CONICAL VALVE springs: what's the verdict?
#2752511
03/16/20 12:08 PM
03/16/20 12:08 PM
|
Joined: Jan 2003
Posts: 7,489 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,489
Minnesota
|
I'm freshening up the 392 Hemi for my hotrod and my head guy suggested that some people are having good experiences with conical valve springs. Not the same as beehive. But he does not have any first-hand experience with them yet. So I'm seeking feedback on them to help me decide whether I should make the switch. I don't like being a guinea pig, but if they are proven, and are right for my application, I would do it to get the benefits. This motor has a 700 lift roller cam and I was previously reving it to about 7200 RPM. I'd like to up the RPM a bit, trying for more horsepower. I'm considering a more aggressive cam lobe. Currently it has titanium intake and stainless exhaust valves and steel retainers. I'm thinking of switching to titanium exhaust valves and titanium retainers and conical springs to try and get the RPM capability of the valve train up to at least eight thousand.
What advice do you guys have for me on this? Does anybody besides Comp cams make a conical spring? Thanks, Joel
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: jcc]
#2752534
03/16/20 01:14 PM
03/16/20 01:14 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
master
|
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
What are the spring pressures and what is the installed height? There are tons of people using Conical springs from Manley and PSI in road racing and other endurance applications *if* you can keep the spring pressure reasonable. There are conical springs that support in the neightborhood of 250/750psi at .800 lift but any more pressure or lift than that and yo are back to a conventional spring. I try to use dual springs (keeps the weight down) with no damper (eats the Ti retainer) if possible.
THe main problem I have had looking for conical valve spring for a big roller cam is installed height. It seems that the newer engines have tiny rocker boxes (aka LS platform) and the installed height is tiny (like 1.800). From my research most of the new style (conical, beehive, etc.) are geared towars newer engine platforms (G3 Hemi, LS, Coyote).
If you are looking for endurance springs the Isky Tool Room, Manley Nextek, and PSI RML series springs might have something for you.
It has been unanimous across all of the manufacturers I have spoken with that using the lightest valve, spring, retainer, lock and lash cap combo one could get away with *reliably* was preferred. That said they were all in to use a lighter spring until we started talking power adders and then they steered me right back to a 1.550ish OD spring again. In my case we are talking 2.050" installed height and 300/900psi with about .800/.787 net lift. I am going to use the PSI 1254RML dual spring in this case as it is the lightest valve spring I could find that supports the pressures my cam grinder spec'd.
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: fourgearsavoy]
#2752572
03/16/20 03:53 PM
03/16/20 03:53 PM
|
Joined: Jan 2003
Posts: 7,489 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,489
Minnesota
|
My heads are set up for PAC 1396 valve springs with 1.950 installed height. Here is PACs description:
Circle Track 1300 Series Valve Spring High Lift Roller Spring - damperless
Outside Diameter 1.574
Outer Spring ID 1.15
Inner Spring ID 0.826
Install Height 2
Load at Installed Height 260
Spring Open Height 1.2
Spring Open Load 690
Recommended Valve Lift 0.8
Spring Rate (lbs/in) 538
Coil Bind (max) 1.15
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: Hemi_Joel]
#2752580
03/16/20 04:24 PM
03/16/20 04:24 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
master
|
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
Joel what is the net valve lift on the intake and exhaust? That thing has a lot of seat pressure (like 305ish) and at .725 assumed gross lift you are at 673psi over the nose of the cam with about .080 to coil bind.
Out of curiosity what size are the valves? If your Ti intake valve is, for example 90g vs. 140g for SS valve how much can you take off of the spring rate...that is the question.
Food for thought...your current spring has a listed weight of 152g. Can you find a spring with comparable IH and spring rate that has less mass to control aka lighter? The accepted theory is lighter = more RPM so you would think moving in that direction will produce your intended results. Maybe we should be comparing the gross mass of the valve/retainer/spring/lash cap combo instead of just the spring vs. cam.
This is a very interesting topic to me as my new beater -1 combo is using 2.25 Ti intakes.
Sorry for geeking out on you lol
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: polyspheric]
#2752704
03/16/20 10:52 PM
03/16/20 10:52 PM
|
Joined: Jan 2003
Posts: 7,489 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,489
Minnesota
|
I was hoping you smart guys would "geek" this for me, because I don't know enough to do it myself. THere is some nasty wear on the some of the valve tips. The one in the picture is by far the worst, some have the same pattern, but less deep, some are good. I don't see any evidence of the valve contacting anything. Also, I have only pulled the springs out of the #1 spot so far, but I found one of the steel locks on the ex side was split in half vertically. SO something bad is happening with the valvetrain.
Here is my stuff, and the cam card, and the weights:
2.205" TI intake valve with hard tips102g 1.800" SS exhaust valve 111g steel locks 7 g tool Steel retainer 22 g exhaust pushrod 146g intake pushrod 138 g Isky bushed roller lifter pair with bar 294 g PAC 1396 dual springs 150g Missle aluminum rocker arms 1.5 ratio I&E no lash caps
What do you think is going on? THanks, Joel
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: Hemi_Joel]
#2752722
03/16/20 11:56 PM
03/16/20 11:56 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
master
|
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
Why doesnt the cam card have spring specs? How tight are the valve guides? If you split a lock what does the associated groove look like?
