New heads, new cam, new experiences

RoushTbird

New Member
Jun 6, 2008
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DFW
So ive installed my emerson .496/.512 cam, and SBF strikeforce heads..... After 2 weeks trying to get timeing done :rolleyes:, i have less power then my stock motor....WTF...

So, I open the valve cover, and found that i had errently set my valvle way to tight. i worked on the drivers side, and reset them to .020 i think..... Any words of wisdom from the community on how to adjust these properly so i can have the power im supposed to?

Any help would be completley welcome.

Tahnks,
 
I would assume the .020 you are talking about is the preload on the lifter. The only trick is to make sure the lifter is on the base-circle and all the lifters plungers have returned to the top. 0 lash then 1/4 turn gets you your .020 preload.

There are several different ways to make sure you are on the base-circle. If you have 360 degrees of timing marks (you actually only need them every 90 degrees) you bring it up to TDC on the compression stroke for #1 then set those. Turn the motor 90 degrees and do #3 keep turning 90 degrees and follow the firing order around. You should loosen all the rockers first then go have a beer so you know all the lifter plungers have returned to the top

You may have more problems then setting the preload though. I hope you checked for proper pushrod length and changed the lifters when you did this swap.
 
I would assume the .020 you are talking about is the preload on the lifter. The only trick is to make sure the lifter is on the base-circle and all the lifters plungers have returned to the top. 0 lash then 1/4 turn gets you your .020 preload.

There are several different ways to make sure you are on the base-circle. If you have 360 degrees of timing marks (you actually only need them every 90 degrees) you bring it up to TDC on the compression stroke for #1 then set those. Turn the motor 90 degrees and do #3 keep turning 90 degrees and follow the firing order around. You should loosen all the rockers first then go have a beer so you know all the lifter plungers have returned to the top

You may have more problems then setting the preload though. I hope you checked for proper pushrod length and changed the lifters when you did this swap.


actually with a 3/8-24 rocker stud. a 1/4 turn is going to be .010" preload.

1 (inch) divided by 24 (theads per inch) = .0416666 (roughly .040")
so full turn of the nut is going to net you .040 preload divide that by 4 and you get .010" per 1/4 turn. so to get .020 preload you need to go 1/2 turn.

my car i went 3/4 turn to get .030 preload and i havent had any problems.


if the car has 7/16-20 rocker stud its a tad different but barely
1 divided by 20 is .050
.050 per full turn of the nut, divide that by 4 and you get .0125 preload per 1/4 turn on that stud. only .0025 off the other stud so IMO i'd just adjust them the say thining that 1/4 turn is .010 preload (2.5 thousandths of an inch isnt going to make any difference.

just remember the stock lifters have about .100 play in the plunger, go too far with the preload and you can run into problems. IMO i wouldnt go past .050 preload. .030 works fine for me. in all actuality .010 is plenty but it doesnt hurt to have a bit more IMO
 
actually with a 3/8-24 rocker stud. a 1/4 turn is going to be .010" preload.

1 (inch) divided by 24 (theads per inch) = .0416666 (roughly .040")
so full turn of the nut is going to net you .040 preload divide that by 4 and you get .010" per 1/4 turn. so to get .020 preload you need to go 1/2 turn.

my car i went 3/4 turn to get .030 preload and i havent had any problems.


if the car has 7/16-20 rocker stud its a tad different but barely
1 divided by 20 is .050
.050 per full turn of the nut, divide that by 4 and you get .0125 preload per 1/4 turn on that stud. only .0025 off the other stud so IMO i'd just adjust them the say thining that 1/4 turn is .010 preload (2.5 thousandths of an inch isnt going to make any difference.

just remember the stock lifters have about .100 play in the plunger, go too far with the preload and you can run into problems. IMO i wouldnt go past .050 preload. .030 works fine for me. in all actuality .010 is plenty but it doesnt hurt to have a bit more IMO

Well the math not withstanding you have to figure in the rocker ratio.

I will have to agree that a 1/2 turn should be fine I prefer 1/4 but in this application it makes little difference IMO. I've run as little as 1/8 turn with no problems but that was on a modified lifter with way more plunger spring than stock.