usually like 1+ hole turn of the bolt not sure what that equates to in Crower.

Zip Corvettes

Are you sure about those mods on the valvetrain. I have not used that setup so I don't want to sound like I know the setup but that sounds way off. I had to go to a shorter pushrod when I went shaft mounts. You have added a half inch in push rod lenght and one inch under the rocker shaft mounts. That doesn't sound right at all. You need to find someone with that setup and see what pushrod length they went to. Just because the roller tip in in the middle does not mean the geometry is correct. Were the valves you used longer than the stock ones? by over a half inch?

Unreal

I don't know if stock ls7 lifters are sufficient for that setup. I wouldn't have reused them.

Check preload. Like someone said above, spec is more in the 60-80 range. You may have too little preload.

erichg1000

From what I have read on the alternate lifters, is that they are nearly identical except they use a ceramic check ball instead of metal. This made them lighter, but that was the only added benefit.

BOTTLE FEDvette

What lifter then?

Unreal

Crane Ultra, Morel, Lunati, etc.

Zip Corvettes

GM Hi rev lifter, right from the GMPP catalog or we have them on our website. zip-corvette.com

Unreal

I wouldn't touch those. They are just GM lifters with ceramic *****. If anything just as many if not more issues. Go with aftermarket if you want a good lifter, and something a bit more suited for high RPM shaft rockers.

djfury05

Johnson lifters are very good as well, pricey but good.

Zip Corvettes

Have seen issues with aftermarket. I have personally had lots of experience with the GM hi rev. I have an LS7 that has spun 8K with them and now has about 50k on the motor. These are in all of our motors that we do and is in my race LS2 motor making 500+ RWHP NA and turning 7k.
GM does not make them, they have big manufactures make them who spend millions of dollars on equipment and testing that a smaller aftermarket company could never afford to do. I would stick with the GM all the way.