absolute minimum engine temp for safe running

dark_knight

dark_knight

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hey.. so after my td04 conversion, all is running well now, with my half rad from a toyota duet.. but i've been curious; what's the safest lowest engine temp for safe running..? since i have my rad fan override, i noticed in the past that even after the engine got warm and i let the fan run longer than necessary without my thermostat (as i was testing stuff), the ecu would throttle up (via the IACV) when the temp dropped below about 70.. which i presume would make perfect sense as the ecu is assuming a cold idle status.

so, for warm oil and coolant that's not overheating, what's the best temps to run both..? i'd say oil at 86 and coolant at 90..
what do you suggest..? :)
 
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Rev

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There are many ways to approach this question depending on engine condition and how you want to drive you new ' toy ' TD04 but I think this link tells you the ecu cold fast idle program finishes at 80deg C 176degF. That's what Toyota gives as an answer to the question regarding minimum water Temp. click...
 
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dark_knight

dark_knight

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my platform is a daily driver with the occasional boosting to scare senior citizens on the road side.. :) lol
i had previously drilled my thermostat to allow some coolant bypass even when shut but i guess i will need to revert to stock on it until i suffer overheating troubles..
 
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AdamB

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Oil temps will vary depending on what grade you use, what your climate is like and how you drive it, bit hard to say really, but somewhere in the region of 90deg-105deg, any higher I would be looking to run an oil cooler.
 
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AdamB

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20w50 is a good choice what brand? Whats your average ambient temp where you are? What does the oil temp get to when your going hard?
 
dark_knight

dark_knight

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i've been switching between shell and total oils -- i seem to prefer the shell oils more. when going hard, the highest i've seen my oil temps go is 98°.. and that was on a long stretch with full boost for stretches of at least 10~15 minutes at 0.9bar when i was still on the ct9. i guess my cooling circuit is super efficient because my coolant temps always keep my oil temps in check.. :)
 
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AdamB

Member +
You won't have any problems with them sort of temps mate and your using a good brand of oil in the Shell stuff.
 
dark_knight

dark_knight

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good stuff AdamB.. i flush my oil and element every 35 hundred km, not the 5,000 mark.. i guess that helps somewhat too.. :)
 
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Paul_JJ

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dark_knight said:
95°..? sure..? that's just for coolant, how about ideal oil temps..? i'm trying to get the best balance..
Click to expand...

I'm positive mate, it says in my manual book translated from Japanese. This is the ideal engine temperature for our cars. Just like I said ages ago, all you need is a TRD Thermostat and your engine temperature will be fine for your hot climate.
 
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AdamB

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Replacing the oil more often is never a bad thing, its just some peoples pockets feel it more than others.
The TRD thermo opens at 71 deg, I think others like the Sard also open at the same temp.
 
dark_knight

dark_knight

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hmm.. any daily drivers with a trd thermo here..? that sounds more like a track thermo setup. would it be ideal for daily driving.. maybe in my climate it would..
 
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Rev

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Definitely daily drive is different to track as Paul pointed out ,
Paul_JJ said:
I'm positive mate, it says in my manual book translated from Japanese. This is the ideal engine temperature for our cars.
Click to expand...

In other words Paul is pointing out is combustion temperature that will give power from best combustion and some headroom for preignition for daily drive. 90deg C water temp is actually a compromise temperature. The irony being a cooler intake charge will get more oxygen in the engine but once in the chamber hotter air is what you want. I have seen figures showing 33% more combustion pressure from 24.6degC temperature difference in unburt gas. If you run at 71deg compared to 90degC say off boost that is a 19degC difference. But of course a track car running full revs doesn't have that big a temperature difference.
 
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Rev

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You seem to have options for cooler temp these will depend on the limiting factor of your new smaller radiator on the hottest days and at highest boost. If you are not boosting high 90degs is a good optimum but boost is addictive.
 
dark_knight

dark_knight

Member +
most days are pretty warm at between 25~27° colder days will see anything from 18~22°. will sure need to run more tests on the smaller rad. for now, i'm at 0.6bar but want to notch it down to 0.4 until i'm sure all is well..
 
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Rev

Member +
Your gauge posts show you are well prepared to monitor temps. Some one with a tdo4l may comment better but I would think you will be running much higher boost for efficiency on your TD04L your climate temp seems managable boost temp will be the one to watch when you get above 1bar assuming you have fueling sorted.
 
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