Comp Cams conical valve springs

[CGT]

I purchased a set of these (7256-16) for my LS3 based project overflowz. I probably should have looked at the dimensions on these a little closer prior to purchasing.

I made the assumption that they were a drop in LS spring.....they are not. They do not fit the spring seats of a production LS head. Has anyone had any experience with these on a factory casting? And if so, what locators, seals, machining etc were used?

I'd really like to use them but it's kinda looking like I may have to go a different route.

Thanks

[Newold1]

Done a few sets of LS3, L92 heads with that newer Comp Cam conical 7256 valve spring.

You can also buy a valve seat cutter -part #4732 Arbor for cutter -part#4730 and easily cut the spring pads on the LS heads out to 1.440"
Simple job even with just a hand drill.

I use the US Seal-EOK seals - this top hat seal matches the type on the LS heads and will not pop off like some push on seals.

I use 8-part # VSG-31P for the intake and 8-part# VSG31V for the exhaust
These top hat seals have a larger outside diameter to accommodate the base of this larger diameter spring. Don't use the stock top hat seals!!

If you are using a very high valve lift you may have to shorten the guides and use a shorter seal to keep from having bottom of retainer hit top of seal at max lift.

I would also recommend you use the Comp light weight steel retainers and cnc locks to make the assembly as light as you can for higher rpms.

The sets I have done work very well with that spring and will be compatible at those pressures (force) with good hydraulic roller lifters.

[CGT]

Done a few sets of LS3, L92 heads with that newer Comp Cam conical 7256 valve spring.

You can also buy a valve seat cutter -part #4732 Arbor for cutter -part#4730 and easily cut the spring pads on the LS heads out to 1.440"
Simple job even with just a hand drill.

I use the US Seal-EOK seals - this top hat seal matches the type on the LS heads and will not pop off like some push on seals.

I use 8-part # VSG-31P for the intake and 8-part# VSG31V for the exhaust
These top hat seals have a larger outside diameter to accommodate the base of this larger diameter spring. Don't use the stock top hat seals!!

If you are using a very high valve lift you may have to shorten the guides and use a shorter seal to keep from having bottom of retainer hit top of seal at max lift.

I would also recommend you use the Comp light weight steel retainers and cnc locks to make the assembly as light as you can for higher rpms.

The sets I have done work very well with that spring and will be compatible at those pressures (force) with good hydraulic roller lifters.

Where can these seals be purchased? I'd have to look at one of those. Thanks for the information. Or where I might view a pic or dimensions of the seal.

[groberts101]

I purchased a set of these (7256-16) for my LS3 based project overflowz. I probably should have looked at the dimensions on these a little closer prior to purchasing.

I made the assumption that they were a drop in LS spring.....they are not. They do not fit the spring seats of a production LS head. Has anyone had any experience with these on a factory casting? And if so, what locators, seals, machining etc were used?

I'd really like to use them but it's kinda looking like I may have to go a different route.

Thanks

My buddy just used these same springs on his LS3 we did several weeks back. I just did some minor pocket porting and guide thinning after he had them all freshened up so I'm not 100% sure if they were stock dimension guides or not. After talking with Comp here is what he ordered to make it all fit together.

All Comp part #'s.. 7256-16 springs, 511 valve seals, 1772 lightweight steel retainers, 623 locks, 4670 seat cups. Sorry I don't know spec's for all these parts right off hand but that is what he ordered and it all fit together perfectly with room to spare. With a custom cam that thing will be an oversized buzzsaw to say the least. Really looking forward to a few quick ride alongs this spring!

Hope that helps at all but maybe call Comp to verify after measuring your guides for seal and spring cups.

[Newold1]

CGT

Just go to www.usseal-eok.com

[needforspeed66gt]

You guys are using the wrong part numbers, the 7228-16 springs, 4680-16 locators, and OE retainers drop right in the LS3 heads.

[Newold1]

Nate the 7228 conical spring has a much lower closed pressure along with less open pressure at near coil bind which may not be adequate for CGT's usage.

[CGT]

You guys are using the wrong part numbers, the 7228-16 springs, 4680-16 locators, and OE retainers drop right in the LS3 heads.

Thanks Nate. Unfortunately I'd really need to set those up at 1.900 to make room for lift, and their wouldn't be much seat pressure at that installed height. Not sure yet what I'm going to do.

[Newold1]

Do the simple cut on the spring pads in the aluminum and use the better technology and performance of the conical spring!

[CGT]

Do the simple cut on the spring pads in the aluminum and use the better technology and performance of the conical spring!

The spring over hangs the spring pad in places...by quite a bit , a cutter wont solve that. It would make them "fit". But it really comes down to the mentioned valve seals. I can't find them, dimensions on them etc. I'd need to know that they will support and locate the spring correctly first.

[groberts101]

Do the simple cut on the spring pads in the aluminum and use the better technology and performance of the conical spring!

The spring over hangs the spring pad in places...by quite a bit , a cutter wont solve that. It would make them "fit". But it really comes down to the mentioned valve seals. I can't find them, dimensions on them etc. I'd need to know that they will support and locate the spring correctly first.

Are you saying you won't be using spring cups specifically intended for those springs?

Those cups would eliminate spring movement and locate the springs to reduce wear rates. If you're hurting for installed height then maybe just run a +.050 lock to help compensate for the locators?

Oh, and those seals mentioned prior by newold won't truly locate the spring like the specified spring cups that were used on my buddies build. These springs are located on OD.. not ID. Which is why comp only makes cup style for these particular springs.

[Newold1]

The valve guide seal I use and listed is a Top hat combination seal and spring locator. It fits nicely over the stock .505 steel guide and the larger OD section at the bottom locates and contains the 7256 spring nicely. I don't like the separate push on seals that Comp has in their kits for this spring as I have had and seen many pop off. This seal is a spring base, locater and seal all rolled into one much like the stock GM LS top hat seal. Just my preference.