Is Your Chevy Engine Running Hot?

[vintageracer]

I have noticed lately that the Special High Performance 307 2 BBl engine with a Powerglide Transmission in my 1970 Chevelle Convertible was running hot on the interstate at speeds over 80 MPH. I decided to see what the problem was.

A quick check of the cooling system revealed that the lower suction radiator hose did not have a spring installed in the hose to prevent the hose from collapsing under higher speed and water pump suction.

No big deal, just buy another hose! Yes it is a big deal. I checked Goodyear Brand, Gates Brand hoses, hoses from Napa, Advanced, Carquest, Autozone and more. NONE of the curved/formed hoses had the sping in the hose. This was always installed in the past. The only hose available that would not collapse was everyone's favorite, the Flexible hose since they have a wire wound into the exterior of the hose for support. I hate the look of those hoses so that was not an option.

Fortunately I was able to scratch around the shop and find an old lower radiator hose with the spring still installed. I have kept these hoses in the past for just such an occasion.

If you are having cooling issues, particularly at higher engine speeds or with interstate/highway driving, with your old style Chevy engine (non reverse cooling flow), look at the lower radiator hose. Check to see if the large spring is installed to prevent the hose from collapsing under suction. There is a good chance that the lower hose may not have the spring installed if the hose has been replaced anytime in the recent past. Apparently the current supply of NEW hoses that are available do not include the spring and the parts stores do not stock the spring as a separate part. The spring needed for the lower radiator hose may now be a junkyard only available item!

Just a heads up for the rest of the summer driving season!

[megaladon6]

i've been wondering why i can't find one with a spring. though mine only gets hot if i hit the gas hard, then back off and repeat. i think it's just that i have a stock radiator and there's too much restriction for large changes in flow.

[vintageracer]

Still could be the hose collapsing due to the suction. Do you have a spring in your bottom hose?

[megaladon6]

sorry that's kinda what i meant, but didn't say. i think the radiator isn't flowing quite fast enough, causing the bottom hose to collapse. i've been trying to find one with a spring, but no luck.
like i said, it's only with rapid throttle changes, and it cools off pretty quick after i ease up.

[Bill Howell]

I thought all old chevys had LS1 motors in them now????

Special High Performance 307/2barrel..........

[streetk14]

I thought all old chevys had LS1 motors in them now????

Special High Performance 307/2barrel..........

Sometimes seems like it in out world. Funny stuff........

[shmoov69]

thanks for the heads up!! I had to put one in my upper because it was collapsing too. What would cause that??

[springman]

If finding a hose spring is really an issue, let me know. We can make them for you.

Todd