Miles in Michigan

I'd always heard that the heads need to be machined to use dual valve springs. Here are some that don't:

http://www.aandacorvette.com/cart/sh...p?MainCatID=10

They are called "REV 1116 Valve Springs", and require drop-in spring seats, available on the same page, made by West Coast Cylinder heads.

Anyone know if these are as good as the other dual springs, that require machining of the spring seats area on the heads?

Richard@WCCH

iTrader: (3)

The REV 1116 valve spring measures 1.25" in od. That's about the same as stock. The key to this dual spring combo is the inner spring. Specially made for REV. At the moment, everyone is waiting for more spring sets to become available. That should happen within a week or so. We've sold about a dozen sets since January and have not seen a single broken or sacked out spring yet. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />
It's important to add that valve springs, especially dual assemblies should have a properly fitted seat to locate them. I see very few shops providing a proper spring seat, yet they are very important in adding stability to the spring.
Generally a 1.25" single spring is good for about .520" valve lift. Those planning to use a cam with more lift should always choose a dual spring. The spring assemblies Andy is selling are well engineered and should provide trouble free service without the hassle of having to machine the heads. Hope this answers your question. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />
Richard

TenaciousD

I was looking at dual springs, but heard they were noiser, and since the 918's could handle up to .625 lift (on comp cams site), weren't necessary. I don't profess to know anything at all about this, but am now wondering about dual springs since this is the first time I've heard single springs were only good to .520.. since a large number of people are using the 918's, with no failures I've read about yet, is there really a need to do dual springs? and is there really a noise difference?

p.s. I ask because I'm about a week away from ordering the 918's with a .561 lift cam, and wondering if that's the correct thing to do...

<small>[ June 18, 2002, 09:03 AM: Message edited by: TenaciousD ]</small>

wizkid

iTrader: (3)

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by TenaciousD:
<strong>I don't profess to know anything at all about this, but am now wondering about dual springs since this is the first time I've heard single springs were only good to .520.. since a large number of people are using the 918's, with no failures I've read about yet, is there really a need to do dual springs? and is there really a noise difference?

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">He said a single spring 1.25" diameter is only good to about 0.520, not double springs. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

I run 987 double springs with a 1.440" diameter. My setup is quite compared to many other heads/cam cars.

Eric

TenaciousD

I don't get it, that's what I said,
"it's the first time I've heard single springs are only good to .520".

I know dual springs are good for more. I just don't know if 918 springs are a 1.25" diameter and thus only good to .520" lift <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

<small>[ June 18, 2002, 11:55 AM: Message edited by: TenaciousD ]</small>

Richard@WCCH

iTrader: (3)

TenaciousD,
The Comp Cam 918 valve spring is a rather different spring. They call the spring wire "ovate wire" because it's crossection is oval. Furthermore the spring is listed a 1.290" at the base and 1.060" at the top giving it a tapered or conical shape. Comp says that the spring can handle up to .625" valve lift. The advancement in spring technology never ceases to amaze me. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />
IMO the greater the valve lift beyond .520" the greater the reason for two springs. Two springs handle the load better than just one. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

Mike Norris

iTrader: (10)

We have been using these for about 6-8 months on the more aggressive packages with very good luck. They fit LS1 heads fit pretty nice after machining the spring pocket deep enough, but the LS6 heads are a bit tougher due to the larger intake runner. Can be done though <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> The spring seats needed are not a common piece as of yet, but necessary to be set up correctly.

Later,

Mike

Miles in Michigan

Any more opinions on these springs vs. comp 918s, on a moderate lift cam (0.56x"), and stock heads? I don't plan to rev too high (6600?), and will use titanium retainers with either spring.

thanks.

JS

iTrader: (4)

I have a Cartek duel spring that fits the seat with a special cup.Call Cartek for more info..

Yes they are nosier but I wont have to worry about breaking one.

JS

Richard@WCCH

iTrader: (3)

JS,
You mentioned the springs were "noisier". Was that the only change that was made? That's the first time I have heard anybody report noisier valve train with only a spring change. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" />

JS

iTrader: (4)

They tick slightly more than the single did.
I run one of Carteks fast ramping cams too.

I've HAMMERED on the car repeatedly,No problems with KR or broken springs.Its a great mod.Cartek keeps improving there stuff and then passes it onto there coustomers.

Unike some other shop who replaces broken springs with soon to be broken springs <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

JS

<small>[ June 21, 2002, 07:31 AM: Message edited by: JS ]</small>

JP98SS

How are the 918s soon to be broken springs?