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Rocker arm geometry on a 440 #1414007 04/02/13 10:32 PM 04/02/13 10:32 PM
Joined: Jan 2003 Posts: 1,272 Minneapolis, MN M moparguy OP pro stock
moparguy OP pro stock M Joined: Jan 2003 Posts: 1,272 Minneapolis, MN	I picked up a set of Harland Sharp roller rocker arms for my 440. It looks like the roller may be abit far forward on the valve tip. Will this be alright or is there some way to fix the geometry? There is nothing fancy about my set up. i am running a 545 lift cam however.

Re: Rocker arm geometry on a 440 [Re: moparguy] #1414008 04/02/13 10:38 PM 04/02/13 10:38 PM
Joined: Oct 2010 Posts: 2,407 Ambridge, Pa. R rickraw top fuel
rickraw top fuel R Joined: Oct 2010 Posts: 2,407 Ambridge, Pa.	shim up the shaft. that will move the scrub pattern more towards the center.

Re: Rocker arm geometry on a 440 [Re: moparguy] #1414009 04/02/13 10:39 PM 04/02/13 10:39 PM
Joined: Aug 2009 Posts: 2,042 Mooresburg, Tn ' '72CudaRacer top fuel
'72CudaRacer top fuel ' Joined: Aug 2009 Posts: 2,042 Mooresburg, Tn	Shim up the rocker arm shaft? Brian

Re: Rocker arm geometry on a 440 [Re: '72CudaRacer] #1414010 04/02/13 10:57 PM 04/02/13 10:57 PM
Joined: Jan 2003 Posts: 1,272 Minneapolis, MN M moparguy OP pro stock
moparguy OP pro stock M Joined: Jan 2003 Posts: 1,272 Minneapolis, MN	For some reason I was thinking backwards and thinking that if I shimmed it up it would get worse. Thanks guys!

Re: Rocker arm geometry on a 440 [Re: moparguy] #1414011 04/02/13 11:02 PM 04/02/13 11:02 PM
Joined: Sep 2006 Posts: 685 SW Ohio AAR-B4 mopar
AAR-B4 mopar Joined: Sep 2006 Posts: 685 SW Ohio	You are right, shimming the shaft up will move the contact farther to the outside of the valve tip. For me...........I'd leave alone, it will be ok.

Re: Rocker arm geometry on a 440 [Re: AAR-B4] #1414012 04/02/13 11:16 PM 04/02/13 11:16 PM
Joined: Jul 2012 Posts: 429 Washington skrews mopar
skrews mopar Joined: Jul 2012 Posts: 429 Washington	Shimming the shafts up will make the problem worse. Lash caps will improve the situation, but may not fit your retainer/keeper combo.

Re: Rocker arm geometry on a 440 [Re: skrews] #1414013 04/02/13 11:24 PM 04/02/13 11:24 PM
Joined: Jul 2006 Posts: 4,319 Puyallup, WA S StealthWedge67 master
StealthWedge67 master S Joined: Jul 2006 Posts: 4,319 Puyallup, WA	Are the contact patterns shown in the pictures of a full sweep on the cam lobe? LemonWedge - Street heavy / Strip ready - 11.07 @ 120

Re: Rocker arm geometry on a 440 [Re: StealthWedge67] #1414014 04/02/13 11:25 PM 04/02/13 11:25 PM
Joined: Jan 2003 Posts: 1,272 Minneapolis, MN M moparguy OP pro stock
moparguy OP pro stock M Joined: Jan 2003 Posts: 1,272 Minneapolis, MN	Yes Stealthwedge, I marked it and turned the engine over 2 times to get a good rubbing.

Re: Rocker arm geometry on a 440 [Re: moparguy] #1414015 04/02/13 11:44 PM 04/02/13 11:44 PM
Joined: Jan 2003 Posts: 75,005 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,005 U.S.S.A.	Add me to the shim up the shaft crowd. How do those springs fit on those retainers , the retainers look a little small ??

Re: Rocker arm geometry on a 440 [Re: rickraw] #1414016 04/03/13 12:41 AM 04/03/13 12:41 AM
Joined: Jan 2003 Posts: 9,996 Frostbitefalls MN (Rocky&Bullw... gregsdart master
gregsdart master Joined: Jan 2003 Posts: 9,996 Frostbitefalls MN (Rocky&Bullw...	Quote: shim up the shaft. that will move the scrub pattern more towards the center. I don't agree with that. The rocker shaft bolt is not parallel with the intake valve, it is inclined towards it. The higher you move the rocker shaft, the closer the rocker and valve tip get, and the further out the scrub pattern will be, given you are going in the right direction to get the proper rocker arm to valve angle. The first thing to do is to figure out at what angle the rocker is to the valve stem right now. 8..603 156 mph best, 2905 lbs 549, indy 572-13, alky

