Trinten

So I had my car dyno'd, and the engine puts down a fairly nice plateau of peak HP of 371 starting at 5750 and running till 6500 before dropping off.

I then found out, that through my own oversight, I'm running 1.52 rockers instead of the recommended 1.6 rockers for my cam ( comp cam 07-467-8, 230/236 at .050 lift, 280/288 advertised duration).

The springs are the ones that came on my AFR 1040 heads. I don't remember their specs right now, just remember calling them, asking, telling my builder, and he said 'that should be fine'. I've got hardened stock length 7.2" ball-end rods.

So since I found out I've shorted myself some power, I'm going to setup to the Ultra Pro Magnum 1.6 rockers, and was debating on if I should change the springs while I'm at it.

Comp Cams, of course, suggested their 918 springs, but to this day I still read bad things regarding those springs (though I understand that bad stuff can sometimes good more press than good products). Also, he didn't ask (and I forgot to mention) where my engine makes peak horsepower, which I'd think would have influenced his answer.

Also I've also read that spring pressure is very important, to control valve float, especially when you get up near/over 6k.

I looked at the valve springs on summit... but I just don't know enough to even begin to narrow down my search or select anything.

I also haven't ruled out beehives or dual springs. They both have advantages from what I've read.

So, my two questions are, do I need to replace my springs, and if so - given where my peak HP is, how strong of a spring should I get?

And

If I stay with the same "style" of springs I have now (the dual springs that came with my heads), do I need to get all new retaining hardware and such?

If you guys need to know the stats on the AFR springs, what should I ask them? It seems that springs are measured at a few different points for their pressure - which ones are important? Or should get I ask for the whole rundown?

BTW, here is my dynochart - that little warble that's on my plateau (and in the decline of my torque), I have no idea if that's normal, or indicative or valve float. Just don't look at that many charts. Any thoughts? Thanks guys!

Alain2

I just want to say that Comp Cam have solved the 918 springs problems long time ago. Internet will always make it worse than it really is. I run the 918 in my +600hp LS6 and it easily holds the valves up to my red line 6500rpm and I am sure they are good for higher rpm. There are absolutly no recent case of failure where Comp Cam quality is the problem. If you go beehive you will need new retainers, perfect time to get the bling bling titanium retainers!

If you do not feel safe with the 918 go with the dual and sleep better.

Trinten

Called AFR this morning, they said that my heads originally came with their 8017 springs. Here is the info on those:

Dual spring (Summit mistakenly lists it as a single spring)
135# @ 1.800
340# @ 1.230
spring rate 360 lbs./in.
Coil bind height 1.050
Outside diameter 1.290
Inside diameter .685

Trinten

Hi Alain, thanks for the info! I didn't realize they had solved the issue, I had run across some "recent" posts (mid-late 2011) when searching, guys stating theirs had failed - however they did not say when theirs failed, they could have been referencing a much older event.

Now that I found what springs I already have, it'll make it a little easier to pick out replacements - any thoughts if that warble in my dyno is typical, or if that means I might need a spring with a little more pressure?

Thanks again!

skinny z

[QUOTE=Trinten;5295376
Comp Cams, of course, suggested their 918 springs, but to this day I still read bad things regarding those springs (though I understand that bad stuff can sometimes good more press than good products).

I also haven't ruled out beehives....

The 918's are beehive. Comp PN 26918. They'll handle any cam you might throw at it with the power levels you're working with. That and more.
There is price hit though and also a need for retainers and locks. Possibly seat locators too depending on the guide size and pocket diameter.

Trinten

Thanks Skinny,

I should have been more clear. I know the 918s are beehives, I was just saying I hadn't ruled anything out, as I know other companies make the beehive style as well.

New dumb question - looking at the info on my heads (at least the stuff Summit lists), I don't see any info on the guide size or pocket diameter - unless it's called something else. How do I find that information out? Can it be derived from my existing spring specs?

ASE doc

To prevent valve float, the most important value is seat pressure. But as we get into larger lobes, open pressure(which is the pressure at your cam's max lift) becomes important as well. Open pressure of 345lbs at .570 is not bad for 6,500rpm. 400lbs is better. But again, it depends on max lift. 135 seat pressure is on the low side, 145 would be better. You don't state what max lift will be with the 1.6 rockers. It is vital that you use springs that allow at least .020 between max lift and coil bind. Otherwise you will break any spring and/or bend push rods. AFR would be the best people to give an easy answer as to what springs will work best. In fact, they probably have the perfect springs for you on the shelf. They built your heads and know installed height of the valves. Installed height and max lift are the key factors in determining both seat pressure, open pressure, and coil bind.

Beehive springs allow more lift before coil bind and are only necessary when installed height is not sufficient to allow use of straight coils at a certain max lift. I only have experience with beehives in OE applications where it seems like I replace alot of broken beehive springs. I can't speak for aftermarket beehives. Your AFRs, I'm sure, will allow for plenty of lift( at least .600) for any cam that you are likely to run, without the need for beehive springs. For your application, as much as I can tell with the information you have provided, I would definitely recommend dual springs. One more thing is be sure if you are running a roller cam, be sure to tell your spring supplier this. Roller cam profiles are much more aggressive than flat tappet and will cause spring failure if the springs are not rated for a roller cam.

