Cooling issue

[cuda hunter]

Built 440
Aluminum heads
Electric water pump
Electric fans

This is a track car.  The previous owner only used it 1/2 mile at a time.  1/4 down, 1/4 back.

I rarely get to take it to the track.
So I drive it around town here and there.

After driving it 20 minutes around town, slow speeds, at about 35/40 mph I had the lower radiator hose blow off.
Drove it home about 4 blocks. 

Radiator cap is 18 lbs. 

Replacing it with a 16 lb to start with to see if that was the problem.

Any of yal have any suggestions or thoughts as to why the lower hose would have blown off?

There is an after market catch can (that I hate) required at the strips. 
It was filled up and did not return the antifreeze to the radiator. 

I really don't want to have the radiator fluid just dropping to the ground or flowing along the body while I drive it.  Suggestions?

[cuda hunter]

Technically not a cooling issue as the gauges did not show that I was overheating.

[70 Challenger Lover]

I can't imagine that the radiator cap would make any difference in this case. It just sounds like it wasn't secure enough or that the clamp was positioned incorrectly. Seems to me if the hose is positioned properly and the clamp tight enough, that the hose would rupture before it blew off.

I had a 64 corvette with a closed system and a recovery tank. It was a pain to get all the air bubbles out so it would function correctly but the point I wanted to make was I ran a cap rated in the low 20s and never had a problem. The cooling system on that car worked much better with that higher pressure cap. So well in fact that I drove it through the desert in 118 degree heat. Car, no trouble but I was dying without A/C!

[cuda hunter]

Aluminum aftermarket radiator. 
It does not have the bulge around the flange like the original equipment has. 
I have double clamped it to see if that makes a difference. 

[70 Challenger Lover]

Aluminum aftermarket radiator. 
It does not have the bulge around the flange like the original equipment has. 
I have double clamped it to see if that makes a difference.

Ah, that could make a big difference. You could probably take it to a weld shop and have them put a thin bead around the outlet tip for small cost. I had an aluminum radiator with no brackets for a shroud and a local welded added them for like $25. I'd say radiator shop but they are about as rare as telephone booths anymore.

[HP2]

So the hose blew off the radiator nipple and not the water pump housing? IMO, 18# cap and a poor clamp position or tightness could definitely cause this. Dual clamps will certainly help with this. I have run pressure caps as high as 22# with dual clamps without issue on  radiators without a flange on them. Make sure the flange and hose are clean and dry to aid in sealing and prevent any sliding from the lost coolant.

Since this has a recovery tank, did it have the proper dual seal cap and did you replace it with a similar dual seal cap? This is necessary for it to properly vent and recover coolant with the recovery tank. Otherwise it will only puke it out and never pull it back in.

[cuda hunter]

Correct, off of the radiator nipple. 

@HP2 Do you know where I can read and view the difference of the two types of caps?

@70 Challenger Lover  Will have to consider welding a raised flange. 

[HP2]

Dual seal has the rubber on the disc on the spring as well as up inside the twist on cap.

Reading info here: https://partsavatar.ca/blog/engine-cooling/the-ultimate-radiator-cap-buying-guide/#:~:text=Single%20seal%20radiator%20caps%20are,the%20recovery%20or%20expansion%20tank.

[Bullitt-]

  I've seen TV shows where bead rollers were used on larger pipes.
Looking I ran across this video using wire crimpers just like I have
     https://youtu.be/uSSPpN3CGAY?si=1qjm19YPpp3CJkGl&t=83
 Think I could make a tool from an old pair of channel locks that would do better

[cuda hunter]

This is the radiator.

Griffin Thermal Products Radiators 5-571HC-BXX
Radiator, Barracuda 70-73, TL BR, 1.25", no add ons, 18 x 22 core

[Brads70]

I can't say I have much faith in that machined reverse bead. I'd say that is the cause of your issue. I agree...Get a bead welded around it?

[Bullitt-]

  Seeing that grove gave me an idea....cut the ends off a corbin clamp and slip into the groove before the rubber hose goes on

[YellowThumper]

I made a crimper using an old pare of vice grips.
Used them on my turbo plumbing. Not pretty but functional. Also doesn't need to be a smooth finish because function is only to eliminate slippage.

[cuda hunter]

With the nipple being cast aluminum, I don't think that crimping it would work to well. 

[Jay Bee]

If you used a Corbin clamp wouldn't it compress the hose into that groove?     Might keep it from popping off. Or, the hose clamp up on the flat portion and a Corbin clamp where the groove is.