tinker-27

hi guys we have a RHS motor that runs comp 259/275 cam with comp trunion kit comp link bar followers and comp 26969 Spring kit , steel Spring seats with a outer lip to locate Spring . The seats have shattered and sent metal all through the motor making a right mess !! . We think it could be valve float but it showed no signs off it on Dyno etc , we have found two different specs for the comp Spring 129lb and 159lb at 1,835" but they measure at 120lb . I've used these springs before with no issues , I've never seem anything like this before on a Ls , we are only raving it to 7200 so not even pushing it yet !! It's only done 4 hrs from new build . Any ideas would be grateful

KCS

iTrader: (20)

What's the valve lift? Coilbind?

tinker-27

.624 lift so should be no way of coil bind , we are on 1.8 rockers

truckdoug

iTrader: (25)

looks like the retainer was mashing into the top of the seal?

MuhThugga

Is that .624 lift number rated with 1.7 or 1.8 rockers?

TurboBuick6

iTrader: (2)

What is the raised boss in th first picture? If all your pockets have that, that would be why your seats broke.

tinker-27

the pic shows where the spring seat has shattered and disappeared , so the two Spring are now running on the head not the seat !!

SAPPER

iTrader: (10)

Wow, this was just a discussion on YB about RHS heads. One of the Aussies had this same issue.

TurboBuick6

iTrader: (2)

What's the cam numbers, what rocker arm and installed height?

I can think of two things here, 1) your going into bind 2) the seats have been hardened too much and are just too brittle.

Whistler

iTrader: (46)

What do the springs look like?

Old Geezer

iTrader: (3)

From the way the seats are broken into little pieces, it looks like they are some kind of cast material, like powdered metal......

slogo

This question was never answered.

I have a cam that was recommended for me, cam card says for LS1 so spec's are for 1.7 rockers, I am using 1.8 as well but that was all considered from the beginning.
In my particular case that is a difference of .035 on the lift.
Looks like .037 in your case. Not a huge difference, but.

140K_GXP

I think it is .624 lift with 1.7 rockers for that cam. So with 1.8 rockers, lift will be 0.660. This is probably the issue.

But need to know the specs of the springs also.