500@10psi

iTrader: (5)

so i've heard that they are only good to .6 lift and i've also heard that they are good to .625. now on comps web sight they say .625 but on tsp's they say .6. so which is it? can some guys with some experience pushing it chime in. i'm trying to see if they will work with a .598 lift cam and still have a decent safety margin. i would also like to put this dispute to bed.

02*C5

iTrader: (1)

If they are a comp spring which they are and they are advertising .625 i would take their word for it. Each retailer will advertise what they need to to make sure they are safe from liability. Go with the comp numbers make sure that your when you set them up you do it correctly and make sure that the cam is with with in specs. Now and this is personal choice. If your cam is .625 lift I would rather do a spring with a .675 lift. Give your self some room for an accidental over rev or something. Rule of thumb .050 lift more than your final lift number. But that is just a personal choice.

The_Rizzle

iTrader: (4)

the the rated number for the springs includes a bit of room for coil bind. With a beehive its a bit more difficult to see, but if you look at the installed height minus the coil bind number, it gives you the total amount the spring could theoretically take, but is not rated for. ie, in the case of the 918's, installed height is 1.8, coil bind it 1.110, so the spring has .690 of travel. There's lots left from coil bind at .625.

The only other thing to worry about is how intense your cam profile is, a very agressive lobe getting to .625 could be hell on that spring, even if it's rated for the same lift. A very aggressive lobe usually calls for more spring pressure though.

I saw an ad in an older (2007) EMC mag, and even then they said .625, so if it fits into the rest of your build, I'd say go for it.

FC3S Murray

So are the 918's finally over the hic-up they had a while ago with breaking..?..?

The_Rizzle

iTrader: (4)

Apparently theres a new set out (again). Its too bad they dropped PAC as their supplier years ago.

I just installed a used set (i know, extreme budget build) into an offroad racing truck, the thing saw 7500 more than a couple times this weekend. Checked out ok.

If you're not very comfortable with the 918's, PAC has a hi quality beehive rated to the same specs, 1218's, thats well known for being reliable. They also have a better (I think nitrided) version thats rated to .650, if you've got lightweight valve-train, 1518, but they ain't as cheap...

Emulsifide

iTrader: (22)

Here's the scoup according to the packaging of my brand new 918 springs.

The absolute newest set of 918 springs come in a satin finish and can handle a lift of .625".

Also, they no longer have a blue stripe. Here's a picture:



Here's a picture of an older blue stripe 918 next to a stock ls1 spring:



Even though the white balance is different between my picture and the one I found on the internet, you can deduce the following. In the blue stripe picture, the 918 spring is darker than the ls1 spring. Have a look at my picture and you can see the updated 918 spring is much lighter than my stock 799 head springs that are in the same picture (which are the same color as my ls1 springs off of my 241 heads). With that, you can say the color difference between the two is significantly different and it should be pretty easy to tell the two apart.

9t8z28

iTrader: (19)

Never had a problem with my 918's on my blown LS1 and over revving. Sometimes when your fooling around, its impossible to keep it off of the rev limiter. The only reason I sold my 918's was because the Trick Flow heads came with springs. I bought my 918's new about 2 years ago. I think the issues were hear and there and not as common as you think. You mostly hear the bad and not so much of the good.

Derek@KY-Turbo

iTrader: (4)

depending upon the installed height you set them up at, you can get a little more psi out of them...just double check for coil bind...

Beaflag VonRathburg

iTrader: (176)

This is how you should go about looking at springs if you don't see the lift rating for them. You can figure out the total lift they'll take pre coil bind, but know there needs to be a slight safety buffer in there. This post encompasses what you need to know.