BSiegPaint

The more I dig into this, the more questions I seem to have, and the fewer answers that appear to be out there...

I have a pair of the 062 casting Vortec heads. I want to run a Comp Cams Magnum 270H cam with them. This cam has a .470/.470 lift, the maximum that the Vortec heads can take. Therefore, I need to use a different spring or have the heads machined. I chose the former.

I have found out that by using Comp Cams "918" springs, the maximum lift attainable is increased to .550, which is perfect for my installation. These springs are used by many LS engine builders as they are a nice upgrade from the GM springs. I, however, don't quite need the performance or the cost of the 918's, and since the stock yellow Z06 springs have the same measurements, I bought a set of those. Has anyone else installed these beehive springs on their Vortec heads? I'm wondering what you used for a retainer and what you used for a retainer lock, by name and part number if you have it. I want to buy the same things, but can't find out what I need. Also, where did you find spring shims for the Vortec heads? I've found several that say they are for the Vortec heads, but the inner diameter is 55/64", which is too small for the .880 diameter of the spring seat.

Any successful Vortec build stories are welcome as well - what you used and how it came out. I'd like to get started on these heads next week, but want to make sure I'm not building a set that will fly apart.

TimAT

I always use the springs recommended by the guys that made the cam. reason? Increased durability. They know how hard a particular cam is going to be on the springs- open/close rate, lift, etc., IMHO, not a good place to mix and match parts.

That said, if the ZO6 springs you're talking about have the same seat pressure and open pressure, will handle the lift of your cam, then they should be OK to use. there are more specs to a spring other than it fits the spring seats. Retainers and locks are another thing- they really have to be compatible with the spring AND each other. Be a real bite to get it all together and running good and then lose the game because a spring broke and dropped a valve.

BSiegPaint

The Z06 springs meet the requirements of lift and spring pressure almost perfectly. My only issue is getting them to stay in place. I have a set of the Z06 retainers coming with the springs, however the Z valve stems are a different size than the valves I am using. I'm curious to see if anyone has used the retainer locks for an 11/32" valve with the retainers from the Z. While both use 7 degree locks, I'm not sure if the inner diameter of the Z retainers is the same as the 11/32" valve stem retainers. They also need to be installed at 1.80", and will likely need to be shimmed, but I can't find the shims for these heads anywhere. Several places list their "Vortec" shims but measure them at 55/64" ID, which is smaller than the .880 ID the shims need to be on a Vortec head. I suppose I could be the first to do this combo, but I'd be surprised. I know a lot of people just install a lesser cam with these heads and run the stock springs. I just don't want to do that. Maybe I'll just be the Guinea Pig...

Rotonda

One thing to check very carefully when using unmachined Vortec heads is the INSIDE diameter of the spring. The Vortec valve guide boss has a very large outside diameter and most stock (1.255) small block springs will not seat fully without interference. I wound up using Crane H-11 springs, which are pricey but allow the use of stock retainers. I also installed them with +.050 locks which allow an additional .050 cam lift in stock Vortec heads.

BSiegPaint

The recommendation for the heads is the Comp Cams 918 "beehive" springs, which are an upgrade to the Z06 springs. A lot of LS engine builders change from the stock Z springs to the 918's to get a higher lift cam in the LS engine. Stock will take up to .550", I believe. The Z06 springs seem to be a perfect match for the unmachined Vortecs. The tops of these springs are narrower than the bottoms, and I guess I'll just have to find out for myself if the stock Z06 spring retainers will be held in place by 11/32" locks. If not, I can go with the Comp Cams retainers for the 918's, but they are a bit spendy for a simple retainer... Thanks for the input!

BSiegPaint

Well I've gotten all the pieces parts in the mail and have test assembled them off the head. The locks for the standard valves seem to work fine with the Z06 keepers and springs. The 7 degree angles match fine. The locks stick up from the keepers about 1/16 of an inch, about the same as I see the stock Vortec locks. I'll get a pair of the valves swapped onto one head for test fit in a day or so and post the results. Looks like it will all work.

'75

I'm doing a similar project and am wondering how the springs worked out?

GasketDude

Here's an article CarCraft did on the use of the Beehive springs AND retainers for the Vortex heads. Remember, it's the retainer that contacts the top of the guide/valve stem seal that limits total cam lift.

http://www.carcraft.com/techarticles...ade/index.html

If you have the heads off ('75 I believe you do) why not just machine the heads now and have them ready for any future upgrades later. As you kno you are just opening up the pocket for the spring O.D. and taking down the height of the guide. Here's another link for the tools.

http://www.chevyhiperformance.com/te...ift/index.html

Might be a good time to put in screw in studs too.

Hope this helps,
GD

'75

Well then, if the retainer to valve seal dimension is the limiting factor, then I don't have a problem, I just measured the travel with a spring removed and the retainer and keepers in place. Using a dial indicator, I measured .508" travel when the retainer touches the seal. Now I guess I just need to know at what height I will get spring bind with the original vortec springs.

GasketDude

First you need to check if the Vortec springs are within range of the cam(s) you plan on using. This seat and load pressure is spec'd by cam manufacturer. Most likely they (Vortec) are going to be to light and will need to be changed out. This is where the problem lies. Both of those articles give a starting point depending on your final cam spec.

You'll need to check the new springs installed height, clearance at lift (retainer to seal/guide) and any coil bind of spring at lift to ensure trouble free use.

These two give you two basic choices, machine the heads and use "common" hardware for current and future upgrades or purchase the Beehive style spring w/retainers (more costly) and stay within their capabilities in regards to cam selection while installed.

Guess that's where you pocket book and skill comes into play.

Good luck with your selection.
Later.

tt 383

Its a fine line to walk on a head that doesn't really flow past .500 lift. These heads no matter how big the valve tend to backup somewhere between .500 to .600 lift on the intake. To me using the cheap spring upgrade is the way to go. This has been done with good results.

http://www.thirdgen.org/techboard/te...tec-heads.html

'75

I'm thinking of going with this spring kit, the price looks good. I'm just trying to bolt on a little more power for as little as possible. I got the heads from a wrecking yard for $200 for the set and they are in good shape, guides are good and tight, so with this spring kit and a free manifold from my brother, I should be good to go.

http://cgi.ebay.com/ebaymotors/ws/eB...=STRK:MEWAX:IT

I already have the summit 1103 cam in the L48 now. 445/465 lift.