408 hyd roller, too much spring pressure?

Bewy

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I should clarify the second sentence above. BHs can use lighter VT components, but do not require they be lighter. The spring, whatever type, needs to have enough pressure to control the VT. BHs do not relay on light retainers, it is a product of their design that allows lighter retainers, thereby reducing the load that the spring has to control.
 

Rat Bastid

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^^^^ Read post #64. BHs do not require lighter valves more than other type of spring. Of course, one would use the lightest valves & valvetrain possible in the interest of VT stability & VT life; only a fool would use parts heavier than necessary.

Production vehicles have multi year warranties. The fact that OEMs use BHs while warrantee-ing their engines for 3-5 yrs speaks volumes about BH reliability.

Isky said it best in Tech Tip: Is extra exh duration necessary? Habit, he said.
I think it is the same here. Folks get into a habit, & will not accept new technology. Some are probably using crank handles to start their engines...


That’s the thing Bewy. They aren’t “new technology”.

I also never said one spring required lighter components. My point was you can save far more weight with a lighter valve than you can with a spring and retainer.

It wasn’t that long ago when Ti locks were all the rage. Of course, I looked into them far more than I should have.

In the end, the weight savings for a Ti lock was so minuscule that unless I was using a Ti valve with a 7 mm stem the locks didn’t matter.

It’s the same with a BH spring. There is much more low hanging fruit to grab that will give a much better return on investment.

And, back to the original issue…using a BH spring when the geometry is wrong isn’t fixing anything.
 

Rat Bastid

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One spring is cheaper than a double plus a damper. Simple as that.
A BH spring has fewer resonant frequencies, but not "none". They avoid surge and bounce for less cost.
OEM engines are built to price point.

Spring life depends largely on the mass of the material involved. A smaller spring is stiffer, but can't take as much stress. Larger wire diameters can take more stress and increase stiffness. For heavy use applications, a BH would be going backwards. Multiple nested springs will always have more mass. Once a BH is made from thick enough wire, it won't fit..

BHs thus require lighter valves, and rely on their lighter retainers. Then the lobes have to be engineered along with the rockers to control the load and unload rate to prevent spikes which might exacerbate surge.

All that changes when one moves into high output builds. Bigger valves, faster ramps, higher lift - they all work against a BH design..


I agree. The OEM’s place a high priority on saving money. Which is exactly why Chrysler used short valves and short installed height springs.

Shorter valves and springs cost less money. Let’s say they saved 5 cents per valve and 2 cents per spring. Times 16. Times several millions used.

It adds up right quick. That’s why the SBC was designed with a stamped steel rocker and ball/stud mounting.

It wasn’t better but it was a damn sight cheaper than a shaft system and a forged or even cast rocker.

The vast majority of times an OE does something it’s cost related.
 

Bewy

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Rat,
I know it wasn't you who made the claim about lighter components, it was Phreakish.


I am well aware that BHs are not new. My understanding is what is new is the Ovate shaped wire that maintains the strength for a lighter more compact spring, and also allows for more valve lift.
 

Ted265

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It’s the same with a BH spring. There is much more low hanging fruit to grab that will give a much better return on investment.

And, back to the original issue…using a BH spring when the geometry is wrong isn’t fixing anything.
I don't think anyone is really arguing with you on that point, geometry would be the first place to look at if you want a happy and stable valvetrain, get that sorted, select springs that suit your requirements (beehive or conventional as long as it suits the application) and if you can save some weight in the process then that's a bonus.
I was surprised when my B3 kit arrived how far things needed to move:

20220826_180932.jpg
 
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Aussie Charger

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Hi!

I have finished my 360 based 408 stroker with good result so far!
I am however starting to worry about my spring pressure...

The engine is based on a -89 roller 360.
I used stock replacement roller lifters with the stock spider like plate to hold down the "figure 8 shaped" anti rotation plates.
The cam is a Lunati VooDoo 20200712
As far as I can see, this is a cast core cam.
231/239 degrees @0.050"
.535/.550 lift
I checked during installation, and there is a good margin to the "figure 8" plates at max lift.

