which valve springs for Comp 220/220

[deboeWE4]

I'm ordering new valve springs and just wanted to check if anyone had any opinions on what to go with. I have a Comp 220/220 roller with .513 lift and 112 lobe separation and 1.65 roller rockers. I talked to comp and they recommended 918's. I know very little about this so any thoughts would be greatly appreciated.

 

[bison]

What lobes?

 

[deboeWE4]

 

[deboeWE4]

Figured it'd be easier to just show you the entire cam card lol

 

[bison]

Your math is wrong. Your lift is .564 with 1.65 rocker ratio. I'd shoot for 155-160 on the seat for 6000 rpm. If you mean 26918 id say that's a no go with 1.65 rocker. Probably ok for a 1.5 rocker. You will not have enough seat pressure with those. Even if you go .030" from coil bind it may not be enough.

 

[deboeWE4]

Ok. It looks like the comp 918's have a seat pressure around 130 so I'm assuming they aren't the way to go in my case. Any recommendations that'll have 150-160?

 

[deboeWE4]

Sorry I wasn't seeing your entire post before I responded, yes I mean the 26918.

 

[Kevin87TurboT]

The 26918 would be a really good spring in your application. I'd recommend that you install them around 1.730". That'll get you a little over 150 lbs of seat pressure. Coil bind on those are around 1.100", so you'll have plenty of room to spare.

 

[deboeWE4]

So you recommend the 26918 installed at 1.730 over the 26926 or the PAC 1203?

 

[Kevin87TurboT]

I would install the 26918 springs if it were me. They have a 372 lb/in rate. They are also very light. You'll have great valve control with them.
Another reason that I don't like the 26926 in this application is that it will shorten the life of an austempered core cam if you exceed much over 400 lbs over the nose. I try to keep it around 380 lbs or less. The K factor is just too high on the 26926 and the PAC 1203. Now if you were to run a billet core, then I would be afraid of those springs. Which lifters are you going to run?

 

[deboeWE4]

I see what you're saying about the spring rates and it makes sense to me. I'm keeping the lifters that are in the car, unfortunately I don't know which ones they are. I wasn't involved with the build when they were ordered and installed. The Invoice from the shop just says "Roller Lifters Comp Cams," but no part numbers.