W2 head installed valve spring height

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PRH said:
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.
Click to expand...


So using your equations I come up with different answers.

[email protected]
[email protected]
186/.55 = 338 lbs.

[email protected]
[email protected]
221/.60 = 368 lbs.

Am I missing something?
 
Timmy's Toy said:
So using your equations I come up with different answers.

[email protected]
[email protected]
186/.55 = 338 lbs.

[email protected]
[email protected]
221/.60 = 368 lbs.

Am I missing something?
Click to expand...

No, you’re not missing anything.

I didn’t come up with the rate for those two springs...... that’s the rate that’s posted in the catalog.
So, as you can see...... “something” isn’t correct.
The load, the lift, the rate...... something.

If I tested them, then I’d know what they really were.

The main point being...... don’t count on the catalog being 100% accurate.
At best, the rate listed for those springs is way off.
But is that really the spec that’s off? Maybe one of the other parameters is wrong and the published rate is actually correct.

A few measurements on the spring tester would tell the story.
 
Last edited:
PRH said:
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.

Especially with the old H11 springs, which would lose a bunch of load in short order.
Click to expand...
My fav are cam grinders giving pressures theyd like to see used, then they have no actual spring part # recommendation.
I find a spring that ends up either lighter on seat than what they want and just right at the open...or higher seat and open than they want and definitely higher than I'd set them up at.
Old purple solid cams would run all day with 120seat and 300-open less sometimes..
Mp .557 and smaller ran with springs that were 120 and 275
By the time I pulled some 847 singles off that I used with a .528, the seat went from 120 to about 100 lbs and the open was down to 260 something iirr.
Wide margin before you break something.

Newer stuff works w/ 135-145seat and 305-315 by .500..but usually no more than about 330.

Spring pressures...what's ideal for street , is not adequate for strip ... and what's adequate for strip is too much for Street and ime a parts killer most everytime.
Anyone wanting to run on the high side spring pressure if they're breaking in the can better do it with the outer spring only or it will definitely wipe it out
 
For the SB oval track stuff we were building, running fast rate SFT cams, I ran quite a bit more open load than 330lbs.
 
PRH said:
For the SB oval track stuff we were building, running fast rate SFT cams, I ran quite a bit more open load than 330lbs.
Click to expand...
Oval track. Yes.
I was vague, Street motors require less open is what I was getting at.

Like usual all depends on what you're doing if you're going to rev it higher and more often you going to want some more pressure to control it.
 
I've been toying with buying a spring tester. I'm going to know. I'm going to spend a little money and get a good one.

I'm being educated. Thank you guys for your comments and help.
 
Be sure to get a calibration spring at the same time.

One of my friends bought one of the less expensive testers...... it was way off, and got sent back.
 
PRH said:
Be sure to get a calibration spring at the same time.

One of my friends bought one of the less expensive testers...... it was way off, and got sent back.
Click to expand...


You’d be surprised (maybe not but I was) how many shops dont have a calibration spring, and how many shops have one, and haven’t used it in years.
 
yellow rose said:
You’d be surprised (maybe not but I was) how many shops dont have a calibration spring, and how many shops have one, and haven’t used it in years.
Click to expand...
I have two.

The first one didn’t have enough data points for my liking...... but at least you knew if something was way out to lunch or not.
Tha PAC calibration spring has loads listed for several lift points.

I use a lot of the same springs over and over, so I pretty much know what I’m looking for in terms of load/height from one of the “usual” springs.
I get out the calibration spring most often when it’s a spring I’m not familiar with....... and the observed loads don’t agree with the published specs.
The tester has always been fine...... the observed loads vs published specs?
Not always in agreement.
 
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