Valve Train Experts Needed-Roller Cam Valve Spring Help

[mtocrs1]

I need help like always.
I decided on a 212/212 roller comp cam so I ordered the springs comp recommended. 26915.
I had my heads gone through and the new Comp 26915 springs installed. They were installed at an installed height of 1.7 with 140# on the seat.
I decided on a full throttle 210/215 cam instead and have since learned that the comp 26915 dont have enough open pressure for any roller cam with high boost.
What springs would be good at my installed height of 1.7. I am hoping for a direct swap without going back to the machine shop.
I have done some searching on here and seen guys recommend the comp 941 at an installed height of 1.7.
I have also seen some recommend the K-Motion 750's.
Please Advise.

 

[bison]

I thought I answered this somewhere already. Anyway you need to have a shop measure a set then you install at the heights to hit the pressure you want and be sure you're not near coil bind. The one you listed as 212/212 is likely 3312/3312 extreme energy and requires more spring than the full throttle cam which is likely 3050/3108 high energy lobes. Comp 941, k motion 750, and a few others including 26918 conical will easily cover the FT cam with 140-150 on the seat.


BPE2013@hotmail.com

 

[mtocrs1]

You did however I didn't understand the response. I need like 6th grade level descriptions with things I don't understand. Lol
It would be great if I could use the 26918's so I could reuse the retainers.
What kind of open spring pressure is needed?
I thought the open spring pressure is the big area of concern with the roller cams.
The machine shop told me that I currently have 140 on the seat at 1.7 with the 26915's




Sent from my iPhone using Tapatalk

 

[mtocrs1]

The place I take the heads to does great work and I trust them. However they are not familiar with the buick stuff. He will set them up to whatever I ask for. So if all I need to tell him is install these 26918's with a seat pressure of 140-150 and make sure they aren't near binding at max lift great. However is that really all I need to tell him? I'm not questioning your response just making sure I understand it correctly.


Sent from my iPhone using Tapatalk

 

[bison]

The seat pressure is more of a concern. Open pressure is the product of high seat pressures with aggressive small single springs. They told you? At 1.800" they advertise at 105lbs. 313lbs/inch rate. Simple math. I doubt the springs are 15% stronger than advertised. I've got a bridge for sale. It's located in Brooklyn NY. Install the new spring at the heights to achieve the proper pressure. Must use a good spring tester.


BPE2013@hotmail.com

 

[mtocrs1]

Maybe I'm losing my mind but my math gives me a theoretical value of 136.3 at an installed height of 1.7
2.6% difference vs the measured 140 value


Sent from my iPhone using Tapatalk

 

[mtocrs1]

The 26918's have an advertised value of 125@1.8
Spring rate of 372lb/in
At my 1.7 I should have a theoretical value of 162.2 seat pressure.
At max lift I should be at roughly 350.
Does this make sense?
Is 162 to high of a seat pressure?
I will have everything checked. Just want to make sure I am understanding things correctly.


Sent from my iPhone using Tapatalk

 

[bison]

It's not too high. A little more is better than not enough. Believe me I've setup hundreds of valvetrains. Seen power go up 200+ at higher rpm with just a spring change. Measure every spring and measure every height and write it down. This way you know exactly what you have. You can run the conical spring close to bind with no issue. Typical rec is .060" from bind.


BPE2013@hotmail.com

 

[Steve V]

Hijack...Bison do you like the PAC-1219 for the 210/215 Mike sells? says 135@ 1.8 348@1.175

 

[bison]

Hijack...Bison do you like the PAC-1219 for the 210/215 Mike sells? says 135@ 1.8 348@1.175

I never used them but they would work on that cam. I like staying .060-.080" from coil bind in everything. I've found the moderate aggressive xer lobes are just as easy to setup and springs can be had for about the same price. The high energy will require somewhat less spring and are more forgiving as far as spring pressure requirement.


BPE2013@hotmail.com

 

[turbofabricator]

I agree with Bison. We are running 9.9's @136 with the Comp springs shimmed to 1.7" on pump gas and alky.

 

[mtocrs1]

I agree with Bison. We are running 9.9's @136 with the Comp springs shimmed to 1.7" on pump gas and alky.

The Comp 26918's?


Sent from my iPhone using Tapatalk