Another blow thru 1600 build

[John S.]

All plumbed with new regulator. But! I have a problem. My old malpassi never went less than 11psi. I blame it on my too small of return line. I used the stock vw supply line. Now with the new regulator, I have all 5/16 and 6an line. And it returns to the top of the tank. Also, this regulator claims zero to the moon psi. And the reviews claim out of the box low psi is not possible. Heating and shortening the spring gets you there. I’m somewhere bellow 5 psi with the mod. But, every time I check the system for leaks the carb just over flows with gas. The car last ran on thanksgiving and all I did was braided lines and regulator. And I actually have lower idle/static psi than the other regulator. I took the top of the carb (drla) off and the float wasn’t stuck, needle and seat are sealing and the float, floats in a cup of water. Any ideas?

[John S.]

I’m going to try swapping floats from another carb. Maybe this one is heavy. The needle and seat seal when I have the top off and blow in the hose.

[rubenski]

I once had a geniune AN fitting with what looked like a hair that was stuck in de flange surface when being anodised, super hard to see but fuell kept leaking.

Fuell somehow has a way to find the path if there is one.

Maybe it´s coming from somewhere else than your needle valve and float? Any other gaskets that need replacing?

Verstuurd vanaf mijn SM-A528B met Tapatalk

[Ol'fogasaurus]

Military standards (AN being just one of many Mil designed items and/or designs) are very tightly controlled for mix of materials, coherence to the manufacturing of the part(s), e.g., forming to the controlled design (and this includes other things that just parts) and protective covering (all the specs for the item is tied up in the coding of the part's whole part number). They are then checked and tested for meeting all properties which includes strength of the basic design components, and other design coherence of the parts to the design, and component detail of the parts of the design. The final tests of a run of Mil spec designs are extreme and if there are any that fail the check, the whole run is scrapped.

If you are talking about fittings that are commercial/similar copies the Mil Spec, checking of the could be at a lower level if checked at all. One of the reasons for the difference in price (assuming they are company design parts not sold as Mil parts that is). I have seen some real good-looking parts and some not too good parts where even the parts that look good fail. Remember, there is also a limit of the number of cycles of a Mil object.

Part of my job to know this during the time I was working and withhold my signature if a/the design was not complete or correct when I was checking other's work. It was the engineer's responsibility for the design but mine for presentation and company and (sometimes) fed rules on our parts, assemblies and installations.

Lee

[madmike]

what brand reg?I like the Aeromotive brand , pricey but ya get what ya pay for

[Ol'fogasaurus]

what brand reg?I like the Aeromotive brand , pricey but ya get what ya pay for

https://www.fastenal.com/content/merch_ ... 0Guide.pdf

All designs have design standards they must meet, but they may not necessarily be of the same load carrying. US Military standards meet design requirements from almost nothing to very high grades. National Areospace standards are very close to MIL standards and even may be the same thing. The above URL I posted is ASTM standards which may or may not meet MIL standards or different US companies. As far as I know, all countries have standards they want designs held to.

The reason I talk about MIL Standards is because the AN word is used as a quick term, but it covers more things than people think. As I remember the term "AN" arrived during the Korean War and dealt with the mechanics of the jet planes and maybe tanks.

A bolt is not just a bolt as there are many different designs and grades, plus the "shank" can be fully threaded designed to use either cut threads of rolled forming of the threads (I think there may be other ways now as I have been retired nearly 20 years. A long time ago here the term AN was used to mean braided fuel lines which were AN parts but it's use was wrong unless the car was a show rig that was going for looks.

Depending on what you look at the shank can be described as the unthreaded part of the bolt (stud?) but in MIL standards (for example) the unthreaded part is the "grip". The shank can be fully threaded or the grip, that goes up to the head of the fastener is "the grip". The shank is the part that can be fully threaded. The Grip deals with shear loading way better than threads do (I can't find a picture of the fastener's material when either of the two styles of forming threads are done.

Basically, the grain in a bolt is in a straight line down the shank but if you cut the threads the grain is cut also weakening the threads. On rolling the threads the grain is compacted towards the center of the bolt making them stronger.

The material is partly determined by the mixing of metallic materials then comes the forming of the fastener along with the forming of the head, shank and especially the radius of the shank where it attaches to the head of the fastener. As the fastener is designed to be stronger the radius also changes to a bigger radius.

Remember that a fastener and what is used to "clamp things together".

I'm getting into this farther than I wanted to I was just trying to get people from not using the term "AN" which means nothing... especially a complete "nothing".

Not too long before I retired, I was called into a meeting where a fastener was failing before the assembly of the parts could be completed. The part of the company that was assembling the parts together had run out of the higher-grade fasteners but found a substitution source that never should have been created. Someone put a substitution to the higher-grade fastener by a very low grade fully threaded (cut threads) that would not deal with shear applications in almost any fashion.

The lower grade fastener would not take the assembling loads that were applied causing the structure to fail but if they did manage to assemble this then even light shear loads was cause the whole structural assembly to fail.

Anyway, I hope this helps get rid of the doesn't mean anything, "AN" use.

Lee

https://www.aircraftspruce.com/catalog/ ... ashers.php

I did a search (just for the heck of it) for the common AN960 washer and this is what I came up with. I am surprised to even see it mentioned on the web as it is a military spec.

The longest part number of a Mil-spec part was (if I remember correctly) either 17 or 18 digits long. Digits in this case are letters and numbers after the basic spec number (AN960 for example).

Lee

[John S.]

It’s a no name Amazon. I think I’ll try to add the fittings to the CB malapsi regulator

[madmike]

Guess it wouldn't hurt to try it

[John S.]

It worked before with too small of a return line. Should work with the better return design.

[madmike]

Is that a Pressure switch on the fuel line???

[John S.]

Yes, it’s a electric fuel pressure sensor. And now the carb does leak with the new regulator.

[madmike]

what the pressure at idle? should be about 3 1/2 lbs,so that sensor is for a fuel gauge?

[John S.]

That’s exactly where it’s at. And yes, it’s a cool cheap Amazon fuel pressure gauge. Next I have to see if the psi rises ahead of the boost. If it ever stops raining. Also, have to change the oil. I dumped a lot of fuel down the carb.

[madmike]

I don't know if I'd trust that Gauge? check it with a regular gauge and compare
Raining here on & off too ,we had 90* + temps here now back in the darn 39*-50*range ,,

[John S.]

It reacted to all the regulator swaps and adjustments. It’s at 3.5 and the carb is behaving.
It’s been cool here, too. We were spoiled with some 80 degree days. We are having a VW cruise night on Wednesday at Sonic. Would like to make it there.