Re: small block rocker arm clearance help needed
[Re: rumundo]
#2425001
12/28/17 06:45 PM
12/28/17 06:45 PM
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Joined: Oct 2005
Posts: 1,927 Seaford, Va
Kindafast
top fuel
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top fuel
Joined: Oct 2005
Posts: 1,927
Seaford, Va
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Hey Ray , Welcome to my world . LOL I have a set of HS Rollers and they were machined by HS before I got them. Grind them to fit but take your time and go slow. My 2 cents only.
6.50 @105.26
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Re: small block rocker arm clearance help needed
[Re: Kindafast]
#2425012
12/28/17 07:20 PM
12/28/17 07:20 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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How close are they.. are you using 1.55 dia springs.. I have clearanced a couple sets of rockers to clear for roller springs.. make sure you get a radius in the corner so they dont crack... the rockers I did were the blue MP (Crane) alum ones
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Re: small block rocker arm clearance help needed
[Re: MR_P_BODY]
#2425013
12/28/17 07:25 PM
12/28/17 07:25 PM
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Joined: Oct 2005
Posts: 1,927 Seaford, Va
Kindafast
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top fuel
Joined: Oct 2005
Posts: 1,927
Seaford, Va
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How close are they.. are you using 1.55 dia springs.. I have clearanced a couple sets of rockers to clear for roller springs.. make sure you get a radius in the corner so they dont crack... the rockers I did were the blue MP (Crane) alum ones Hey Mike I like the pictures of his because they don't look like they need too much work and they also look to be reinforced in the fulcrum area.
6.50 @105.26
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Re: small block rocker arm clearance help needed
[Re: Kindafast]
#2425030
12/28/17 07:45 PM
12/28/17 07:45 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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How close are they.. are you using 1.55 dia springs.. I have clearanced a couple sets of rockers to clear for roller springs.. make sure you get a radius in the corner so they dont crack... the rockers I did were the blue MP (Crane) alum ones Hey Mike I like the pictures of his because they don't look like they need too much work and they also look to be reinforced in the fulcrum area. Yeah they are decent rockers.. even after I cut them.. I put them in the mill to do it.. I had to have a cutter made for the radius that I wanted.. wasnt too bad on price and I still have that bit
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Re: small block rocker arm clearance help needed
[Re: rumundo]
#2425063
12/28/17 09:16 PM
12/28/17 09:16 PM
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Joined: Jan 2003
Posts: 1,255 Columbus, GA
Michael Ecks
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,255
Columbus, GA
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FWIW I ran the exact same cam with Comp 901 springs (single with damper) and stock retainers with no problem. Totally different rocker arms, just saying I don't think you need the dual springs Lunati recommends. I think they call for their same dual spring for the voodoo cam that is a step below that too. Before I set mine up I looked at all the other cam manufacturers and no one else was calling for a dual spring for the cams in the 60403's duration and lift range.
What retainers are you using? In the pics you posted it almost looks like the retainer you are using is wider than the spring itself. IIRC retainers are usually slightly smaller diameter than the spring OD. It looks like you're pretty close, if that's the case a smaller retainer diameter may get you where you need to be.
"The happiness of your life depends upon the quality of your thoughts" ~ Roman Emperor Marcus Aurelius
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Re: small block rocker arm clearance help needed
[Re: rumundo]
#2425096
12/28/17 10:31 PM
12/28/17 10:31 PM
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Joined: Oct 2007
Posts: 4,213 New York
polyspheric
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master
Joined: Oct 2007
Posts: 4,213
New York
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You're removing metal at one of the worst possible places: it's always in tension, and near the mid-point (between the rocker shaft and the roller axle) is even worse. Make the smallest possible notch, only exactly where you need it, and blend it into the remaining shape until it's invisible. An FEA projection will show the notch in bright red. Yes, that's exactly where it may break.
Boffin Emeritus
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Re: small block rocker arm clearance help needed
[Re: polyspheric]
#2425101
12/28/17 10:41 PM
12/28/17 10:41 PM
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Joined: Feb 2007
Posts: 1,608 fresno ca
mikeysmopars
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Joined: Feb 2007
Posts: 1,608
fresno ca
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[quote=polyspheric]You're removing metal at one of the worst possible places:
Just had a buddy cause a bunch of damage to his small block because of this exact thing. The machine shop that built his engine clearanced his HS rockers and left less than an 1/8 " of material at it's weakest spot and when it broke pieces went through the oil system, it's looking like he will go back with HS rockers and they told him they could clearance them without sacrificing strength.
Last edited by mikeysmopars; 12/28/17 10:42 PM.
Founder and CEO of the Central Valley Mopar Drag Pack
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Re: small block rocker arm clearance help needed
[Re: mikeysmopars]
#2425110
12/28/17 10:56 PM
12/28/17 10:56 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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There have been HUNDREDS of guys that did this with no issues.. I did it running roller cams and high spring pressures.. hell they tell you that you can in the Mopar small block book
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Re: small block rocker arm clearance help needed
[Re: rumundo]
#2425122
12/28/17 11:07 PM
12/28/17 11:07 PM
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Joined: Oct 2007
Posts: 4,213 New York
polyspheric
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master
Joined: Oct 2007
Posts: 4,213
New York
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It's actually not strength but stiffness - the rocker shape concentrates bending stress right there, and when it bends a few thousand times the aluminum just gives up. Steel would not only be much stiffer (1/3 as much material with equal stiffness - yes, really) but also recover from worse distortion without failure.
