W2 head installed valve spring height

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Timmy's Toy

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I've read and been told that long valve W2 head valve spring installed height is between 1.9 and 2.0 inches. Is that correct? I found an old post from 2006 that Guitar Jones said 2.0 inches.

Thanks!
 
Yup. That sounds about right.
 
Heck, my hot slant head is set up at 1.82". LOL
 
805moparkid said:
lift (minus lash) + .050 + coil bind height = Installed height
Click to expand...

only problem is the long valves and rocker pedestals are set up for 2 inch spring height...

if you run a small cam with small springs...you will have a stack on shims under the springs....

with a solid cam I usually use the old Mopar Battleship Dual spring...the right spring height...good seat and open pressure for solid cam...and they were inexpensive..aka cheap


http://www.summitracing.com/parts/dcc-5249849

not available...LOL....got one set still in boxes
 
I am currently using the Mopar dual springs and they have a stack of shims under them. I am now going to a Lunati cam and they are supplying new springs at 1.97 installed height. It looks like I will be using quite a few less shims.
 
I've been going through my old posts and updating them. I installed that Lunati cam, lifter, spring, kit in November of 2013. It's first hit at the track was the Thanksgiving race at Las Vegas. It was a disaster. It bent several pushrods and destroyed 2 rockers. I had checked for clearance with putty and found .200 inches + when I assembled the engine. I also degreed the cam. I didn't have spring bind, and was at a loss to explain what happened. I replaced the damaged parts and reinstalled the .557 Mopar cam and ran for about a year with no concern when I sucked an exhaust valve in number 8 cylinder. I found the springs were already worn out and had less than 90 lbs pressure, (so I'm not happy with Lunati) Luckily I had only damage to the #8 exhaust valve, it was stuck in the head and didn't damage the piston, (there's a tiny little scuff mark on the piston). I had the machine shop replace with Comp Cams springs. and redo the valves and guides on both heads. Reassembled and had no concern until I tore it down in 2019 for maintenance and upgrade. I freshened the engine and installed a Mopar 590 cam. Degreed the cam and checked for interference and spring bind. Looked really good, lots of clearance. The putty test showed .220 inches of valve clearance. I wasn't able to put I back into the car until February of 2020. After break in, best hit on the track recorded a best of 10.95 in a head wind in Phoenix with letting off the throttle. Went to Tucson (3150' track altitude) and ran a best of 11.14. With the Covid-19 restrictions haven't been able to race anymore.

I recently found 32 (brand new in the original boxes unopened!) discontinued P2946353 Mopar Performance valve springs which are supposed to be the bomb for W2 heads. They have the proper installed height and good spring pressure, (I'm taking them in to find the installed and over the nose pressures). My plan is to try the Lunati cam again with these springs and see what happens. I'll do all the clearance checks very closely for safe's sake. Most likely won't occur until next year. The Lunati cam spec's are: Intake Lift .597, exhaust .620 (with 1.5 ratio). duration at .050 = IN 263 degrees, EX 271 degrees. LSA = 106 degrees. Centerline is 100 (yes that's correct) degrees with a 6 degree advanced set up in the cam.

I welcome any comments!
 
Comments?

Assuming you’re running a flat tappet cam.....
You’ll have way more open load than I’d want in a bracket motor(along with very questionable cam/lifter life).

If it’s a roller cam, you’d have less than I’d want.

The specs are listed at [email protected], with a rate of 571lbs/in.

For either a SFT or roller...... there would be better options imo.
 
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it is very simple to measure from where the spring will sit to where it will contact retainer, this can be adjusted. then we need springs that have dimensions for this space with loads the cam wants
 
PRH said:
Comments?

Assuming you’re running a flat tappet cam.....
You’ll have way more open load than I’d want in a bracket motor(along with very questionable cam/lifter life).

If it’s a roller cam, you’d have less than I’d want.

The specs are listed at [email protected], with a rate of 571lbs/in.

For either a SFT or roller...... there would be better options imo.
Click to expand...
It's a solid flat tappet. Where did you get those spec's?
 
Interesting. MP performance book recommends these springs for this cam and others. When you say MP engine manual, I'm not familiar with that. Where'd you get it?
 
They were “parts” in the MP catalog.

This one is P4452790
The small block section is about 140 pages.

Just take the springs to someone with a spring tester and check them(with a suitable retainer to properly preload the inner spring).
If you’re comfortable with the loads you’ll get with those springs on that cam..... then run em.

419D35AE-6AEA-462A-ACA5-5BE91EA4A8A0.jpeg


They’re out of print, and I’m not saying you should get one....... but if you wanted one:
Mopar Engines P5249010 Racing Mods V8, V6, I6 - 8th ed, Chrysler Dodge Plymouth | eBay
 
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What is your measured distance from head to underside of retainer, can be measured simply, this is maximum installed spring height. Adjusted with spring shims, keepers, retainers. Happy to say my .550" flat lifter solid happy to 7000 for 20 years with Elgin outer and comp inner at 135 seat, and 335 open load.
 
This is the book that I have. It was edited by Larry Shepard. I'm not sure, but I think it might have superseded the book you have. Anyway see below. Thanks to both of you for your comments and such. Great info! I appreciate it.

upload_2020-4-14_17-14-23.png


On page 203, this is what is said about the P2946353 springs. They have 130 lbs. of pressure closed at 2". Lunati says I need 120 lbs. Interesting the difference in spec's between the two books. I'll take the springs in and have them checked. I'll keep you informed.

upload_2020-4-14_17-17-37.png
 
This is where you get into one of those “ask 10 people...... get 10 answers” situations.

