Hey guys,

Did a cam/head swap on my truck. 2003 Silverado 2500. LQ4 with a few miles (213k) but, no piston slap, no oil useage and spotless clean inside, so should last untill I build the replacment for boost. I went with a TSP 220R cam with a 114 LSA and a set of ported 4k mile 243's with Comp 918's. and 4k mile stock rockers. New GM oil pump with a shim. 72psi at cruise and 40psi at hot idle. Lifter preload is maybe a bit tight at 3/4 turn on the intake and exhaust, but should be ok. Truck makes great power and runs nice with a notable lope at idle. Valves sound ok at idle but anything 1200 and up make a fair amount of noise, some floaty ticks and some more rythmic ticks. Just not sure how much noise to expect with this cam profile?

Thanks in advance for any input

-Ryan

 

When I first had the cam swap done in my truck it did have a little bit of noise, even parked while idling sounded kinda like a sewing machine. On these LS engines and after a cam swap it is normal for them to be noticeable so don't worry. Mine quieted down after I changed the oil in it about a week later after the cam swap. Have you changed your oil yet and if so maybe try a thicker oil?

 

Mine did the same thing after both of my cam swaps, but after a couple weeks and after changing the oil it went away.

 

what lift on the cam? what springs did you use? what's the pushrod length? did you torque them down to 22-23ftlbs?

 

Explain this... Did you take the slack out of the rocker, then tighten it down with a torque wrench and get 3/4 of a turn from the rocker bolt to get 22ft-lbs? If so, you need a longer pushrod.

 

TSP 220R is a .581" Lift. Cant remenber the pushrod length. Comp 918 Springs.

 

Tightened the bolt with my hand and a socket untill there was zero lash, the instant the pushrod got taught. From there it was exactly 3/4 turn untill the rocker was bottomed. Then i did the torque step.

So there is exactly 3/4 turn preload on the lifter.

 

Increased valve train noise is par for the course with an aftermarket cam and springs, but since you did heads also, it would really be a good idea to check lifter preload the correct way, with a pushrod length checker. The turn method isn't always accurate and I've noticed that a lot of folks who do it that way end up with problems and eventually get a pr length checker and end up needing a different length pushrod. There's a sticky in the internal engine mod section about "lifter preload" that is a good read

 

Ok, thatnks for the sticky note! I read it all and came up with some very conflicting numbers for proper preload on the LS7 lifters. I do have length tools and a 12" dial caliper to measure them.

So the question is, what is the optimum or proper preload!?