Overheating problem

[petes32]

Need some ideas blokes got a 350sbc fresh rebuild in a angila replaced water pump,cleaned radiator,built a fan shroud,new thermo fan,15 lb cap, overflow tank,coolant 50/50,temp rises slowly to 210 whilst driving,then we shut it down,airflow prob?radiator is550mmx350 high old school copper,does not make any difference with thermostat in or not,starting to do my head in,maybe new radiator,higher flow water pump? Any ideas would be appreciated.regd Peter.

[Good Captain]

Have you got the engine sitting at right angle , if the front is low you will get air locks seen it happen before .

[petes32]

Motor at correct angle,radiator did burp after a quick run?air?

[blown36]

Any measurement of temp drop through the radiator core?

[cdansie]

Is the gauge reading correctly?
Have you used an adapter for the sender unit? Adapters sometimes place the sender unit out of the water flow and cause the gauge to read too hot.

Chris

[32coupe]

What size is your thermo fan?
I had a lot of overheating with a 14", all stopped when I fitted a 16".

[woody28A]

What size is your thermo fan?
I had a lot of overheating with a 14", all stopped when I fitted a 16".

Yep, and also look at the CFM of the fan. The higher flow rate will help.

[woody28A]

Need some ideas blokes got a 350sbc fresh rebuild in a angila replaced water pump,cleaned radiator,built a fan shroud,new thermo fan,15 lb cap, overflow tank,coolant 50/50,temp rises slowly to 210 whilst driving,then we shut it down,airflow prob?radiator is550mmx350 high old school copper,does not make any difference with thermostat in or not,starting to do my head in,maybe new radiator,higher flow water pump? Any ideas would be appreciated.regd Peter.

G'day Peter, couple of questions. Is the radiator new? You said it has been cleaned, has it been flow checked and flushed? With your measurements I assume the radiator is 550 high and 350 wide or is it crossflow 350 high and 550 wide?
You mention you have a fan shroud. do you have an engine fan as well as a thermo fan. Or do you have the thermo fan mounted on the front of the radiator? If so make sure its a pusher not a sucker. An engine side mounted sucker fan will work more effectively than a pusher, but if space is limited you don't have a choice.
Also leave the thermstat in and make sure its working and the the correct one. A higher flow waterpump may only add to your problems by not allowing the water to stay in the radiator long enough to effectively transmit its heat to the tubes and fins, thus rentering the engine at too high a temperature.
Just some observations from what you have posted. have fun.

[FRANK BASILE]

Also fresh rebuild could be slightly warmer due to bed in friction . Is it over bored to max or not ? Ignition timing and fuel mixtures correct ?
" Whilst driving " Is temp climbing with speed ? or climbing more than what you feel is normal at idle? Does it actually boil or just show hot on the gauge ?

[petes32]

550x350 downflow radiator flushed flow checked ,temp increases to 220plus when driving,no room for fan on engine side,fresh 383

[woody28A]

550x350 downflow radiator flushed flow checked ,temp increases to 220plus when driving,no room for fan on engine side,fresh 383

The 383 will generate a bit more heat than the standard 350 and as Frank said running in clearances will be tight etc. I wonder if the block needs a back flush?
Top radiator hose not sucking in or collapsing under suction pressure?
The radiator core size sounds small to me.I realize space is at a premium in a angliron. What is the core thickness and what are the number of rows etc.
If you don't have much joy, one of the guys in the Shifters has a angleiron with a small block, runs it at the drags etc, don't think he has any probs. I may be able to put you in touch with him.
Just a thought.

[pencil]

383 chev - what static compression.
Core size is really too small unless core is close tube pitch like a 8.4mm 58mm thick 3 row 20fpi.
Radiator should have had at least top tank removed for a proper cleanout.
You can try multi passing your current radiator.
As a comparison just think a hq Holden has a core approx 367h x 610w 3 row for a 308 std. If you compare your radiator surface area is approx 14% less with an increase in cubic inches of 24%. That is a net impact of 38%
Hope this helps, regards Richard

[petes32]

10-1 comp,top and bottom tank renewed core is 115 mm thick,no room for bigger radiator,

[pencil]

Sounds like an open fin style forklift core. Are you able to get hold of a airflow meter to check how much is actually passing through the core. If the fan is a pusher on the front it will need to have killer airflow.

[woody28A]

If the fan is a pusher on the front it will need to have killer airflow.

Definitely. By the sizing it will probably only be a 14'' fan. There are some high cfm 14" fans, but they seem to be hard to find. The pusher is getting too much resistance on a core of 115 mm.