Best springs for GN1's with mild flat tappet

[tttype]

Have a Comp 260 flat tappet cam (212-212) , with 1.65 rockers give gross lift of .488
What should the spring seat & open pressures be ?

Installed height is 1.75
Rpm about 5600 max.

Currently have CC 980's that came with kit, but I believe that these are way to weak. May be a blessing as cam was had it really easy for the first 500 miles.

Any spring recomendations ?

 

[billsgn]

Just out of curiousity, why do you feel the 980's are too weak? Reason I ask is I have the same camshaft as you, but Im running Champion Irons. Ive been told that Champion uses very good springs in their heads but the springs have gone weak in mine and I was considering going with the brand new 980's that came with my cam kit.

I cant wait to see the responses you get as Im sure they will answer my questions as well.

Thanks, Bill

 

[49-blues]

I have a new set of GN-1 springs that came off new set of aluminum heads because I'm using a roller cam/spring set up- best offer if anyone needs these.

 

[vacuum 6]

Call Tom or Jack.

 

[tttype]

My 980's @ 1.75 height measure 55# pressure on my tester.
Even on the CC site they state 77# at 1.750

I'm thinking the alum heads must have higher installed height than irons.

Just out of curiousity, why do you feel the 980's are too weak? Reason I ask is I have the same camshaft as you, but Im running Champion Irons. Ive been told that Champion uses very good springs in their heads but the springs have gone weak in mine and I was considering going with the brand new 980's that came with my cam kit.

I cant wait to see the responses you get as Im sure they will answer my questions as well.

Thanks, Bill

 

[49-blues]

I think I remember 1.70" as being the correct installed height on my Gn-1 paperwork.

 

[bison]

Comp 980's are crap if you are turning the boost up and revving over 5600 which you should be with those heads or id use a smaller cam. Below that they are fine. Most dont give the advertised numbers. Champion doesnt spec springs per application in most instances since their heads are often sold through vendors. The vendors often dont know better or dont care as long as they sell the heads. Most often they are under springed from what ive seen and different cars ive worked on. If you order heads from Champion you can tell them to use whatever spring you want. Id use comp 26915 with i.d. locators. You should be good up to about 6000 with those. Shim so your at about 100-105lbs on the seat.

 

[bison]

I think I remember 1.70" as being the correct installed height on my Gn-1 paperwork.

The installed height isnt set in stone. It often needs to be adjusted to achieve proper spring pressures.

 

[bison]

My 980's @ 1.75 height measure 55# pressure on my tester.
Even on the CC site they state 77# at 1.750

I'm thinking the alum heads must have higher installed height than irons.

You have to measure and adjust every spring. A lot more than the heads can cause variances on the installed height.

 

[WSLN 6]

Good info Bison. ow do the 915's compare to the 918's?

 

[billsgn]

Bison,

To pick your brain a little more, what are your thoughts on LT1 springs?

 

[bison]

Bison,

To pick your brain a little more, what are your thoughts on LT1 springs?

My thoughts are that they need to be tested to be sure your setting enough pressure. Id want 100-105lbs on the seat. That will often require a lot of shimming. I never ran more than about .460 lift with a flat cam. I dont think its necessary and it will just increase the ramp rate more and require more spring pressure. Conical springs are better and dont need as much pressure over the nose to keep control. Id rather see the spring i rec'd above be run at 90lbs on the seat before i ran any LT1 spring. If your not planning on running high boost or over 5500 rpm it wont matter much but you wont be making much power if you dont.

 

[bison]

Good info Bison. ow do the 915's compare to the 918's?

918 is too much for a flat cam. 918 is good to about 5900 on a hyd roller if shimmed to about .040 from coil bind and the lift is under .550. They dont last very long when worked hard. If your running aluminum heads and hyd roller there is no reason not to go to 26120 springs. I have 26918 on my iron headed engine in my blue car and it has been to 5900 many times. Its a strong running engine with a tiny TE61 turbo and 212/212 cam with under .500 lift.

 

[billsgn]

Thanks for sharing your knowledge....

Bill

 

[tttype]

CC980 suck

Speaking of LT1 springs, thats what I went with.

Tom at Champion mentioned " for flat tappet , nothing special, any old Z28 spring " is what we use.

Couldnt find any vs739R sealed power locally, but found the Elgin V943xs.
Rated at 106#, @ 1.700 height.

This comes out to a comfy 85-90# at the Champions 1.750 height.
Checked every one at seat & open height & all are within 5#.

Took car our for a run & have 5psi more boost now ?
Revs alot quicker too.

Now do I have a good enough arm to throw those CC980's through Comps Cams windows from here.

Lost half their pressure in under 500 miles !

 

[billsgn]

Cool, then thats what I will run as well. Anyone know where I can get a set of LT1's for a decent price?

Thanks, Bill

 

[tttype]

Pull into the next parts store you drive by.

Or Summit, Jegs etc.

Sealed power, Elgin, Frontier are pretty common lines

 

[Chris McDade]

I've been 10.40's @129 with CC980 springs on Iron head 218/218 cam.

Im not sure how long the springs will last. Might have to change them out every 5000 miles or so.

 

[tttype]

I've been 10.40's @129 with CC980 springs on Iron head 218/218 cam.

Im not sure how long the springs will last. Might have to change them out every 5000 miles or so.

You want another set cheap ?:tongue:
These ones will be easier on your cam