I use bronze bushed steel 1:1,5 shaft rockers, very similar to Comp cams ultra pro magnum rockers

Lunati recommended a spring kt for the Eddy heads I planned on using. Before I got them I ended up buying Trick flow heads instead.
The spricg choices for the Trick Flow heads ended up being lower than recommended with the 1,46" diameter spring, and a bit over recomended for the 1,55" spring. After recommendation from Trick Flow I went with the 1.55" diameter spring heads, p.n. TFS-61417802-C00.

According to the specs I end up with 138 lbs seat pressure and 369 lbs open pressure (on the exhaust lobes)

- Is this too much for the stock replacement roller lifters?

- Is this too much for the cast core roller cam?

The engine runs great! But the valvetrain noise is a bit more than expected. When starting up, there is a few seconds of rattle befor the lifters fill up. I guess they drain during standstill? I would consider this normal with hydraulic lifters, but I'm surprised what short time is needed for them to drain.

/Magnus

View attachment 1715952500
Hey OP, I'll list some more info on cast cores for you (the last specs I provided were for a billet core).

These are GT40P heads with aforementioned Pac 1218X springs. Cam is a cast core custom Crow hydraulic roller. All specs below – note that the seat pressure is actual seat pressure as measured and after running the springs in on my 408 Mopar. The springs lost about 5lb on the seat after run-in.

Engine = 5lt EFI Windsor (1.94" intake, 1.55" exhaust, Ferrea 6000 series)
Cast core hydraulic roller
Spring = PAC 1218X
Rate = 318lb
Advertised seat pressure = 140lb at 1.800"
Actual seat pressure = 130lb at 1.820"
Open pressure = 304lb at 1.273"
Lift = .547"

IMG_5954.jpg
 

Aussie Charger

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I don't think anyone is really arguing with you on that point, geometry would be the first place to look at if you want a happy and stable valvetrain, get that sorted, select springs that suit your requirements (beehive or conventional as long as it suits the application) and if you can save some weight in the process then that's a bonus.
I was surprised when my B3 kit arrived how far things needed to move:

View attachment 1715975938
Nice. What springs are you running?

FWIW, my 1.65 T&D shaft rockers were spot on for geometry straight out of the box on a set of Eddy RPMs. They were heavy and needed more spring than expected, but c'est la vie.
 

Aussie Charger

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Rat Bastid

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That 2.3 litre cam that spun to 9200rpm (stock cam???) with beehives was a .575" Schneider – a pretty hot cam for that engine.

Please read this again properly before you comment: Ford Lima 2300 cam help please - Don Terrill’s Speed-Talk


And I addressed this in an earlier post. And I explained it. Maybe you should read what I wrote properly. Or better yet, get over it. I have explained myself repeatedly here and you don’t like it. So move along.
 

Aussie Charger

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And I addressed this in an earlier post. And I explained it. Maybe you should read what I wrote properly. Or better yet, get over it. I have explained myself repeatedly here and you don’t like it. So move along.
No you didn't. You said it was "slightly hotter than stock".

You also wrote:
Put lobes on it that make power at 9k and it will bust springs.
If you're going to claim BH springs can't turn more than 8K – even after people provide evidence to the contrary – then might I suggest you're the one who needs to learn to read properly?

It's not that I don't like what you say, I just hold what you say to account. It appears you are the one who doesn't like that.
 

Rat Bastid

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No you didn't. You said it was "slightly hotter than stock".

You also wrote:

If you're going to claim BH springs can't turn more than 8K – even after people provide evidence to the contrary – then might I suggest you're the one who needs to learn to read properly?

It's not that I don't like what you say, I just hold what you say to account. It appears you are the one who doesn't like that.


Not at all. I don’t care what you say. It’s as simple as that.
 

Aussie Charger

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Lunati 74895 beehives, fairly mild street setup with a small solid flat tappet.
Cheers mate. Do you mind my asking cam, rocker ratio and rpm specs? Just curious. A bit of real-world data always helps.

Had to laugh at your TF heads – what on earth were you doing swapping out those "premium" springs for lowly beehives? Unless you bought bare heads. :p

I see Lunati recommends that spring on nearly all their HR and SFT cams for SBM – some of which are rated for 7500+rpm. The alternative dual spring with damper (73195) has 402lb rate compared to 280lb for the beehives. That's a big difference.
 

