390 Valve Spring
Thread Starter
|
Senior User
Joined: Dec 2012
Posts: 103
Likes: 0
390 Valve Spring
Hey all, long time lurker but first post.
I've got a 75 f-250 with the 390. I've currently got the motor torn down and am in the process of cleaning, inspecting, and resealing everything. This next weeks project is disassembling and cleaning the heads up. The truck ran fine, only has 5xxxx miles on it, and the valves visually look ok (doesn't look like any are getting hot, so my plan was just to hand lap em, throw new stem seals on and call it a day. However I can't find a spec anywhere for what the extended length of the valve springs should be. I'd be replacing any that are sagging. Anyone have this information?
I've got a 75 f-250 with the 390. I've currently got the motor torn down and am in the process of cleaning, inspecting, and resealing everything. This next weeks project is disassembling and cleaning the heads up. The truck ran fine, only has 5xxxx miles on it, and the valves visually look ok (doesn't look like any are getting hot, so my plan was just to hand lap em, throw new stem seals on and call it a day. However I can't find a spec anywhere for what the extended length of the valve springs should be. I'd be replacing any that are sagging. Anyone have this information?
Thread Starter
|
Senior User
Joined: Dec 2012
Posts: 103
Likes: 0
To be honest i've never even heard of that although what you are saying makes sense. However I don't know of any place around that would have one I could borrow.
I don't suspect any issues with them. Just wanted to check before I put it all together again. And its not like the truck is going to see high RPM by any means. And its not hard to change a spring either if a problem did present itself.
I don't suspect any issues with them. Just wanted to check before I put it all together again. And its not like the truck is going to see high RPM by any means. And its not hard to change a spring either if a problem did present itself.
Cross-Country
Joined: Sep 2012
Posts: 58
Likes: 12
From: shuswap lake
when i rebuilt my 360 in high school i used one of those tools to check the spring pressure, I'm not sure what its called, if you called a machine shop theyd tell ya what it is, then if there not to bad to my recolection you put in shims under the spring to get the proper tension, they're not to hard to change if the head is off, if its on you could use air to pressuize the cylinder and hold the valves up well you remove the spring retainers so the valves dont drop just make sure its on compression stroke.
Last edited by rempel429; Dec 9, 2012 at 10:57 PM. Reason: spelling mistake
Fleet Owner
Joined: Dec 2009
Posts: 20,678
Likes: 83
From: NorCal
when i rebuilt my 360 in high school i used one of those tools to check the spring pressure, I'm not sure what its called, if you called a machine shop theyd tell ya what it is, then if there not to bad to my recolection you put in shims under the spring to get the proper tension, they're not to hard to change if the head is off, if its on you could use air to pressuize the cylinder and hold the valves up well you remove the spring retainers so the valves dont drop just make sure its on compression stroke.
Or with the spark plug removed, stuff cotton rope into the cylinder so it holds up the valve.
Installed height is around 1.75 to 1.9 inches... but seat pressures at installed height (closed) and open height is the info you really need to know. A spring may stand correctly but be weak.
Hotshot
Joined: Apr 2009
Posts: 14,333
Likes: 247
From: Stanley, VA
According to Rock Auto (FTE sponsor) the "free length", and that's what you're asking about, is 2.12".
If you have a concern, they're cheap enough, why not replace them all?
Sealed Power VS682 $2.26 each.
If you have a concern, they're cheap enough, why not replace them all?
Sealed Power VS682 $2.26 each.
Logistics Pro
Joined: Feb 2000
Posts: 3,955
Likes: 50
From: Mesa
I would be tempted to change cam, timing chain, lifters and springs. Something like the Edelbrock Performer cam.
Trending Topics
Thread Starter
|
Senior User
Joined: Dec 2012
Posts: 103
Likes: 0
I don't have any concerns. Just figured i'd check it out since I was there.
I've used the rope method of holding valves up myself.
And I don't see any need to change the cam. lol. Not going for any performance here. Nor do I really want to deal with it.
I've used the rope method of holding valves up myself.
And I don't see any need to change the cam. lol. Not going for any performance here. Nor do I really want to deal with it.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote
10 Ugly Ford Trucks That We Still Kinda Love
Joe Kucinski
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
Certified Thread Hijacker
Joined: Aug 2001
Posts: 14,441
Likes: 60
You're better off buying new springs and knowing they are ready and good to go than driving around to machine shops or sourcing scales and presses to test old worn out springs.
The old school/ redneck method is to use a bathroom scale and a press btw.
Josh
The old school/ redneck method is to use a bathroom scale and a press btw.
Josh
Thread
Thread Starter
Forum
Replies
Last Post
z31freakify
1994.5 - 1997 7.3L Power Stroke Diesel
14
Feb 13, 2023 09:01 AM
Jason01
1999 - 2003 7.3L Power Stroke Diesel
5
Apr 30, 2012 08:54 PM
closer9
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
5
Dec 12, 2005 04:11 PM
PJX390
FE & FT Big Block V8 (332, 352, 360, 390, 406, 410, 427, 428)
6
Sep 18, 2004 05:45 AM