FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: Boiler Ben on June 30, 2025, 08:19:14 AM
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I am building my 390 and have finally gotten my intake installed with thick gaskets. It went well and I’ve moved on to rocker installation. I have Edelbrock heads/intake, hydraulic rollers, adjustable bushed rocker system with end stands from Precision Oil Pump, ball/ball style pushrods, oiling through the heads with restrictors.
I have it all shimmed, installed, torqued. Engine rotates fine with no rubbing or strange noises. For rocker adjustment, I went one at a time through the firing order, making sure the lifters were on the cam base circle (using EVO and IVC to adjust the opposite rocker). I adjusted until it seemed like there was no “slop”, then went one full turn, then tightened the nut. The force needed to make that final full turn was not consistent, some were easier than others. None of them needed much force, it’s just some turned pretty easy.
When I was finished, the adjusters all ended up pretty much exactly where I predicted they would be based on my initial pushrod length measurement (measure length with checking tool and add 0.050”). I thought this was a good sign, but I noticed something that seemed strange to me. If I grab one of the rockers that is in a neutral position (lifter on cam base circle) and manually try to rotate it, it moves slightly. As if the pushrod is compressing the lifter just a bit.
The last time I spun the oil pump was a week or two ago. I turned slowly by hand just to check the oiling at the valves. So maybe the lifters aren’t “pumped up”? Would this explain why I can manually move those rockers? Is this just normal? Should I recheck this after spinning the pump with the drill? Should I readjust the rockers using a different method?
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Prime the pump and try it again. It should harden up.
Just as an aside, when you use the EVO method, you don't have to go by the firing order. I find it quicker to just rip down one side of the engine and then hop over to the other and rip down that side.
The reason the torque on the adjuster necessary to make a full turn seemed different from rocker to rocker is based on a couple things. The first thing is that there may have been more oil in a lifter than another, so you're compressing the lifter versus not compressing the lifter. On some, you will find that the valve will start to go down first and then when the spring load overcomes to the lifter, it will slowly start to close.
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Thanks Brent. I’m going to give it a try.
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It worked. The rockers stiffened up after priming the pump. But then loosened up after sitting a bit. I saw oil at all 16 valve tips so was happy about that. Didn’t see oil at any of the pushrods but maybe that’s normal. Think I’m just going to button it up. Just need to make some mods to the valve cover baffles.