this is a picture of the stock LT1 spring sitting on the stock seat/locator (left) vs the LS6 spring sitting on a comp cams 4693 seat/locator

the stock seat was too small for the LS6 inner diameter of the spring, the new seats are 1.300 x .800 x .570 but look at the height.. am i going to run into a problem using these on the stock heads?

 

free height is meaningless.

 

Install them, set it and forget it.....

 

first, did you measure the installed height that you need? If so, then what is the reading of that yellow spring at the installed height that you need(don't forget the shims). Is the yellow spring enough pressure for your HR?

 

I have nkt yet installed them because i wanted to ask here first. Im using stock length valves too. I sent an email to comp cams tech dept to ask what Height and pressure the cam needs

 

Comp's rpm ranges are wrong for the LT1 so therefore their spring recommendations are often wrong.
What are the cam specs?

 

If it's an aftermarket cam chances are LS6 springs are too weak for the heavy LT1 valvetrain.

 

your cam card will have spring specs on it. find out what the LS6 spring spec is and at what installed height and see if that matches what the cam card says for spring specs. These typically are minimum seat and open pressure specs listed on a cam card.

"stock" LT1 heads spring height is 1.70"-1.75" IIRC. "Most" aftermarket springs are designed to install at 1.800" which means the spring pockets on the heads are machined down to allow those springs to be set at a 1.80" installed height. Putting a 1.8" spring in at 1.7 or 1.75 will increase it's seat and open pressure. On high lift cams you could then get closer to coil bind if your lift is very high since you are runnning a spring designed for 1.8" at a lower installed height. In most cases coil bind won't be a problem but you will see higher open and seat loads on springs installed at a lower height than spec.

Can't answer your ? on these springs working with your unpublished cam specs. The height difference unloaded is not what you need to be concerned with...

 

and this is not something you want to slap in and hope for the best. especially since you are going with an aftermarket cam.

 

cam is comp cams XR270HR (yes it works with LT1, its a custom order)

218/224 .528/.535 with 1.6rr on 110* LSA

the recommended spring from comp cams is the 986

i had these LS6 springs laying around (brand new) from the LS1 days, thought they might work with this cam..

if comps recommended springs are wrong, what should i be using instead then?

 

from what i just read the yellow ls6 springs are good to .550/.550 lift. So your within that (barely) But what you need is your open and closed seat pressure's that are on your cam card.

 

If you already have the hardware for the LS6 springs I would just throw in some 918's.

 

A little googling says the LS6 springs are like 90lbs on the seat, not going to be enough for aggressive aftermarket lobes, there is more to picking springs than just lift. Too little seat pressure and a cam that sets the valve down fast and the valve will bounce and blow the compression right back out.

For comparison the 918s are like 140lbs at the LS 1.800 installed height.

The 918s should be a good choice for that cam even though we don't know what lobes those are.

Why did you get a custom cam with such low lift?

 

Says who?

I would trust Comp Cams over some internet guy who claims Comp's rpm ranges are off on all of their LT1 cams. Funny thing is that I have run 2 Comp Cams in my LT1 cars and they make power just like Comp says they should. Unless you sell everything you have and start running AI stuff, 96 capricemgr will tell you everything is wrong with your combo.

That cam you have is somewhat mild. A 918 beehive would do the trick.

 

Comp's specs are not always wrong but the cams usually need more rpm in an LT1 than they list which can lead to the springs being insufficient. Really pretty well documented it is a product of the ultra short intake runners of the LT1.

I did not say anything about AI, I did not say Comp made bad products or anything else, just trying to help you get the right spring. joelster is just a troublemaker blindly taking shots at me even as he agrees with the springs several of us already agreed would work.

 

I agree with the 918's because I run them myself, not because of what I hear from internet guys like you. I use them and take them to 7000rpm with a much hotter camshaft than what the op has. My cam is the XFI468, and COMP recommends 918 beehives for my cam. I guess they must have nailed it in my case only. All of their other recommendations are wrong according to you. You call me a troublemaker because I call you out on your constant rehashing of crap. Blindly taking shots at you? Hardly. It would be a blind shot if I didn't have any data to back up what I say. You are the one that has a lot of enemies on these boards, not me. Why do you think that is?

 

ok kids.. play nice..

so basically either the 986 or 918 springs will work.. the 986 are double springs and the 918 are single beehives..

i currently do have the 787 retainers for the beehives, as well as the 7* locks.. i just need to get the 4705 seats.. and the 918 springs and im ready to go.

If i go with the 986 springs, i need new locks, retainers, seats and springs..

i think i will go with 918's then..

to the person who asked why i bought this cam.. well i was wanting originally the LT4 hotcam.. a person on this board had something similar.. its not that "custom" its that it is the same grind for the GEN I block, but has the longer dowl pin and larger hole for the optispark..

i dont have the cam card.. just what i can find on comp's website about the cam.. found here: http://www.compcams.com/Company/CC/c...?csid=187&sb=0

 

According to comp you should only be taking that cam to 6200.

http://www.compcams.com/Company/CC/c...csid=1112&sb=0

 

the ls6 springs will be a fine replacement for the recommended 986 springs. Measure actual coil bind on them and set them up .025 from bind and you'll be good.

 

LOL. It's called rpm range. According to you it must not idle either, right? I mean it only works from 2200-6200. It must not work at all around 1000rpm. Can't possibly spin it higher than 6200, the power must drop way off. In my case with a single plane I spin it higher. It feels like it peaks around 6500 for me, but I shift it at 68-6900.Way off from what they say :yeahright: