sbc 355, 2:1 reduction, 78 " sesnich S series

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undicided
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sbc 355, 2:1 reduction, 78 " sesnich S series

Post by undicided » Tue Nov 15, 2011 6:08 am

its about 425 hp. running a electric water pump, 180 degree stat. put a new electric temo gauge and sensor from classic airboat and the temp gauge pegs out. when I do a temp check on outside of temp sensor in the head its reads 180 degrees. any ideas I cant figure it out. also what size radiator should I be running

Ruagatr
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by Ruagatr » Tue Nov 15, 2011 6:46 am

Sender or gauge is bad.
Last edited by Ruagatr on Tue Nov 15, 2011 7:40 am, edited 1 time in total.

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SwampCritter84
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by SwampCritter84 » Tue Nov 15, 2011 7:30 am

If tour running an electric water pump you can't run a 180 thermostat. You can't run one at all. You can put a restrictor plate in but this could be why its getting hot.
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SwampCritter84
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by SwampCritter84 » Tue Nov 15, 2011 7:31 am

If I'm not mistaken :dontknow:
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FLCGC4H2O
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by FLCGC4H2O » Tue Nov 15, 2011 7:40 am

The benefit of running an electric water pump is lost by running too hot. Extra heat kills. Either switch to belt pump, change t-stat and check your sender. It shouldn't take oversize radiator to cool that engine. Also check to see if you have any trash or debris in the coolant lines.
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by undicided » Tue Nov 15, 2011 9:38 am

swampcritter84 wrote:If tour running an electric water pump you can't run a 180 thermostat. You can't run one at all. You can put a restrictor plate in but this could be why its getting hot.
Spoke with proform your right have to run a high performance stat w holes on outer edges for constant water flow or run run a restrictor instead. I'll have to change it out

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SwampCritter84
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by SwampCritter84 » Tue Nov 15, 2011 11:55 am

Cool glad you figured it out
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by flying fish » Tue Nov 15, 2011 3:07 pm

You have a 180 stat, and you are seeing 180 degree temps at the head where the sender is mounted. If you are using a infrared heat gun to achieve this 180 degree temperature reading, and you are obtaining this reading where the temp sender is located in the head, your thermostat is not the problem.

If I have assumed right, your thermostat is doing it's job quite well. Also assuming thermostat is downstream of temp sender and hose down stream of thremostat (to radiator) is hot when getting this 180 degree reading at the head.

Still, your (new) temp gauge is pegged and your water temp is showing 180 degrees using another type heat gauge???

One .125 or one 1/8" hole is sufficient in the flat surface on your thermostat housing. JMO-
Keeps stat from slamming shut and slamming open. Makes themostat "More Active"

I would try a mechanical temp gauge before making any other changes.
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nomad41
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by nomad41 » Tue Nov 15, 2011 3:45 pm

Ok does it peg when you turn on the ign. ? if so its wired wrong. When it pegs and you know the temp. is 180. Discount the sender wire from the gauge and then what does it do? I'll bet its the sender. But thats my opinion.
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SwampCritter84
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by SwampCritter84 » Tue Nov 15, 2011 6:49 pm

All of this is very true but if his thermostat is not letting water in his sending unit is going to read the steam and pressure of the motor internally if I'm not mistaken. But yes he should check into the sending unit as well.
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filetnrelease
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by filetnrelease » Tue Nov 15, 2011 7:40 pm

X2 on what Fish and Nomad suggested. I personally don't care for the "electric" guages... although they are the most common choice of the factory(s). They use a varying resistance reading to determine where the gauge points and in my experience gives more opportunities for problems... but that's JMO based on my experiences.

BTW, Critter... the thermostat actually lets the coolant out of the engine and into the radiator to be cooled on the gen-1 SBC..
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SwampCritter84
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by SwampCritter84 » Tue Nov 15, 2011 9:41 pm

Wasn't trying to confuse anybody, just looking at all angles. Wasn't sure on the second part I posted, but I know your not supposed to run a thermostat with an electric water pump... At least that's what I've been told
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by cuncrt » Wed Nov 16, 2011 3:40 pm

Don't mean to hijack the thread, but why run an electric water pump as opposed to belt driven?
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watersports7
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Re: sbc 355, 2:1 reduction, 78 " sesnich S series

Post by watersports7 » Thu Nov 17, 2011 7:19 am

Electric pumps add a few HP since the pump isnt being spun off the crankshaft. Another benefit is coolant circulation without running motor.
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