StangGang702

Hey guys question all answers much appreciated. I have a Lunati Cam supposedly (stage 2 cam) and I need to know what kind of rod length id need with my gt40 aluminum heads, starting to make a very faint tickin noise. Not Knocking. Cam to big? Rods loose ? Hopefully not lifter. Probaly end up changing the lifters anyways and rods with rocker arms. Anyone no what kind of rods the gt40 use? Here majority are pedestal. Haven't removed anything yet just what the car came with cause I need to order parts before tear down (daily driving car) thanks guys

dawson1112

No one can tell you what rod length you need. That has to be measured at the time of the build.

That ticking is probly nothing to worry about, the old push rod engines always sound like a sewing machine. Especially if it has roller rockers. But it could also be a leaky exhaust header causing the noise.

StangGang702

Really?.. I did my rebuild on my bronco 351 and put new rods and lifters in and it was smooth no ticking or anything. What's the difference both being pushrod motors ?

StangGang702

Also passenger front side has always made that sound when I got the car, no difference in performance or anything. But now the right side front has also developed this ticking sound. So that's why I'm worried. And I'm assuming it has something to do with either a lifter, rod or rocker area.. I'm almost thinking maybe the cam is to big for the valvetrain

barnett468

it should not tick like a loose lifter. check the preload, it should be from 1/2 - 1 1/4 turns. if they are in this range and thry are ticking they might be varnished inside or just bad or the cam lobes are going flat. try adding a qt of rislone and drive it for around 200 miles. if they still tick they are bad or the cam lobes are going flat.

mjr46

you sure it isn't an exhaust/ header leak?? doubt you need to replace a roller lifter, they typically do not go bad and if they do the 100's I've run across in engine builds have suffered from a roller imploding. more detailed info on your combo needs to be listed , like what type of rockers?? stud?? pedestal?? and was push rod length measured...did you recently install all these parts??

StangGang702

I did not do the build so I'm not sure what's inside exactly sorry, I kinda want to do my own later but for now just get rid of the ticking noise. I'm assuming there pedestal mount heads just wondering the size maybe the rods are so I can get this ticking out lol

mjr46

size of rods?? push rod size should be 5/16, I think you mean length?? stock length is 6.250 for a roller set up, check adjustment, bring each valve checked up on the base circle of the cam undo pedestal bolt , allow a few min for lifter to recover/ decompress then check.....pedestal bolt should reach 23-25 ft lbs of torque from the point tat the push rod and rocker cup have "0" lash. from 0 lash iirc you should reach 23-25 ft lbs of torque for pedestal set ups in 3/4 to 1 full turn max...if not pedestal shims will be needed

StangGang702

Ok cool thank you so much! I pulled the valve cover and there's 1.6 Scorpion Rockers so idk if that helps with anything or not ?

barnett468

Scorpions, nice score, and it is possible that some of the some of the rocker bearings are getting loose, I had this exact prob before with some Crane Gold Series rockers, otherwise, you need to check for exhaust leaks as dawson1112 suggested and if that's not it the try some Rislone or check the amount of preload as I previously suggested.
.