Right/Left Wound Beehive Spring Mystery. 3

[Torquey]

Today I was lining up a collection of ovate beehive valve springs (because I have that kind of time) from a Ford 4.6 DOHC 4-valve motor. While doing this, I noticed that roughly half the springs were wound to the right and half wound to the left. Is there any good reason why Ford would specify springs wound in different directions? These are not nested springs... they are the single OEM springs from Ford. I looked at a couple of brand-new heads and all those springs seemed to be wound the same direction. My guess is that some machines wind right, others left but it's all the same to Ford. Is there more to this?

 

[CH5OH]

I assume while compressing the spring, some of the force translates into a rotating motion of the valve, which helps to keep the valve and seat clean on closure.On opening it also makes the passing gas rotate a bit.so I guess it gives a better flow pattern if inlet an exhaust gasses are counter rotated.

 

[Torquey]

That is some excellent insight, insight I never would have dreamed.

 

[CH5OH]

you're welcome

 

[BrianGar]

I dont honestly think the small bit a valve turns once it opens has any effect on air passing between it and the seat but I could be wrong, Ive been wrong before..

 

[SomptingGuy]

I'd be very surprised if the reason was gas dynamics. My hunch would be valvetrain dynamics, possibly connected with tappet offsets.

- Steve

 

[MiketheEngineer]

It may keep the valve from seating at the same spot every time - thus keeping the fit between seat and valve always "ground" and tight fitting.

 

[SomptingGuy]

That's quite obvious, but left vs right bank windings?

If there were nested spings, you'd expect them to be differently wound to prvent lock-up.

There must be a reason. Maybe someone from Frod Munter can chime in?

- Steve

 

[dgallup]

Obviously, the left hand springs are from down under.

 

[RossABQ]

I assume by "roughly half" you mean it isn't intakes one way, exhausts the other?

 

[BrianPetersen]

If there is meant to be a difference in the way the left-hand and right-hand springs are installed, the assembly instructions ought to cover it, and if they're not OEM parts, the supplier ought to cover it.

 

[dicer]

Maybe on set is an american company that could follow directions and the other set from a country that couldn't.

It would be nice to know if there is some though out reason for it though.

 

[swall]

It could just be the result of using different spring vendors and one vendor just happened to have spring coilers that were set up for left hand winding. It may also be that if some sort of automated assembly equipment were in use, and two springs were fed to the assembly point, that having LH and RH wound springs would prevent them from nesting in the feeding mechanism.

 

[kitabel]

Just a guess?
Ford found that more springs could be made from the same stock, lower scrap rate, some bean-counting factor.

 

[TurboRagtop]

SomtingGuy: The Ford 4.6L DOHC engine uses a RFF valvetrain (Roller Finger Follower) and has no tappets per se. Pushrod style engines use tappet offset to ensure rotation of the tappets, but there is no need to do this with a RFF valvetrain, as the cam followers have a roller incorporated directly into them. (Your comment: "...valvetrain dynamics, possibly connected with tappet offsets")

I suspect valvetrain dynamics figures into why springs are wound in different directions, but it's not tappet offset.

 

[ivymike]

an idea: if the intake springs have a different rate/number of coils/fitted length/etc than the exhaust, having them wound opposite ways would make the types visually distinguishable.

 

[ivymike]

a friend of a friend of mine might have design responsibility for that part... I'll see if I can fish out any info from my "network."

 

[RossABQ]

I was perusing the Summit catalog and some other sources to see if they showed these. Interestingly, the searches pulled up Chev springs; apparently some are using Chev beehive springs on mod-motors? Even Ford Racing springs for the 4.6 are not beehive type, this may be a high-RPM upgrade?

 

[ornerynorsk]

The valve spring never is exposed to either the intake or exhaust gases. The helical of the spring has nothing whatsoever to do with flow turbulence. And yes, valves do rotate ever so slightly with each open and close. No idea why one would be right and another left hand.

 

[Torquey]

RossABQ: You definitely picked up some errant information there. The 4.6 dohc modular came out circa 1994 and some of those real early motors did not use beehives (I know because I've disassembled several in a junk yard) but, for the most part, all dohc modulars have OEM ovate beehive springs. Comp Cams is the only aftermarket supplier of mod springs and they are also ovate beehive, all winding the same direction. Frankly, I believe the Comp Cam product is a failure because they cause the cam bearings to wipe (too much spring) but that is another subject. If Chevy springs work in these heads, I would be surprised, as the mod springs are only about an inch in O.D. Thank you for your interest in this subject.