Engine temps vs. wear - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 12-10-2013, 04:24 PM   #1
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default Engine temps vs. wear

So I am curious on theories for engine wear vs oil temp vs coolant temp.

Currently I am running a no T-stat reroute and an oil cooler on the car. Generally speaking on track my oil temps will get up to 190-ish, while coolant temperatures will run between 120-180 depending on the track and speed.

should I be worried about engine wear if my coolant temps are running low, even though oil temps are normal? I am assuming oil temp is a pretty good indicator of bearing temps, and coolant is probably more accurate for piston/cylinder walls, etc.

what do you guys think?

Also, what do you guys think about methods of blocking off the mouth of the car? does one method work better than another? for example taping off the outside vs. making a block off plate directly in front of the radiator?
Seefo is offline   Reply With Quote
Old 12-10-2013, 04:32 PM   #2
Senior Member
 
Join Date: Sep 2013
Posts: 903
Total Cats: 59
Default

I told you over this weekend that operating the engine below 170F or so will greatly increase piston ring wear and that you'll wind up killing a few orders of magnitude for "cycles" (like 10^6 vs 10^9). I know just enough to get me into trouble when it comes to material science/engineering, so I'm hoping that a few guys come in and drop some knowledge bombs.
Dunning Kruger Affect is offline   Reply With Quote
Old 12-10-2013, 04:33 PM   #3
Elite Member
iTrader: (2)
 
Join Date: Aug 2012
Location: Indianapolis
Posts: 3,325
Total Cats: 235
Default

Quote:
Originally Posted by Track View Post
Also, what do you guys think about methods of blocking off the mouth of the car? does one method work better than another? for example taping off the outside vs. making a block off plate directly in front of the radiator?
You'd probably have to run a bunch of CFD sims to know for sure, but my guess is that the difference in drag in blocking off the mouth vs the rad will negligible. I don't see why one way would be more or less effective as the other as far as cooling (or lack thereof) effect.
thenuge26 is offline   Reply With Quote
Old 12-10-2013, 04:55 PM   #4
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Quote:
Originally Posted by Dunning Kruger Affect View Post
I told you over this weekend that operating the engine below 170F or so will greatly increase piston ring wear and that you'll wind up killing a few orders of magnitude for "cycles" (like 10^6 vs 10^9). I know just enough to get me into trouble when it comes to material science/engineering, so I'm hoping that a few guys come in and drop some knowledge bombs.
bish please, I took the same class. lol.
Seefo is offline   Reply With Quote
Old 12-10-2013, 05:48 PM   #5
Elite Member
iTrader: (1)
 
Leafy's Avatar
 
Join Date: Jun 2012
Location: NH
Posts: 9,093
Total Cats: 90
Default

Quote:
Originally Posted by thenuge26 View Post
You'd probably have to run a bunch of CFD sims to know for sure, but my guess is that the difference in drag in blocking off the mouth vs the rad will negligible. I don't see why one way would be more or less effective as the other as far as cooling (or lack thereof) effect.
If the ducting is sealed, blocking the rad vs blocking the mouth is negligible, high pressure in the mouth from blocking the rad will act like blocking the mouth.

The easier solution to this problem is to install a thermostat.
Leafy is offline   Reply With Quote
Old 12-10-2013, 08:00 PM   #6
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,107
Total Cats: 518
Default

Save time, install thermostat.

Post #3:

optimum coolant temp for longevity • Speed Talk
curly is offline   Reply With Quote
Old 12-10-2013, 11:40 PM   #7
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

sounds like a headache dealing with a t-stat in the back of the engine. what do you guys do when you need to replace it? is there a way to add a t-stat to another location?
Seefo is offline   Reply With Quote
Old 12-11-2013, 01:11 AM   #8
Junior Member
iTrader: (1)
 
Join Date: Apr 2012
Posts: 187
Total Cats: 3
Default

if you have the m-tuned reroute, the t-stat is in line so you can place it in a more accessible spot.
motormechanic is offline   Reply With Quote
Old 12-11-2013, 01:19 AM   #9
Elite Member
iTrader: (1)
 
Join Date: May 2009
Location: Jacksonville, FL
Posts: 4,682
Total Cats: 216
Default