Being the OCD that you all love, let me amend their statement: "we can clearance the rocker to safety without compromising the strength... to the point of failure... in your engine". With a 900 lb. spring, or 10,000 RPM, that wouldn't be safe.
For long mileage with big springs, investment cast steel rockers is the best bang for the buck. Any structural aluminum part will eventually fail in service, it's not a quality or design flaw, they just don't have the "memory" of steel parts. Pratt Institute has steam engines built in 1900, still running with the original rocker arms.
Boffin Emeritus
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Re: small block rocker arm clearance help needed
[Re: rumundo]
#2425156
12/28/17 11:53 PM
12/28/17 11:53 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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master
Joined: Sep 2014
Posts: 4,457
Washington
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DO NOT GRIND ON THE ROCKER ARMS.
That's not the correct way to fix it. You don't have enough spring diameter to have an issue.
What you have is a geometry problem. Fix the problem it's your geometry and you won't have rockers hitting the springs. You don't need beehive springs.
Contact Mike at b3racingengines and have him help you correct the geometry.
I run the same rockers as you do and a 1.500 spring. With the geometry correct I can run a 1.625 spring and not hit the rocker.
FWIW I had to raise my shafts .280 and IIRC .100 towards the intake manifold.
Don't grind the rockers.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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Re: small block rocker arm clearance help needed
[Re: madscientist]
#2425296
12/29/17 12:24 PM
12/29/17 12:24 PM
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Joined: Oct 2011
Posts: 559 Idaho
LaRoy Engines
mopar
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mopar
Joined: Oct 2011
Posts: 559
Idaho
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DO NOT GRIND ON THE ROCKER ARMS.
That's not the correct way to fix it. You don't have enough spring diameter to have an issue.
What you have is a geometry problem. Fix the problem it's your geometry and you won't have rockers hitting the springs. You don't need beehive springs.
Contact Mike at b3racingengines and have him help you correct the geometry.
I run the same rockers as you do and a 1.500 spring. With the geometry correct I can run a 1.625 spring and not hit the rocker.
FWIW I had to raise my shafts .280 and IIRC .100 towards the intake manifold.
Don't grind the rockers. I'm inclined to agree. Nothing wrong with the rockers, the shafts are in the wrong location.
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Re: small block rocker arm clearance help needed
[Re: LaRoy Engines]
#2425307
12/29/17 12:44 PM
12/29/17 12:44 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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On my W-5 heads I had to add a .060 piece of stock under the mounts to get things right but those use TD paired rockers and PR oiling.. they are great now.. I dont like to grind on steel rockers.. they have less material to work with.. unlike the alum rockers which have a pretty thick section where it touches(at least with a 1.55 spring and the Crane rockers)
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Re: small block rocker arm clearance help needed
[Re: MR_P_BODY]
#2425320
12/29/17 01:08 PM
12/29/17 01:08 PM
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Joined: Oct 2005
Posts: 1,927 Seaford, Va
Kindafast
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Joined: Oct 2005
Posts: 1,927
Seaford, Va
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Anytime you grind on something I agree it looses strength but for the nominal amount needed from what I see on the rockers I would say sure try to adjust your shafts a little but at the end of the day if the rockers are too close grind them if needed. I have seen it done over the years to many , many setups and have not seen them fail yet. Again my 2 cents only
6.50 @105.26
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Re: small block rocker arm clearance help needed
[Re: Kindafast]
#2425368
12/29/17 02:43 PM
12/29/17 02:43 PM
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Joined: Sep 2014
Posts: 4,457 Washington
madscientist
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master
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Washington
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Anytime you grind on something I agree it looses strength but for the nominal amount needed from what I see on the rockers I would say sure try to adjust your shafts a little but at the end of the day if the rockers are too close grind them if needed. I have seen it done over the years to many , many setups and have not seen them fail yet. Again my 2 cents only I'd agree with you if he was running a bigger diameter spring. They just aren't that big. The reason the rockers are hitting is because the OP has changed enough pieces in the system that the rocker shaft is now too low, and too close to the springs. The shaft needs to go up, and towards the intake manifold. Back in the day, the ONLY way to fix this issue was to mill down the stands and use offset blocks and shafts just like W-2 stuff. It was costly and most guys wouldn't do it, so they ran with geometry wrong. The only guy I know who makes the pieces to correct geometry without milling the stands is Mike at B3 racing engines. His system is cost effective and works. It's very simple. I used it with my PRW rockers. Lash caps and all that other stuff won't correct the geometry. It just kills me to see guys grinding rockers, running lash caps and doing all kinds of things to cobble the valve train together. Someone has made it simple to correct and we should all be doing it, rather than grind on a rocker arm.
Just because you think it won't make it true. Horsepower is KING. To dispute this is stupid. C. Alston
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