I was asked a question and got me started to thinking about it very in depth. My uncle is a mechanic and says a 195 degree thermo is standard and should be kept on the car so the coolant can have the right air/fuel mixture so the computer will not mess up. I am aware the computer does most of the controlling for a fuel injected engine. What I am unaware of is what if I want to change to a 180/170/160 degree thermostat?
What would I have to do to make sure everything checks out and I have no issues with it. In respects to that nature I was told by a third party that coolant helps but the thermostat can only do so muh when it comes to keeping 305 engines cool.

My main question which I sort of know the answer to but want verification from experts and people that know alot more about the type of engine I am using and trying to replace.

The main question is about the coolant issue for the 305 TBI as well as what do I need to keep my engine at around 165 to 170 degrees all year round no matter how hot it is outside. I was told that keeping the radiator fan on all the time would help but to me that isnt enough.

Please help me with answers, I want to know what I need before I go pick up my engine for my car and have everything setup for it.

Thanks guys/girls

Mike

 

Alright I'll take this one because I did a load of searching when I was going to change my thermostat. It is true the computer has alot to do with cooling, mostly the temperature at which the fans are turned on. Basically you wouldnt want to sink below a 180, (170 pushing it) thermostat because the computer still is telling fans to turn on at 210 I beleive which is more in conjunction with the 195 thermostat rather than a 180. It also has alot to do with your car not heating up properly in the cold/heat (cant remember which it is). Basically your safe to go to 180 without changing the computer. Anything lower I would get a new chip.

 

Thank you r0nin89, I just wanted to make sure and I am going to buy it for the engine I purchase, the overheating issue caused my engine to pop the radiator hoses AND burn up the engine. The guy I bought the car from did not tell me the fan was broken and the water temp gauge was over 250 and I thought the gauge was broken. I made two mistake which will not happen again.

Thanks a bunch

 

just remember that the thermastat only controls minimum operating temperature and that the temp rating indicated the temperature that it starts to open and not the temperature that it is fully open at.
ex: a 195 thermastat starts to open at 195 and is fully open at about 210-225 its usually about a 15-30 or so difference. and installing a lower temp thermasta is not beneficial really because it does not provide the proper restriction of coolant flow so although your temp gauge may say for example 190 or whatever thats only the temp of the coolant and not the temp of the engine. so the engine block itself can actually be much hotter like around 240 for example and that is much to hot for the block.

so baisically if the coolant is allowed to circulate to fast it cant absorb enough heat from the engine and you start having issues like hot spots developing as well as pre-ignition and detonation and excessive carbon buid up.


you also need to tune your fans to tthe new lower thermostat if you want to get the most out of it.

 

So if I have the radiator fan set always on, the coolant would recirculate and keep the engine block cool, correct?

 

The thermostat is the restriction in the cooling circuit.

Put a 180 in, get a lower temp fan switch, and call it a day.

 

i know the thermostat is the restriction, but what im saying is that a low temp thermostat opens earlier and than doesnt provide the proper restriction because it is wide open. and i agree with the lower fan switch but the majority of people i see here just change the thermostat and not the fan switch as well so i am saying that it is not really beneficial to just change to a lower temp thermostat.
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i think its better to have the fan work properly. not only does it save the fan and give it a longer life but it gives you peace of mind so you dont have to remember to turn it on. if you get a new fan switch make sure that the thermostat starts to open like 10-15 degrees or so before the fan turns on.

but yo answer your question with the fan always on the coolant will be allowed to circulate and will be cooled all the time.

 

Thank you, and I found that advance auto near me carries the hypertech fan switch for 180 degree thermos and I am getting it when I get my engine. I found one in roanoke va for 550 (not sure how many miles but its a deal)

 

Forgetting the ECM and the fact the bores would wear more rapidly a 160* would be ideal. But that is for a race engine. 170* is what I put in everything that I own. Even my vortec has a 170*.

 

Fast...........what fan temps do you have the EBL setup for with a 170* t-stat?

 

On @ 85* C or 185*F
Off @ 80*C or 176*F

In reality the fans almost never run, except with the A/C on, and then only under 38 MPH. When they run it is usually for only a short period of time. I have yet to see a datalog get much over 175*F.

Edit-oops, forgot part of this post.

 

Thanks Chris. I might try a 180* instead of my 195*. Even my oil temp seems to have skyrocketed lately.

 

Thats kewl, let me know what the results are, I need to get my engine first so I can atleast get it on the road. I just need to find a place that will sell one for a reasonable price. Let me know if anyone around richmond might have one, I got 2 more weeks before I can purchase one. I have to wait till I get my check from the just I just completed.