I going to be running an LE2 camshaft with 1.6 rockers. Which springs should I go with the 1218's or the 1518. I know I will be a little over on the lift with 1218's but I have talked to pac and they said I shouldn't have a problem. Just looking for advice?

 

id be safe and get the 1518s
their not that much more $$ either

 

Installed Height - Lift = x

Coil Bind + 0.060 = y

as long as x > y you should be ok.

 

QFT

they are really not that much more, dont be cheap

 

With aggressive hydraulic roller cams, the lobe ramps can be as much or more of a factor than the actual lift.

I’m in the progress of upgrading from Comp 918s (same as PAC-1218s) to the PAC-1518s with titanium retainers. I have everything ready to go (springs and retainers) and I’m starting the install this weekend.

So, I say PAC-1518s and then you error on the side of caution.

WD

 

If you're on the edge go with the 1518s.

 

how much lift are the 918s rated to with 1.6 rollers?

 

As already stated, you need installed height-lift >0.060" from coil bind. If you want to run them as close at 0.060" you need to be meticulous about setup. But closer does work better at controlling the spring with the valve open, up to a point. When you look at spring specs, it's best to think of the "rated" installed height as an "example". You may need to set it up shorter, for more pressure (provided adeqaute clearance is maintained) or taller to accomodate the lift (provided adequate pressure is maintained).

Rich

 

They are "rated" at .650 lift at the valve (rocker ratio isn't an issue) with a 1.800" installed heigth. But as Rich pointed out, there are some variables at play.

WD

 

Just to elaborate at the risk of being repetitive. The maximum lift a spring is good for is best conceptualized as follows. Start with the height that gives the desired seat pressure. Subtract the sum of the coil bind height plus 0.060" and that is the max lift at the valve the spring can be used for. You may prefer to run more than 0.060" clearance, I'd advise against less. Of course, always check for other sources of interference, correct pushrod length, etc.

Rich