as usual the search function has not turned up what i need... i am building a hih out of 3/8 aluminum tubing and 5/8 heater hose and the local lowes is sadly lacking in suitable connecters. i would like to see some different designs, preferably the most bulletproof (no hose clamping the heater hose to the fuel line to seal it up!). I have a whole bunch of stainless 3/8 npt to 3/8 compression fittings i was going to use but the inside diameter will not permit feeding the fuel line all the way through. How do you guys build your hih setups? (parts list ormaybe some pics, pplease!!!) of if someone could point me to an old post that has this info, i would me most appreciative. planning on ordering from mcmaster tomorrow. thanks

I drill out the compression fitting so that the 3/8 will slid inside. Most people like 3/4

i keep hearing about useing 5/8 heater hose with 3/8" tubing. seems the hose barb fittings for 5/8" hose are too small to let much water through. i tried to strech a 5/8" hose onto a 3/4" hose barb without success. i'm useing 3/4" for the supply and 5/8" for the return.

you can drill out the compression fittings to 25/64" to allow the aluminum or nylon tubing to slip through. be sure and change the compression rings to nylon instead of the copper ones supplied.

pat

There's a good picture of my design on the gallery page on my site... 5/8" brass barbed T's soldired to a brass comp fitting.. I use nylon ferruls... Part #'s are aviliable on the FGF... I get everything from mc master..

Here is a BOM for the one I made:


Description source part # prics UOM qty ext. cost
3/4" T, brass, rated for 150 PSI mcmaster 5346K28 $6.77 ea 2 $13.54
3/4 NPT to 1/2" OD compression fiting mcmaster 50915K329 $4.28 ea 2 $8.56
3/4 NPT to 3/4" ID barbed fitting mcmaster 5346K28 $4.45 pack of 2 1 $4.45
3/4" NPT male to 3/8 barbed fiting mcmaster 5346K87 $10.97 pack of 5 1 $10.97
25' roll of 1/2" OD aluminum fuel line jegs.com ? $25.00 roll 1 $25.00
5' of 3/4" ID heater hose local Kragen ? $20.00 1 $20.00


The formatting will come out a bit difficult to read I'm sure, but it is pretty straightforward to put togeter once you have the parts.

You are talking about 3/8 hose in a 5/8 tube, which is a size down in diameter from what I did, so you couldn't quite use these exact part numbers but you'll get the idea when you see the stuff on mcmaster.com

The compression fittings that close down on the fuel line to keep the coolant in need to be drilled out to accept the tube all the way through. In my case I used a 1/2" compresstion fiting to accept and 1/2" tube and of course a 1/2" drill bit. In your case... same thing but 3/8.


If you want to see this in a more clear format, this discussion:

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/159605551/m/9101082331

has a link to an excel file that has the BOM for my entire conversion, and I recently updated the file to include the BOM for the HIH also. Mcmaster has drawings of all these parts also, which helps to visualize the whole thing...

Good luck.


Charlie

Fattywagonman:
what is the fgf?
Thanks for the replys, hadnt thought of drilling them. maybe better to just use brass as drilling out a stainless compression fitting could prove to be a pain... once this whole project is underway i will post pics of the whole conversion.

Good luck with the conversion. One thing I forgot to mention... some people prefernylon ferrules, some prefer brass with a bit of loctite in there to mak surethe seal stays good. I have plainold brass with no loctite and it has held up fine with no leaks. I only have about 4 months worth of data, wo we'll have to see how it holds up over time.

Charlie

i did some welding today for some folks with a metal fabrication /blacksmith shop and they have a large bridgeport mill that will easily drill the stainless compresion fittings, so it looks like i will be using these. they seem to make a good seal on their own, but i am curious about these nylon ferules as it seems like they could be removed a lot easier if i ever want to disassemble it all. will they work with swagelok fittings and if so, does anyone have a part number , from mcmaster or elsewhere? also, i'm still wonderong what "fgf" is. some other forum? 3000 series aluminum fuel line with all stainless fittings sure seems like it will be a nice setup, and probably last for eternity!!

bob, i think fgf is forrest gump forums. here's a link to the post.

http://www.takeforum.com/forum/viewtopic.php?t=5&sid=99...a&mforum=forrestgump

oh and fattywagonman, thank you so much for the posting of that. it's been a ginormous help!

thanks a lot this has been a great help. the stainless is proving to be a lot of trouble to drill out so i may have to go back to brass compresiion fittings. any one have problems with galvanic corrosion where the aluminum and brass are in contact? does it matter?