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Having an extra set of formerly sludged up and oil caked rockers and shafts for a 3.5, I decided to engineer up an adjustable rocker arm. I cut the top off the hydraulic arm, pressed out the hydraulic guts, then honed the opening to .495", and pressed in a .500" by .75" bushing. That was threaded with a 3/8-24 pitch tap. I used a Crane adjustable rocker screw and locknut and redrilled the oil hole so oil will flow out the top of the rocker just behind the locknut and oil the top end like the hydraulic rocker would.
Now, you may be asking why I would take a perfectly good rocker arm and do this, and to what end. My devious mechanical mind knows that a solid valvetrain can handle more lift, operate faster, and go to a higher rpm without valve float. This is a major advantage when using custom ground cams, since the base circle is reduced to increase the duration, but at the cost of lift. The adjustable rocker arm shaft can make up some of that lift, and eliminate the need for lash caps. Those little rascals are over $100 bucks for a set for our engines. You also have no lifter/lash oil up when the engine is cold, just an occasional valve adjustment. Stay tuned, as I make 23 more of these fascinating little rockers and try an install and adjust on the mighty stroker.:D

 

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That's radical, dude!
 

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Discussion Starter #5
If this works out, I may have to source a set and get a custom set from you!!
I'm thinking that I may custom make some. Have to see what it costs me to make a set and figure out some labor costs.
 

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Noice....
Staying tuned
 

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Discussion Starter #9
Thank you Gentlemen, I appreciate it. I'm pretty satisfied with how the first one turned out, I have the rest of the rockers, stands and shafts soaking in acetone to get rid of the sludge (if you followed the stroker buildup you saw them on the first engine I brought home). Looking into adding a valve spring damper to the Nitro springs, just for the high rpm dampening effect. I'm feeling that this motor will top 7 grand before the speed limiter kicks in. Unless there is a rev limiter too, I know at idle in neutral it shuts down at about 3500 rpm. I can wind it out easily to about 6500 before I top 35 or 40 mph, so the potential is there for more rpm's before the shift point. Thats holding it in gear and then slapping the B&M into second/third. If I let it upshift on its own, it goes one to two at about 5500 and dogs out for a second like an old 440 with a thermoquad. Sick. Hoping the juice will carry it over that slump.:hit1:
 

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If you dont make it to Carlise this year...I will be eternally disappointed.
 

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I am really thinking I need to source another 3.5 HO to stroke and beef up. I wonder if I could still get asymmetrical pistons tho...
 

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I have a spare set laying around myself. Maybe your modifications will cure that FREAKING ticking at start up. If I prime the engine with the gas pedal to the floor and crank it, start it up, turn it off and crank again for another few seconds she doesn't tap at the top.
 

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Discussion Starter #14
I am really thinking I need to source another 3.5 HO to stroke and beef up. I wonder if I could still get asymmetrical pistons tho...
Asymmetrical pistons???.....:smileyvault-newhere
 

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My devious mechanical mind knows that a solid valvetrain can handle more lift, operate faster, and go to a higher rpm without valve float.
only if it ends up being lighter than the hydraulic it replaces.
Maybe your modifications will cure that FREAKING ticking at start up
it will probably create more, as some lash is necessary to allow for expansion of parts. but probably less lash/tick than a pushrod engine.
but a neat project. like to see how it ends up.
 

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Discussion Starter #17
only if it ends up being lighter than the hydraulic it replaces.

Aha, interesting point, I will have to weigh them. I'm gonna guess the adjustable is a few grams lighter than the hydraulic.

it will probably create more, as some lash is necessary to allow for expansion of parts. but probably less lash/tick than a pushrod engine.
but a neat project. like to see how it ends up.

And yes, there is the inevitable mechanical valve train tick, I'm trying to decipher what cold and hot lash should be for this motor.
 

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Nice mechanical work. I'm surprised you put a 0.005" press fit into a 0.500" hole. Seems the wall thickness of the lifter will hold it.

What machine-device did you use to hone out the lifter? Naturally you re-tapped the 3/8-24 holes afterwards. Custom made bushing or aftermarket valve train stuff?

My Machinist mind would like to know. Plus awesome project!
 

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Discussion Starter #19 (Edited)
Nice mechanical work. I'm surprised you put a 0.005" press fit into a 0.500" hole. Seems the wall thickness of the lifter will hold it.

What machine-device did you use to hone out the lifter? Naturally you re-tapped the 3/8-24 holes afterwards. Custom made bushing or aftermarket valve train stuff?

My Machinist mind would like to know. Plus awesome project!
Yeah I was concerned about splitting the end of the rocker by doing a tight press fit, but the bushing has to fit tight enough so it wont ever move with the constant pounding its gonna take. Plus the bushing will compress a miniscule amount and make thread cutting even better. I used off the shelf pre-fabbed aluminum bushings, .375" i.d., .500" o.d. and .750" long. I used a cut off wheel to cut off the top of the rocker (the curved part facing up). After that I used a 7/16 drill to open the rocker to expose the check valves inside. I then used a press to push the check valve assembly out the bottom of the rocker. I drilled the rocker out to 7/16 then finish honed it with a 80 grit cylindrical roll hone, make a couple passes and mike it, make a couple passes and mike it, till I had it opened up to about .495"-.497". The bushing is a really tight squeeze, but like I said, it can't move. The results would be devastating at 6500 rpm. :shitbricks:

The reason for the sloppy hone, is a handheld die grinder. I'm going to opt for a drill press for the rest of them to get an even and square bore.
 

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Discussion Starter #20
http://www.jepistons.com/Articles/101124-Asymmetrical-Forged-Pistons.aspx

Basically, it reduces the weight and friction of the pistons by reducing the size of the non thrust side piston skirt.

The things I have learned from thinking outside the box and analyzing all forms of 'import tuning' lol
Well that's a new one on me, but I'm an old dog and not into tuners so I miss a lot of new wave stuff. My initial thought on those it that you would set up for some odd cylinder bore wear patterns or undesirable vibrations from offset weight, but I'm guessing they have this solved if they are selling them and people are running them. I get the idea of why they work, but....hmmm, sure does look funny.
 
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