Hey guys,
Getting sick of the rocker noise in the 351w, when I went through it and did my GT40Ps I left the stock cam and lifters in it and went with 1.72 roller scorpion rockers on it. I bought the shim kit with it on the stand I went through checked all of them I did not need to shim them with the shim in place the rocker was loose. they all were around 1/2 to 3/4 of a turn to the 18ft lb they were torqued to. the pushrods were barely pushing down the plunger on the lifters but they were in spec as far as rocker was concerned they all fell in the center of the valves.

But in the morning this thing is noisy at idle and I am sick of it, with the pushrods barely pushing the plunger off the seat do I need longer pushrods?

Specs untouched 96 351w roller block came apart with ford on all gaskets bearings pump etc so it was original, all replaced all was in good shape but didn't want to swap heads without knowing condition of lower end or just freshen up lower end. Heads GT40P from a 99 or 00 explorer with under 50k on them, put the trick flow spring kit on it the scorpion 1.72s and that was it.

Here soon truck is going to get the new bigger engine but this one will be living on in another so I want to just address it.

Thank you,
Curtis

 

Is it only noisy on cold starts or all the time?
Did you clearance the baffles in the valve covers for the rockers?

 

The truck will do it cold, warm, I have been paying attention to it a lot here lately, I run maybe 6-8miles at highway speed to work once I get there the noise is gone idling nice and quiet. But this weekend it did it at operating temp, once its about 950-1000rpm it is gone until then it is noisy.

I did not clearence the baffles I have had the covers off to check them no signs of contact anywhere on the covers or the rockers.

The noise almost sounds like the chattering when adjusting valvetrain on a gen1 sbc. But being when I did my checking the pushrods were not loose or anything of the nature I just kind of assumed it was the nature of the beast, especially after the search on some stang forums they were content with it I am not I hate it.

Thank you,
Curtis

 

pushrods? covers?

Thank you
Curtis

 

Pushrods may be a little too short then, usually people need to shim them but every motor is different.

 

How much seat of the pants difference do you feel with the 1.72 rockers?

 

Hard to say how much of a difference they alone gave me. When I did the rockers, I also did gt-40p heads, short tube JBA headers, port matched 351w lower to 5.0 truck upper, BBK twin 61mm throttle body, magna flow Y pipe, all with stock cam. I fought with it on lean codes finally swapped 24lb injectors in it shortly after and that took care of it. For a 4x4 xcab f150 it will move pretty well better than any stock 351 I have ever seen I like the combination but want to swap the 5.0HO cam into it the puny explorer cam lacks.

Curtis

 

How did you check your rocker arm geometry? increased ratio with increased spring can bleed down hyd. lifters.

 

Don't waste your time with the HO roller. It's only 10-20 degrees more duration on the intake side (depending on where you look for these figures) and .030 lift on the intake side. The F4TE specs out like this: 256/266 advertised duration, .422/445 lift. The HO is 266/276 (or 276/276 in some books) and .445/.445 lift

 

That's what I'm thinkin too, he changed the springs. That could benefit the topend but also cause the lifters to bleed down.

 

right with a stock cam no reason to upgrade the valve springs I would think. Your not running a Fram oil filter are you by chance?