Adapt stud mounted full roller rockers to a 144-250?

[cameljockey]

Please bear with my ignorance
The following musings are predicated on my suspicion and the suspicion of some others I have seen on another thread that the Yella Terra shaft mounted system is merely an adaption from another motor. (I don’t really know I’m just being Suspicious Aloicois)

1st off I THINK (just my un- informed opinion) stud mounted full rollers are easier to adjust while the engine is running b/c the adjustment is at the fulcrum instead of at the push-rod. Better adjustment means more stability through out the RPM range & longer valve train life, right?

2nd They are cheaper! Almost half the cost of the Yella Terra shaft mounted system. (depending on the vendor of your choice)

3rd high RPM stability is not an issue for the Ford in-lines if I understand correctly they don’t like the REV’s at least the 250 CI does not like to rev past 6000 if we’re lucky! (a stud girdle would be a simple affair I think; but valve cover clearance might pose an issue)

4th did I mention they are cheaper!

5th we could use the same approach for adapting them to our head as the Yella Terra system which looks to me like a properly sized piece of bar-stock with holes in the right locations.(bar-stock is CHEAP!)

I have been pinging some folks at different rocker arm houses around the country.

Compcams is mum so far but I am in touch with a technical consultant over there who is “looking into itâ€￾ right now. :roll:

Harland sharp has suggested using their PN S4002 (see: http://harlandsharp.com/inlineford_amc.htm)
These are meant for the 240-300 Ford 6 if the distances across the head are the same y not? I need to look into this still. But if the distances are the same shouldn’t the angles be also? (By which I mean when the engine is off and the valve closed at TDC the angle between the pushrod and the vertical ideally 90 deg right?)

I have yet to contact Jesel but every thing they make is usually prohibitively expensive even if it isn’t a custom piece.

Besides which there are warranty concerns that get raised with an “off label useâ€￾ which makes any of them some what reluctant to make a suggestion.

Questions that I think need to be answered in order to find a good alternative:
1. valve-stem installed height (known from any manufacturer who makes em)
2. valve-spring diameter (ditto)
3. anything else?
:

If all else fails I will take a rocker arm off of my spare assy in the shed to my local Pick Your Part with my vernier calipers and start comparing there IN the Yard!!!! (I really want and answer)
This is a problem that has weighed heavily on my mind since I joined this forum.
Keep Sixin`

 

[Stubby]

Shaft mounted rockers are more stable.
When setup properly, the geometry is as good as it gets.
Stud mounted rockers are cheaper.
If you look at a roller rocker, you will notice that it has a shaft in it, with a hole drilled in it. It is cheaper to machine one shaft and slide the rockers on it than it is to machine 16 shafts and assemble 16 rockers.

I have purchased several sets of used Nascar rockers ranging from 1.6 to 2.0 ratios. Some Ford and some Chevy. These are shaft mounted and they were very cheap. My intention is to remove the shafts and make a new shaft and stands if nessesary.

If I talked to Comp, I would inquire about the Pro Magnum stainless rockers. The FE rockers should be close. However, from what I have seen for FE motors and Chryslers, they will be priced similar to the Yella Terras.

You are thinking on the right track. That is the track on the outside of the box.

 

[JackFish]

FE rockers are being used on 2.3 engines, which are based on the I6.
And they come in 1.7+ ratios! 8)

 

[Does10s]

Cameljockey,
It can be done quite easily. I've been thinking about it for years!

I'm going to fab a set up using my old 1.72 ratio FMS rockers arm off of my 5.0.

But the Yella Terra do work very well!
Later,
Will

 

[michael_cini]

Wow, I want to see this. I'm curious what the cost would work out to. Please post pics when you get to it!

Cameljockey,
I'm going to fab a set up using my old 1.72 ratio FMS rockers arm off of my 5.0.
Later,
Will

 

[cameljockey]

Does 10s:

I am also incredibly interested in how you might achieve this.
Have you already measured what size of bar stock you would need and to what size you would have to mill it down to.

Jack Fish:

You mentioned the use of FE rockers on 2.3 4 cyl I searched high and low for an instance of this on the internet (Which I only recently discovered they have on computers now!) but I could not find anything I KNOW that I am probably searching in the all the wrong places.

Could you please send me a link?
Thanks for the input

Keep Sixn'

 

[XFlow_Fairlane]

easy solution to this ....they bolt right on the stock head with no mods....


you just need the right stock head!!

Aussie XFlow motor....uses cleveland rocker arms (same as 3.8L v6 and BBC rockers) nice and cheap!!! the allow head and bolt on EFI are a nice bonus too

 

[ap-engines]

I was going to do this on my hot rod Bronco engine, but didn't have the time. One thing for sure with the stud mounted rockers you could run a longer valve and actually get some installed hieght on the springs. .600 lift could be very possible.
What I wanted to do was use a set of used Jesel 2.0 ratio rockers