Hey all, new here and new with modifying LS style engines as well, but could really use some help. I have a 2012 Silverado with a 5.3 in it that ate a lifter and destroyed the cam. Long story short, yanked the motor and am in the process of doing a DOD/AFM delete. I had the block and heads cleaned and cam bearings replaced and the block had to be bored .020 over. I ordered a delete/overhaul kit from ams racing, but I have one concern with it. The kit says for motors up to 2011, but the guy there assured me it will work in mine, only difference is the kit has flat top pistons with no valve reliefs and the originals had valve reliefs. I am going to be using their stock non dod cam and keeping VVT, but will I have any problems running pistons with no valve reliefs? Any help is greatly appreciated

 

I'm not sure what the answer is but I would definitely do a mild performance cam if you're already paying for one, something like a stage 1 drop in truck cam at least so that you keep low end but gain pretty much everywhere.

Texas speed does a lot of vvt cams and may be able to answer your question over the phone and spec/recommend a great cam for it.

From what I understand though, the valve reliefs are for the vvt though, so I would say it is important to have them. But I certainly don't know everything so don't go solely off what I say.

 

 

thanks for the replies guys. what do you mean by limiters?

 

 

If you retain VVT and go with an aftermarket cam you will have to install a limiter into the phaser.

My speakers at home are broken so I couldn't hear what they said in this video but it should be what you need to know.

 

 

Increased cam duration and flat top pistons without valve reliefs would definitely result in PTV clearance issues. My question is it even worth the effort in this case where by putting limiters you limit the advantage provided by the VVT and from what I remember the aftermarket VVT cams cost more than normal cams . I would just delete the VVT and pick a nice torquey truck cam and be done with it . Since you are putting in new pistons you could also bore the 5.3 out to 5.7 and get some low end grunt and more compression at the same time .

 

Good to know they don't all need them. Every cam I've looked at and read on so far did, so I assumed they just went together.

I personally would rather have a cam with a broader range, so that's cool that it can be had. (a cam that doesn't require a limiter)

 

An oil issue can cause the phaser to act poorly so the limiter is also there to keep the phaser in check as a safeguard. Some 07-08 phasers are different also.

You will need the pistons with the valve reliefs.