Personally, I’d never try and run a cam like that Lunati with 120 on the seat.

The specs in your book are a little lower than mine.
Perhaps MP started getting that spring from another supplier, which could account for the differing specs.
Perhaps one of the books is just wrong....... or maybe they’re both wrong.
Even your book shows a rate of 540lbs/in....... which imo is crazy high for a SFT cam.

I trust the numbers from my tester....... which often disagree with specs in a catalog.
Which is why I always suggest having them tested so you know what you have.

Looking at some other numbers in your chart, the specs/loads for the listed heights are incorrect for the 933 spring.
The numbers for the 077 springs at the heights listed are also way off.

I don’t really have much confidence in charts from Mopar books.
 
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The springs on my W-2 heads are 140/400 @ 1.95 installed height. They are Crower. These are older springs from the 90's.
 
PRH said:
This is where you get into one of those “ask 10 people...... get 10 answers” situations.

Personally, I’d never try and run a cam like that Lunati with 120 on the seat.

The specs in your book are a little lower than mine.
Perhaps MP started getting that spring from another supplier, which could account for the differing specs.
Perhaps one of the books is just wrong....... or maybe they’re both wrong.
Even your book shows a rate of 540lbs/in....... which imo is crazy high for a SFT cam.

I trust the numbers from my tester....... which often disagree with specs in a catalog.
Which is why I always suggest having them tested so you know what you have.

Looking at some other numbers in your chart, the specs/loads for the listed heights are incorrect for the 933 spring.
The numbers for the 077 springs at the heights listed are also way off.

I don’t really have much confidence in charts from Mopar books.
Click to expand...


The 120 seems too low for me as well. I'm confused about the 540lbs/in. Where is that?
 
Timmy's Toy said:
The 120 seems too low for me as well. I'm confused about the 540lbs/in. Where is that?
Click to expand...
Specs are [email protected] & [email protected]
That’s a gain of 270lbs in .500.

270/.500 = 540

I find that spring specs in catalogs are just wrong surprisingly often.
For example, the paperwork that comes with a set of TF240 heads for a BB Mopar shows the part number and specs for the three spring options for those heads.
The specs for the middle option, the hyd roller spring, are just wrong. Seat load, open load, rate...... all wrong.
It’s a PAC spring...... if you look in the PAC catalog the specs are correct.
If you go on line and look up the specs in the valve spring section of the TF website, the specs agree with the PAC catalog.
So, the specs from TF are different...... depending on where you look.
One set of specs is correct, the other isn’t.

One of the warehouses I buy from has there own “house brand” of springs.
They buy them from some supplier and put them in their own boxes.
Most of the specs for them are wrong in the catalog...... and some are pretty far off.
The catalog shows the seat load, open load, and rate...... and for many of them...... the numbers don’t add up.
Either the loads are wrong, or the rate is wrong, or the checking heights are wrong.
Where ever the problem lies, the result is the same....... the springs don’t(and can’t) match the specs in the catalog.
Here’s two examples:
Specs:
[email protected]/[email protected], rate = 269lbs/in
[email protected]/[email protected], rate = 300lbs/in
I’ll let you do the math..... you tell me if all those specs are correct.


I would never use a set of springs(without testing them) where I wasn’t very familiar with that brand & part number without making sure they were close to the published specs

I’ll be curious as to how those MP springs of yours check out.
 
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I have a new 077 and 933 spring here.

Your chart shows:
933 - [email protected]/[email protected]
077 - [email protected]/[email protected]

My chart shows:
933 - [email protected]/[email protected]
077 - [email protected]/[email protected]

Obviously, taken at face value..... they’re way off from each other.

What they actually test at:
933:
[email protected]
[email protected]
[email protected]
[email protected]
Coil bind @ 1.300

So, that one is pretty close to the specs in my book.

The 077 on the other hand, isn’t even close. Tested with a retainer that has a .100 step for the inner spring:
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
[email protected]
Coil bind 1.200

The 077 spring is listed as for use with the MP590 cam.
If you ran it at 1.860 installed height you’d have not enough seat load, and more open load than really necessary.
It’s just not a good option, IMO.

On the plus side(not really), they’re pretty damn expensive.

0E2E6D07-EC5D-4370-845B-AC180CD9E300.jpeg
 
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MOPAROFFICIAL said:
I find many springs to be 10-15lbs off.
Example...
Comp 995..
Inst. @1.65 chart shows 135lbs..and @1.150 shows 335/340 ...but is actually more like [email protected] and [email protected]
1.72 125lbs , 1.220 335lbs.
Click to expand...

I find that to be true pretty often for many new-in-box springs.
They’ll often fall back closer to “spec” after several high rpm blasts.
But not always.
I’ve had the heads come in for freshening after a couple of seasons and the springs still test higher than spec.

My experience is the old H11 drag race springs would lose a bunch of load in short order.
You really had to be sure to crunch them to coil bind several times before doing any testing.
I’d seen them lose 40lbs doing just that.
Then another 20lbs could easily be lost in a pretty short time if you were running a valvetrain combo that got into some unhappiness.
I’ve removed many dead K-950’s from bracket race heads, that should have been a pretty good match for the combo...... on paper....... but were obviously not up to the task.
 
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