Flex Heater Hoses

[Trochu]

An issue most of us probably have, finding premolded heater hoses. I've looked into using flex hose and have come to the following conclusions:

Pros:
-Easy; and,
-Cheap.

Cons:
-Depending upon your view, may not look as nice;
-Could restrict flow depending upon which type of hose you use (some have the wire/spring indents inside which restrict flow); and,
-In rare cases, may cause your inlet/outlet on your rad to crack as the hose will be constantly "pushing" on it.

What I typically read, is that given the wide range of automotive applications currently available, bend a coat hanger to the shape you need and then go to your local auto shop and your almost guaranteed to find the shape you need. Well, I went to six different shops looking for a simple 180 bend to eliminate the heater core for my project and walked away empty handed. I then ended up paying $25.20 and ordered one online. I kinda suspect this is an issue most Canadians have that most US builders don't. Seeing as a little 6", 180 bend heater hose cost me $25.20, I can only imagine what I'd end up paying, and how many stores I'd have to visit, before I found heater hose for the rad.

I don't know alot about the flex hose as I've never actually used them. Anyone know if once bent, it somewhat retains is shape and if the stress cracks on the rad inlet/outlet are actual concerns? I don't know if I"ll really care about the appearance, as the hoses won't really be visible unless I take the nose cone off.

[botbasher]

You can always go prowl the bone yards and find donors. I have found brand new hoses on cars there (owners fixing before ditching). At min, you get a great selection of models and VIN and can then take that to the parts store and get your parts there.

Since my donor was FWD, I'm planning on some short silicone couplers with a nice selection of copper pipe (generously donated scraps from work) to run the side facing outlets to my front mounted radiator. I may hit you up for the source of that 180 pipe, my lower outlet is giving me fits trying to turn it around!

K "tubular" S

[1055]

Gates makes a phenomenal product called the "vulco flex II". I have used it on a few projects before, and it works wonderfully. Is available in a ton of lengths, and diameters and different sized diameter ends as well. My only piece of advice about it is to order it two inches longer than you need.



Also, I'm not sure if they still sell the vulco flex I, but the I came without the internal metal spring, making it prone to kinking. The II is a little bit stiffer, and has the internal spring in it.

[botbasher]

Gates makes a phenomenal product called the "vulco flex II"

Never heard of that one before, but Jegs, Speedway and WalMart all sell it. Can't be too bad!! Guess I never really looked outside of stock hoses before!

How tight a bend can you make with a 32mm (1.25") hose, do you recall? Does it compress (accordion) well? It goes from 19" right to 26" (1.25" size). Doesn't appear to have very incremental sizes (least on Jegs).

Maybe I'll ditch the copper??

K "hosed" S

[davew]

It would be a little more work, but I've use pre-bent header tubing to fit between fan belts on a mid-engine build. Just use 4 or 5" of hose at each end. Plus you can weld a mounting tab(s) mid-way to hold it in position. Dave W

[turbo_bird]

I figured out roughly what bends I'd need for each hose, than went to Canadian Tire and talked the guy behind the counter into letting me go look at what they had. I found some that looked about right, then cut the bends out that I needed and joined them with sections of exhaust pipe. I managed to get things close enough that I have a single straight piece in each rad hose.
Kristian

[bob]

I have the gates catalog in paper form but this looks nearly as useful.

http://www.gates.com/~/media/files/gate ... .pdf?la=en

[1055]

Gates makes a phenomenal product called the "vulco flex II"

Never heard of that one before, but Jegs, Speedway and WalMart all sell it. Can't be too bad!! Guess I never really looked outside of stock hoses before!

How tight a bend can you make with a 32mm (1.25") hose, do you recall? Does it compress (accordion) well? It goes from 19" right to 26" (1.25" size). Doesn't appear to have very incremental sizes (least on Jegs).

Maybe I'll ditch the copper??

K "hosed" S

Well; I haven't ever used it in anything less than 1.5" ID, so I can't really comment on anything smaller than that. Its stiffer than you would expect, and compresses (accordion wise) Fairly well, though not as much as you would expect. in the 1.5" ID, a 90* bend requires ~3" of space. I have the benefit of working in industrial distribution, and order it right from Gates now. Prior to that, I always ordered it off ebay, as it seems that different retailers have different sizes available, and they all culminate in one large pile on ebay. A quick glance shows that they have sizes from 8.5" length all the way up to 30".

