BetMinesFaster

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

jrmchevyman

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?

Bama2door

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

iamkeniff

iTrader: (16)

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

Coban

iTrader: (14)

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.

BetMinesFaster

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

BetMinesFaster

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.

budhayes3

iTrader: (19)

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

BetMinesFaster

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!?