Trinten

Thanks ASE Doc, those numbers are very helpful!

As for my max lift I pulled up the spec sheet on comp cams site here and it looks like max lift is .576 on the intake and .57 on exhaust. That is assuming I'm reading that sheet right.

If I am, I'd just call AFR and say "my max lift is x and y, I'd like a set of dual spring that are in the ballpark of having an open pressure of around 400 lbs, and a seat pressure of 145 lbs."?

If that cam sheet changes your recommendations on spring strength, please let me know!

(this is more an FYI than to start a tangent or anything - One of the reasons I was considering the beehive was because I had read, and took with a grain of salt, that the beehives both eliminated resonance like the dual springs, but also generated less friction/heat than the duals from rubbing together, but I am far more concerned about durability and longevity than a few degree difference in heat, as long as that heat doesn't compromise said durability).

Orr89RocZ

iTrader: (20)

I'm not a fan of beehives and still consider comp's 918's to be on the marginal side of things for aggressive rollers. No particular reason other than its a single spring and a failure will leave nothing to keep valve up, unlike a dual spring. With AFR's heads the light valves (8mm stem) will likely be ok with beehives to that rpm. Aparently the 8017's are working alright at the current lift level. 1.6's is gonna make it abit harder to control but it may still work. I consider the 8017's on the marginal side for 6200+ rpms and that cam...just a tad low on pressure but its working so far on your setup. So beehives should be alright. A better beehive is Pac springs 1219 springs...abit more open pressures to control things.

However your solution to this problem, if wanting to change springs, is to call AFR back and order their 8019 upgrade spring! They drop RIGHT in to the stock seats/retainers on the AFR 1040's. That is the spring for that cam. 150-155lbs seat and near 412 open pressure at max lift.

Trinten

Thank you very, very much! That is exactly what I needed to know.
And order those 8019s is also going to save me (a little) money on the supplementary hardware. I'm sure they can tell me if I can reuse my retainers and such when I order.

Thank you guys, it's great coming to a place like this, where guys like me - trying to learn stuff - can get well explained, straight forward answers without all the B.S. that can creep up in other places!

Sorry I couldn't/didn't provide all that additional info in my initial post. Thanks again!

Orr89RocZ

iTrader: (20)

Not sure of the current pricing but its exactly what I did when I ordered my heads and my custom cam grinder said I should run more spring. I called AFR and told them I want the 8019's over the 8017's and since I didnt use my heads yet, they took the 8017's back and swapped the 8019's for 100 bucks.

The springs themselves however are around 15 each so thats 240 for a set of 16... BUT they are quality springs and will handle just about any typical hyd roller you will find in a street car... and you wont have to replace seats/retainers/locks. Just drops in and reuses old hardware.

FIRST thing I'd try is the 1.6 rockers on the current springs just to see what it does. I'd look for signs of float via the dyno again but as soon as you start seeing major waves up and down on the graph, stop the pull and order springs

Trinten

Thanks Orr,

When looking into the 8019, I found a Corvette forum thread, and they talked about also using the AFR Hydra-rev kit for cams with an aggressive ramp rate that went over 6k. Many commented that the 8019 was about as powerful of a spring as they felt comfortable running on a hydraulic lifter.

So I'm probably going to get that too, regardless of which springs I go with. Maybe the Rev kit will just be all it needs to make my springs "ideal" for my setup with the 1.6!

Thanks again for all the info!

(Just in case anyone wants to read the thread I was referencing from the Corvette guys - http://www.corvetteguruforum.com/mod...topic_id=10257 the OP has a different cam than I do, but has the same lift... if I read it all right).

Orr89RocZ

iTrader: (20)

I dont buy into rev kits too much. If there is risk of valvespring failure its a good safety measure to keep lifters from jumping around. But if things are set up right and monitored then springs shouldnt break. It does put more pressure on lifter body to keep things in control since hyd lifters can only take so much on the pushrod cup. But regular springs can handle that cam and less stuff you have to install/worry about. Ls7 lifters are the best factory lifter and will handle this no problem. I ran them to 7k with 8019 springs.

So maybe 8017's will handle that cam by themselves but i think its borderline. Rev kit may help relieve valvesprings of their duty so you could try that or just do 8019 springs alone

Trinten

Great! I'll go with just the springs first, and if anything seems wonky in the future, toss in the Rev-kit. It just makes me wonder what other unspoken tweaks AFR did on their before/after runs with their hydra kits to get the results they did - they make some suspiciously impressive claims - http://www.airflowresearch.com/index.php?cPath=75

Orr89RocZ

iTrader: (20)

Its extremely misleading because they dont say what spring they tested with. Sure it used their 195 heads but i'd bet money that it was not with their 8017 or 8019 springs. Those cams would never float under those springs imo. Unless lifters were weak valved cheap replacements that collapsed but rev kit wouldnt solve that problem. Good lifter like ls7 would handle it fine. I know because i've run a bigger cam to 7k with no float using shimmed 8019's. Now i ran 165lb seat pressure but still same open pressures at max lift.

