All Big Six Ordered the Scorpion 1059 Roller Rockers

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efloth

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Just ordered the set and should have them next week. I called Scorpion and asked if I should try the new adjustable 3224 set and they sent me one to check valve cover clearance! Unfortunately, no go on the EFI setup. The valve cover rests on the adjusting nut with the valve closed. I tested on cylinder #3 since that is under the intake and the VC is shorter there. The VC would need at least a 1/2" spacer and I don't think it would fit without modifying the intake above.

I am running a 1991 4.9 with everything basically stock. Any pitfalls I should be aware of when installing these? I am shooting for 17ft lbs at 3/4 turn past zero lash but how much variance can hydraulic lifters compensate for? Most of the info out there deals with stud mount rockers but these are pedestal mount. Any insight would be appreciated. TIA
 

THE FRENCHTOWN FLYER

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I think the lifter plunger has about .150" of travel. It would be best to use a collapsed tappet gap checker to verify the preload. It is essentially a pry bar. But be careful - it is pretty easy to bend the puny 5/16 pushrod if too much pressure is exerted on the rocker arm after the lifter plunger goes solid. There is no advantage to having a lot of preload vs only a little bit of preload. Indeed, many performance manuals recommend only a little preload to preclude valve damage from valve toss.
 

bubba22349

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Speaking of the roller rocker arm to valve cover clearance problem you could easyly solve it by raising the upper EFI Manifold by using a simple spacer between the lower and upper manifolds. This was often done on the 5.0 V8's. Best of luck
 

efloth

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Thanks for the input guys,

If I compress the lifters Is there a spec for valve lash on the pedestal setup?

Is spacer something that is readily available or something I would need to fabricate? I have a 3d printer but not sure if ABS would hold up engine temps. Maybe nylon would work. Does anyone have a model already designed?
 
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bubba22349

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The lifter lash is fixed at about half of the lifters piston travel. I don't know of any spacers currently being made for the 4.9, but I doubt that they are. The 5.0 spacers were quite common and were made of a bakelite material if I remember correctly. This also offered the secondary benefit of being an insolator against heat transfer, ABS might be able to work if fuel dosnt harm it seems to be a very tough plastic. Some of old time racers such as Dyno Don Nickelson even used plywood to make spacers and parts of intakes manifolds.
 

pmuller9

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The Scorpion roller rockers will need to be checked for good geometry meaning the roller tip should travel across the center of the valve stem tip.
This adjustment is done FIRST!
You may be OK as is but if the rocker height need to be adjusted it is done by using shims under the pedestals.
You will find many different shim thicknesses on line.
The standard way of checking travel is to mark the top of the valve stem tip with some type of marking pen then install the rocker arms and pushrods and turn the crank and cam few revolutions, remove the rockers and see how close the pattern is to center.

As FTF pointed out the lifter plungers only need to be pushed down about .050" to .075" from the retaining clip.
If you can't get enough preload then you need longer pushrods.

Just to summarize.
When you are using a non-adjustable pedestal mount rocker arm the rocker geometry is set with pedestal shims and the lifter preload is adjusted by pushrod length.
 
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efloth

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I never even considered making it out of wood lol great idea. I hope the non adjustable rockers will just fit. I think that's why the made them that way. I'll keep you posted. Btw I've converted to E85 on this motor running 80lb injectors and oh boy what fun it is to drive now. Was able to add 7 degrees of timing down low and 4-6 above 3k RPM.

Wow, thanks for clearing that up. Sounds like I should pull the lifter cover off to be sure of correct lifter preload. I wasn't planning on doing that but just doing a compression test before and after.
 
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efloth

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Well I'm not sure if they sent me the correct pedestals because I have about 1/8-3/16 inch of play with it torqued down. I measured the pushrods and they are stock. This motor has never been modified or decked so I'm at a loss at this point. Everything looks good if I reinstall the stock rocker. I'll call Scorpion tomorrow but any input would be appreciated. I tried them on multiple valves with the same results.
 

pmuller9

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does it make a difference if you turn the roller shaft 180 degrees so the pedestal sits on the other side?
 

pmuller9

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This is important!
The rocker geometry might be correct with the tall pedestals.

When bolted in place, where does the roller tip sit on the valve stem tip.
Does it look centered or toward the inside of the center?

Mark the top of the valve stem with a marker then install the roller rocker and push the rocker tip down as far as you can (opening the valve) then remove the rocker and see how centered the pattern is.
 
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bubba22349

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HI FTF, Lol well us as some of them I hit the 72 mark a couple days ago! Mostly I meant their ingenuity, resourcefulness in making things work, or solving problems with low budget solutions you certainly fit into that group, maybe I should of said the old school masters instead?
 

efloth

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Yeah the geometry looks good. Scorpion said get longer pushrods. Question is were to source them pre-fabbed in lengths over 10.140
 

pmuller9

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I buy pushrods from Manton
They will make the pushrods in whatever length you specify.
You can use their Series 1 pushrods.

You can also get pushrods from Smith Brothers.

You can make an adjustable length pushrod for checking the needed pushrod length out of a stock pushrod or get Comps adjustable pushrod 7903-1
 
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efloth

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I don't have a caliper so would comp 7706-1 work? Scorpion tech suggested getting a 3/8 pushrod with 5/16 balls if ordering custom ones. Any issues with that?
 

pmuller9

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I don't have a caliper so would comp 7706-1 work? Scorpion tech suggested getting a 3/8 pushrod with 5/16 balls if ordering custom ones. Any issues with that?
The 7706-1 will work. Even though it has it's own gauge when you take the first reading I would take the checker to your machinist and verify the length with calipers. I like to check equipment calibration before spending money on parts.

The 3/8" pushrod is good.
You should check the clearance to the inside of the pushrod holes in both the head and block when you install them.
 
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