Water Injection Hardware
Copyright © 2004 Eric Fahlgren
Last updated 2007-09-18 11:15 PDT

Water Injection Hardware


Use a MegaSquirt.


Pictures of injector side and injector end.

Summit Racing MSD 2015 US$80, really a 96 lb/hr Delphi Rochestor. They also have the 50 lb/hr jobs, 2013; 72 lb/hr 2014.

2005-04-05 Update: Rick Yacoucci (turborick.com) has tried to use the above injector style with pure water and had problems with corrosion within a few days. If you have experience with these injectors and various non-gasoline liquids, let me know so I can pass the info along. Here are Rick's comments:

Looks like the injectors are not the way to go with straight water... It got stuck shut after sitting for about a week with water in it. It open'd up when I banged it on the table a few times. On another note nitrous solenoids are all stainless.... but not sure how fast they can be pulsed.


Picture of pump, with instant swivel-T mentioned in the fittings section below. The outlet goes straight over to the accumulator, the 90 holds the line to the injector.

Marked SHURflo Diaphragm Pump 8000-541-236 1.0 GPM 3.78 l/min, 12 VDC, 5.0 Amps Max, 60 PSI

http://www.northerntool.com/ Search for item 342811 (480 lb/hr@60 psi), $40 on 2004-02-16

If you want a bigger pump, search for this one at Northern: 2687 (850 lb/hr@60 psi)


Picture of accumulator, you can see the instant tube fittings again.

Marked SHURflo Accumulator, Model# 181-203, SN 429447, Precharged pressure 20 PSI, Max capacity 125 PSI. Molded into shell near Schraeder valve: Max pressure 125 PSI.

I paid $25 on sale from SailNet.com, part 13887.


I got a poly chemical can, but later realized that the perfect WI tank is a plastic kart fuel tank usually made for methanol. The extra benefit is that they are meant to be used in applications with high lateral G forces, so the pickup is already in the right place.

Here's the first place I found when doing a web search, there are probably better or cheaper ones around. If you have experience with kart tanks, let me know.


Tubing and fittings

Picture of tubing, fittings and injector

I purchased all my bits from McMaster-Carr. I'm using 0.250" Nylon 11 hose, marked 250 PSI WP @ 75 F.

Here are some McMaster part numbers for the plumbing hardware, to get you started:

5548K295 Nylon 11 tubing
5779K206 Swivel-T instant tube fitting, 3/8 NPT
5779K111 Straight adaptor, 3/8 NPT
5779K109 Straight adapter, 1/4 NPT

These "instant tube fittings" are really quite slick, the tube slides right into the fitting, which grabs it securely, but if you press the collar on the end back into the fitting, it releases the tube which slides back out. This makes routing and fitting the system very much easier than permanent crush fittings.

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