[promptcritical]

Can valve spring parameters other than closed pressure be measured with the springs installed on the heads and on the motor?

[Firebob]

They make "on head" spring testers. Check Summit.

[promptcritical]

Yes. We have one that we use on our late model motors, but all we do is look at seat pressure with it. I guess you could check installed height okay, but open pressure and coil bind is best checked with with a bench tester.

[Firebob]

Seat pressure and installed height pressure would amount to the same thing, no?

[promptcritical]

Yeah. I meant that you could measure installed height (the length measurement) and seat pressure.

[chuckies76ta]

So are the Proform 67597 testers worth the money?
https://www.proformparts.com/product...ategory_id/171
or
The LSM tester?
http://www.lsmproducts.com/lsm_produ...essure_testers

Anyone use these, pros or cons

[Firebob]

I'm curious if rocker ratio has any effect on readings with that type of on head gauge?

[chuckies76ta]

Originally Posted by Firebob

I'm curious if rocker ratio has any effect on readings with that type of on head gauge?

I don't know. That's why I was asking. This unit does have adjustments for rocker ratio.
http://www.buxtonengineering.com/on_...ing_tester.php

[HWYSTR455]

The on head ones are basically for giving you an 'idea' if there's a big discrepancy, for more accurate readings, you should really take it apart. But, if by chance you are chasing a miss or something, the on head ones are good enough. That's kind of why they call it 'track side'.

I wouldn't spend too much money on one of those, and there can be a variance of as much as 10%. But that would be across all readings, so would still give you an idea if something is amuck.

As for open psi, you can look and see how far another valve is opening, maybe hold a rule up to it, and move it the same amount, see what the reading is. Again, it's really only supposed to give you an idea. True readings should be of the spring, off the head.

.

[STEELCITYFIREBIRD]

I have used the Moroso one extensively in monitoring valve train on circle track motors. It's not really a gauge of exact psi, more of a baseline established when the springs were installed to compare, if you notice a variance from that baseline you established, you start investigating. Either the spring is loosing pressure or the IH is changing. Bench testing the spring/s will incriminate the spring or the valve/seat etc.

Regimented replication of the test procedure is imperative for comparable results.

Spring changes were every 5-10 max nights of racing.... or weekly if motor was over revved from a poor final drive ration choice for conditions on the GM 604" crate" engine till the legal spec'ed springs were updated to the newer beehive springs.

New "update" ovate wire beehive springs last a whole season easily if not mistreated... and beyond if you are a gambler.

Same logic used on open/unlimited engine, but much better springs so replacement of springs is rare.

[chuckies76ta]

Thanks guys. I appreciate it..

Charles