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It seems I am having some problems getting the rockers set right. I blew a head gasket on the truck (roller cam 351) recently and replaced my heads while I was putting it back together. I installed some 7/16" stud mounted rockers and adjusted them all to zero lash. I had some tapping and a miss on the pass. side bank so I went back in and readjusted again. They seem to be overly tight now, causing it to run rough.
My question is could the lifters be too pumped up? I am going to pull the intake again and crank all the rockers down and leave them over night to try to bleed them down, then readjust again.
Any advice or suggestions on getting the rockers set right is appreciated.
Only thing I can think of would be, are you adjusting each rocker with the lifter on the base circle of the cam? Did you use the proper length pushrods? I would imagine you are, so don't take offense for my asking, just throwing ideas out there. Good luck getting the rockers adjusted, later
You need to adjust them while the motor is running. Loosen the rocker until it makes noise and then tighten it until it stops. Once the noiose stops i think you are supposed to go 90 degrees more tightening.
If you used an early head which it sounds like you did you may have a push rod length issue. I would have stayed with the late model heads that do not require the adjustment I described. Torque them and your done.
Originally posted by jwtaylor Only thing I can think of would be, are you adjusting each rocker with the lifter on the base circle of the cam? Did you use the proper length pushrods? I would imagine you are, so don't take offense for my asking, just throwing ideas out there. Good luck getting the rockers adjusted, later
Yeah, each adjustment at tdc. I am using stock length pushrods. With the adjustable rockers I wouldn't think that would be the problem.
Originally posted by RTM You need to adjust them while the motor is running. Loosen the rocker until it makes noise and then tighten it until it stops. Once the noiose stops i think you are supposed to go 90 degrees more tightening.
Thats a little difficult/impossible to do with the intake on a 95.
Originally posted by RTM If you used an early head which it sounds like you did you may have a push rod length issue. I would have stayed with the late model heads that do not require the adjustment I described. Torque them and your done.
The angle of the rocker looks fine, as does the contact between rocker and valve stem with the stock pushrods, what would cause an issue there with adjustable rockers?
I have done the swap from pedestal to stud mount rockers numerous times, I prefer the adjustable rockers.
It may be impossible but thats how it should be done. I haven't seen or heard of anyone adjusting the rockers on a cold motor, guessing at the preload and getting it right.
I am sure you can get it close and the motor will run fine. You have said yourself you believe you are at the proper cam angle to adjust each lifter so that only leaves one thing, their to tight.
It sounds like you are the one with the experience on this type of swap. What push rods did you use, late or the early style? Even at that I don't think it will matter becuase you have a roller cam and that in it's self is a different pushrod from a flat tappet cam and from an adjustable flat tappet cam.
At this point I can only guess there may be a push rod issue but you say it looks good so other than the two things I mentioned I am lost.
Keep me posted as to what you come with. Things like this are good to know.
Yeah, thats my guess too. It must have too much load on them, thats why I was going to try and bleed them down and start over. Taking the intake off to do it is a bit of a hassle. I used the factory length 95 roller pushrods, they seem to fit well and offer enough room for adjustment in both directions, I just haven't hit that middle ground yet.
If it were carbureted, believe me I would have adjusted them running by now, lol.
Thanks for the suggestions.
Well good luck, I noticed in your first post, you mentioned the engine runs rough. Honestly I don't know, but would pushrods that are a little tighter than usual make the engine run rough? Let us know what you find out. I would associate noise with loose adjustment or lifters, instead of tight. Let us know what you find out. Later
I had the adjustment too loose the first time, it caused the tapping and slight miss. Now I have the whole bank too tight and it is running rough. I'll have to take it back down and get this right sooner or later.
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