HEMI Tech- Rockers, valves, pushrods, springs

Makes sense. To be honest I don't know a lot of folks running solid lifters on the street. If rev kit type helper springs were placed on the rockers would it just transfer the wear to the valve stem side of the rocker?

 

I did that back in the sixties (and I still run them) but they're not available anymore as far as I know. I was wondering what others were doing.

 

I havent seen them as a kit other than on ebay and the only once or twice. i have seen similar springs and wondered if i could find the right ones. I do remember seeing pics of yours.

 

Milodon made them. we ran them on out AA/FD front engine car in the mid sixties. I put a set on my hemi in '65 and solved the pushrod wear issue. I bought a spare set a couple of year later and had to use one of the springs last fall when one of my original springs broke.

I've looked off and on for years and never saw any listed anywhere.

They're a pretty simple arrangement -- springs, chrome-moly rings (to hold the spring onto the outer end of the rocker) and over-the-counter hose clamps.

All you need is a chunk of 1/2" square stock with a slot in it to install the springs under the chrome-moly rings. Slip the bar in a 1/2" drive extension for leverage and pull the spring down to the tip of the rocker and slip the ring over it.

 

Note the missing portion of the spring on #8 intake rocker

 

Are they needed on a street car?
Are they harder on the valvetrain?

 

If you're running a solid lifter cam, yes, they're definitely necessary.

Any lash in the valvetrain will cause the pushrod to beat itself into the oil holes in the rockers and since valve lash is necessary with solid lifter cams pushrod wear is a given. It's a non-issue with a hydraulic lifter.

The springs (they're, actually a Milodon super Rev kit from the sixties) put tension on the entire valvetrain so that the pushrod and rocker maintain constant LUBRICATED contact.

 

What did the factory do to avoid this issue?

 

The factory used adjustable rockers with a ball end that fit into a cupped pushrod end for the solid lifter engines (Industrial and Marine applications).

Examples can be found in previous replies to this post.

Here's a cut and past from a few replies back. A bit more high tech but nearly identical to the factory adjustable rocker set-up. This style rocker cannot be used with stock valve covers as the exhaust rocker adjuster hits the cover. All Industrial and Marine engines have dimples between the spark plug holes on the valve covers to clear the adjuster nuts.

For the passenger car engines (except the 300 series) they used hydraulic lifters. If slack started to build up (usually due to a collapsed lifter) the pushrod would eat it's way into the rocker arm. Same was true of the poly head engines.

 

Thank you. I'm using factory adjustable rockers with a solid cam so I guess I'm ok.

Adam

 

Yea, that's the way to go but those rockers aren't as plentiful as the hydraulic ones and guys are making the mistake of trying to use non-adjustable rockers with solid lifters without thinking about the consequences.

I was wondering if anyone had come up with a solution similar to the Milodon set-up.

 

This might be a dumb question, but were your rockers thermally cleaned? Or any other process that may have tempered some of the hardness out of them? I thought the rockers were (induction?) hardened at the pushrod seats...

One more thing... Skip is using the 1/4" dia ball pushrods which has much less area than the 3/8" dia ball used on the 300 rockers - so the contact stress is much much higher.

 

The bottom line is that you can't use the hydraulic lifter rocker arm setup without using some sort of extra equipment to remove the slack from the valve train when you run a solid lifter cam. Even in stock hydraulic configuration, if a lifter went south, the slack would eat up a pushrod as it worked it's way into the rocker arm oil hole. That happened to my dad's '55 Windsor poly-head before I was even old enough to drive.

I want to know if there's anything other than the sixties-era Milodon setup available for the task.

FWW, I haven't eaten up any more pushrods in normal street driving (everything from going to local rod runs to Banzai 3000+ mile round trips to the Canadian Nationals and/or Bonneville) since installing the Milodon setup in 1965.

Since the Milodon stuff isn't available anymore and I have been, recently, involved in addressing a similar issue in two different engines, I've started looking for alternatives for these guys.

 

Is there different length pushrods for adjustable vs non-adjustable rockers? I'm thinking about converting my rockers and have been wondering about the pushrod length, seems like the stock pushrod will be too long and also wondering if I can shorten them or are they hardened at the tip?

 

Since you like the way that your particular system works why not just have some new 'mouse-trap' springs made for the new projects?
And, with a wee bit-o-pondering you could likely find a way around the hose clamp if desired.

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They're not "new" projects. They're someone else's broken projects awaiting repairs.

Gotta fine someone to make the springs and the chrome-moly loops if I go that route.

 

I have a connection at a local shop that makes (winds) springs...

 

What are you planning on using for the adjuster screws?

