50mm gate spring question.
 

Good morning Lance.
What would be your best guess on the change in opening pressure between running the 50mm gate with the stiffest large spring, and running the stiffest large spring with the added smaller spring that fits in the middle. Also, what grease do you recommend on the piston O-rings when I put it back together?
Thanks.
Ron Allen

We use high temp silicone O-ring lube from mcmaster.com, that's the best I found. A little silicone grease they sell for caliper slides seems okay too.
Just apply the thinnest skim of lube.
What a spring is worth depends on which gate your installing it.
The large top 500R the springs are worthless in terms of actuator pressure.
I had this all worked out some where, IIRC the preload of the small heavy should be worth 10-12psi of top pressure. The large heavy is similar if not a little lighter.

And when I say actuator pressure I mean pressure applied in the top wastegate port.

This is what I have.
2.33 piston
.162dia. large spring
.125 inner spring.

I knew I had a 50/50 chance... In that case-
Changes it to +12-15psi by adding smaller spring.
Again this is a rough guesstimate of what the spring pre-load is worth in top port air pressure.

That's about what I'm looking for. Thanks Lance.

RonA

When applying psi to top port only, should I plug or leave open bottom port?

Bump. Anybody?

Let it vent to atmosphere.

That's what I thought. Thanks.

On the bench, if you hook up a regulated supply to the bottom port, as soon as the valve lifts, I hear air passing through the valve guide. (Clearance of course.)
If I am using a boost controller, would I not plug the bottom port, as the control is done through the top port only. (Solenoid energized to keep gate closed, another solenoid to bleed pressure off the top, opening the gate...nothing on bottom port at all.)

Leaving it open just allows the soot to pass through the bottom port, an just gets everything dirty.

fwiw, this was the best control I had as well.

If you PLUG the lower port the gate will draw air from the guide but then it will be awful slow to return, not good.

I dream of a seal that would actually last but its nto an option in the given situation.

Tighter clearances = a higher jamming risk.
Looking in to some coatings that will keep the soot from sticking.

I'm thinking of running an air system, so no more hot dirty air inside the cylinder. (Yes, I have a filter on the lines now.)

Shouldn't be a slow return using solenoids to pressure up, and vent off the top of the actuator. (Air to close it, and vent it off to open it.)