Thread: New 350 ran 10 minutes - radiator boiled...

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Hey all,
I just fired my '68 Camaro for the first time tonight with the new crate 350. Build went smooth, timing went great (I'm usually 180* off), and it fired right up after I primed the fuel bowls. The idle was great, so I put it at 1500 RPM and let it run. About 10 minutes into my checks for leaks, charging, etc, the radiator started to boil over. I immediately shut it down, but the thing creaked and groaned and spewed for about five minutes afterward. I have a 180* stat in, and the upper hose was hot to the touch during my checks so I thought the stat had opened.

I need those who have more experience than me to let me know what to check first for damage, etc.

Thanks!

Check your bottom hose it may be colapsing. Also you got the right water pump???

Originally Posted by hobo

Hey all,
I just fired my '68 Camaro for the first time tonight with the new crate 350. Build went smooth, timing went great (I'm usually 180* off), and it fired right up after I primed the fuel bowls. The idle was great, so I put it at 1500 RPM and let it run. About 10 minutes into my checks for leaks, charging, etc, the radiator started to boil over. I immediately shut it down, but the thing creaked and groaned and spewed for about five minutes afterward. I have a 180* stat in, and the upper hose was hot to the touch during my checks so I thought the stat had opened.

I need those who have more experience than me to let me know what to check first for damage, etc.

Thanks!

after the stat opens you need to add a lot more water. if you just filled the rad. up , cranked the motor up and when the stat opened you didn't add anymore water then thats the problem.

Did you check the timing with a light?

You should never let a new engine idle prior to break in.
Vary the engine rpm: 1500, 1800, 2000, 2500, 2000, 1800, 1500, 1800, ...
holding each rpm 5-10 min.

You should have no parts damage if it was only hot a couple of minutes.

I always fill the systems through the block vs through the radiator.

If it boiled over that fast, I would have to suspect a head gasket problem. Do a cooling system pressure check. Your local Big-box parts store will loan you a tester.

Thanks CFFisher. I had to replace a lower hose that leaked, and the replacement doesn't have springs inside like the old one. Didn't think of that. As for the water pump, I had the guys at Lane Automotive pull one of the chrome Mr. Gasket ones off the shelf. (I thought being from Constantine you probably knew about Lane - I'm in Elkhart). Is there a way I can tell from the outside of the pump whether it is spinning the right way for my 350?

Thanks!

If there is a way I don't know it

before you start pullings heads and stuff off hobo, if you did not top off the rad. after the stat opened then its gonna run hot. if you did get it full of water after the stat opened, then you got other problems.

I agree with Mike, you didn't have it full of coolant.

Thanks guys. I didn't top it off, so I'll do that and I'll also see if I can put the springs into the replaced lower hose just in case it was collapsing. I just checked the catalog for the 1st gen camaros and the lower rad hose came stock with springs to prevent collapse.

The resources in this group are top notch. Thanks everyone...

Hobo

I also agree with mike