Anyone used this vendor before?

[SeanH]

I'm on the hunt for some short air horn/velocity stacks and I was wondering if anyone had used this vendor before:

http://www.truechoice.com/prodinfo.asp?number=PIP%20W4545S

I'm interested in these because they have the small bolt holes on the side, which my cards have as well (picture below).

But, hey, do I need to bolt these in? I noticed that a lot of stacks just slide in. My question: is that an option I have as well? Do I have to bolt these things in?

Cheers!

Sean

[BWAutosport]

I've used Truechoice once before, to acquire Pipercross socks for my Mini. They are a regular supplier to many SCCA/Vintage racers.

I would say they're probably pretty decent, at least they were quick to quote me on some of the Piper parts not necessarily available stateside.

I would suggest bolting the horns on no matter what, our engines tend to be a bit shaky to begin with. I've only ever seen bolt-on horns, there may be slid-in options, but I wouldn't rely on a passive fit to keep them in place.

What kind of carbs are those? DCOE's?

Have fun!

-Ian

[SeanH]

Yeah, those are 45mm DCOE Webers. Pretty old, so I'm a bit worried about them.

I'm also concerned about that inlet in the top right. Is that something that needs to be covered? What is that anyway? Some sort of idle or cold start inlet? It's dangerous when I start thinking . . .

Sean

[BWAutosport]

I'm not 100% certain, I'm sure someone will chime in with the proper explanation, but I believe it affects the air/fuel mixture slightly. It should not be covered, to the best of my knowledge.

Rebuilding them is not that difficult, there are professionals who can help with that if you aren't feeling adventurous and wanted to learn.

However, they are said to be difficult to tune, so, if they're running well for you, I wouldn't mess with them.

[Emyers]

Correct...inlet for the cold start devices.

Earl

74 02Lux

02 M Roadster

72 Volvo 1800ES

[Fishhead]

I'm also concerned about that inlet in the top right. Is that something that needs to be covered? What is that anyway? Some sort of idle or cold start inlet? It's dangerous when I start thinking . . .

Sean

That's a vent for the float bowl. Don't cover it up. The Cold start valves get their air from the bottom of the cold start mechanism. The air jets in the carb all get their air from the float bowl vent.

Most of the (DCOE) velocity stacks I have seen usually slide in between the Aux. venturi and the carb body to hold the Aux venturi tight in place.

[c.d.iesel]

well whatever you do - get the alternator wiring away

from the carb - rubbing and sparking leads to -=FIRE!!=-

[Emyers]

"That's a vent for the float bowl. Don't cover it up. The Cold start valves get their air from the bottom of the cold start mechanism. The air jets in the carb all get their air from the float bowl vent."

The cold start devices draw air from the float chamber, that air is supplied thru the vent. Unless one is running straight velocity stacks, they are drawing filtered air as they are within most air filter assemblies. That is why they must not be covered. See Haynes Weber Workshop Manual P.143, Fig 11-7.

Earl

74 02Lux

02 M Roadster

72 Volvo 1800ES

[TobyB]

Fishhead is right for the 8 dcoes I own-

the cold start circuit air correctors pull unfiltered air

from the engine side of the carb.

the main and progression a/c's pull from the float bowl.

And if your aux venturis are not a tight fit in the bores,

you have to use slip- in horns.

t

[Emyers]

Fishhead is right for the 8 dcoes I own-

the cold start circuit air correctors pull unfiltered air

from the engine side of the carb.

the main and progression a/c's pull from the float bowl.

And if your aux venturis are not a tight fit in the bores,

you have to use slip- in horns.

t

Thanks, learn something new everyday.

Earl

[Fishhead]

The cold start devices draw air from the float chamber, that air is supplied thru the vent. Unless one is running straight velocity stacks, they are drawing filtered air as they are within most air filter assemblies. That is why they must not be covered. See Haynes Weber Workshop Manual P.143, Fig 11-7.

In the Weber manual, the cold starting jets get their air from the float bowl vent (air flow #29) and they also get air from the outside of the carb (air flow #34). So I guess we are both kinda right....

Either way, dont cover the hole above the venturi.