Comps Beehive Springs - What Spring Load for TTA heads

[Jan Larsson]

Ported stock TTA heads, slightly larger than stock valves, Harland sharps roller rockers ...

Anyway will be running comps beehive springs (#26918) anyone use these and can help with the installed height (spring load in lbs) I should be using?

Julio I beleive you might have installed the same springs?

 

[HouseofSpeed]

Jan...I am not a huge fan of the 918 spring...Comp originally brought that spring to market as an LS1 replacement and had tons of problems with them. Isky makes some really nice springs in their tool room series that would work for your application. I have them on my TA heads....my part number wouldn't work for your app (I am running a pretty big solid in my car)...but give me your cam specs and rocker info and I will be glad to pick a spring for you.

 

[Razor]

The heads need a negative retainer lock. The installed height on stock locks I believe was like 1.725. Using the negative keepers increased that to 1.75. You cannot get anymore height than that without milling into heads or having a custom valve made. On my heads Champion used a very thin shim, the negative keepers.. and that was it.

You dont want to put the spring into coil bind, and you want to keep pressure on the cam. There is a chart Comp has that shows this. And most of their charts set the springs for 1.80 which you cannot get on a TTA head.

No biggie.. its been a while since I went through this. But do specifically remember the keepers and locks deal.

HTH

 

[bkoons]

I was told by Tom @ champion that you want 140# min closed and less than 400# open with a hyd. roller. I have the 26915 springs installed between 1.695" to 1.705" & I needed +.050 keepers to obtain that... I have fwd heads & stock length valves. I think the 26918 springs you have will have a higher load than mine. I think you also want at least .060" between coils at max lift.

 

[Jan Larsson]

I do have the +.050 keepers (or locks) (so comps part number 614 with their 795 retainers), I'm with the guys setting this up for me on Monday so just need as much info I can before hand.

Will have steel shims installed so the springs don't eat into the heads so we can do some machining if needed. Also new valves will be installed etc so we can do some work if needed to get the correct installed height for the springs.

If we can get 1.75 is that ok or should we try to get as close to 1.80 as possible?

 

[Jan Larsson]

Looking at comps spec for the 918 springs an installed height of 1.800 would give me 146lbs and at 1.750 130lbs

 

[bkoons]

Think you got that backwards... 130lbs @ 1.800 & 146lbs @ 1.750. Set the installed height to provide the desired spring pressure at zero lift. Then check at full lift to verify you dont have coil bind or too much spring pressure.

Based on the spring specs 1.750" would be a good target but you should physically check the spring force.

 

[Jan Larsson]

Think you got that backwards... 130lbs @ 1.800 & 146lbs @ 1.750. Set the installed height to provide the desired spring pressure at zero lift. Then check at full lift to verify you dont have coil bind or too much spring pressure.

Based on the spring specs 1.750" would be a good target but you should physically check the spring force.

Sorry yes, too late when I did my original post last night 130lbs @ 1.800 and 146lbs @ 1.750 ....

So there is no problem running with 146lbs on the comp cams rev xr1 roller cam then? I don't see any specs of max load on the cam card or anywhere else on cams web site. Just want to be sure I don't run with too much load.

Will double check for spring bind as well when we got it mocket up

 

[Razor]

You'll be fine.

Julio

 

[89ICBM]

Ported stock TTA heads, slightly larger than stock valves, Harland sharps roller rockers ...

Anyway will be running comps beehive springs (#26918) anyone use these and can help with the installed height (spring load in lbs) I should be using?

Julio I beleive you might have installed the same springs?


Jan,

Seat pressure on these motors isn't a big issue, 130# is fine. These motors don't turn enough rpm's to float a valve. The issue is valve open pressure with a hydraulic flat tappit cam. You need to be under 290# at open pressure. You should witness your head guys reading to make sure the springs aren't going in or over 290# range. The cam won't take it. If you have a roller cam 350# range open is fine but 400# and up may be a bit much. Really the cam manufacturer will give you the limits. I'm running a DLS Engine Development 218/218 roller at 375# with no problems.

 

[Jan Larsson]

Ported stock TTA heads, slightly larger than stock valves, Harland sharps roller rockers ...

Anyway will be running comps beehive springs (#26918) anyone use these and can help with the installed height (spring load in lbs) I should be using?

Julio I beleive you might have installed the same springs?


Jan,

Seat pressure on these motors isn't a big issue, 130# is fine. These motors don't turn enough rpm's to float a valve. The issue is valve open pressure with a hydraulic flat tappit cam. You need to be under 290# at open pressure. You should witness your head guys reading to make sure the springs aren't going in or over 290# range. The cam won't take it. If you have a roller cam 350# range open is fine but 400# and up may be a bit much. Really the cam manufacturer will give you the limits. I'm running a DLS Engine Development 218/218 roller at 375# with no problems.

Thx Frank, I'm installing comp cams Extreme 206/210 roller cam so should be good. I'll double check the upper (open) pressure and also coil bind to be on the safe side.