Edelbrock heads - how to determine correct pushrod length

[timmycharger]

Ever since I refreshed my 440 and fired it up a few years ago I have had an annoying ticking sound that will not go away.  I have about 40 miles on the motor since the rebuild and it has plenty of power, oil pressure is good (60 cold, 40 warm). 

I ran this same motor before the refresh using the same pistons/rods cam, pushrods/lifters intake, carbs, headers. Only thing that was changed was aluminum heads. (Edelbrock 60929 84CC).

I first thought that something was hitting the valvecovers so I inspected the rockers and a few had some scratches near where the baffle was so I clearanced that area but nothing changed in the sound.

I then swapped out the Hughes 1.6 roller rockers and 3/8 pushrods for a set of my stock stamped rockers and 5/16 pushrods thinking it was that, still the noise was there.

I put the roller rockers back in, adjusted the preload to zero plus a 1/2 turn, then 3/4 turn, then back to 1/4 turn, still no changes in the noise.

I then swapped out all of the lifters for new Comp Cams ones and still no change.  Here is the noise I am talking about:

https://www.youtube.com/watch?v=rFh6mxFDMrE

I am now thinking that my prior iron heads from Muscle Motors were a different height than my current Eddys and that I may be needing longer pushrods?

My question is how do I know what the proper length should be? I got custom pushrods made with my old motor setup when I bought my Hughes rockers, they sent me an adjustable pushrod and I sent it back to them. That was over 15 years ago and I lost all of the paperwork that came from them.   On the Edelbrock instructions they state: "Use supplied spacer shims as needed to ensure adequate clearance between pushrods and intake port walls "  I don't recall getting any spacer shims in the box, I have no idea what this means.

[69wannabe]

As long as the adjuster on your rocker arms is about half way between all the way up and all the way down that should be pretty close. I have noticed that on my rocker arms that 1/2 preload on my hydraulic lifters was not the recommended 40 to 60 thousands that it should be. After checking with a dial gauge I found that 1 full turn from zero lash works for the rocker's I have. I can't remember what brand I am using but they are the comp knock off's but I wound up ordering comp adjusters and lock nut's since the one's they came with were pot metal and kept breaking on me. The adjuster's seem to be very fine threaded on most of the rocker arm's like the one's I have and most of the aluminum one's I have seen. The one's I have are not proform but something like that tho, I think 440 source sell's the one's I have.

[Mopar Nut]

You can buy adjustable pushrod at most major auto stores.

http://www.jegs.com/i/Comp-Cams/249/7903-1/10002/-1?CAWELAID=1710867046&CAGPSPN=pla&CAAGID=44693592161&CATCI=pla-209599197191&CATARGETID=230006180039217768&cadevice=c&gclid=CLic5ICV7NQCFci1wAodaRkP9w

[chapel40]

Almost sounds like a rod bearing. Doesn't it sound like a 1 to 1 noise? That's what mine sounded like.

[timmycharger]

Thanks for the feedback guys, much appreciated.  I ended up giving Hughes engines a call since they were the ones that I bought my rockers and custom pushrods from back in 2001 when I first put them on my 440.  The tech I spoke to recommended that pushrod length be checked anytime anything new is introduced into the valve train.

They sent me out an adjustable pushrod checking tool/kit like the first time back in 2001. I will take my measurements and see where I end up and if the ones I am running are in fact too short. 

God I hope its nothing in the bottom end (bearings, rods, etc).

[chapel40]

I hope its the valve train. Bottom end would be a pain.

[69wannabe]

Thanks for the feedback guys, much appreciated.  I ended up giving Hughes engines a call since they were the ones that I bought my rockers and custom pushrods from back in 2001 when I first put them on my 440.  The tech I spoke to recommended that pushrod length be checked anytime anything new is introduced into the valve train.

They sent me out an adjustable pushrod checking tool/kit like the first time back in 2001. I will take my measurements and see where I end up and if the ones I am running are in fact too short. 

God I hope its nothing in the bottom end (bearings, rods, etc).

Hope not either dude!!! These big block mopar valvetrain's can be a pain, I been running a set of 9.150 length pushrod's in my engine for years with the factory heads and when I went to the stealth heads my pushrod's were too long for several of the valves. I am not sure if the valves were a tad bit longer or if the rocker arm shaft's sat a little deeper in the head. Anyway after making a pretty good guess I ordered a set of 9.100 length pushrod's and they fit great. Got the valves adjusted and so far haven't had any problems.  Hope you get it figured out!!!!!

[timmycharger]

Thank you, that is interesting, good to know what size pushrods you had, helpful for reference.    Hopefully I can get in there this weekend to start my measurements, I received my checking push rod tool from Hughes, I am really curious as to what I come up with.

[LowDeck451]

Just shotgunning here but, sounds like more of a 'clank' than a 'tick' to me. Did you check for a torque converter bolt backing out, or a rod bolt hitting the windage tray? Is the noise louder from under the car?

[timmycharger]

Yes it sort of does clank but the cadence of it sounds top end.  It's a 4 speed with a lakewood bell. Can't see a thing in there.