Valvetrain upgrades

[windrunner408]

According to the machinist who I'm having do my heads, one gains about .020-.030" of "installed height" when the heads are machined with a valve job and everything so that decreases the factory spring pressure about 5lbs. So with a .030" shim, it brings the pressure back to just over stock. He said a .060" shim wouldn't be too much and typically .030" adds about 5-10lbs of spring pressure so if I did a .050-.060" shim, that would add a solid 10 extra lbs of seat pressure and shims are about $.30 a piece. For a frame of reference, .060" is only 1.5mm (pretty thin if you ask me).

 

[windrunner408]

Why not try and actually calculate what thickness shim you need to get to the spring rate you want? It shouldn't be very difficult....

Actually according to the machinist, what you do is you tell him what you want the seat pressure to be and he puts the corresponding shim in to give you the required seat pressure so this way there is an even spring pressure accross all of the valves. He says that his "stock" springs are typically 80-90lbs so I just had him do 95 lbs and call it good. This way I get a little extra closing force without putting a whole lot of extra force on the lifters. Just my thoughts.

 

[Breaking Habits]

Decided to go with RCD for both. Jarred gives us a great deal that's hard to pass up.

Thanks Colin, Hope you enjoy

 

[Extended Power]

Proper way to get seating pressure all starts with the valve job.
Ensuring that all the valve recessions are the same is just one of many points.
The valve lengths, valve face, and margins are others.

Then, when your assembling the valves, to get the proper spring pressure, you install the valve, keeping that valve in that guide. Don't mix them up on assembly.
Install a retainer, and keepers. Then use a special tool to get the height from the spring seat, to the retainer...or, you can use a snap gauge, and measure it with calipers.
Document all the installed heights of all the valves.

Keep everything organized "to it's spot".

Throw away the stock springs, as they reach coil bind before you can get enough seat pressure to be of any use...get some beehive style springs.

If you don't have a spring pressure tester, find a shop that does have one. But, the new springs will/should come with a card that states the spring pressure at such and such installed height.

Compare the height (measurement) you documented for each valve/retainer, and figure out how much shim you require to attain the seat pressure you desire.

For example, stock ford valves have between 70-85# of seating pressure, and something like 120# at max lift.
The springs I run have 120# of seating pressure, and around 250+# at max lift.
So no valve float on my setup.lol

Hope this helps.

 

[Josh@DirtyDiesels]

RCD springs in mine and custom made chromoly pushrods slightly thicker than stock. Couldn't tell you a difference in how it feels, just peace of mind which is always nice.

 

[windrunner408]

Do the RCD springs require upgraded retainers or will the stock ones hold up just fine??

 

[Josh@DirtyDiesels]

Do the RCD springs require upgraded retainers or will the stock ones hold up just fine??

Hoping they hold up fine. No one ever told me I would need anything else... Just used the stock stuff when I did my springs on saturday...

 

[windrunner408]

Decided to go with RCD for both. Jarred gives us a great deal that's hard to pass up.

Well I ordered the valve springs from RCD today. You are correct sir. Jared does give a deal that is hard to pass up. I decided to say screw shimming and just went with better springs. Jared did say that these do not require any aftermarket retainers or locks. True drop in upgrade. I'm excited.

 

[MorganY]

They're a nice upgrade, you'll be happy