BLOWNMERO

Has anyone here used these springs? Right now I have the comp cams 978s and I get valve float. I was wondering if anyone has had trouble with the 977s. Any help would be appreciated.

LOnSLO

iTrader: (15)

You get valve float with 978s? Are you sure you don't have 987's? The 978s have 405 lbs seat pressure at 1.1". That's about 40 more pounds than the 987s. Are you running a solid roller, or do you have 15 lbs boost? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

BLOWNMERO

the 978s are rated at
126 lbs @ 1.85 seat pressure and
368 lbs @ 1.250 open pressure
yeah.. im sure they are the 978s, ive had this problem the whole time they have been in the car, with or without the supercharger. I read a post a long time ago of someone that was having the same problem and he also had 978s. I clearanced my rocker arms, checked for lifter preload got shorter pushrods and nothing. It has to be the springs.

LOnSLO

iTrader: (15)

Maybe it is the springs then. What kind of lift are you running, and how many miles do they have on them? The 978s should be set at 1.8" installed height, which is 146 pounds seat pressure. With a .550 lift cam you should see 368 pounds at max lift, compared to 310 pounds with the 987. If you are convinced you still have float, then the 977s would be in order. It will wear on your valvetrain more though. I've never heard of any probs with the 987s running .600" lift cams. Have you checked your installed height?

<small>[ February 07, 2003, 11:25 PM: Message edited by: LOnSLO ]</small>

BLOWNMERO

I believe they were installed to 1.8. Thats what I told the machine shop to put em too, ive never personally checked though. Maybe that is my problem.

My cam is a .563 lift on intake and exhaust. I have about 13k miles on them now. It has done it since they have been in the car though. Even if you just threw the springs in there wouldnt they be right around 1.8 or real close to that?

<small>[ February 08, 2003, 01:26 AM: Message edited by: BLOWNMERO ]</small>

LOnSLO

iTrader: (15)

OK, those springs are major overkill for that cam, so it's not the spring. It's possible that your lifters are collapsing under the pressure, or, the machine shop cut the pockets too deep. You need to pull the valve covers and check for pushrod play, or rocker arm play. On a side note, how do you know you have valve float?

SStrokerAce

iTrader: (2)

With that cam, lifter and sprign combo, if the springs are still good there is almost no chance of valve float if all the parts in the system are good.

Bret

BLOWNMERO

I can never hit my rev limiter. Right at 6k rpm it starts to rev real slow and stops around 6400 or so, sometimes popping (not rev limiter). I have comp R lifters and I read somewhere that they are good up into the 400lb spring rates so I doubt im collapsing a lifter. I bet the machine shop cut the pockets too deep and the springs are installed to high.