Ford Power Stroke Nation banner

1 - 16 of 16 Posts

·
bring the chain
Joined
·
1,345 Posts
Discussion Starter #1
i bought a set of comp valve springs from a company for my 6l(not bashing im just informing) this company said they were direct fit!! well we checked to make sure that we would be able to get the seat pressure that was advertised on the box which would be [email protected] installed height! well the 6l valve spring has a installed height of 1.8. this spring if it was just install assuming that it is a direct fit spring is going to have no more spring pressure at 1.8 than stock!!! you need to shim this spring .204 to achieve 120 psi of seat pressure. bolth the comp spring as well as the stock spring have 90ish psi of seat psi at a installed height of 1.8. make sure you shim this spring so you are increasing psi. i called the vendor back and told them this,and they said oh yeah they do need to be shimed!!!! beware of this
 

·
< YOU WISH...
Joined
·
775 Posts
I wonder what the seat pressure would be on a shimmed stock spring? If spring bind does not come into play you might have wasted your $$$$
 

·
bring the chain
Joined
·
1,345 Posts
Discussion Starter #4
the stock springs bind quickly. shiming them would not really do anything. dont even think about a cam with stock springs!!!
 

·
Captain Negativity!
Joined
·
3,109 Posts
I wonder what the seat pressure would be on a shimmed stock spring? If spring bind does not come into play you might have wasted your $$$$
(1.51 in @ 191 ± 9.7 lb)

Lobe lift Intake — 5.744 mm (0.2261 in)
Lobe lift Exhaust — 5.832 mm (0.2296 in)

1.4 rocker ratio. .321 is the lift on the exhaust side. So check and see if you hit coil bind before that.

I can modify the lifters for you to make them solid.
 

·
Registered
Joined
·
84 Posts
Shimming springs is part of the game. If the spring drops in, that is direct fit to me. Did the seller tell you they would have specific seat pressure at the factory installed height, and they don't? I appreciate you posting the info up about the installed height for guys to look at and help them. But I don't see where the vendor did anything wrong or misinformed you based on your first post.
 

·
Captain Negativity!
Joined
·
3,109 Posts
Shimming springs is part of the game. If the spring drops in, that is direct fit to me. Did the seller tell you they would have specific seat pressure at the factory installed height, and they don't? I appreciate you posting the info up about the installed height for guys to look at and help them. But I don't see where the vendor did anything wrong or misinformed you based on your first post.
Not when you mark up a comp cams spring 500dollars over.
 

·
bring the chain
Joined
·
1,345 Posts
Discussion Starter #12
Shimming springs is part of the game. If the spring drops in, that is direct fit to me. Did the seller tell you they would have specific seat pressure at the factory installed height, and they don't? I appreciate you posting the info up about the installed height for guys to look at and help them. But I don't see where the vendor did anything wrong or misinformed you based on your first post.
when the vendor says direct fit,and i say need nothing to use them,and vendor says no,and in reality they do need shims. then i call vendor back and them them about my finding,and then vendor says oh yeah they do need shims!!!! well then i guess i can see your point where they did nothing wrong:poke:
 

·
I know nothing...
Joined
·
6,115 Posts
Buying Valve springs is like buying shoes, you wouldn't just jump in them because they have your size on the sole. When I buy springs I look at 4 measurments- bottom i/o top i/o installed height and open. That size not rate or preasure. To instal springs correctly its always been my opinion/assumption that each spring and rate has to be measured. You may have 1 spring w/less/more installed height to gain the correct rate. That's not say someone didn't screw-up by not telling you this. Your installed height change as well as you run the engine, if this is to be a comp engine you'll want to check them from time to time. Good luck!
 

·
bring the chain
Joined
·
1,345 Posts
Discussion Starter #14
Buying Valve springs is like buying shoes, you wouldn't just jump in them because they have your size on the sole. When I buy springs I look at 4 measurments- bottom i/o top i/o installed height and open. That size not rate or preasure. To instal springs correctly its always been my opinion/assumption that each spring and rate has to be measured. You may have 1 spring w/less/more installed height to gain the correct rate. That's not say someone didn't screw-up by not telling you this. Your installed height change as well as you run the engine, if this is to be a comp engine you'll want to check them from time to time. Good luck!
the springs were going to be checked regardless of what anyone said. my original post was for the people on here that might have just thrown them on,because they were told they could,not knowing any better.
 

·
I know nothing...
Joined
·
6,115 Posts
the springs were going to be checked regardless of what anyone said. my original post was for the people on here that might have just thrown them on,because they were told they could,not knowing any better.
I wasn't piling on, I thought you were questioning why they weren't "drop-in". I was just pointing out that for a blueprinted valvetrain all things must be measured. Sounds like I was preaching to the choir, my bad.
 
1 - 16 of 16 Posts
Top