Heavier Weight Oil ... Cooler Temps!

[SHOWYA]

I've always used 5-w50 Castrol Syntec as oil for my car. With the new setup the car ran hotter but that was also because of the way ive been tunning the car, running richer.

My radiator had a cow ... so i got a double core ... helped on the cooling.
Since the weather has been hotter i decided to switch to a thicker oil ... 10w40.
My pressure gauge shows a constant 20psi at idle where before it was 15. When running a little under 50psi and when running hard over 50psi. And it definetly ran cooler too. Temps seem to be more consistent than before. It will reach 210deg on stop and go driving. Performance/Race oil (20w50?) will probably be better for summer weather.

I beleive that the bumper is very restrictive on air flow. I wondered if a under plate to cover the gap between the bumper and subframe would force more air through the radiator ... a top radiator plate also.

I have been looking into modding the front bumper to improove cooling. I will post designs later.

Anybody else had experiences similar to mine as far as the weight of the oil is concerned?

 

[NJSHO]

What made you decide to run such a heavy oil to begin with?

 

[RICHARD ROWLEY]

Amsoil 5w30 works great. I removed the fog lights and a using ram air via pvc pipe to cool the engine on my 92 mtx. My 89 mtx ran much cooler than my 92 mtx.

 

[gmorrell]

I've always used 5-w50 Castrol Syntec as oil for my car. With the new setup the car ran hotter but that was also because of the way I've been tuning the car, running richer.

Richer A/F ratios run cooler, leaner A/F ratios run hotter.
******** timing runs cooler, advanced timing runs hotter.

Since the weather has been hotter i decided to switch to a thicker oil ... 10w40.

Once the oil temperature is at 100C, its operating at the higher viscosity number, so if you went from 50 to 40, you changed to a lighter (less viscous) oil, not thicker. The number preceeding the "w" is the cold (40C) viscosity.

At 100C, the typical 50 weight synthetic oil is nearly 50% more viscous then a 40 weight.

Redline Oil has a nice chart here comparing the properties of their various synthetic oils: http://www.redlineoil.com/pdf/4.pdf

 

[SHOtime2511]

maybe you should try a diffrent t-stat,210's pretty hott!

 

[SHOWYA]

maybe you should try a diffrent t-stat,210's pretty hott!

i have a 180 t-stat. It does run at 180 deg when on the expressway. but i think 210 is not bad since stock programming for a SHO will kick the fans on at 215deg. Correct me if im wrong

Richer A/F ratios run cooler, leaner A/F ratios run hotter.
******** timing runs cooler, advanced timing runs hotter.

I going to have to retard the timing at low rpm/load and see what happens.

thanks for the info!

 

[LeddZepp8687]

i have a 180 t-stat. It does run at 180 deg when on the expressway. but i think 210 is not bad since stock programming for a SHO will kick the fans on at 215deg. Correct me if im wrong



I going to have to retard the timing at low rpm/load and see what happens.

thanks for the info!

Yea, Low speed fans are kicked in at 215..IIRC

Maybe I should load up a stock programming and look...

 

[SHOtime2511]

i thought that hi speed was 215....i dunno though
what does 210 register as on the stock dash gauge?

 

[Axianator]

i thought that hi speed was 215....i dunno though
what does 210 register as on the stock dash gauge?

The factory '89-'95 MTX programming will enable low-speed fan operation at 216 DegF and turn it off at 192 DegF (per the readings that it receives from the ECT sensor). OTOH, high-speed fan operation on the '89-'95 MTX is determined solely by the EATC.

 

[TYSHO]

i thought that hi speed was 215....i dunno though

High speed is around 230 and kicks off around 224. Low speed kicks off around 210.

what does 210 register as on the stock dash gauge?

Usually between the O and R.


BTW, my car stays around 195-205 and I rarely hear the fans kick on [when I sit in traffic]!

 

[SHOWYA]

i thought that hi speed was 215....i dunno though
what does 210 register as on the stock dash gauge?

210 register on my aftermarket gauge.

So i guess 210 is pretty normal for the engine then?

 

[Axianator]

Low speed kicks off around 210.

Read my previous post, Brian - low speed kicks off at 192 DegF.

So i guess 210 is pretty normal for the engine then?

While it's warmer than is desired, 210 is often typical for a heat-soaked engine in stop-and-go traffic.

I assume you have tested your fan for correct operation (e.g. it kicks on at the proper temperatures)?

 

[yamahaSHO]

****, if I could keep it at 210 on track, I'd be happy.

 

[SHOWYA]

Read my previous post, Brian - low speed kicks off at 192 DegF.

While it's warmer than is desired, 210 is often typical for a heat-soaked engine in stop-and-go traffic.

I assume you have tested your fan for correct operation (e.g. it kicks on at the proper temperatures)?

I do have it to kick on at 195 (not sure) and off at 180. Maybe i should have it sooner maybe 190 so it wont get to 210 that easy. But yes ... its only in stop and go traffic.

****, if I could keep it at 210 on track, I'd be happy.

So far as i been testing the car when dataloging i been at around 190-200deg ... punch it and get in triple digits on speed and will see the tempeture drop very quickly. It will go up after driving normally after a few minutes.

I think i will retard the timing. I will maybe even save on gas if i do so.

 

[yamahaSHO]

Track conditions do not equal freeway conditions. NA does not compete with boost. My heat issue was not a problem on the freeway either

 

[tracy_s_1993_atx]

I also installed an aftermarket temp gauge to watch the temps of my SHO. With a stock thermostat:

At idle A/C off: Fans on at 224, off at 218
At idle A/C on: temp never gets above 195

Stop and go traffic with A/C on: 195 - 205

On the highway temps stay around 205 - 210 depending on the outside temp. When the temp outside gets around 100, the temps go into the 220 range, but never above 225.

I have a new stock radiator, new rev b thermostat and the green stuff with water wetter.

So I guess that these are okay for a 120k mile SHO?

Later,
Michael

 

[SASHO91]

With my setup (Dual Core rad., 180* tstat, no condensor)
Highway with temps at 100---190-200 (210 after a hard pull but drops back quick enough though)
highway with temps at 80-----187-195
around town with fan on temp 100-------185-190
town with temps 80-------same

I want to cut some "grills" into the stock radiator shroud for highway cooling purposes.

 

[NotSoSlowSHO]

Im SOO glad setting the fan kick-on and kick-off temps is as easy as it is with the TWEECER.

I never see temps above 200.

Kick on at 195, off at 180.

 

[SASHO91]

can you cancel the fan off@45mph thingy.... i wish it would stay on at highway speed, just on low though...

 

[NotSoSlowSHO]

Im not sure, but I wouldnt want to anyhow. Having the fans turning at highway spweed would probably be more of a negative than anything. Id see the fan as a restriction at those speeds.