VAP

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I've tossed the idea of precision sub-miniature adjustable stainless valves out the window due to cost and am going with electroless nickel-plated brass barbs that are silver-soldered with solder containing 20% silver. Everything I've read said nickel-plating cannot be easily soldered beyond 2-3 days after plating but I found a way to make it work.

Barbs will be soldered internally as in picture. Then each solenoids vacuum needs will be determined. When precise solenoid "need" is determined then a "pre-soldered" barb will be chucked in the lathe and a metering orifice will be center-drilled thru the solder in the barb ID that best meets a specific solenoid's need without excess vacuum. The silver solder I'm using is 20% silver content and not the hobby store variety (Stay-Brite) containing only 2% silver. I have tested the solder inside the barbs with a precision tipped piece of piano wire in the press and solder holds to 265lbs of pressure (not "psi") inside the barbs internal bore to punch "thru" that solder! So I figure 30IN HG is not gonna come anywhere close to pulling the solder out of these when in use. Also 20% silver resin-core solder doesn't even begin to flow until 615+F so under-hood temps won't be a problem unless there's an engine fire in which case these barbs are the LEAST of my concerns!

If using metering drill bits I have in-house I can drill these in .002" increments from the smallest size I stock of .024" (standing vac fitting on right in pic) to .150" which is a 50% larger bore than non-soldered standing fitting in left of pic. I already know I'll be doing specifically that to the fitting I'll use for manifld switch-over as I want manifold switchover to be as rapid as possible. In fact if I find a MUCH larger barb fitting better accomplishes that I'll go with whatever size snaps the bad-boy open as fast as possible even if it means boring out and attaching a larger vac service line to the cross-over actuator.diaphram housing and capping off the stock vac nipple.

Plastic pieces in pic surrounding barbs are filters of varying micron filtration sizes from 5 micron to 45 micron. This will initially be a trial &amp; error affair choosing the correct particulate trapping size. I'll start small and work my way up when/if they start clogging too quickly. The assymetrical plastic parts in pic are check valves to prevent "back-pressue" or reverse-vacuum flow from occuring. Their body shape reveals their flow direction when viewed from the side, ie; their body looks like an arrow of direction which I've emphasized by red lines in the pic. Filters are uni-directional and filter identically either way which is emphasized by the blue lines in pic. All plastic filters/check-valves have a working temperature of 250F and can take temp spikes of up to 4 hours duration at 350F before distortion occurs.

I still plan on using airbox lid for EGR solenoid valve pressure-relief. But far better to have a LOT of this stuff and not need it for prototyping than need something even once and not have it.

After lunch I'm gonna go out and CNC the prototype vacuum distribution manifold that the above hose barbs will thread into and supply vacuum to the various solenoids and other ancillary devices. I should have pics of that up by this evening.

2.812vqt

valves?

VAP

a "quality" check valve out of stainless would "start at" $130 and go well over $600 each for "serviceable" medical/anasthesia or laboratory reference grade! These are $5-$8 each depending on micron size.

This stuff is available GAZILLIONS of places. I just get mine locally from a company I've traded with for 30+ years.

And again, you're reading/comprehension skills are WAY off. I've NEVER said anything about a "dedicated brake vacuum accumulator." We already have exactly that as things exist on EVERY 12V car Audi ever made! When I make something i'm not inclined duplicate or challenged by duplicating what the car came with when new.

2.812vqt

those crapy vw ones leak and dont flow too great...its not that my comprehension skills are too far off, but i dont always have time to search back through the forums (even though i would like to)

VAP

you're right, I shoulda said "retention level" and not "comprehension skills" ;-)