It looks like the tip is getting it's as$ kicked for a short duration of RPM. Have you ever found valve float RPM? Maybe if it isnt getting beat to death the guide is sticking keeping the valve from rotating causing the pattern? Is that roller on the rocker smooth in operation?
If that close up is a Ti intake it almost looks like the tip insert is coming out. Lack of lash could make things ugly too.
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: Jeremiah]
#2752843
03/17/20 02:13 PM
03/17/20 02:13 PM
|
Joined: Jan 2003
Posts: 7,489 Minnesota
Hemi_Joel
OP
master
|
OP
master
Joined: Jan 2003
Posts: 7,489
Minnesota
|
Why doesnt the cam card have spring specs? How tight are the valve guides? If you split a lock what does the associated groove look like?
It looks like the tip is getting it's as$ kicked for a short duration of RPM. Have you ever found valve float RPM? Maybe if it isnt getting beat to death the guide is sticking keeping the valve from rotating causing the pattern? Is that roller on the rocker smooth in operation?
If that close up is a Ti intake it almost looks like the tip insert is coming out. Lack of lash could make things ugly too. I'll get you some more info. I'm going to finish disassembling the heads, check all the valve spring pressures. The guides were not tight by any means, but I'll check the actual clearance. I don't know what the cam card doesn't have spring specs.
[img]http://i.imgur.com/boeexFms.jpg[/img]31 Plymouth Coupe, 392 Hemi, T56 magnum RS23J71 RS27J77 RP23J71 RO23J71 WM21J8A I don't regret the things I've done. I only regret the things I didn't do. "Wise men talk because they have something to say; fools because they have to say something. ~ Plato"
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: Hemi_Joel]
#2752848
03/17/20 02:30 PM
03/17/20 02:30 PM
|
Joined: Aug 2003
Posts: 43,157 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,157
Bend,OR USA
|
I would replace all the valves that had that ugly wear pattern on the tips now, not wait for them to fail on the road. Something is really wrong somewhere Joel with the wear on the tips like that Maybe a bad valve tip or something not correct to start with
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: Cab_Burge]
#2752853
03/17/20 02:46 PM
03/17/20 02:46 PM
|
Joined: Jan 2003
Posts: 14,496 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,496
So. Burlington, Vt.
|
My .02 is....... it looks like the tip isn’t hard enough...... and/or there’s not enough lube at the roller/tip.
I’d see about having the tip hardness tested on a couple of the ugly ones.
Do you have the springs set up so they are fairly close to coil bind? You’re running .800 lift springs with what’s probably a net .700 lift cam. There could be a spring surge condition going on if they’re installed too tall.
Is there any correlation between how bad they look vs being an intake or exhaust valve?
For the street duty portion of Drag Week....... the lash could really stand to be tightened up....... by quite a bit(vs what’s on the card).
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: fast68plymouth]
#2752881
03/17/20 05:03 PM
03/17/20 05:03 PM
|
Joined: Mar 2003
Posts: 9,099 Rogue River, OR
Jeremiah
master
|
master
Joined: Mar 2003
Posts: 9,099
Rogue River, OR
|
Judging by my post above and the .700 net lift that makes .130 to coil bind. That is outside the spec.
Is this a custom cam?
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: fast68plymouth]
#2754005
03/21/20 12:19 AM
03/21/20 12:19 AM
|
Joined: May 2019
Posts: 712 Lake Villa Il
INTMD8
super stock
|
super stock
Joined: May 2019
Posts: 712
Lake Villa Il
|
My .02 is....... it looks like the tip isn’t hard enough...... Agree with this. What defines "hard tip" on a ti valve? Serious question, I do not know. Is it a hardened steel tip or hardening of the ti base metal? Dealing mostly with LS engines over the years, the photos above look exactly like LS7's I've seen where previous shop/tech omitted lash caps on the ti intake valves or mistakenly put the caps on exhaust instead of intake.
69 Charger. 438ci Gen2 hemi. Flex fuel. Holley HP efi. 650rwhp @7250 510rwtq @5700
|
|
|
Re: CONICAL VALVEsprings: what's the verdict? was
[Re: INTMD8]
#2754121
03/21/20 11:29 AM
03/21/20 11:29 AM
|
Joined: Jan 2003
Posts: 14,496 So. Burlington, Vt.
fast68plymouth
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 14,496
So. Burlington, Vt.
|
I’m not sure all the valve suppliers do it the same way, but custom Manley Ti valves can be ordered with or without hardened tips. The hardened tip is easily seen if you’re looking for it(as well as being magnetic), and makes the tip length .049 longer. Most Manley’s with hardened tips have a .290 tip length. Ti valves w/o hardened tips require the use of lash caps.
The first pic is of a Del West Ti valve with a hardened tip. If you look close you can see a slight different in color/texture at the top. The tip length on that valve is about .310.
The second pic is what the top looks like after a few thousand miles of use in an 18* SBC that runs over 8000rpm lap after lap.
68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123 Dealer for Comp Cams/Indy Heads
|
|
|
|
|