[chuckies76ta]

Where do you take your reading from on the Valve Spring when checking for coil bind? Top,middle or bottom area?

I seem to have different readings caused because of the way the spring if wound if that makes any sense..

Thanks for any help.

[TCSGTO]

Put the retainer you’re using on top of the spring. Compress it until all the coils are stacked. Measure from the retainer bottom to the bottom of the spring.

[chuckies76ta]

Oh, OK that makes more sense to me. Thank you..

[chuckies76ta]

Any other tips, tricks, pointers when checking springs? Anybody.

[chuckies76ta]

Originally Posted by TCSGTO

Put the retainer you’re using on top of the spring. Compress it until all the coils are stacked. Measure from the retainer bottom to the bottom of the spring.

Ok, So I stacked the coils on the tester on a spring and it came out at 1.010 on two different springs from the car. I tried it with and without retainers. Same reading

The spec from manufacture is coil bind at 1.080

So 1.080-1.010 = .070 difference.

Any thoughts?

I'm wondering is spring manufactures build in safety margin?

Thanks

[gtofreek]

Those spring manufacturer specs are just guidelines. The springs will not all be the same as those specs. I see actual coil bind all over the board compared to those specs. That coil bind height listed in catalogs is usually at least what you will get, but usually it's more.

[Steve C.]

Stated- "Those spring manufacturer specs are just guidelines"

Related, also never assume the specification in the catalog are always correct regarding spring pressure as well. They will vary from batch-to-batch. Example we recently tested a set of valve springs that had 20-25 lbs more seat pressure than they were rated at.


.

[chuckies76ta]

Originally Posted by gtofreek

Those spring manufacturer specs are just guidelines. The springs will not all be the same as those specs. I see actual coil bind all over the board compared to those specs. That coil bind height listed in catalogs is usually at least what you will get, but usually it's more.

Ok, Thanks for the info... What kinda pressures you like to see on Roller Cams open and seat pressures?

How about hydraulic roller cams with solid lifters?

Thanks

[tom s]

200 on the seats.Tom

[gtofreek]

Originally Posted by Steve C.

Stated- "Those spring manufacturer specs are just guidelines"

Related, also never assume the specification in the catalog are always correct regarding spring pressure as well. They will vary from batch-to-batch. Example we recently tested a set of valve springs that had 20-25 lbs more seat pressure than they were rated at.


.

Comp 995's are famous for that.

[chuckies76ta]

Originally Posted by Steve C.

Stated- "Those spring manufacturer specs are just guidelines"

Related, also never assume the specification in the catalog are always correct regarding spring pressure as well. They will vary from batch-to-batch. Example we recently tested a set of valve springs that had 20-25 lbs more seat pressure than they were rated at.


.

Thanks Steve. Ya I'm seeing a difference between new and used or springs that have been run in so to speak. a difference of +or- 10 pounds.

[chuckies76ta]

Originally Posted by tom s

200 on the seats.Tom

Wow, The reading I been doing is saying around 160 seat 400 open..

I realize there are a lot of variables involved, which has mostly to do with weight of valve train and rpm..

Thanks

[gtofreek]

160/400 is for hydraulic roller lifters. You said you were running solid rollers. You now need to think "spring it like a solid roller".

[chuckies76ta]

Originally Posted by gtofreek

160/400 is for hydraulic roller lifters. You said you were running solid rollers. You now need to think "spring it like a solid roller".

Ok, so can you shed some light on this scenario. What changes because of the solid lifter? other than it's a solid lifter.

Thank you

[tom s]

Your up Paul!

[Cliff R]

"Stack" height and "coil bind" are not the same measurement.

Coil bind is when the coils of the springs start rubbing together and will typically occur quite a bit before the springs actually stack solid.

I've always used the "stack height" plus .080" as the minimum running room for any set of springs and it's served me well for many years now. Some engine builders use the coil bind spec plus .060".

When checking springs (unless they are single) the seat and open pressures will vary some with the retainers being used due to the inner step. This can also effect the coil bind specs as well, so always test the springs you are going to use with the retainers you are going to use.

+2 on Comp 995 spring being all over the map for seat and open pressures, and typically quite a bit higher than the specs you get in the box with them or what Comp Cams posts on their website, or what's listed by any company selling them. I've used a few sets over the years but not overly fond of them, and the dampners need to be smoothed some on the bottom or they will eat pretty hard into the shims under them and put metal into the assembly.......Cliff

[Steve C.]

"When checking springs (unless they are single) the seat and open pressures will vary some with the retainers being used due to the inner step. This can also effect the coil bind specs as well, so always test the springs you are going to use with the retainers you are going to use."


I believe it was Paul Carter that posted the different amounts of pressure with the same spring tested with different retainers. It was an eye opener.


.

[chuckies76ta]

Thanks Cliff and Steve for the info..

"Stack" height and "coil bind" are not the same measurement.
Coil bind is when the coils of the springs start rubbing together and will typically occur quite a bit before the springs actually stack solid.
I've always used the "stack height" plus .080" as the minimum running room for any set of springs and it's served me well for many years now. Some engine builders use the coil bind spec plus .060".

That makes sense.. so I just took a spring and tried that. I used a .0015 feeler gauge to check between coils as they just started to touch. I then stacked the coils and my measurement was .018 to .020 difference. Sound about right?

[Cliff R]

Correct, but not the same for all springs due to wire diameter, number of coils, diameter of the spring and number of coils, etc.

I've used stack height plus .080" for at least 40 years as the "running room" for the springs with zero issues......Cliff

[chuckies76ta]

Awesome, Thank you Cliff