5.3 lifter noise or piston slap? With a cam question.

[85 Jimmy]

So the 5.3 in my 2005 Z71 has been making some noises for awhile, but I've learned to live with it. I'm thinking about some possible upgrades and would like to fix the issue while I'm in it.

Every once in a while I get what I believe to be a lifter noise. My best description of it would be it's a light tap or tick noise that sounds almost identical to zip ties on a driveshaft. Some times it does it when the engines cold, other times it appears after the engine's warmed up. Then it'll just stop and be quiet. Does this sound like lifters? As I type this, the engine has 163,795 miles on it and gets an oil change when the dash display says to.

If I'm replacing lifters, I figure I might as well put a cam in it. What cams should I look at? This is a daily driver that does everything from getting me to work and school or dropping off my kids at daycare, to towing my boat or getting me to my favorite hunting spot.
I've read that LQ4 cams are a popular swap, but haven't really looked into the numbers. I've also read that it's super easy to swap a cam into these engines, I've done complete rebuilds and cam swaps before, but on older SBC's and some ford stuff. I can't imagine it's much different than them.
If I put a cam in, what else should I change, other than a program and valve springs (if required)?

Another thing I'd like to make an attempt at, a few years from now, is installing a turbo. So I want to keep that in mind with my cam swap.

 

[wetoolowdingbangow]

More than likely that's piston slap. It's not great but not horrible either. It would be good to check the lifters too since piston slap or manifold leaks knock when the motor is cold.

As far as cams go it makes me go limp when people "upgrade" to another motors cam. There's way too many good options for off the shelf cams like Texas speed or comp.

If you went turbo you'd buy a custom grind cam to complement the turbo to get the full potential. Not sure what emissions tests or like where you're at but I would look at ls1techs forums on cam selection.

There are packages on summit that include everything you need for a cam swap and theyre really reasonable. It's not unheard of to make 50hp off a good cam. Ls1tech is where it's at for info. I find many of the performance mags go straight for numbers so I don't pay them much attention. Also tsp has a 383 kit for 5.3l...

 

[diesel4me]

Also,ALWAYS replace the lifters when installing a new cam !...
Not doing so is almost sure to sign it's death warrant...once lifters "wear in" and mate with a cam,they cant be re-used,unless they are to be used with the same cam in the same location again..even then its risky,they could still chow a lobe flat..

NOTE :

What I posted applies to old flat tappet cams...later engines with roller cams I have not dealt with,so that advice may not apply to them..

 

[Team208Motorsports]

Wow, this is why LS cams and engines get a bad wrap. Inaccurate info.

You probably are hearing some piston slap, its a very normal thing. It can affect things though. The ECM can pick it up as knock and start to de-rate timing to the low octane side. There are ways around this but its all in tuning.

With the cams. The later LQ4 cam is a great power upgrade for the 5.3. There could be more to gain from a slightly larger cam but thats it. Anything larger and you are out of air in the heads and your high dollar TSP cam is useless everywhere. If you are looking for turbo later cam then just grab an LS6 cam. We just tuned a 5.3 with LQ4 heads, LS6 cam and twins. It put down a little of 700hp to the tires. There is room for more but the LS6 cam is out for that to happen. Its still an awesome rig.

These are also hydro roller lifters, no need to replace unless you want to rev higher or are going to go turbo. Then just install some GM LS7 lifter. You will need springs for any cam as the truck springs are very light at the seat and float stock. LS2 springs are a great budget upgrade..... unless you go boost.

Most guys WAY WAY WAY over cam LS engines based on what the interwebs says. We ran all our own cam data and had our own cams cut.

5.3 with LQ4 cam

 

[85 Jimmy]

Wow, this is why LS cams and engines get a bad wrap. Inaccurate info.

You probably are hearing some piston slap, its a very normal thing. It can affect things though. The ECM can pick it up as knock and start to de-rate timing to the low octane side. There are ways around this but its all in tuning.

With the cams. The later LQ4 cam is a great power upgrade for the 5.3. There could be more to gain from a slightly larger cam but thats it. Anything larger and you are out of air in the heads and your high dollar TSP cam is useless everywhere. If you are looking for turbo later cam then just grab an LS6 cam. We just tuned a 5.3 with LQ4 heads, LS6 cam and twins. It put down a little of 700hp to the tires. There is room for more but the LS6 cam is out for that to happen. Its still an awesome rig.

These are also hydro roller lifters, no need to replace unless you want to rev higher or are going to go turbo. Then just install some GM LS7 lifter. You will need springs for any cam as the truck springs are very light at the seat and float stock. LS2 springs are a great budget upgrade..... unless you go boost.