Re: Rocker arm geometry on a 440 [Re: rickraw] #1414017 04/03/13 01:18 AM 04/03/13 01:18 AM
Joined: Jul 2004 Posts: 19,317 State of confusion T Thumperdart I Live Here
Thumperdart I Live Here T Joined: Jul 2004 Posts: 19,317 State of confusion	Quote: shim up the shaft. that will move the scrub pattern more towards the center. Ya. the shaft shimming doesn`t work here but lash caps may help and also spread the load.............that`s what I`ve done 4 years. 72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

Re: Rocker arm geometry on a 440 [Re: Thumperdart] #1414018 04/03/13 06:05 AM 04/03/13 06:05 AM
Joined: Dec 2012 Posts: 50 Australia B big_wedge member
big_wedge member B Joined: Dec 2012 Posts: 50 Australia	those retainers look way to small for those springs... jus sayin

Re: Rocker arm geometry on a 440 [Re: gregsdart] #1414019 04/03/13 11:00 AM 04/03/13 11:00 AM
Joined: Jan 2003 Posts: 75,005 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,005 U.S.S.A.	Quote: Quote: shim up the shaft. that will move the scrub pattern more towards the center. I don't agree with that. The rocker shaft bolt is not parallel with the intake valve, it is inclined towards it. The higher you move the rocker shaft, the closer the rocker and valve tip get, and the further out the scrub pattern will be, given you are going in the right direction to get the proper rocker arm to valve angle. The first thing to do is to figure out at what angle the rocker is to the valve stem right now. I never looked at the hold down bolt to valve angle relationship, if this is the case then shimming the shaft up would move the shaft towards the valve. Lash caps would be the easier way to do do it , the OP will need to change his valve locks because those are the kind that accept lash caps. Otherwise it's machining off, or machining of, the stands .

Re: Rocker arm geometry on a 440 [Re: JohnRR] #1414020 04/03/13 12:48 PM 04/03/13 12:48 PM
Joined: Aug 2009 Posts: 1,317 Ohio J jlatessa pro stock
jlatessa pro stock J Joined: Aug 2009 Posts: 1,317 Ohio	I'm not sure that shimming will make it worse, take it to the extreme i.e. if you shimmed it an inch, the arc of the tip would be passing the valve on the inside, or is my reasoning wrong?? Joe

Re: Rocker arm geometry on a 440 [Re: jlatessa] #1414021 04/03/13 01:06 PM 04/03/13 01:06 PM
Joined: Jan 2003 Posts: 75,005 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,005 U.S.S.A.	Quote: I'm not sure that shimming will make it worse, take it to the extreme i.e. if you shimmed it an inch, the arc of the tip would be passing the valve on the inside, or is my reasoning wrong?? Joe that was my thought , but that was ASSuMEing the rocker shaft holdown pedestals were parallel to the valve stems , they angle toward the valves it seems, I don't have a head handy to confirm this.

Re: Rocker arm geometry on a 440 [Re: JohnRR] #1414022 04/03/13 01:17 PM 04/03/13 01:17 PM
Joined: Aug 2009 Posts: 1,317 Ohio J jlatessa pro stock
jlatessa pro stock J Joined: Aug 2009 Posts: 1,317 Ohio	I think what some are missing is that the tip of the rocker travels in an arc and the contact point has to move because of that...Hmmm I have a head in the basement, I'll see if I can see some change. Joe

Re: Rocker arm geometry on a 440 [Re: jlatessa] #1414023 04/03/13 01:33 PM 04/03/13 01:33 PM
Joined: Aug 2009 Posts: 1,317 Ohio J jlatessa pro stock
jlatessa pro stock J Joined: Aug 2009 Posts: 1,317 Ohio	With the stamped rockers I have, the contact point is not easily seen. Joe

Re: Rocker arm geometry on a 440 [Re: jlatessa] #1414024 04/03/13 01:44 PM 04/03/13 01:44 PM
Joined: Jan 2003 Posts: 75,005 U.S.S.A. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,005 U.S.S.A.	I'll be interesting to see what the fix is , I have sharps going on 906's when I get my block back .

Re: Rocker arm geometry on a 440 [Re: JohnRR] #1414025 04/03/13 01:52 PM 04/03/13 01:52 PM
Joined: Oct 2012 Posts: 235 Gilbert AZ tsanchez enthusiast
tsanchez enthusiast Joined: Oct 2012 Posts: 235 Gilbert AZ	The fulcrum point needs to be lowered to fix the geometry, by milling or removing shims if there is some. Raising will make it worse.

Re: Rocker arm geometry on a 440 [Re: moparguy] #1414026 04/03/13 03:48 PM 04/03/13 03:48 PM
Joined: Jan 2003 Posts: 31,027 Oregon A AndyF I Win
AndyF I Win A Joined: Jan 2003 Posts: 31,027 Oregon	To make it perfect you need longer valves or you need to lower the rocker shaft. Neither of those fixes is very simple. Lash caps will help but they add another part to the mix and you will most likely need to change pushrods. Setting up a BB Mopar to have "perfect" valvetrain geometry is no picnic. Flip thru the valvetrain chapter in my big block book. I show a bunch of examples and some fixes. The best fix is to buy rocker arms which are the correct length for the application. Some rocker arms are really short, others are too long.

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