Valve springs squareness

[Wolf_Tm250]

Hi,
do you check valve spring squareness before installing?
I read on a engine manual it must be less than 2mm (0.08), otherwise discard the spring.
Unfortunately when dealing with aftermarket springs, I found that many of them are slightly out of spec, but discarding them would mean to ship all of them back... to receive another batch back with the same problem...
How much is too much for you?
Thanks

[BOOT]

Once you compress/install them they would be square I'd think, but still interested to see what others say.

[Matt80]

Yep, happened to me too! Interested too to see what other say

[Newold1]

I am assuming in your case the valve springs are being used in a double overhead cam engine where lifter buckets are in play. I have always been told in these overhead cam engines with shorter and smaller diameter springs that being square is much more important that in push rod overhead valve engines where the springs tend to be longer, larger in diameter and subject to both lower rpms and more compression dimensions. If your engine rebuild or repair manual says keep those dimensions then I think you should have a conversation with the replacement supplier or manufacturer and find out why they have not held that dimension. Usually the OEM manufacturers, especially Toyota have done a lot of engineering, testing and durability determinations to come up with those specifications. JMO

How do the stock or original valve springs measure as a comparison?

[piston guy]

Common sense must be used here. If the spring looks like the Tower of Pisa , it is going to "side load" the valve in the valve guide during operation. In your case the more "square" , the better. the spring will compress more evenly and reduce failure.

[Greenlight]

When the springs are manufactured, they are cut square. The only way they become "out of square" is if:
1) The spring has yielded/deformed due to excessive stresses.
2) The spring had residual stresses when it was manufactured and those stresses became relieved during operation, causing the spring shape to change.

In either case, I would replace the spring.

[dhidaka]

Replace the springs!
Titanium valves
19 runs
.080 before coil bind
126lb seat pressure OK
Thankfully no valve dropped.
Replaced with PSI with no more issues.