Conical valve springs.

[ptuomov]

Valve springs by design generally have their pressures determined by the wire size, shape and type. Hence heavier pressure springs are available in matching OD's with stronger wire and this increase spring pressures without increasing the size of the spring.

Isn’t the spring rate mainly determined by the number of coil loops that are wound into the spring? Few loops, high rate. Many loops, low rate. The wire shape and thickness of course matters, too.

[andyf]

I think I'm finally ready to finish up the install with the new cam and the conical springs. The springs went on without any issues but I wanted to triple check everything since I'm running a fair amount of lift and this is the first time I've used these springs. My installed height is 1.975 but that only applies to the outer spring. The inner spring is 0.150 shorter due to the steps on the retainer and the locator so it has an installed height of 1.825. The shorter install height on the inner spring means it needs to be checked for bind. Also, since the inner spring has a conical shape we wanted to make sure that it wasn't hitting the valve seal when compressed.

Best way to check all this stuff was to install the inner spring first and roll the engine over and then install the outer spring and roll it over again. I'm right at 0.800 lift with this cam so the springs are close to their max.

DSC_2021 (Large).JPG

[Newold1]

Just pick up and compare two valve springs with a 1.80" to 2.00" installed height and spring rates of one at about 300lbs per inch and one a 500lbs per inch and I think you will quickly see how wire size will make a bigger difference than number of coils loops as you call them.

[Newold1]

Just pick up and compare two valve springs with a 1.80" to 2.00" installed height and spring rates of one at about 300lbs per inch and one at 500lbs per inch and I think you will quickly see how wire size will make a bigger difference than number of coils loops as you call them.

[ptuomov]

Just pick up and compare two valve springs with a 1.80" to 2.00" installed height and spring rates of one at about 300lbs per inch and one at 500lbs per inch and I think you will quickly see how wire size will make a bigger difference than number of coils loops as you call them.

The number of coil loops is inversely proportional to the spring rate, I think.

[MadBill]

Spring stiffness varies as the fourth power of the wire diameter, so it is by far the most critical dimension.

[ptuomov]

Spring stiffness varies as the fourth power of the wire diameter, so it is by far the most critical dimension.

Makes sense.

So the fewer coil loops works in two ways. First, directly. Second, allowing for a thicker wire to be used.

[andyf]

I ran a couple days of dyno tests with the dual conical springs. Everything worked great, engine pulled hard up past 7000 rpm. This is a big block Mopar engine with a 2.190 steel valve so we were giving the springs a work out. Camshaft had a very aggressive QRI lobe from Comp with 0.780 lift.

I think the springs are the real deal. The seat load spec in the catalog is way low. The springs were right at 200 lbs at 1.975 installed height but the catalog says 150 lbs at 2.00 installed height. I think the spec in the catalog was measured wrong or perhaps it is a typo. I like the extra clearance that you get from the small retainer and the weight savings seems like a good thing. I'm going to leave these springs on the engine and keep using them.

http://www.hotrod.com/articles/dyno-tes ... e-springs/

[groberts101]

I ran a couple days of dyno tests with the dual conical springs. Everything worked great, engine pulled hard up past 7000 rpm. This is a big block Mopar engine with a 2.190 steel valve so we were giving the springs a work out. Camshaft had a very aggressive QRI lobe from Comp with 0.780 lift.

I think the springs are the real deal. The seat load spec in the catalog is way low. The springs were right at 200 lbs at 1.975 installed height but the catalog says 150 lbs at 2.00 installed height. I think the spec in the catalog was measured wrong or perhaps it is a typo. I like the extra clearance that you get from the small retainer and the weight savings seems like a good thing. I'm going to leave these springs on the engine and keep using them.

http://www.hotrod.com/articles/dyno-tes ... e-springs/

Surely a typo there, Andy. My little brother 7228 springs have near 140 seat at about half the size of those things! My Jones cam is pretty small(230/.600" lift) but has a fairly aggressive lift curve. Fortunately, the spring mass above the first few bottom coils along with a Ti retainer easily bests a much bigger spring when it comes to controlling the valve motion. Still a bit squeamish to run a single spring again after a few "issues" in the past.. but I think(hope and pray) the better materials and mfgr'ing processes might gain back a little more safety margin.

Dids you write that article?

If so.. nice work!.. love those see through valve covers!

[Casper393W]

I ran a couple days of dyno tests with the dual conical springs. Everything worked great, engine pulled hard up past 7000 rpm. This is a big block Mopar engine with a 2.190 steel valve so we were giving the springs a work out. Camshaft had a very aggressive QRI lobe from Comp with 0.780 lift.

I think the springs are the real deal. The seat load spec in the catalog is way low. The springs were right at 200 lbs at 1.975 installed height but the catalog says 150 lbs at 2.00 installed height. I think the spec in the catalog was measured wrong or perhaps it is a typo. I like the extra clearance that you get from the small retainer and the weight savings seems like a good thing. I'm going to leave these springs on the engine and keep using them.

http://www.hotrod.com/articles/dyno-tes ... e-springs/

Hey just letting you know I'm a fan!!! It's always awesome to see a Mopar get some love in Hot rod! Keep up the good work