995-16 valve spring alternatives

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ProStocker273

ProStocker273

MoPar N Jeep
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When I build my motor I had intended to use my 273 rockers. As most know my 273 pushrods are too long so I been running some sloppy stamped rockers. Got a push rod checker tool in the mail. Gonna order springs and pushrods in one order. My cam is a comp thumper cam. .235in .249exh @50 .494in .483exh 107 lsa 2200-6100rpm range. Now onto my question, comp cam's recommends their 995-16 DUAL SPRINGS. My heads are not machined for dual springs and I do not want to pull heads to machine them.

What is another single spring that will work with my cam/rpm range?
 
Might be best to measure your installed height first. You can get retainers that add height at well. Should be buying 10 degree retainers/locks anyways. Then once you know the installed height, you could search some of the spring catalogs to see if there's something that will fit.
 
from Hughes...

7° vs. 10° locks. We do not recommend 10° locks unless you are using extremely high valve spring pressures (such as 650lbs or more open pressure). The colleting action (clamping) of 7° is much tighter than the 10°. If you should encounter valve float, 10° locks will unlock much easier than 7° locks.
 
I agree with 80Fbody. You need to know what installed height your working with to pick springs. As with Hughes I also believe 7* retainers and locks are sufficient.
 
There is a beehive alernative to it but it's also footnoted as machining the heads needed. Probably for guice clearance as opposed to the spring seat.
Out of curiosity - what cam was in this engine? What was done to the heads already?
 
Comp-Cams #995-16 Dual-Springs

Load-Rate
#115 lbs. = Valve-Closed {Spring Height = 1.70"}
#336 lbs. = Valve-Open {Spring Height = 1.15"}

I'll check, as Lunati, Crower and Racer Brown offer a Single-Coil
Valve Spring with a similar Load-Rate.
 
Comp #901 might work for you but I don't know the specs. There a quite a few here that have used them on their 273's.. tmm
 
69 Cuda 440 said:
Comp-Cams #995-16 Dual-Springs

Load-Rate
#115 lbs. = Valve-Closed {Spring Height = 1.70"}
#336 lbs. = Valve-Open {Spring Height = 1.15"}

I'll check, as Lunati, Crower and Racer Brown offer a Single-Coil
Valve Spring with a similar Load-Rate.
Click to expand...

------------------------------------------------------------------------------

These are 'the units' to choose......

Hughes #1110 ~ Single Coil w/Damper

Outside Diameter = 1.440"
Inside Diameter = 1.033"

Load-Rate
#120 lbs. = Valve-Closed {Spring Height = 1.66"}
#310 lbs. = Valve-Open {Spring Height = 1.10"}

Good for 6200 RPM's
 
There are a three types of 7 degree setups. Stock, aftermarket & Super 7 I believe. I wouldn't trust stock as they could pull thru. I guess 7 degree aftermarket ok. We've always switched to 10 degree. Never heard of them popping loose but I'm sure it's possible if the piston smacks the valve. You'd probably have more issues at that point, though.
 
My heads have been gasket matched and bouls blended 1.88 intake 1.5 exhaust valves.

Well it sounds like the 1110 are what I'm looking for. The ID/OD is about what my shims measure at. I am still going to measure installed height this week end before I order springs. I'm still open to suggestion, but 1110 if installed height is close will work just fine. Im looking around for locks and retainers.
 
Lunati also makes a good set, Single-Coil w/Damper

#73126

1.500" = O.D.
1.086" = I.D.

#103 lbs. @ 1.80"
#303 lbs. @ 1.25"

Good units for a Hydraulic Camshaft with a Lift between .480" and .500"
 
With those springs, assuming a 1.66 installed height, he'd be a little closer to the coil bind height at max lift compared to the Hughes 1110. Not saying they're not a good spring, but the installed height and open height number specs are being exceeded. Would that not shorten the service life a little? 1.8" installed height almost sounds more like a drop in for SBF or SBC...
 
IMO - the Hughes springs noted are light. you need to look at the spring rate and the installed hieght, then figure the pressures on the 995s and find a duplicate. Using the figures posted the Hughes is a lighter spring rate - which is usually the issue that drives the inclusion of an inner spring.
 
Could also call Comp once you have your actual install height & see if they can help you out. They're usually very helpful if you have all your data/numbers together. Just make sure you understand what you're looking for as well.
 
I have a Lunati cam that required spring specs similar to those comp 995. Mine were 120 seat and 319 open. My machinist says that is too much for a street engine and will shorten cam life. I do have the recommended dual springs but he set them up a little lighter than Lunati recommended. He told me that he has been on the phone too many times with several of the big name cam companies about their high spring pressures and wiping lobes off the cam prematurely. He decided to do it his way and all has been well. Now those pressures on a race engine he says are fine because of the of application.
 
Comp is crazy. Run the 901-16. It will be fine.
 
By luck,

I you could locate a set of Racer Brown VR-18X Valve Springs, that would be a superb set.

#313 lbs. = Valve Open @ 1.05"
#150 lbs. = Valve Closed @ 1.55"

But, instead of setting the Spring Height at 1.55", you set them at 1.70".

A lighter Load-Rate, saves the life of the Camshaft and Valve Spring, and prevents 'Bulldozing' at higher RPM's.

Worked great with the 1966 273/275 HP 'D-Dart' engine.
 
So... the spring rates are not even close between the 901 and the 995, and Comp says the lobe design that they developed needs that higher pressure, but Comp is nuts? If it walks like a duck, and quacks like a duck, it's a chicken? Gotcha...lol.
 
moper said:
So... the spring rates are not even close between the 901 and the 995, and Comp says the lobe design that they developed needs that higher pressure, but Comp is nuts? If it walks like a duck, and quacks like a duck, it's a chicken? Gotcha...lol.
Click to expand...

Compu-Cams #901

Single-Coil w/Damper

1.494" O.D.
1.080" I.D.

#101 lbs. @ 1.650" {Valve-Open}
#242 lbs. @ 1.250" {Valve-Closed}

A 'Big' difference between these Valve Springs and the #995 Units.

Coil-Bind @ 1.100"

#353 lbs./Inch Load-Rate

These units are equal to 'stock' 340 Valve Springs
 
It used to be easy picking out springs, but with the fast ramps on some of these new off the shelf grinds, it throws a monkey wrench into the old school thinking. I agree, and i'm not surprised, that the cam companies may be over "springing" their recommendations a hair. I've tried to research springs for a few members that have asked this same question, and it's not easy to find a single that will really give the top performance needed vs a good mild double that they recommend.
 
OldmanRick said:
It used to be easy picking out springs, but with the fast ramps on some of these new off the shelf grinds, it throw a monkey wrench into the old school thinking. I agree, and i'm not surprised, that the cam companies may be over "springing" their recommendations a hair. I've tried to research springs for a few members that have asked this same question, and it's not easy to find a single that will really give the top performance needed vs a good mild double that they recommend.
Click to expand...

That is what my machinist did. He still wanted to use the double springs but lightened up the seat pressure.
 
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