Thread: Solutions for Custom Rad hoses

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Hello everyone,

Does anyone have advice on how to make custom rad hoses?

I have a tall deck 427 that is going into my 72 blazer. One problem I've come accross is that I will have to make custom rad hoses (upper and lower). I've looked at coolflex but their max hose size diameter is 2". My tall deck engine has the original intake manifold with a 2-1/8" water neck and uses the original water pump with a 2-3/4" inlet. These will hook up to the radiator's 1-9/16" upper inlet and 1-7/8" lower outlet. I can't change the water pump to one with a smaller inlet for several reasons (Bypass size ,pulley alignment ...etc)

Does anyone have suggestions of how I can make the custom hoses I need?

So far, I thought of using short straight pieces of rad hose for the inlets/outlets and getting custom bent exhaust pipe to go in-between but the guy at the exhaust shop I went to can't bend the pipe as tight as I need.
I've also looked through the rad hose inventories of several auto parts stores and nothing comes close. Especially the 2-3/4 inch requirement.

I'm sure that I'm not the only one who has had this problem.
Any other suggestions would be great,

thanks,

ottoman

Instead of exhaust tubing, try using copper plumbing pipe and fittings. You can get very sharp 45 and 90 degree bends and many different diameters. Also, it wont rust.

sells pre-bent 90*'s and 180*'s in stainless for building headers, that might work.

Plus it would be shiny!!!!

Your radiator inlet/outlet size don't sound right.....Crossflows of that era should have at least 2in necks.... If your radiator is only one or two core you need to install a larger one anyways for the big block.. Also there are radiator hose adapters made to increase neck size...

I would like to thank everyone who came up with suggestions.

I settled on using a 2-1/8 upper rad hose that went from the thermostat housing to within 4 " of the upper rad water neck (looked at a lot of hoses at the parts store). Then, with an exhaust reducer and 3" long short piece of smaller hose, I coupled it to the rad. (An idea I got from the coloradok5 website).

For the bottom, I went to the hardware store and found two pipe end caps for 1-1/2" and 2-1/2" standard pipe (I believe). When the end caps are reversed they fit snug into the hoses. I took a hole saw, cut openings in the ends of the caps, and welded them together. Along with a little grinding (inside and out) they worked well for a short reducer (2 inches). I could then put a 2" piece of 2-3/4" hose on the pump end and the regular lower hose on the other. The lower hose is rubbing the frame but I may be able to use a coolflex or something else to go to the rad.

I fired it up yesterday, ran it up to temperature, and everything held.

I'm sure the upper and lower rad hose inlets and outlets are correct because a few years back, I ordered rad hoses for that truck and they fit perfectly on the those rad outlets.

thanks again to everyone who responded,

ottoman