Trinten

Thanks Orr,

It's funny that you mention your shimmed springs, I ran across another post of yours someplace else discussing the 8019s and talking about how you shimmed them and what you rev up to there as well.

I noticed that the AFR springs don't appear to be nitride treated. Is that as important as some places make it out to be? Is it worth it to find a place that can do that? What about cryotreating? I know there are many places near me that offer that service, and it's fairly inexpensive. I was thinking about having them do the 1.6 rockers (the ones I'm getting are chromemoly) and the springs. Thoughts?

Orr89RocZ

iTrader: (20)

It helps with strength and longevity I believe but not really necessary. If you wanted a nitrided double spring, you'd want to look into PAC springs. They have a setup that will work on AFR's really well and may even use the retainers/locks you have.

skinny z

Just a quick word on the 918's.
It's not so much the advantage of the coil design and their ability to go further before coil bind.
It's that the spring and retainer are LIGHTER and provide greater control of the valve train before it becomes unstable.
You can run LESS spring pressure with a beehive style spring and get higher rpm function before there's either component seperation (valve float) and valve bounce.
As with anything else, they have their limitations. But why run a heavy spring with high spring pressure values (which is hard on valve train parts) when there's an excellent alternative available?
Example. Comp 987 vs Comp 918.

Orr89RocZ

iTrader: (20)

I agree and thats one of the big trends since the dawn of LS1s... small diameter but stiff double springs. Cuts mass down ALOT since most hyd roller springs were 1.4-1.5" diameter! Now they are common at 1.25-1.3's diameter. Much lighter, much higher spring frequency so less chance of resonance at rpm leading to valve float. Combine with titanium retainers for ultimate setup. Thats why I love the Patriot Extreme gold kits with titanium retainers... ~290 bucks for a good spring and retainer combo. Thats great bang for your buck but too bad they were on back order as of a few weeks ago from what I seen in another post here.

skinny z

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Trinten

Thanks guys.

When I had the engine built, I had asked the builder about titanium retainers - now please keep in mind this is just what I was told and what I dug up on some subsequent searches:

He told me he didn't like titanium retainers because, in his opinion, they needed to checked often in a frequently driven car. He said that while they are harder and lighter than the steel ones, they also had a lower fatigue limit from being more brittle, and would look fine one second, and have serious cracks (or break apart) the next.

Where with steel, it could take more punishment because it had a balance between strength and malleability/high fatigue. I am paraphrasing all that, as this was a discussion I had with in the summer of 2009, so please don't hold it word for word.

But from what you guys are saying, that isn't an issue anymore? Or is that only with titanium retainers that haven't been treated or properly alloyed?

On the springs - are the nitrided springs better? I'm not as concerned about cost (to a point, of course), as I am getting something that I won't need to worry about breaking catastrophically down the road.

(I know that any mechanical part wears out eventually, but I'd like it to last more than 20k or 30k, if that's possible.)

Thanks for pointing out the other benefit(s) of the beehives, I didn't know that.

Thanks again to all of you for the great feedback and insight!

Orr89RocZ

iTrader: (20)

Probably wont need titanium with that setup. But I havent seen a failure posted around anywhere. I would think in a valve retainer application, this would be after long time spent racing with heavy spring pressures fluctuations in order to have something fail but I doubt you'll see that on the street.

Nitriding helps with durability/fatigue life of the spring. Valvesprings typically lose pressure after running awhile in the motor. Nitriding supposively delays the onset of fatigue in the spring and helps them hold pressure alot longer. Good insurance but not always needed. If you go beehive I'd definately go nitrided since your dealing with 1 spring coil and if it ever failed, there'd be nothing holding valve up.

With that cam however, i'm not sure if it will go 20-30K miles of moderate heavy driving action. Thats a fairly aggressive lobe with alot of lift. It may tho I'm just not sure. If you wanted something that will give rpm and power yet retain spring life, you'd have to go custom grind likely or try the old comp magnum lobes. 230 deg with .560" lift but lazier opening rate. Seems to work well.

Trinten

Awesome info, thanks for the breakdown and explanation on things - very much appreciated, as always.

Sounds like staying with the plan for the 8019 springs and getting them cryotreated is going to be the best way to to go then. And just plan on replacing them at around 20k (or at the first sign of trouble).

Like others have said, with the dual spring, it at least reduces the change of dropping a valve, and if the pressures are right on the edge of being healthy for a hydraulic roller is accurate, then it'll fall into something safer with a little mileage on them.

Hopefully this thread will be useful to many other people who have similar cam behaviors and hydraulic lifters! Thanks again guys!

Alain2

On Corvette forums there are tons of high HP engines running double springs.

Trinten

Alright, 1.6 Ultra Pro Magnum rockers ordered along with a set of the 8019s!!

I'll see how these hold up and what (if any) unwanted side effects there are, and then might revisit the beehive springs, since it seems you can run ones with less pressures and maintain the same level of control.

Thanks again everyone!