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-   -   496 Rocker Arm Stud (https://www.offshoreonly.com/forums/general-q/386972-496-rocker-arm-stud.html)

SB 11-28-2025 06:03 PM

Is it done yet ? :kiss::p
Just poking fun. :wink

Brad Christy 11-28-2025 06:11 PM


Originally Posted by SB (Post 4939311)
Is it done yet ? :kiss::p
Just poking fun. :wink

SB,

Stuck somewhere between scope creep and snowball. :picard1::faint2:

It’s gonna be a long winter.

Thanks. Brad.

Tartilla 11-28-2025 11:30 PM


Originally Posted by Brad Christy (Post 4939278)
Tartilla,

I don’t need the tooling. We’ve got all that. I was hoping for a drill/tap guide that would save me a bunch of setup time on the mill. But, with the compound angle of the stud holes, that’s probably not a feasible prospect. Nothing worth doing is easy, I guess. :rolleyes:

Thanks. Brad.

Those pilots are not very long for a hand held solution in my opinion.

The hand held cutters for spring side guides remediation are suitable.


powerboatr 11-29-2025 10:19 AM


Originally Posted by Brad Christy (Post 4939312)
SB,

Stuck somewhere between scope creep and snowball. :picard1::faint2:

It’s gonna be a long winter.

Thanks. Brad.

try being sidelined now 6 weeks, with broken foot
Boxes of stuff sitting on tool box ...that are for the liberator
still have 3 weeks until next x ray
at this rate. March i might get done , at least I broke the foot while in the boat

You are embarking on a path of time, think, set up
action, check and finish, and go.
I am eager to see how good it turns out.



ICDEDPPL 11-29-2025 10:48 AM

The geometry isn`t perfect so you`re going to reinvent the wheel?
You over think wayyy too much buddy.

When I took off the valve covers for the first time after a season of running the Cig this is what I found.
Ran fine, anything better than this will be just fine, go find something else to do.:D



https://cimg8.ibsrv.net/gimg/www.off...67d6799cca.jpg



powerboatr 11-29-2025 11:38 AM


Originally Posted by ICDEDPPL (Post 4939331)
The geometry isn`t perfect so you`re going to reinvent the wheel?
You over think wayyy too much buddy.

When I took off the valve covers for the first time after a season of running the Cig this is what I found.
Ran fine, anything better than this will be just fine, go find something else to do.:D



https://cimg8.ibsrv.net/gimg/www.off...67d6799cca.jpg

faaaaackkkk. Daaammm
All or just the one.
is it just camera angle or is rocker arm bent or twisted ...the high side on valve
the other side looks lower.
That would certainly give me the oh **** look

snapmorgan 11-29-2025 08:30 PM

Just chuck one of the center studs in your mill and then tilt the table to the bottom of the head. Compound angle found. Just that easy

Brad Christy 12-04-2025 08:54 PM


Originally Posted by snapmorgan (Post 4939349)
Just chuck one of the center studs in your mill and then tilt the table to the bottom of the head. Compound angle found. Just that easy

Snap,

https://cimg0.ibsrv.net/gimg/www.off...57f9d60b1.jpeg
https://cimg1.ibsrv.net/gimg/www.off...46f6646d3.jpeg

Pretty much what I did. First you rotate the head on the tilting table until it’s straight in the “X” axis, then tilt the tilting table until it’s straight in the “Y”. There was a bit more to it than that, but that’s the gist. We set up a “guide” against the intake side of the first head, then did either the intake or exhaust studs for both heads (can’t remember which we did first), holding the second head against the guide, eliminating the need to “find” the first angle, then rinse/repeat for the other set of studs. As is very typical with these sorts of projects, there was a lot of setup for not a lot of chip.

https://cimg1.ibsrv.net/gimg/www.off...eb682d0c6.jpeg
Turbulence ramp in the intake runner.

https://cimg2.ibsrv.net/gimg/www.off...6925c484c.jpeg
Gone.

https://cimg3.ibsrv.net/gimg/www.off...824992ddc.jpeg
Quarter sized flat surface facing incoming exhaust flow in exhaust runner.

https://cimg5.ibsrv.net/gimg/www.off...b5accadcf.jpeg
Streamlined. Probably could have done more here. Didn’t have the sack.

Per advice from Larry, Mr. Raylar himself, I decided to do some minor port work, while the heads were all dirty. Larry told me what to avoid. Also cleaned up any parting line flashing and general smoothing of the ports. No real material removal other than the obvious. Took them to the machine shop to be tank washed.

Got my Summit box today, with the new rocker studs and pushrods. I won’t get to play this weekend for reasons, so reassembly will start on Monday. Hopefully.

Thanks. Brad.

Brad Christy 12-04-2025 09:14 PM


Originally Posted by ICDEDPPL (Post 4939331)
The geometry isn`t perfect so you`re going to reinvent the wheel?
You over think wayyy too much buddy.

When I took off the valve covers for the first time after a season of running the Cig this is what I found.
Ran fine, anything better than this will be just fine, go find something else to do.:D



https://cimg8.ibsrv.net/gimg/www.off...67d6799cca.jpg

Dan,

My issue with rocker geometry was in the other direction; the rockers were tilted WAY back, to recover rocker nut thread engagement. The builder had even added a spacer under the studs to recover a couple threads.

Drilling and tapping the rocker stud holes in these heads is not a novel idea. It’s actually a fairly common modification among those who can’t afford the Raylar aluminum heads.

As it is now, I will have 7/16” bottom threads, with deeper engagement than the M10 bottom threads, almost double the rocker nut thread engagement, AND “perfect” rocker geometry, other than the roller being slightly off center on the valve step tip, front to back. I’m good side to side.

Thanks. Brad.

Tartilla 12-04-2025 09:39 PM

Hard to say how you'll fare without the ski jumps. The help bias the port flow and induce swirl...helping keep the fuel atomized and assist in healthy turbulence. It should increase the cfm a bit.

You can have too much swirl. Biased ports are often sufficient.

Have you back cut your intake valves 30°?

Helps with low lift flow..and getting the air moving earlier...allowing it to flow more on the larger valve opening phase.


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