cam and valvetrain gods help me out please!

**DjLunchbox** · 07-12-2006, 02:21 PM

guys, i am in dire need of help. i think i have a solution, but i want as much experience and advice as you all have before i spend more money.

i have a 95 LT1 stroker, fully BP'd and balenced, the works...
over 5-5500rpm's, i hear the lifters act up, and eventually the plunger/cap/clips blow off and end up in my oil pan i cannot have this happening, this motor cost waaaay too much. i don;t know why it's doing it, but i have a feeling that it's something between the valve springs and the stock lifters. i am 99% sure that i am setting the lash correctly (used multiple methods from shoebox's site(an LT1 site)) and i have polylocks

i called comp cams, gave them the details, and they reccomended this setup.

my cam is PN 07-000-8

with the 1.6 cc magnum rollers, this equates to .547lift/220 dur. on the intake and .533lift/224 duration on the exhaust, the lobe sep. is 112* +4*advanced, so if i remember , that's like a 108* centerline (i'm not sure, pretty cam stupid here )

i have stock lifters for now, and i was told by the builder my springs are 120 seat pressure / 250 open.

so i told comp cams this, and they said that's too little on the springs, they need to be at least 135 seat/ 340 open to be able to rev @ 6000rpm's.

they reccomend getting the 26918 springs and the pro mag 885 lifters.

please tell me if you think this will help, who has used these parts, and how are they working for you. i need this info quickly, i have a show the first week in august and i have to get her running in no less than a week and a half. thank you very much for your help
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**Gran Patron** · 07-12-2006, 04:37 PM

You can trust what Comp Cams recommends since they specialize in that kinda of stuff. But it is always recommened to swap out stock springs for stiffer ones when adding a bigger cam and the lifters,too.

**HaulnA$$** · 07-12-2006, 06:42 PM

When you installed the lifters, did you soak them in oil? If so, this could be your problem. While I have not experienced this personally as I do not soak my lifters, I have heard others experience similar problems to yours that were cured by simply dipping the lifters in oil or coating them with assembly lube prior to installing them. There is a long technical theory on why this happens but I will spare you the details, unless you want to hear them. As far as parts combinations go, always go with what the cam manufacturer recommends over what the engine builder says. The builder does not spend the time or money that the manufacturers do in testing. HTH

**4 Speed Dave** · 07-12-2006, 09:12 PM

It's simple, Not enough spring force, you can sort of help the situation out by increasing the lifter preload slightly. Add an additional 1/4 turn. Just think about what is happening. You see at higher rpm's in your case about 5500 when the lifter is on its way down from peak lift there is not enough spring force to push up on the rocker arm and pushord to keep it seated in the lifter cup. Thus the small c shaped retainer clip is quickly thrusted up against it's locking groove so hard that it comes out of the groove and ends up in the pan.

**DjLunchbox** · 07-12-2006, 10:06 PM

Originally Posted by 4 Speed Dave

It's simple, Not enough spring force, you can sort of help the situation out by increasing the lifter preload slightly. Add an additional 1/4 turn. Just think about what is happening. You see at higher rpm's in your case about 5500 when the lifter is on its way down from peak lift there is not enough spring force to push up on the rocker arm and pushord to keep it seated in the lifter cup. Thus the small c shaped retainer clip is quickly thrusted up against it's locking groove so hard that it comes out of the groove and ends up in the pan.

is that what they call valve float? where in CT are you from, i need a good EFI tune shop

thanks for the info guys! keep it coming!

is soaking the lifters overnight in oil enough? should i be "pre-pumping" the lifters with a pushrod or something before i install them?

**airdeano** · 07-12-2006, 10:34 PM

what valve spring was used on the intial install?
coil bind is what height? retainer thickness and
installed spring height?
with an agressively high lift cam (rocker ratio unknown)
cc is right.. not enough closed seat pressure and way short
on open, which will cause float. valve may not hit the
piston but will bind on guide.
whats the guide/retainer clearance on full lift?
these should be on the "blue-print details"

airdeano

**HaulnA$$** · 07-12-2006, 10:38 PM

Originally Posted by DjLunchbox

is that what they call valve float? where in CT are you from, i need a good EFI tune shop

thanks for the info guys! keep it coming!

is soaking the lifters overnight in oil enough? should i be "pre-pumping" the lifters with a pushrod or something before i install them?

Don't soak them at all, don't pump 'em up or anything of the sort. Just dip 'em in oil or coat them with assembly lube, then install them. Let them pump up on their own when you first start the engine, then bleed down as normal. Depending on the lifters, I typicaly use 1/4 to 1/2 turn of preload to to extend the RPM at which the valves float. HTH

**SFVetteman** · 07-13-2006, 01:41 AM

Soaking the lifters in oil is the way most builders do it.

The 26918 springs will eliminate your valve float and can easily handle the lift of your setup.

Nothing wrong with the Pro Mag 885 lifters either but the stock lifters can handle your setup just as well up to 6800+ RPM

**Gran Patron** · 07-13-2006, 02:34 PM

Originally Posted by SFVetteman

The 26918 springs will eliminate your valve float and can easily handle the lift of your setup.

Your good to go with the 918's they are advertised to handle up to a .590 lift, if im not mistaken.

**SFVetteman** · 07-14-2006, 01:32 AM

Originally Posted by DjLunchbox

they reccomend getting the 26918 springs and the pro mag 885 lifters.

Are you sure they didn't say pro magnum 875 lifters? I believe the 885 lifters are for the pre-87's. You don't want the 875 lifters because of oiling problems. Stick with the stockers.