Rocker Arms

cr_bobcat

cr_bobcat

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So I'm curious about how to go about picking rocker arms. I understand the ratios and what it does to valve lift, but I'm more looking at what is and is not interchangeable. Ford didn't really create 1-off rockers for the small inline 6 did they? Would they do something that foolish? Can I use the adjustable rockers from an FE without a significant amount of pain?

I would like to find an economical set of adjustable rocker arms. I know CI sells the adjustables for about $300 (assuming some shipping cost there). But, I can find FE rockers on the ebays for significantly less...

What I am up to for some background information: I'm intending to keep the stock cam for now as this is a head swap/upgrade. I'm not necessarily looking to change the geometry, but looking for adjustable ones because I'm planning on having the head milled to compensate for the larger combustion chambers (Large log replacing a small log). An adjustable set, in theory, would make that transition easier, right? I'm planning on measuring each chamber and my goal is to shoot for something in the neighborhood of 49 cc. Which would mean milling in the 60-80 thou range if I math'd it right (assuming the head is at the spec'd value of ~62cc).

Does this make sense or will my non-adjustable rockers be just fine and dandy if I acquire shorter rods?
 
Fe's are not at all close to fitting, all wrong. Just check when done,may be fine with what you have.
 
I am assuming you are working with a Small Six, look for an early small six, like a 1961 or 62 Falcon, these had adjustable rocker arm assemblies that will bolt onto the later hydraulic lifter head.
 
i keep watching for them to come available, but they are few and far between in these parts. I was hoping that there would be a more readily available solution other than continuing to play the waiting game. I figure that I can always use my existing components till I find something at a reasonable price, but was curious as to what might be out there.

Just out of curiosity, what is it about the small six rockers that there isn't an easily procurable substitute? They some sort of funky, non-standard size? Just seems like a pretty poor job on Ford's part if they weren't sharing components across designs. These are the guys that invented the assembly line so I would've figured that commonality in parts would have been something they would have been familiar with....
 
Hydraulic Lifters replaced the adjustable lifters, no need to adjust every 5K miles or so. I believe 1962 was the last year solid lifters were available in production Ford cars.
 
Howdy:

Adjustable rocker arms and corresponding pushrods were seen in production engines as late as the 1965 model year. officially hydraulic lifters first appeared in the '65 model year, but due to FoMoCos "Empty Bin" policies, adjustable rockers cam even with hydraulic lifters.

Yes, Pre-65 OEM adjustable rockers are getting scarce but they do show up.

The stock hydraulic lifters can compensate for about .125" + or -. So you may be ok with a mill of up to .075". To be on the safe side measure first.

BTW, did you account for the thicker aftermarket head gasket you'll likely be using? Stock steel shim gaskets typically measure in the .025" compressed thickness. Aftermarket composite gaskets measure .045" to .055" depending on brand and head bolt torque. What head gasket will you be using?

Adios, David
 
Hey David!

Yeah, I keep watching for the adjustable train but not much happening in circle that I'm watching in.

I did just order the adjustable pushrods to from Mike to make sure I'm square once I've got the thing in. I'm not counting on finding an adjustable train before this thing goes live so I plan for contingencies. It's the engineer in me...

Speaking of nerdy engineers, yeah, I'm compensating for a thicker gasket. I wrote up a quick GUI program in Matlab where I can enter in various parameters (bore, stroke, deck height, gasket thickness, gasket diameter, chamber volume, and piston dish volume) to compute the static compression ratio. I'm also nerdy enough that I may expand to add in the cam specs and compute a theoretical dynamic compression ratio. For no other reason than "just because I can". I think this thing will evolve as I do other things to the car (cam selection, rear-end ratio, etc). It won't be a full blown Gonkulator, but I'm going to let it evolve...
 
I do not agree with the method of shiming the stands,if you do you will change the geometry between the rocker and the valve tip,may be better but most likely not.
 
Are all the old Falcon adjustable rockers a 1.5 ratio? I see CI sells both 1.5 and 1.6 ratios. Is there an easy way to tell what you're getting? If I try to piece a set together from mulitple places, I want to make sure I don't mix and match...
 
drag-200stang":3ddg0q51 said:
I do not agree with the method of shiming the stands,if you do you will change the geometry between the rocker and the valve tip,may be better but most likely not.
Click to expand...

Should have stated I use adjustable rockers also a help. The factory style slipper tips are much more forgiving and operate over a much wider range than a roller tip rocker. I also detest the use of a roller only tip rockers waist of money in my book and testing at Ford proved it. A full roller rocker or a roller fulcrum wit ha slipper tip has my ok.

Another reason I stopped milling the head around .060 was how close the milling was to cutting into the spark plug threads.
 
Howdy:

All OEM adjustable rocker arms manufactured by FoMoCo are 1.5:1 ratio. Aftermarket 1.6:1 ratio rocker arms are stock arms rebushed with a bias toward the push rod side increasing the effective ratio. It is a very efficient way to gain about .030" of lift on a stock cam.

Hey Turbo, Milling the deck surface of the head is no where near the spark plug threads.

Adios, David
 
Hey David. Thanks! That doesn't sound like something I can do on my own. I have changed my google'ing keywords and am now getting a bit better results. The search continues....

Prost! :beer:
 
Managed to finally find something on fleabay for $85. It's a NOS rocker shaft and 11 used adjustable rockers. 9 of the rockers are complete and 2 are missing the adjusters. I made a second purchase of $35 for 6 adjustable rockers still in the packaging. I assume I can re-use the pedestals from my non-adjustable set. May place an order for new spacer springs but will check the condition of the existing ones first.

I see there is an auxiliary oiling system that can be had for these systems. This worth it?
 
Dumb question, but how much free motion should the adjuster have? The ones I have all appear to be frozen. I was thinking about soaking them all in some penetrating oil, the using blocks of wood to protect the rocker arms, clamp them in a vice and back out the adjusters.

Like I said, probably a dumb question but I've never played with adjustable rockers before.

Prost! :beer:
 
Mine came out with just a bit of muscle to break them loose. I'm not sure what keeps them from coming out of adjustment once they are screwed back in. Locktite?
 
The Rocker adjusters have an interference fit to keep them from moving (and that type will be very hard to turn if it's not still on the shaft and mounted to the head or held in a good vise). Some of the real early model Rockers use a jamb nut to lock them in position. Good luck :nod:
 
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