yeah that sounds right, its a 86.

 

I just put a 180 back in my LT4 after reading all the articles about how the 160 is harmful to the engine & throws the air / fuel ratio off.I swear the car runs better , idles smoother & runs right around 200 degrees.

 

Al:

Thanks for the info and the article. Am continuing to resolve the dilemma that has affected the 383. Almost the entire air pump assembly i.e.,switching and check valves have been replaced. This helped the integrator numbers however the BLM numbers continue to show a lean mixture. Will get in touch in the near future.

Rich

 

thats because 180-200* operating temps for coolant and 200-220* for oil is ideal for a daily driver.

 

Good, I thought I read you had an 85

Behind the alt between 1&3 is a switch(sensor) in the head between the 2 plugs - that is the one that 65Z01 was referring to -

I have on the is supposed to be 200 on 185 off - my gauge shows it comes on at 185 and off just below 170 -
I have a 180 stat - the fan switch could be seeing the 200 but the temp sensor is giving me 185 reading - and it is consistant.

Thinking that you only have the one fan, wothout looking at the helms -
If you have the fan switch by #1&3 I would think the guy had put it in to lower the fan temp, and not have the chip changing the temp.

That fan switch was intended for the aux fan and the main fan was controlled by the prom chip.

 

yes i only have one fan. if i have the switch for the fan between 1 & 3 then i could just swap it for a higher temp one. what would be good combo with a 195 stat? if its that easy i could put a higher one in for winter and lower one for summer and emissions tests, i would think the hotter engine temp may help burn fuel better?

 

Thanks for the article. Will digest and wrench on....

62k

 

The vehicle in question is an 85-383.

 

Those with "conventional flow" cooling systems like the L98 should ignore this post.

Quote from the linked article above:
"There is a range where both optimum performance as well as minimal wear share similar characteristics. That number lies in the 175-180 degree range as shown by the overlap in the chart which correspondingly requires a 180 degree thermostat. "

When warmed up with a 160 degree thermostat, the lowest "block" temperature (in the winter) my LT1 runs is 172 degrees. Most of the time my LT1 block temperature in Florida is about 185 degrees with a 160 degree thermostat due to reverse flow. The heads, however, are lower in temperature.
So, according to the article, I am very close to the "optimum performance with minimal wear" area with a 160 degree thermostat.

In addition, I should point out I have AFR heads. And, I noticed a higher temperature with AFR heads vs stock heads. So, I am not sure how this would affect "block" temperature with OEM heads....it may be too cool.
But, for my application, the 160 degree thermostat is almost ideal.

Tom Piper

 

Holy cows on a cold start at 10 degrees you would destroy the engine immediately??????

[IMG]
http://www.carnut.com/ramblin/img212.gif[/IMG]

 

Neat curve, but who did this test???? Many unanswered questions, type of oil, was condensation present, environment of test, rpm, etc

Despite the many statements that the danger of using a 160 stat is well documented I am still skeptical.........

One real problem is if you don't go into closed loop operation......oil viscosity could be, but my opinion is that is not a factor with high quality synthetic.....

OK crucify me, I expressed an opinion rather than documented fact...

But for now I am sticking with a 160 stat, but will always

 

If you have only one fan, it is not controlled by a switch, its controlled by the ECM.

Only the auxiliary is directly controlled from a switch, it is in front of the radiator.

 

Lt4bud, Continental Motors tested some engines at coolant temps from 160 to above 180 and found 160 caused lower hp, more cylinder wear, lower fuel economy and the opposite with increasing coolant temps. Three CF members changed stats to a 160 during dyno runs and found no difference in HP. From a number of oil companies, wear charts have been posted in the past on C4 tech and 160 coolant temp is shown increasing cylinder wear. Use the search function.

 

i am creating a system with dry ice that will get my operating temperatures down to 120 degrees sitting in traffic in phoenix arizona while the outside temp is 110 degrees.... since this entire forum is obsessed with getting the lowest temperatures available, this will be a big seller...

i still may be new to this, however i do not see any reason why the factory settings and running 215-220 or 230 in traffic is so wrong for the car. i have had no problems whatsoever.

 

Thanks for your response .....I just tried the search engine and I found your reference to Continental Motors, but couldn't find a link to the actual test report?? Ditto on any other actual test data or report?? I would really like to know what is best for my engine, if 160 is wrong I would certainly change to the best.......

 

I am wondering just how cold the ambient temperature would have to be to have operating coolant temperatures stay at 160 degrees. I live in South Florida and have a 160 degree thermostat. My operating temperatures are never below 195 at any time of the year. Summertime in stop and go traffic maybe 220. It seems to me it would be impossible to keep coolant temps as low as 160 regardless of the thermostat.

 

177 degrees is the coldest i've seen in a LT1 steady state with w 160 thermostat. I do alot of datamaster datalog reading from across the country.

177 coolant temp in a LT1 is probally around 185-190 oil temp

 

Even when I'm at home in SC for winter, it wont stay at 160.

The only time I recall having the coolant remain near 160 was on a short trip on the hwy in 25F temps. The thermostat was constantly opening and closing. Oil still got to 180 on that trip. I rarely drive the car when its that cold outside anyway. In Louisiana I'm in the same situation you have in Florida.

 

Partial quote:
I would really like to know what is best for my engine, if 160 is wrong I would certainly change to the best.......
________________________________________ ____________________

The thermostat that GM put in it. Except in winter, your 160 stat is wide open all the time, you might as well not even have one in it.

 

I must respectfully disagree with this. A 160 'stat will remain closed until the coolant reaches 160*F minimum. That's a huge difference from having no 'stat in the engine at all, which would cause delayed warm-ups.

I have a 160 'stat in my '94 LT1. The coolest it ever runs (open road, cool day) is 171 to 174, which is right about the "ideal" temp (from a cylinder wall wear standpoint) that was cited in the article at the link that appears in another post earlier in this thread. If I ran mine in the dead of winter (I live in Maryland), it might be a different story, but I don't.

If the ambient temp is hot, the engine runs in the 180 to 185*F range on the open road.

At idle, the temps will run up to at least the kick-on temps of my fans (which I've had reprogrammed to 190 primary, 195 secondary).

Considering all of this, it seems to me I'm doing just fine with the 160 'stat.

I also now enjoy much more headroom in my typical running temps before Really Bad Things happen. If I see my ECT rising above 210*F, I'll watch it like a hawk because that probably means something's going wrong, and I can get off the road before a meltdown occurs. I also think the soft parts under my hood (belts, hoses, gaskets, seals, etc) will last longer as the underhood temps are significantly lowered.

My oil temps typically run 10-20*F hotter than the ECT, so I don't worry about moisture accumulation in the oil. I just changed my oil, and saw zero evidence of sludging, foaming, etc of the oil that came out of the crankcase after thousands of miles. Remember, you don't have to boil water to make it evaporate.

I simply can't imagine that I'm causing significant premature wear on my cylinder walls by operating the engine at minimum ECT of 171-174*F, and I plan to stick with the current setup indefinitely.

YMMV, and it's your car. Do with it as you wish.

Be well,

SJW