Most guys WAY WAY WAY over cam LS engines based on what the interwebs says. We ran all our own cam data and had our own cams cut.

5.3 with LQ4 cam

So you're saying I should go with a LS6 cam, LS7 lifters, and LS2 valve springs?

I'd like to put boost to it later on, but I can't say for sure if I'm going to. But, I don't want to do rework later on if I decide to.

Do you have dyno figures for just those upgrades? How much lower rpm torque and hp will I loose, if any? I normally don't get the engine up past 2500 rpm, but sometimes I get on it for fun. I also don't really want to put headers on it now, if I'm going to rework the exhaust for a turbo later on.

 

[wetoolowdingbangow]

Wow, this is why LS cams and engines get a bad wrap. Inaccurate info.

You probably are hearing some piston slap, its a very normal thing. It can affect things though. The ECM can pick it up as knock and start to de-rate timing to the low octane side. There are ways around this but its all in tuning.

With the cams. The later LQ4 cam is a great power upgrade for the 5.3. There could be more to gain from a slightly larger cam but thats it. Anything larger and you are out of air in the heads and your high dollar TSP cam is useless everywhere. If you are looking for turbo later cam then just grab an LS6 cam. We just tuned a 5.3 with LQ4 heads, LS6 cam and twins. It put down a little of 700hp to the tires. There is room for more but the LS6 cam is out for that to happen. Its still an awesome rig.

These are also hydro roller lifters, no need to replace unless you want to rev higher or are going to go turbo. Then just install some GM LS7 lifter. You will need springs for any cam as the truck springs are very light at the seat and float stock. LS2 springs are a great budget upgrade..... unless you go boost.

Most guys WAY WAY WAY over cam LS engines based on what the interwebs says. We ran all our own cam data and had our own cams cut.

5.3 with LQ4 cam

Since when do ls cams and engines get a bad wrap? I wasnt saying its bad i was just saying theres better options out there.

 

[Team208Motorsports]

So you're saying I should go with a LS6 cam, LS7 lifters, and LS2 valve springs?

I'd like to put boost to it later on, but I can't say for sure if I'm going to. But, I don't want to do rework later on if I decide to.

Do you have dyno figures for just those upgrades? How much lower rpm torque and hp will I loose, if any? I normally don't get the engine up past 2500 rpm, but sometimes I get on it for fun. I also don't really want to put headers on it now, if I'm going to rework the exhaust for a turbo later on.

How you build now depends on boost. You could prep to a point but how much boost do you want?

 

[Team208Motorsports]

Since when do ls cams and engines get a bad wrap? I wasnt saying its bad i was just saying theres better options out there.

Sorry, my head and my typing skills are not in sync some days.

What I meant to say was the bad wrap comes from poor cam selection. Guys jump straight to the largest best SOUNDING cam they can, then wonder why drive-ability is lost. Over cam an LS and you get something that sounds mean, falls on its face and has power for 2k. Match airflows and you have something that pulls hard throughout. Yeah an LS that can rev to 7k sounds awesome but what does it really take to make power while doing that, nothing the stock head can support. That's not even scratching the surface of needing an intake, injectors....... All the supporting needs.

So yeah, I got side ways and thought my one sentence meant all that. LOL OOPS

 

[85 Jimmy]

How you build now depends on boost. You could prep to a point but how much boost do you want?

I guess I don't plan on running tons of boost, just what stock rods and pistons can handle. If the truck has good power with just a cam I may not run a turbo. Like I said before, it may be a few years before a turbo comes into play.

 

[Team208Motorsports]

I guess I don't plan on running tons of boost, just what stock rods and pistons can handle. If the truck has good power with just a cam I may not run a turbo. Like I said before, it may be a few years before a turbo comes into play.

The LS6 cam is a good start for the money. Some guys will say LS9 but thats not a good cam for turbo or a 5.3.

If I was pre-building for boost based on the LS6 cam, this would be my parts list.
LS6 cam
LS7 Lifters
5/16 080 wall push rods
stock rockers with bearing upgrade kit
LS2 valve springs
You can get buy with stock injector as the heads/intake will limit air.
Converter for the trans. You will want this. I would look in the 2200-2500 range.
Remember that the truck intake and head is not optimized for this cam. Once you go boost its all out the window... To a point.


When you go boost you will want better valve springs if you are looking to go more than 6ish PSI. Even then you may see boost loss from low valve control.
2 bar map sensor from cobalt - direct swap just needs tuning.
Larger Injectors - this depends on total boost wanted. I would guess 42-50 lb range with a boost modulated fuel pressure regulator. The 8.1 marine injectors are 42lb and are a direct swap. Other tuners say they are hard to tune. Guess they aren't too hard, we run them a lot.