 

That would be my next question, I could use the 426 hemi adjusters and a cup on the pushrod or Ford FE adjusters that have a cup end like the original and then use stock type end on the pushrod. The FE adjusters are salty.

 

Howdy, everybody, newbie here. I'm a lifelong Mopar man, having gone through enough A-B-C bodies with various LA/RB engines, A833s, 727s, 904s and everything associated I could have retired long ago had I, like many of you, only held onto them. Oh, well.
I dragged home a '51 Imperial several months ago, for no reason other than I had to. It is 99% factory original. I am going through the entire engine now after it ran pretty poorly once I got it started. My problem right now is that I have not been able to find any info among all the great stuff here and elsewhere regarding exactly how to remove the turned-down dowel in the No. 2 rocker supports to clean the gunk out of this critical oil passage. I have already discovered that it has to come out from the bottom, and that pressure alone isn't going to work. I'm thinking it needs a hot wrench while being slowly pressed. How much heat do I need? Or is there a better way?

 

Disassemble the rocker assembly completely, shafts and all. Drop the two oil feed rocker stanchions (one from each side) in a jar of acetone and close the lid for a couple of days.

Pull them out a couple of days later and rinse the crud away.

While you're at it, knock the Welch plugs out of the ends of the shafts and clean them as well. A new set of plugs and you're in business.

Re-assemble the rockers, flip them over and, with a Plews oiler, pressure-fill the rockers through the oil feed hole in the stanchion until oil oozes out around every rocker. Now plug the oil feed hole in the second stanchion with a dab of chassis grease to prevent the oil from draining back out and re-install the now-filled rockers back on the heads.

When the engine fires, the grease will be pushed up into the rocker shaft where it will dissolve in the oil.

 

Thanks, Desoto. I've already done all the rest (except the oil fill). I just need to get that coked-up crud out of the two feed stanchions. I will treat them to an acetone soak, then use the same to flush until it runs clear. Thanks again.

 

But that 3/8" ball on the 300 and industrial engines is on the rocker adjuster stud and the pushrod has a cupped end, not a ball end that wears into the lubrication hole in a non-adjustable rocker.

 

At the risk of pushing a sore topic, I was wondering if anyone has experience with SBC valves in a high block DeSoto. Specifically, I was wondering if anyone has looked at flow using 15* undercut valves or tulip valves in the Hemi heads. Do they help, hinder or just make no difference at all? Looking at little tricks that can be borrowed. Of course, I realize that valve guides would need to be redone to take the 11/32 or 8mm stems.

 

A valve is a valve is a valve........The only real requirement is that it fits properly. Not too tall, not too short. The stem diameter is a non-issue.
For length you do have some wiggle room but you must consider all of the operating parameters which then includes the springs (coil bind anyone?) and rockerarm geometry.
For example, the use of a 'tall' valve in a Hemi usually often causes conflict between the retainer and the underside of the rocker arm so then you need to look at using beehive springs or raising the shaft centerlines of rockers and......
The valve face is not usually an issue but do not sink the seat into the head as this will screw up air flow. A heavy/deep tulip will add cc's to the chamber.


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I've never run a early hemi with solids. How often do you have to change valve lash? Henry did it on flat heads by grinding valve stems some engines do it with select fit lash caps.

 

The problem with the early hemi is the short installed height. There is no room under the retainer. Using a cam over 500 lift can create problems. The spring selection is poor. That led to the bandaid helper spring.
The fix is using .100 longer valves and the proper stands that lift and spread the rocker shafts.
The last pic shows missle rockers and stands with a two inch installed height. There is plenty of room under the rocker and retainer. The roller wheel is in the center of the valve. The push rods are the correct length with only 1-2 threads showing.

 

I want to get back to potentially mis-matched lifter and pushrods. This is a subject I know nothing about and wonder if I have a potential problem with the engine in my dirt modified. I have an Engle roller tappet cam in the '54 331. I am running after-market adjustable pushrods (sorry, the manufacturer has been lost in the mists of time), Donovan exhaust rockers, and stock intake rocker arms. The engine runs good and strong, and although it may have 50 or so hours on it, I always select the QC gears so the max RPM I run at each track rarely exceeds 5500. The guy who built the engine said nothing about this, and I think he knew what he was doing because he knew enough to get a bronze distributor gear and to replace the "drag race" springs that came with the cam with a set with lower installed pressure. I'm thinking I should get a "Rev-Kit" (if available). Anyone have an opinion?

 

I've seen your car run so you know what you are doing . But because the rocker bolts and the valves are not on the same plane how far can you go adding to the valve stem and raising rockers before the end of the rocker and the valve stem don't line up right.