Best Offster Rockers for RPM

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JedIEG

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I am considering moving the pushrod holes on my RPM heads to open up the pinch point. I would like to use reasonably priced, shelf rockers on this setup (Sub $1000 price point so T&D, Harland Sharp, Manton are not being considered). What offset would you recommend and why?
Here are the readily available offsets I can find-
0- Stock Small block
0.180- Stock Big block (Indy T/A)
0.350- Hughes Big Mouth
0.650- Offset Big Block

The 0.180 offest rockers seems like a good bang for the buck and avalible in stamped steel, stainless and ductile all for around $300. I'm just not sure that is enough offset to be worth the hassle.
 
JedIEG said:
I am considering moving the pushrod holes on my RPM heads to open up the pinch point. I would like to use reasonably priced, shelf rockers on this setup (Sub $1000 price point so T&D, Harland Sharp, Manton are not being considered). What offset would you recommend and why?
Here are the readily available offsets I can find-
0- Stock Small block
0.180- Stock Big block (Indy T/A)
0.350- Hughes Big Mouth
0.650- Offset Big Block

The 0.180 offest rockers seems like a good bang for the buck and avalible in stamped steel, stainless and ductile all for around $300. I'm just not sure that is enough offset to be worth the hassle.
Click to expand...


I’ve traveled this road and I just curious how much cfm are you looking for??? Do you have any rocker arms now???
 
steel rockers does not equal high rpm. Sorry man but you need those Harland sharps
 
pittsburghracer said:
I’ve traveled this road and I just curious how much cfm are you looking for??? Do you have any rocker arms now???
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I think to achieve my goals I need about 300cfm by .550" lift. The Edelbrock intake port is pretty UGLY IMO especially with that pushrod pinch and bolt boss sticking out next to the bowl. My first impression on fixing the port is to smooth out the pinch and try to get rid of the re-expansion from that.
 
Harland Sharp, T&D, Jesel

I know, you weren't considering those, but your title says "best offset rocker". I tend to agree with post #2 as well.
 
JedIEG said:
I think to achieve my goals I need about 300cfm by .550" lift. The Edelbrock intake port is pretty UGLY IMO especially with that pushrod pinch and bolt boss sticking out next to the bowl. My first impression on fixing the port is to smooth out the pinch and try to get rid of the re-expansion from that.
Click to expand...


Ok I went back to look at some of my past flow numbers. [email protected] is doable with a 2.08 valve. [email protected] is doable with a 2.05 valve. The pinnacle isn’t the problem, the last of available good volume is the problem. You still haven’t answered my simple question of “do you presently have rockers”
 
pittsburghracer said:
Ok I went back to look at some of my past flow numbers. [email protected] is doable with a 2.08 valve. [email protected] is doable with a 2.05 valve. The pinnacle isn’t the problem, the last of available good volume is the problem. You still haven’t answered my simple question of “do you presently have rockers”
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^^^Agree^^^

The PR pinch complicates things, but it is capable of well over 300 cfm without relocating. 2.02 valve can flow 290-295 by 0.550.
 
Ok for the sake of this discussion, let me revise my parameters. Let's discuss the best offset regardless of brand to improve the RPM head.
The goal is a steetable head that could go on a ~400cid engine and make 500lbft/500hp


pittsburghracer said:
do you presently have rockers
Click to expand...

I have stock stamped rockers for BB and SB and a set of SB speedmaster stainless on the shelf. So essentially no, I have not purchased a set for this build.
pittsburghracer said:
The pinnacle isn’t the problem, the last of available good volume is the problem.
Click to expand...
Referring to low lift flow I assume? Off topic, but If you had to prioritize either offsetting the pushrod or a bigger valve which would you go after?
 
JedIEG said:
Ok for the sake of this discussion, let me revise my parameters. Let's discuss the best offset regardless of brand to improve the RPM head.
The goal is a steetable head that could go on a ~400cid engine and make 500lbft/500hp




I have stock stamped rockers for BB and SB and a set of SB speedmaster stainless on the shelf. So essentially no, I have not purchased a set for this build.

Referring to low lift flow I assume? Off topic, but If you had to prioritize either offsetting the pushrod or a bigger valve which would you go after?
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Ok that semi simplified the discussion on my end because I was going to say if you already had Harland Sharp rockers they could make you eight .350 offset intake rockers like they did for me. If you look at a couple of builds on this site such as @tvt59, my build, and several other we are all running stock location pushrods. The BPE heads, Edelbrock, Speedmaster, ProMax, and many other heads are easily capable of 500-600 plus horsepower. Heck stock heads can be made to hit over the 500 horsepower mark in the right hands. I would spend some time in the 9-10 second builds area and do some reading. Remember the pinch isn’t the problem
 
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Not addressing the OP’s question directly, but no way would I mess with offset rockers for something in the low 500/500 range.

