Rocker shaft hold downs

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mattsmopars

mattsmopars

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I was wondering what everyone thought about the A/m rocker shaft hold downs for a small block with factory adjustable rockers? I see that mopar performance and Hughes engines has different kits,witch one is the best? Do you think they are needed in engine that will have about 300 pounds of pressure with the valve open? Do they help in the correct rocker aligment? Just a few questions I had on this so let em know.
Matt
 
Matt,

I'm running Hughes rockers and also they're holdown kit. The one thing to note is that the holdown kit requires machining of the spacers to get proper alignment of your rockers. I found this out after I bought they're rocker kit with the holdowns. The Hughes rockers aren't right and left hand but rather all the same so you have to compensate with the spacers to get the right offset on the rockers so that the tips fall as close to center on the valve as possible. It was a slow process of measuring and remeasuring to be sure before I had them milled to fit.

Just a heads up if you go with Hughes.
 
I have the MP units and thery were a bolt on and go. I don't know if there any better or worse than the Huges hold downs. I used them with Comp Cams roller rockers and MP's HD Hyd. rockers. (OE rockers by any other description)
 
I have the MP and they work good. I also run solid lifters. Haven't had any complaints.
 
I have some from Hughes on my 340, my friend also runs them on a 440, work great!
 
Has anyone else had to machine anything to run the hughes hold downs? Or is he talking about the spacers that go under the rocker shafts to space them up? I do not need any thing to move them up as the geometry is good where they are. I am sort of wondering if I need these over the factory hold downs while runnig solid cam and factory type adjustable roackers? Also looking to help with the rocker alinment over the top of the valve tip.Tyanks to all who have replied and keep the info flowing!
Matt
 
Recently bought the Hughes holdowns for a 340 & they are quite nice. Not sure what machining would be needed, mine worked great with the supplied spacers. It was also very easy to set up using feeler gauges to set the side-to-side clearances & get them properly centered visually. To stock stamped ones are much more tedious to set up as you typically have to file the ends of the stampings to get them just right. The only (minor) problem I had with the Hughes setup was the length of the studs, most were a bit too long on the portion that threaded into the heads & required shaving. No big deal but could be big trouble if you didn't notice & just torqued to spec.
 
The maching that was required was to the holdown blocks. Maybe this is only required when you use Hughes rockers and not stock rockers because the rockers are not left/right specific like factory. Maybe Hughes sells factory replacement holdowns that I'm not aware of.
 
416stroker said:
The maching that was required was to the holdown blocks. Maybe this is only required when you use Hughes rockers and not stock rockers because the rockers are not left/right specific like factory. Maybe Hughes sells factory replacement holdowns that I'm not aware of.
Click to expand...

SO THERES NO OFFSET FOR THE PUSH ROD TO CLEAR THE INTAKE RUNNER?
 
I Just Talked To Hughes Engines About Their Hold Downs. They Are Not Aware Of Having To Machine The Hold-downs. The Stock Stamp Rockers Are Marked Lft & Rt, Because They Don't Have Spacers To Alighn Them. If You Look At A Stock Rocker, The Push Rod Is Inline With The Valve Tip. This Is Why The Hughes Complete Rocker & Shaft Kits Come With Spacers & Shims. This Is Used To Alingn The Rocker. There Is No Offset From The Valve To The Push Rod.
 
Okay once again. I have the Hughes rockers and their holdown kit. Right in the instructions it says that you may need to machine as necessary the blocks to to insure proper rocker tip to valve tip alignment. There are round spacers that go in between the intake and exhaust rockers and the shims are used to get the right amount of clearance there. The 2 wider holdown blocks out of the 5 are oversize and these are the ones that need to be machined. I'm running Eddie heads which are designed to accept stock valve train hardware. I compared one of the stock rocker shaft holdown blocks to the Hughes and the Hughes is wider. When I put the Hughes blocks on the shaft, I was no where even close to having the roller tips centered on the valves. When I completely assembled the rocker shaft and tried to install it, I couldn't even get the last holdown bolt into the head because of how much everything was off to one side do to the stack up of the larger spacers.

I called Hughes about it at the time and was told that yes, machining was required on the blocks to get the proper alignment. So I guess they either have changed their design in 4 years or somebody isn't being told the whole story.
 
The instructions in the Hughes rocker holdown kit covers part number 7440 and 7442. The very first paragraph states as follows..."These heavy duty hold-downsare not "drop on" and require custom fitting. Careful attention to our installation intructions will give you the best results".

Then at the bottom of the instruction sheet in the last paragraph is says..
"Tips: If it becomes necessary to remove material from the ends of the hold-downs, keep the cut as square as possible. De-burr before final assembly.

The instructions say that the part number 7442 is for big blocks and the 7440 is for the small blocks.

Like I said before, maybe they aare using something different now that I'm not aware of but if not, user beware. Some machining "may" be necessary depending on your particular setup.

I hope this info helps.
 
I just checked out the Hughes website for part number 7440 hold-downs and they have changed the design of that kit since I bought mine. The ones shown aren't anything like the ones they sold me. My hold-down blocks are a square block and not finished off on the ends like the ones in the picture, so that tells me that they have made a change to the design that I have, in which case they may no longer need to be machined. If thats the case, I wish they would of had that style back when I put my engine together. It would have save a whole lot of time and measuring!!!
 
Yea, I Had Emailed Them. They Didn't Say Anything About Changing Them, That Might Be Why They Supply The Thin Shims Along With The Spacers, To Keep You From Having To Machine The Spacers. I Just Got A Rocker & Shaft Set From Hughes, I Forgot To Order The Hold Downs. When I Seen Your Comment, I Got A Little Concerned.
 
Yeah I talked to them this morning and told them about my hold-downs versus what's now shown on the website and Tim wasn't sure when the change had been made but did remember the style I had after I described them to him. So at some point in time the design got changed and they didn't pay to much attention to it at the time.

Now you can just install the new design and add the necessary shims where needed and be done with it. A whole bunch easier than when I did mine.
 
I am running Edelbrock heads, Comp Cams Pro Magnum rocker arms, and the Hughes Hold Down Kit. Everything fit like it was made for each other. The hold down kit required no modifications. It didn't even need any shims and all the rockers lined right up with about .020" side to side clearance for each pair of rockers.

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