Comp springs WTF????

[jpwalt1987]

Well I finally got around to checking valve spring pressure today on half of my valves. The car has Comp Cams 26926 double springs. The pressures were all over the place. I had one spring that was way off. I checked it twice to make sure it wasn't operator error. Here is a picture of the chart I made with the pressures and one with the spec pressures. Guess I need to get some new springs. Any suggestions on something that won't end up like these after 1400 miles?? PAC 1203?

Here is the link to my first thread about all this.

http://www.turbobuick.com/forums/threads/spring-recommendation-for-gn1s.377393/page-5

Heads are ported GN1s , DLS 218/218 .540/.512 lift cam And all the other stuff to go high 9s.

 

[Mike Licht]

Pac all the way, great product and they stand behind them. I have some in stock.
Mike

 

[Blazer406]

Holy Smokes Batman!

IMHO, the seat pressure is very important on our cars if you run over 20 psi boost.

 

[jpwalt1987]

Pac all the way, great product and they stand behind them. I have some in stock.
Mike

Mike, which PAC springs would you recommend? DLS built the motor a couple of years ago but it only has 1400 miles on it and no full 1/4 mile passes. As for valve train setup it has Comp 885 lifters , T&D shaft mount roller rockers, and Smith Brothers .116 5/16ths pushrods. Not sure how much spring pressure is needed for the cam. Going by the spring that Dan selected I would guess in the 450lb at max lift range. I was hoping that the retainers could also be reused. Any idea if they will fit PAC springs? Thanks Mike.

Jeremy.

 

[8 SEC 109]

Check for coil bind. My DLS built motor was in coil bind which caused all sorts of problems springs, timing chain etc.

 

[8 SEC 109]

While you are at it check your freeze plugs! Make sure they are held in by something better than black rtv like mine.

 

[turbo nasty]

Did you check the springs new in the box? I have bought some that have had a few on the weak side and with miles they were real weak.

 

[Nick Micale]

....... Guess I need to get some new springs. Any suggestions on something that won't end up like these after 1400 miles?? ..........

All valve springs will loose tension just sitting, even with no miles.

It is not unusual for a performance or race car to have very short valve spring life, some will not make it through a season.

If the car sits a lot, like over a winter, loosen the rockers to remove tension on the springs as this will add to their life span.

 

[jpwalt1987]

Did you check the springs new in the box? I have bought some that have had a few on the weak side and with miles they were real weak.

I did not. They were installed when Dan built the motor.

 

[bison]

The PAC 1203's I run have proven to be very reliable. I've got about 5000 miles on a set and they are set up for 200 on the seat and about 510 open.

 

[jpwalt1987]

The PAC 1203's I run have proven to be very reliable. I've got about 5000 miles on a set and they are set up for 200 on the seat and about 510 open.

Do you know if the retainers from the comps will work with the1203s???

 

[bison]

Do you know if the retainers from the comps will work with the1203s???

Idk. You could look at the spring listings for the springs and it gives the spring od and id dimensions. From this you can determine if they will work. It's ok if the od of the retainer overhangs the spring a little. It should be a good fit on the id though. You should locate the
base also. The inners on the 1203's I have on my engine are sitting on top of the id locator so they are actually compressed more than the outer spring. There was no problem with this set up. 5000 miles and made several passes up around 140mph around 4500 miles. When I pull the heads I'll Ck the pressures. I went back to machined standard 7* locks? The smaller locks allowed me to get a taller installed height. Tom at champion hooked me up. I bought springs, retainers and locks from him. The guides need to be machined for .500 seals for those springs.

 

[BEATAV8]

Also curious... how much spring pressure is needed for a cam like that? (.510-.540 lift)

 

[BEATAV8]

Also curious... how much spring pressure is needed for a cam like that? (.510-.540 lift)

Nevermind, found the thread which is linked above..... thanks

 

[jpwalt1987]

bison said:
With a 218/218 the engine shouldn't be over 6000 rpm unless it has enough power to pull that high in 3rd. I run 200lbs on the seat and over 500lbs over the nose with the 218
In my black car. You either need an 885 comp lifter or a solid lifter if you want to run higher spring pressures.

 

[BEATAV8]

Idk. You could look at the spring listings for the springs and it gives the spring od and id dimensions. From this you can determine if they will work. It's ok if the od of the retainer overhangs the spring a little. It should be a good fit on the id though. You should locate the
base also. The inners on the 1203's I have on my engine are sitting on top of the id locator so they are actually compressed more than the outer spring. There was no problem with this set up. 5000 miles and made several passes up around 140mph around 4500 miles. When I pull the heads I'll Ck the pressures. I went back to machined standard 7* locks? The smaller locks allowed me to get a taller installed height. Tom at champion hooked me up. I bought springs, retainers and locks from him. The guides need to be machined for .500 seals for those springs.

Sounds like the GN1 heads need a little bit of machine work to work with the PAC 1203? The spring seats need machining to locate the springs?

 

[bison]

Sounds like the GN1 heads need a little bit of machine work to work with the PAC 1203? The spring seats need machining to locate the springs?

No. The guide od is too much when running a seal to clear the inner springs on the 1203's

 

[BEATAV8]

No. The guide od is too much when running a seal to clear the inner springs on the 1203's

Ah OK. The data sheet for my heads shows .500 dia intake seal and .530 dia exhaust seals. The .530 dia exh is the issue?

 

[bison]

Ah OK. The data sheet for my heads shows .500 dia intake seal and .530 dia exhaust seals. The .530 dia exh is the issue?

Yes unless you leave the seals off

 

[jpwalt1987]

Yes unless you leave the seals off

Well crap. That is the size seals I have on my invoice from Dan. I think I will just have to pull one and measure for myself. I may just have to go back with the Comp 26926 springs to avoid all the headache. Didn't want to but as it stands now I need new retainers, locators, keepers, and springs and now the seals may interfere in order to run the 1203s. Dang.