MFI cold start tee ?

[Jeremy Cottrell]

Has anyone found a suitable alternative to the factory cold start tees on an MFI stack? The factory ones are NLA as far as I know.

[Early_S_Man]

Jeremy,

I built some from brass tubing a bit larger in OD than the OEM 4.5 mm x 9.5 mm hose ... silver-soldered the parts together for best strength. The brass tubing was about 5.0 mm OD. I soldered a couple of 30 ga wire 'rings' around the ends to simulate barbed ends ... for better, tighter fit of the fuel line.

[Jeremy Cottrell]

Great idea Warren. A+ for creativity as well, thanks!

[ed martin]

I was having some problems with my stock T's and my mechanic fabricated some replacements out of metal tubing. The problem was the tubing didn't have any atomizing capability, it just kind of dumped fuel directly into the intake. This created a tendency for the engine to flood- a lot. Fortunately, I kept the originals( they had a suspected air leak) and reinstalled with some gasket seal. The point is, is that the originals produce a very fine mist by means of their tiny pin hole openings. I found this out by filling one with fluid and running compressed air through it. So if you can't find the originals and decide to engineer something, its critical to have that atomizing capability to make it work properly.

[Early_S_Man]

Ed,

I guess your mechanic has no experience in the past with carb tuning and brass jets. Jets that were too big got soldered up and redrilled smaller ... and soldering up the end of a 5 mm brass tube is no big deal. Wire drills in a hand chuck can easily reproduce a hole small enough to atomize the cold-start flow of gas ... no big deal!

[ed martin]

Huh , that's interesting. Actually my mechanic is pretty knowlegeble but kind of sloppy. The reason I go to him is because his prices were so good, and also he would do all the work right there and then and allow me to observe. Great learning experience. Back to the topic, wire drills? Is that a piece of thin wire you just put in a drill chuck?

[Early_S_Man]

Ed,

Wire drill sizes are a distant third in commonly-available drill-bit sizes, after fractional-by-64ths, and letter-sizes used for USS and SAE threading ... the wire-number bit go by commonly-used wire gauge sizes, an inverse by size series ... #1 to #60, and #61 thru #80 are the sizes available, such as from Jensen Tools ...

I have gotten many unusual tools from Jensen over the past 35 years or so ...

http://www.jensentools.com/product/group.asp?parent_id=7290

[ed martin]

Warren, That's interesting , I never knew such a thing existed. I always wondered how they fabricated those little pinholes. They must be made out of some super strong metal to keep from bending. Do you need a special drill with a chuck to accomodate these things?

[Early_S_Man]

Ed,

Typically, for power drilling ... a Dremel-type remote, cable-powered handpiece is used with a collet to hold the bit. Not much force is used, as the amount of material removed is microscopic!

As I indicated earlier ... an Exacto brand/type hand chuck can be used, too, but it is a slow process. Not a real problem for one-off projects, though!

A well equipped hobby shop used to carry all of these items ... but they are getting hard to find these days! There still is one right accross the street from the entrance to the Johnson Space Center, though!

[pwd72s]

I've never had to replace the T's in my system, but I've often wondered if the metal airline T's sold in aquarium shops would work...the ones I've seen appear to be chrome plated brass...

[Early_S_Man]

Paul,

I have wondered the same thing! I guess it would just be a matter of taking the dial calipers to the pet shop and making some measurements!

I didn't actually need to replace my cold-start fittings ... fabing replacements was just a curiosity project while I was replacing the old, crimped hoses ... the possibility of cracking one of those fittings was on the horizon, but never actually materialized!