Boreen

I have a pretty aggressive cam in my ls3, its a custom grind from comp cams. I had to get new valve springs as well to go with the cam. I don't have the specs at the moment but will have to look for them.
I was reading online that longer pushrods are probably needed now tho. I still have the factory pushrods in my engine. I wanna eliminate as much of the lifter tick as I can.
Still running factory rocker arms as well as lifters.
How much longer of pushrods are needed? .025? .050? What's recommended and what brand?

Also, what oil weight is recommended as well? It hits 20-40 degrees Celsius up here In the summers, and this car is only driven on nice days that its warm and sunny. Car maybe sees 1000 miles a year roughly. I can get royal purple oil locally for a good price so I'd like to run that.

Thanks

Pocket

iTrader: (24)

Get an adj PR and find out

Common off the shelf cams have been measured by others already, so the PR length is common knowledge. A custom cam is anyone guess

Jim85IROC

iTrader: (2)

Most big cams are ground on a .100 smaller base circle, but it's never a good idea to just assume when it comes to pushrod length. Get the adjustable pushrod and a checker spring and measure for yourself.

cam-

Stick a stock push rod in there and count how many turns in takes to pre load the lifter. You can guesstimate a length with that info if you dont have a checker

articwhiteZ

iTrader: (56)

first off

your checking foot print the rocker leaves on the valve tip.

for a good run out. ya want the rocker to be just off center. more to the intake side of the valve tip.

as the rocker pushes down on the valve. it moves across the tip of the valve. to the center. and back..even a full lift ya would like it to be still more to the intake side of the valve tip/center..

so with a push rod checker. you can get the run out right. then ya need to mic how long the checker is..after getting the thing set.

push rods run from $30 to $150 for the 5/16 size.
can be custom made for $110. and a week out.

you will want 2 push rod checkers. makes things easy..as you also need to check intake and ex.

checkers $13 ea to $30 ea at summit

you can use a marker on the valve tip. install rocker..at 0 lift..slide rocker back and forth on valve tip.. rotate eng till at full lift. slide rocker.
do this until its back up to 0 lift.. remove rocker ..look at valve tip...see marks... longer push rod moves mark to ex side of eng...shorter one moves it to intake side..easy easy..

just did this. and had to order a set .250 longer then my last eng had in it.. the last eng was 7.950 long.. the new eng is 8.200 long that's almost a 1/4 inch longer... aint this stuff fun!

cam-

^ Thats a load of horse manure. That method only works on floating ball rockers like sbc/bbc not shaft or fixed pedestal rockers like Mopar or LSx

LS1's have fixed pedestal mounted rocker arms. It does not make a bit of difference how long or short the push rod is when looking at valve tip contact. You cannot change the pivot point as it is fixed so the rocker arm swings the exact same arc, ALWAYS. The only thing you can do with a push rod in an LS engine running stock rocker arms is set lifter pre load and thats it. You want it around 0050 to 0080 preload pending on your cam grind.

five7kid

iTrader: (14)

5W-30. Can't say I'm particularly impressed with RP stuff, though.

Not necessary. Just...

I'd add that you need to have the lifter on the heel of the lobe first. Snug down the rocker bolt until there is zero lash (lifter plunger not depressed). Then count the turns until the pedestal is down. The bolt threads are about 20/inch, meaning one turn = 0.050". If you don't get any preload before the pedestal is down, then you need a longer pushrod to check using this method. Most likely, you'll get some preload, even with stock length pushrods.

Make that 0.050" to 0.080", and I'm in.

articwhiteZ

iTrader: (56)

sorry forgot... some guys still play with stock parts...
using anything aftermarket...ya always check the fit.
if ya dont..... well fix it when it brakes I guess
and ya better check the info on your shaft mt rocker arms info...lol
better let all the makers of pushrods know they dont need to make anything but stock ones!
diff heads/deck ht/cams/...diff parts= check...ya just bolt in stock ones..