Ted265

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Cheers mate. Do you mind my asking cam, rocker ratio and rpm specs? Just curious. A bit of real-world data always helps.
Yeah mate, cam is from Howards - 258°@0.020" / 230°@0.050", 0.556" lift after lash on 110LSA.
PRW 1.6 ratio rockers, motor isn't in the car & running yet (not a lot of spare time to work on cars these days) but will probably will only see around 6000RPM.
Just to clarify these aren't Trickflow heads - they are Aeroflow castings - I bought them bare and did some bowl work and minor clean up of the ports, valve job was redone on a Newen CNC and assembled with Ferrea valves and the Lunati spring kit. All up cost me less than a set of ootb Edelbrock heads.
 

Aussie Charger

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Thanks mate. Not dissimilar to mine. My Eddies are ported to within an inch of their lives. I punched through the pushrod pinch on one of the intakes and had to get it re-welded. Also went with bigger 2.05 valves. If I did it again I would start with bare heads.
 

cookietruck

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Lunati 74895 beehives, fairly mild street setup with a small solid flat tappet.

ive got a smallish lunati sft cam that i’m gonna run with some beehive springs. I think they’re pac 1218.
I saw that lunati called their beehives an upgrade and listed them compatible with the cam so I bought the cam (ultradyne nf62 lobes).
the springs were already setup on the heads by a reputable shop (IMM).
haven’t run it yet. Young kids slow things down sometimes…
Pretty confident everything will work ok.
 

Phreakish

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Rat,
I know it wasn't you who made the claim about lighter components, it was Phreakish.


I am well aware that BHs are not new. My understanding is what is new is the Ovate shaped wire that maintains the strength for a lighter more compact spring, and also allows for more valve lift.

BH's DO require lighter components. The synergy is that their shape has an intrinsic weight loss from a smaller retainer.
The requirement stems from the fact that you're losing spring mass. Less mass means less energy the spring can absorb - there's no free lunch.
 

Aussie Charger

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BH's DO require lighter components. The synergy is that their shape has an intrinsic weight loss from a smaller retainer.
The requirement stems from the fact that you're losing spring mass. Less mass means less energy the spring can absorb - there's no free lunch.
Not necessarily. Mass absorbs energy but it also releases it in the form of heat. The transfer of energy from one mass to another (ie: steel spring to air/oil) is a function of surface area.

Valve springs absorb kinetic energy (movement of mass) and store that energy until it is released. However – as you rightly pointed out that there is no such thing as a free lunch – some of that kinetic energy is converted into thermal energy, which is released by the spring mass when it comes into contact with oil and air (conductive and convective heat), and to a lesser extent the other metal surfaces it is in contact with (valve seat, valve stem/retainer etc).

A spring with a smaller mass but a larger surface area (an ovate shaped spring, for example) is able to absorb more energy because it is able to transfer excess energy at a faster rate. The more energy a spring can release in a given amount of time, the more total energy it can absorb in that same amount of time.

Distribution of mass determines rate of energy transfer.

Greater surface area = faster heat transfer = less stored energy.

In addition, lower spring rate = less pressure = less heat = less energy transfer to begin with (they are all the same thing).

Finally, what came first: the chicken or the egg?

A beehive or conical spring, by design, is always going to have a smaller retainer. Suggesting that a beehive needs a smaller retainer (less weight) to control the valve-train is an oxymoron: if the spring didn't have a smaller retainer in the first place, it would not be a beehive.
 

Aussie Charger

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If a greater mass stores more kinetic energy, then at some point it needs to release that greater energy. Sometimes that greater energy is released at an inopportune time, such as when the valve has already closed. This relates to harmonics, or oscillation of the two massed springs.

2016-02-15_01-16-15.jpg
 

MOPAROFFICIAL

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If a greater mass stores more kinetic energy, then at some point it needs to release that greater energy. Sometimes that greater energy is released at an inopportune time, such as when the valve has already closed. This relates to harmonics, or oscillation of the two massed springs.

View attachment 1715979472

What springs do they use in nascar, asshole?
 
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