What's that tapping?

[airbur]

Seem to be coming from cylinder #4 area.

[YouTube]jVecU9Io3J8[/YouTube]

 

[crews44]

Rocker arm with incorrect lifter preload. I have same thing going on right now. May need a longer pushrod and rocker shims to get perfect if you have pedestal mounts.

Everybody says just torque them down but there is a little more to it than that.

Does is seems to follow engine rpms?

 

[airbur]

Rocker arm with incorrect lifter preload. I have same thing going on right now. May need a longer pushrod and rocker shims to get perfect if you have pedestal mounts.

Everybody says just torque them down but there is a little more to it than that.

Does is seems to follow engine rpms?

Yes...it doesn't go away. Follows the RPMs. Well, if that's it, at least I got the other 15 correct Guess I'll be removing the valve cover.

 

[crews44]

Make sure cam is on base circle and you get proper torque at 1/2 to 3/4 turn after zero lash on pushrod. I had to go with longer push rods and then shim accordingly under pedestal to get it where i was at 1/2 turn to get to 25ft/lbs.

I had heads on my 351w and had same noise. Same on my 5.0 now. Got one head good by going this way. Still have to get PS head done.

 

[crews44]

Good job on other 15!

 

[airbur]

Remind me how to verify cam is on base circle? That's when both lifers are down right?

 

[airbur]

Well, it's a Cheby site but....this works... http://www.small-block-chevy.com/cb_6.htm

 

[crews44]

Yeah...the combustion stroke. You can do it where when one valve is open the other is on base as well. If you want to do it as one cylinder get on compression stroke.

 

[crews44]

yes. Both lifters down...to be more accurate Top Dead Center on Combustion stroke they will both be down.

 

[airbur]

Yea.....realized it about impossible to rotate the engine. I have the Explorer serpentine and can't figure out a way to do it manually.

 

[crews44]

Well, it's a Cheby site but....this works... http://www.small-block-chevy.com/cb_6.htm

This accurate if you use stud mounted rocker arms( a nut, not a bolt). You have pedestal mounts with a bolt down thru center I imagine. Thats where the torque reading comes in.

The stud mount are set by number of turns from zero lash. Pushrod length is not really as factor unless your'e building a high revving race motor where you need perfect valve train geometry (another topic) There is a lot more room for adjustment before switching PR length.

The pedestal are not as adjustable or forgiving. Your required to get 25 ft./lbs of torque on the bolt between 1/2 and 3/4 turn of lifter preload. PITA as you have to have correct length pushrod.

 

[crews44]

I have same thing. Get stubby 1/2 drive extention on a short 15/16 socket. Its tight but doable. Or pull coil wire and bump starter till you get one lifter up and adjust other rocker.

 

[airbur]

Mine are stud mounted...

http://www.edelbrock.com/automotive_new/mc/cylheads/ford/sb_victor_jr.shtml

 

[crews44]

Mine are stud mounted...

http://www.edelbrock.com/automotive_new/mc/cylheads/ford/sb_victor_jr.shtml

perfect...easy fix then....fingers crossed for ya....if it wasn't so pretty under the hood, take valve cover off and adjust with motor but its too messy...

wish mine were studs...i have to order new pushrods

 

[nvrstuk]

E-

How's the volume and the pitch of the sound IF you held your video camera below the headers the EXACT same distance as the camera is when taking this video? In other words, have you listened to the sound with your head below the headers to eliminate the chance of an exhaust leak causing this sound? My cheap spkrs at work make it hard to really determine the tone/pitch of the sound, that's why I'm suggesting this.

 

[airbur]

Viper suggested the same thing. I listened to it from all angles and even got down and checked for leaks. Also tightened up a few header bolts. Noise is still there.

 

[TwoDalesDad]

Do you have screw in studs? ..Or Are they Press in studs..."... Your Rockers"..I have had the studs lift out of the head...on more than one engine...mine once....others...more...Then you can not adjust valve correctly...keep lifting...

 

[airbur]

I just opened it up and readjusted #3 and 4....all 4 rockers. Put it back together and same noise. I didn't do 1 or 2 because it really sounds like its coming from 3 or 4.

Not sure on the studs...I think they are threaded.

 

[John Marinan]

Sounds like you blew out an exhaust gasket. No amount of tightening will correct that.

 

[airbur]

It's brand new....can't imagine I blew it out in under 2 miles of driving.

And it was doing it the very first time I started it up.