2F valve spring issues

[Dave-T]

2F valve springs are stacking!

I'm about to drop my freshly rebuilt 2F into the 60. After cold adjusting the valves this morning I was turning the motor over by hand (socket on the crank pulley) and they cycles got way too stiff. I noticed the valve springs were becoming compressed beyond their limits. Here are some specs of the rebuild related to the head/valve train:

cam reground to Mark W specs (similar to MAF rv grind)
head shaved 80 thousandths
newer stock springs shimmed to achieve correct installed load

I can turn the motor completely over with effort, but I think it's too tight. My gut tells me this could be very bad for the valve train, am I correct? I guess a few options would be too remove the shims and settle for less spring pressure, or install new heavy duty springs (sbc chevy springs?). Yeah I was looking for more compression, but not this much! Any suggestions?

 

[agent orange]

What do you mean compressed beyond their limit? Are they stacking up?

 

[Fuzzy Logic]

What do you mean compressed beyond their limit? Are they stacking up?

Commonly referred to as COIL BIND, the s*** has bottomed out!

 

[matt.mcinnes]

You have the spark plugs in while your turning the engine over by hand?

 

[Tinker]

If the springs were shimmed correctly there's no reason to remove the shims. There's something else wrong with the valve train. What do you mean by "newer" stock springs?

 

[Fuzzy Logic]

You have the spark plugs in while your turning the engine over by hand?

what does that have to do with the springs?

 

[agent orange]

what does that have to do with the springs?

If he has the plugs in he might just be surprised by the amount of pressure each cylinder builds with the shaved head and fresh rings.

If the springs are going into coil bind its an entirely different thing.

 

[Fuzzy Logic]

If he has the plugs in he might just be surprised by the amount of pressure each cylinder builds with the shaved head and fresh rings.

If the springs are going into coil bind its an entirely different thing.

seems the springs are the issue..Yes? No?

 

[matt.mcinnes]

It's always hard to say what the problem is but removing the spark plugs makes it easier to turn the engine, as posted above he might just be surprised at the effort needed to turn a fresh 2F thats been shaved.

Removing the plugs removes one part of the equation making it easier to see his true problem.

So we can give a better opinion.

 

[Dave-T]

Yes, as I stated above the springs are stacking, otherwise known as a coil bind. I can't even get the skinniest feeler gauge to slip between the coils when they are compressed. Of course I had the plugs removed!

 

[Dave-T]

If the springs were shimmed correctly there's no reason to remove the shims. There's something else wrong with the valve train. What do you mean by "newer" stock springs?

I had two sets of stock 2f valve springs. We tested both sets and one set was noticeably more worn then the other set. The other newer set was very close to stock specs. But we did have to shim them to get the proper installed load.

 

[matt.mcinnes]

Yes, as I stated above the springs are stacking, otherwise known as a coil bind. I can't even get the skinniest feeler gauge to slip between the coils when they are compressed. Of course I had the plugs removed!

Pull the shims out and see what you have then.

Also your first post did not say you have the plugs out in fact this gives the impression they were in "Yeah I was looking for more compression, but not this much! Any suggestions?"

 

[Dave-T]

Right now the plan is to find some stronger springs that I can put in without any shims. I do not want to reuse the stock ones. Might as well do it right while the engine is out.......

 

[matt.mcinnes]

Right now the plan is to find some stronger springs that I can put in without any shims. I do not want to reuse the stock ones. Might as well do it right while the engine is out.......

I'm using these Valve Springs by Crow Part No4832. GM spring but that's with a Ferrea Valves so not sure if they will suit you.

http://www.crowcams.com.au/templates/Catalogue-Valve-Spring.shtml

 

[weak-link]

head shaved 80 thousandths
newer stock springs shimmed to achieve correct installed height

so did you shim the springs 80?

 

[Dave-T]

so did you shim the springs 80?

Some were 90, and some were 60. We did the intakes all one and the exhausts another, can't remember now which was which. I'm trying to figure out now what SBC head has springs that are similar to the 2f.

 

[Dynosoar]

You need to cut 80 thousands off of your push rods and you should be fine.


Dynosoar

 

[Dave-T]

You need to cut 80 thousands off of your push rods and you should be fine.


Dynosoar

Is that possible? What end would you take material off, the concave or convex? Also it seems if you did that the valve wouldn't open as far as intended.

 

[matt.mcinnes]

Is that possible? What end would you take material off, the concave or convex? Also it seems if you did that the valve wouldn't open as far as intended.

You should have enough adjustment to compensate for the 80 thou shave in the rockers when setting the clearence. I see no need to alter the push rods.

Does the new cam give you more lift? If so how much?

Shimming the springs gives you more seat pressure but less lift before the springs bind
CROWS 2F
2F springs are I/H 1.79. O/D 1.28. I/D 0.92. SEAT PRESS 80. 0.5 LIFT 220. SOLID HEIGHT 1.00

 

[Mark W]

Shaving the head has nothing to do with the valve springs, how they fit or how much pressure they exert.

You do not "cut" pushrods when you remove material from the head. And it would not make any difference if you did.





Take the shims out and let the valve springs have all of their height back. I have been running these cams for years and pushing engines up to and beyond the capabilities of the lower end. I run stock, unshimmed valve springs and have NEVER encountered valve float. The springs will be close to their limits, but they will not stack or bind.


Mark...