The cam I will be running is a 224/236-573/576. I will only be seeing about 6200 rpm. Right now I have AFR heads with 977 springs and steel retainers with comp R lifters. Should I stick with these springs and run Titanium retainers or switch to the 918 beehives with Ti-retainers? I will need about 145# seated pressure and around 340# open for my cam per comp. What do you guys think would be better? I know the 977's are stronger but are a little over on my open pressure (405#) and weight. The beehives are alot lighter but will be border line (135-145# seated and 325-335 open). What is every running for springs and pressures? What cam sizes,boost# and Rpm? Are any of you seeing valve float? Thanks guys for you thought on this. This is the last step before I throw in my new setup......John

 

The beehives are the hot-ticket right now due to their shape, material, and mechanical characteristics. You can achieve more force with a shorter installed height, but the downside to this is your closer to coil bind. My beehives, the 918's, were installed with a height of approx. 1.74 in with +.050 keepers and a 3 angle valve job. The recommended installed height with these springs is 1.80 in. Therefore, my spring as installed is a little stiffer than recommended, but the spring is still capable to handle the cam/valve lift.

You have to double check those calc's whenever installing a high performance cam like yours. The 918 is good to about .600 lift, so you should be fine if the spring is installed at the recommeded 1.80" height.

The beehive springs have been great so far with my combo.

 

That's what I figured. I know it would be close. Are you running cm795 retainers and 611 locks or comp's Titanium retainers. What are you spinning to and what are your seated and open pressures. Any problems with running those springs with the comp R's. Thanks for the reply, I will see if anyone else has any info on this.......John

 

Nobody else?

 

I didn't install the titanium retainers, just the standard chromoly, which are just slightly heavier than titanium. The keepers are from Howards Cams, forged units +.050 over standard.

I rev it to around 6000-6200 normally, but it's seen 6500 maybe. The rev capability is outstanding compared to what it was before with hot-cam kit.

The specs for the 26918 are:

Seat load = 130 lbs @ 1.80"
Open load = 318 lbs @ 1.20"
Coil bind = 1.085"
Spring rate, k = 313 lbs/in

The installed height was approximately 1.74", and the spring rate for the 918's is 313 lb/in, so the calculated seat load would be 149 lbs (closed).

The open load was calculated as 325 lbs @ 1.18" with the exhaust valve lift at 0.555".

With your cam lift of 576 and an installed height of 1.74", your open load will be approx. 330 lbs @ 1.16". This would leave 0.075" until coil bind. The usual accepted clearance is 0.060", so you should be okay there. It is pretty close like you said.

I would recommend you consult with a professional before making the decision. Have you asked Comp Cams?

Also, I know there is a big block beehive spring which came out too, you may want to investigate that.


I haven't had any problems yet with the Comp R lifters.

 

Thanks again for the reply. No I haven't called comp but I am talking to a local engine builder. He also mentioned the big block beehives also. We are looking into it as we speak, thanks again...John

 

I have had no complaints with the Manley Nextek Duals....cam is a
Comp Cams XER 236/240 601/608 114 + 4 LSA

Don