Rocker Arm help

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Archeryguy02

Archeryguy02

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I recently purchased some Mancini 1.5 roller rockers for my bracket car, link below.
Mancini Racing Aluminum Roller Rocker Arm Kit

The motor in my bracket car currently has 273 adjustable iron rockers on it which ran fine last year but I wanted to upgrade. Is it reasonable to believe that I can correct the terrible geometry shown in the pics with a simple pushrod length adjustment or is there a method to change the rocker location that is fairly simple that will be needed as well? At base circle its past center to the outside and almost all the way to the edge at full lift. The dykem barely shows the mark as with it being so bad I only rolled it over a few turns.

The motor is a .030 360 with a .600" solid roller cam.

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That is typical. You can’t fix that with pushrod length because it’s a shaft mounted rocker.

Contact Mike at B3racingengines.com and he will fix you right up.
 
What if you raise the shaft? I'm not able to see where the patch is but iirc raising the shaft will move the contact patch at lift toward the pushrod.
 
i almost ordered those mancini rockers, but i emailed Harlnd Sharp to ask about fulcrum length. the PRW steel rocker arms are shorter so I gave those a shot instead. The contact patch looks better than above...using RHS heads.
 
RustyRatRod said:
You need to contact Mike at B3 engines. He's a member here and can help fix all that up. A pushrod change will not correct "that". You are going to have to relocate the rocker shaft. Nuthin to it. Mike can fix you up.
B3 Racing Engines LLC - Performance Engine Building and Mopar Valvetrains
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Thanks guys talked to Mike, he is a very knowledgeable straight shooter. After talking to him for a bit I am going back to my old rocker set up until I upgrade my heads or take the motor apart as there are no real bolt on options that wont likely require cutting on the heads.

Also I am running Speedmaster heads due to the way the shaft saddles are cut he doesnt condone use of his kit until this issue is corrected.
 
Archeryguy02 said:
due to the way the shaft saddles are cut he doesnt condone use of his kit until this issue is corrected.
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Would that be saddles whose radius does not match the shaft radius, so the shaft slightly rolls or rocks in the saddles? And along with that, the actual width (from pushrod side to valve side) of the saddles radius, as cut, is narrow?
 
12many said:
Would that be saddles whose radius does not match the shaft radius, so the shaft slightly rolls or rocks in the saddles? And along with that, the actual width (from pushrod side to valve side) of the saddles radius, as cut, is narrow?
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Yes, the saddles are incorrectly machined on the speedmaster heads, I've mentioned it numerous times on this site, to the sound of crickets.
 
replicaracer43 said:
Yes, the saddles are incorrectly machined on the speedmaster heads, I've mentioned it numerous times on this site, to the sound of crickets.
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I think the problem with talking about Speedmaster heads is they are a hot button topic for many. Some absolutely hate them, some think they are a good value with some risks, and some wont run anything besides cast iron. I am somewhere in the middle, with good components I am getting a good bang for the buck on these heads until I spend 4 times as much to run Trick Flows something of the like. I also understand there is a bit of elevated risk, I bought bare castings and had them assembled with good components to negate much of that risk. There is also no shortage of quality issues with other domestic manufacturers as well.

I think important stuff like the issues with the saddles gets lost in the mix of the posts about them just being total Chinese garbage.
 
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Have your machinist work the saddles to correct the geometry.
 
Switching from steel to alum rockers is a downgrade, nut an upgrade.
 
I had the same problem you are having, same heads/rockers. I ran lash caps to make sure the roller didn't run off the valve. I ran like that for a season and a half without it being a problem. I will say that if you ever decide to put trick flow's on it those rockers are about a perfect wipe as you can get. They also work good on stock heads.
 
So I inspected my saddles last night and compared them to some J heads I had with a radius gage. There is no high spot in the middle and my rocker shafts nest tightly with no movement. If anything there is a slight amount clearance at the very bottom of the radius allowing the shafts to seat cleanly around the radius. I am guessing my heads are new enough for the high spot issue to have been corrected.

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73smallblock said:
I had the same problem you are having, same heads/rockers. I ran lash caps to make sure the roller didn't run off the valve. I ran like that for a season and a half without it being a problem. I will say that if you ever decide to put trick flow's on it those rockers are about a perfect wipe as you can get. They also work good on stock heads.
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Good to know, I may hang on to them for when I get some Trick Flows or incase I ever go back to my J heads.

I am wondering if the chevy valves my engine builder put in these heads could be contributing to the issue? Because the stock type adjustable iron rockers (273 type) have great geometry on these heads. Also Mike at B3 says 1.6 rollers seem to have way better geometry in general.
 
Archeryguy02 said:
So I inspected my saddles last night and compared them to some J heads I had with a radius gage. There is no high spot in the middle and my rocker shafts nest tightly with no movement. If anything there is a slight amount clearance at the very bottom of the radius allowing the shafts to seat cleanly around the radius. I am guessing my heads are new enough for the high spot issue to have been corrected.

View attachment 1715875694

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My heads have been on for a couple years,I don't recall seeing the issue on mine, but I have one of Mike's kits, so I'm looking through the pictures from my motor build to try and confirm.

Can you post the mfg date that's stamped on your heads?
 
Archeryguy02 said:
Good to know, I may hang on to them for when I get some Trick Flows or incase I ever go back to my J heads.

I am wondering if the chevy valves my engine builder put in these heads could be contributing to the issue? Because the stock type adjustable iron rockers (273 type) have great geometry on these heads. Also Mike at B3 says 1.6 rollers seem to have way better geometry in general.
Click to expand...

What is the length of the Chevy valves that your machinest installed? If they are much different in length from the stock valves that the adjustable rockers were designed to be run with things will change.
 
TurboGLH said:
My heads have been on for a couple years,I don't recall seeing the issue on mine, but I have one of Mike's kits, so I'm looking through the pictures from my motor build to try and confirm.

Can you post the mfg date that's stamped on your heads?
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I will try and find it to see. I would think based on when I bought them sometime in 2020.
 
my68barracuda said:
What is the length of the Chevy valves that your machinest installed? If they are much different in length from the stock valves that the adjustable rockers were designed to be run with things will change.
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I am not sure, I will look to see if its on the old invoice. I believe its all about installed height, but what I know is the stock type adjustable rockers that are on it currently line up great which should indicate the heads are a good copy of factory.
 
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