If you’re not building a combo that’s capable of considerably more power than that…….some basic clean up work on RPM heads is all you need.
 
Buy the T/A offset rockers and do it. You don't need more than the T/A offset so no need to use anything else.

I didn't see how many inches you want to feed or at what RPM but if I had the choice everything would get an offset rocker.

Getting guys to pay for the rockers and doing the work? That's the impossible impossibility.
 
Newbomb Turk said:
Buy the T/A offset rockers and do it. You don't need more than the T/A offset so no need to use anything else.

I didn't see how many inches you want to feed or at what RPM but if I had the choice everything would get an offset rocker.

Getting guys to pay for the rockers and doing the work? That's the impossible impossibility.
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If you are going to recommend doing it why stop short with a TA rocker???

Hardly worth the extra effort
 
pittsburghracer said:
If you are going to recommend doing it why stop short with a TA rocker???

Hardly worth the extra effort
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Because it IS worth the extra work and you can't move the port far enough to need more offset.

Regardless of what the flowbench says, getting the push rod pinch out of there is a power maker. Had I not already had rockers I would have bought offset rockers for mine.
 
I’m pretty sure the factory T/A intake rockers are offset quite a bit more than .180.
More like .300-.350 iirc.

Considering the W2 rocker is like .700-.750…..

42180882-2B0C-4B57-89F8-A83CD96E33D9.png
 
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PRH said:
I’m pretty sure the factory T/A intake rockers are offset quite a bit more than .180.
More like .300-.350 iirc.

Considering the W2 rocker is like .700-.750…..

View attachment 1716225190
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You may be correct on that. I forget what the exact offsets are, but I'm pretty sure I can figure it out as ALL W2 shafts have the oil feed holes in the T/A location. They are wrong for W2 stuff.
 
Newbomb Turk said:
Because it IS worth the extra work and you can't move the port far enough to need more offset.

Regardless of what the flowbench says, getting the push rod pinch out of there is a power maker. Had I not already had rockers I would have bought offset rockers for mine.
Click to expand...
PRH said:
I’m pretty sure the factory T/A intake rockers are offset quite a bit more than .180.
More like .300-.350 iirc.

Considering the W2 rocker is like .700-.750…..

View attachment 1716225190
Click to expand...


W-2 and T/A offset rocker arms the same?
 
To clarify what I was talking about in my original post- I am not talking about the ductile iron hamoligation rockers with .500 offste found on 1970 AAR/T/A 340+6... I think the only set of these avalible at the moment are $4000...

I am referring to the Indy 'T/A' and Edelbrock Victor Jr set up where they uses stock Big Block rockers.

20240322_111939.jpg


20240322_112531.jpg
 
Indy buys that casting from Edelbrock in an unfinished state, and relocates the rocker saddle to facilitate the use of the longer BB rockers.

Since many theoretically “correct” SB rockers are already too long when used on Ede RPM heads……I can only imagine how poor the situation would be by using an even longer BB rocker on heads with the std saddle location.

The Hughes BM intake rocker probably provides the easiest way to run a moderately offset rocker that’s actually designed to fit a SB RPM head.
 
I would research both the TA and big mouth heads because neither showed anything spectacular at the track.
 
JedIEG said:
I am considering moving the pushrod holes on my RPM heads to open up the pinch point. I would like to use reasonably priced, shelf rockers on this setup (Sub $1000 price point so T&D, Harland Sharp, Manton are not being considered). What offset would you recommend and why?
Here are the readily available offsets I can find-
0- Stock Small block
0.180- Stock Big block (Indy T/A)
0.350- Hughes Big Mouth
0.650- Offset Big Block

The 0.180 offest rockers seems like a good bang for the buck and avalible in stamped steel, stainless and ductile all for around $300. I'm just not sure that is enough offset to be worth the hassle.
Click to expand...
Seems to me you are splatted against the flow wall. There is flow volume and flow rate. Combine the two and you come up with port energy. This is an important value to consider. Also the pinch may direct the flow in an advantageous direction.
Seems like you need to watch some David Vizard videos. Some on here complain he only knows Chevy scrap. Not true. He has experience on pretty much everything with pistons and spark plugs. Get his How to Port and Flowtest book. He and his "partners in crime" (Andy Wood and Charles Servidio) are working on a Mission Impossible 318 project and doing some interesting things with it. Port energy and mixture quality are important factors to consider and are related.
 
JedIEG said:
Ok for the sake of this discussion, let me revise my parameters. Let's discuss the best offset regardless of brand to improve the RPM head.
The goal is a steetable head that could go on a ~400cid engine and make 500lbft/500hp
Click to expand...
You should be able to get 500 hp with 275 ish cfm with a reasonable cam and cr.
 
A stock 2.02 valve with a standard pushrod location will flow in the 290cfm area. But and I said BUTT you have to run a big enough cam to take advantage of it.
 
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