Dayco makes a similar product, but it is not nearly as thick - and kind of disappointed me quality wise.

[Trochu]

Well; I haven't ever used it in anything less than 1.5" ID, so I can't really comment on anything smaller than that. Its stiffer than you would expect, and compresses (accordion wise) Fairly well, though not as much as you would expect. in the 1.5" ID, a 90* bend requires ~3" of space. I have the benefit of working in industrial distribution, and order it right from Gates now. Prior to that, I always ordered it off ebay, as it seems that different retailers have different sizes available, and they all culminate in one large pile on ebay. A quick glance shows that they have sizes from 8.5" length all the way up to 30".

Does it hold its shape at all or just spring back to straight as soon as you let go? I'm assuming it springs back, but a moldable hose would be pretty sweet.

I may end up trying Kristian suggestion first, Dave's suggestion second, and use this as a fall back.

[1055]

Well; I haven't ever used it in anything less than 1.5" ID, so I can't really comment on anything smaller than that. Its stiffer than you would expect, and compresses (accordion wise) Fairly well, though not as much as you would expect. in the 1.5" ID, a 90* bend requires ~3" of space. I have the benefit of working in industrial distribution, and order it right from Gates now. Prior to that, I always ordered it off ebay, as it seems that different retailers have different sizes available, and they all culminate in one large pile on ebay. A quick glance shows that they have sizes from 8.5" length all the way up to 30".

Does it hold its shape at all or just spring back to straight as soon as you let go? I'm assuming it springs back, but a moldable hose would be pretty sweet.

I may end up trying Kristian suggestion first, Dave's suggestion second, and use this as a fall back.

brand new, they spring right back. but it all depends on time and heat. I've found that over time, they will form to what shape they are held in. I jumpstart this process with a heat gun, zip ties and a half hour of my time. Its boring, but I feel better about any stress that I may put on the inlet/outlet of coolant system afterwards.

[Miatav8,MstrASE,A&P,F]

DOM or steel pipe, bent/welded to whatever shape you need, transitioning to at least 3 inches of hose on the ends, more for the end that goes to the core. You can weld tabs to bolt it directly to the engine or use clamps.

Thinking about rust? Most engines have a bare cast iron water jacket. I suppose you could powder coat the dom after fab without it being removed by hot glycol. Oems have used thin-walled steel tubing in this manner. The corrosion problems have been external.

[bob]

DOM or steel pipe, bent/welded to whatever shape you need, transitioning to at least 3 inches of hose on the ends, more for the end that goes to the core. You can weld tabs to bolt it directly to the engine or use clamps.

Thinking about rust? Most engines have a bare cast iron water jacket. I suppose you could powder coat the dom after fab without it being removed by hot glycol. Oems have used thin-walled steel tubing in this manner. The corrosion problems have been external.

The way to go. This is my preferred method, run antifreeze/rust inhibitor and you wont have a problem. The Dayco/Gates convoluted hoses with the internal springs in will rust to nothing if you dont run an inhibitor as well.

Bob

[Miatav8,MstrASE,A&P,F]

I forgot to mention the Westfield, which has plenty of steel tubing for coolant routing, including the heater.

[rx7locost]

Thinking about rust? Most engines have a bare cast iron water jacket. I suppose you could powder coat the dom after fab without it being removed by hot glycol. Oems have used thin-walled steel tubing in this manner. The corrosion problems have been external.

Agreed. Except I don't think the powder coat is necessary. The last water pump I replaced had heater hose nipple that was simply a steel tube, maybe 18 ga, that was epoxied into the cast iron. And a plate of steel forming one wall of the impeller on the back side, maybe the same gauge. (GM 4.3L V6) Both the nipple and plate were only zinc plated.

[Miatav8,MstrASE,A&P,F]

I didn't suggest it was necessary. I'm just curious if internal powder coat would hold up or contaminate/clog anything.