wouldn't running .618 lift on a 918 kill the spring prematurly??

 

MAYBE, but for the most part no. Depends on how you set them up and the lobes you run, plus there are some better beehives with some extra TLC from the manufacture that can do .650" lift all day long without problems.

Bret

 

I meant from the lift being over .600 and the spring says max lift is .600

So if you set them up similar(shimmed more) that would get you less lift correct..and more pres. would this wear the spring out quicker?

Bret my reason for asking is....I had some spare stuff so i'm trying something out,

 

Spring wear can be a few things.... one is spring surge, you can control that by setting the bind clearance at the right places, usually tighter controls the surge much much better.

If a 918 binds at 1.140" and is recomended to be installed at 1.800" then they are saying you need .060" to bind.... I don't put them there but I also check my bind and setup the springs at the installed pressure and height that I need. That can easily get you LOTS of miles out of a set of them.

Bret

 

What's the best way to check for coil bind on the beehive springs? With the valve at max lift, the beehives don't compress uniformly, the coils sort of stack up from the bottom and the ones that aren't touching all have different clearances between them.

When I did mine, the only thing I could think of was to make up a solid roller lifter, adjust the rocker to zero lash, turn the engine over to put the cam at max lift, rig a dial indicator to the retainer and then crank down on the polylock until the coils bound up. It's been a while, but as I remember I was getting in the 0.050" - 0.060" range.

I guess that was OK; I have about 2000 miles on the engine since, with no problems so far.

 

I take them off and put them in a vice and compress them as far as they go. Measure that distance with a caliper and there is your coil bind.

Now a LOT of people will tell you that running a spring to coil bind is bad, but that's not the case. Ask the spring manufactures who make the springs, most of them are compressed to bind during the making of the spring to check them so it's not big deal at all.

As for the distance between the coils, if there is any on a single spring like a beehive you have clearance. One of the advantages of them is that the lower coils stack earlier and aren't considered part of the valve mass then. .050-.060" to coil bind is perfectly fine.

Bret

 

Just be careful doing this. There is a LOT of stored energy in a fully compressed valvespring! If you use the same clamp to do this a bunch, then it might not be a bad idea to drill a hole through each end of the vice and run a rod through it to keep the valve spring in place in case something does get out of wack.

 

Oh yeah, people need to be carefull when compressing a spring like this.

Bret

 

Is it okay to shim up a spring? Do you just ask for spring shims at the parts store? I have float on my 3.1 motor at 5600 and I supposedly have bigger than stock springs. I'm thinking that shimming up will increase seat pressure.

 

Yeah, you need to know the coil bind height, the actual valve lift and add in a clearance into that. Then you can setup the springs at that height.

Bret

 

To set up the valve train correctly you need an assortment of shims. Each valve will be a little different and the installed height must be set for each valve separately using the necessary shims. You should get a "shim kit" which typically contains a number of 0.015, 0.030, and 0.060" thick shims.

Rich