This stuff has been studied countless times for roughly a century. There is no mystery.
There is a good relationship between ECT and cylinder wear. The difference between 140F and 180F is probably a factor of 2 or 3 times the wear.
Full_Tilt_Boogie is offline   Reply With Quote
Old 12-11-2013, 01:41 AM   #10
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

Quote:
Originally Posted by Full_Tilt_Boogie View Post
This stuff has been studied countless times for roughly a century. There is no mystery.
There is a good relationship between ECT and cylinder wear. The difference between 140F and 180F is probably a factor of 2 or 3 times the wear.
yea probably. I am not too familiar with engines. but i am learning. I think the confusion for me was really about which is important, oil or coolant temps. it seems both are. There is plenty of bitog discussions on this, but those discussions generally led to the conclusion of "oil temps are more accurate measurement of engine internals". This led to me "not caring" about coolant temps, until Mr. Dunning Kruger and I discussed it at chump this past weekend.


So, is the suggestion to buy an inline t-stat housing? In that case, the gutted t-stat in the back of the engine becomes useless (so I should remove it the next time the engine is out)?
Seefo is offline   Reply With Quote
Old 12-11-2013, 08:46 AM   #11
Elite Member
iTrader: (17)
 
Join Date: Aug 2007
Location: Fort Myers, FL
Posts: 2,791
Total Cats: 130
Default

Do you expect to have regular issues with the thermostat going out? I know they will die occasionally, but in the 15 years I've been driving I've never had one go out. I wouldn't think it's really a wear item that you'd expect to be replacing regularly or anything.

Even if it does go out, or you want to replace it as a preventative measure, getting to it on the back of the head isn't so difficult that it's worth being concerned about, IMO.
pdexta is online now   Reply With Quote
Old 12-11-2013, 09:55 AM   #12
Cpt. Slow
iTrader: (25)
 
curly's Avatar
 
Join Date: Oct 2005
Location: Oregon City, OR
Posts: 12,107
Total Cats: 518
Default

Yeah, my 160f never failed in 5 years (drivability sucked), so when I finally replaced it with a 180f unit, the trick was taking off the three PPF bolt on the back of the transmission and jacking it up there, which pried it away from the fire wall. Worked like a charm.

COPs help too, which give you a little extra room.
curly is offline   Reply With Quote
Old 12-11-2013, 05:57 PM   #13
Junior Member
iTrader: (2)
 
Join Date: Nov 2013
Posts: 90
Total Cats: 5
Default

Quote:
Originally Posted by Track View Post
sounds like a headache dealing with a t-stat in the back of the engine. what do you guys do when you need to replace it? is there a way to add a t-stat to another location?
Weigh number of times you'd swap a thermostat vs. I've ran into issues running a thermostat AND being overcooled in the Pacific Northwest. Had I gone more prepared I would have brought something to block the rad as well.
Raisin is offline   Reply With Quote
Old 12-11-2013, 06:18 PM   #14
Elite Member
Thread Starter
iTrader: (5)
 
Join Date: Dec 2010
Location: Raleigh, NC
Posts: 1,970
Total Cats: 49
Default

dunno, t-stats seemed like a once every year or two item (to me initially), but with everyone else it seems much longer. So if they do last longer, I am sure you will pull the engine out atleast once every few years.

I think if I was running enduros I would probably run an inline or a gutted t-stat. With that said, I am going to try curly's suggestion and see if that works well for replacing it.
Seefo is offline   Reply With Quote
Old 12-12-2013, 09:22 AM   #15
Elite Member
iTrader: (2)
 
fooger03's Avatar
 
Join Date: Jan 2009
Location: Columbus, OH
Posts: 4,132
Total Cats: 187
Default

What kind of thermostats are you using? Do they have "slick 50" stamped on them? I've never had a problem that was fixed by replacing a thermostat - I have replaced many thermostats, using different temperature ranges, different flow-through hole sizes, etc., and they have never fixed the problems; they have only ever shifted the symptoms. I know of *one* person who has had a thermostat fail on them *one* time.

Thermostats really are the one good *solution* to thermal issues with your engine and cooling system; they are rarely, if ever, the problem.

Engines love thermostats; get that engine a thermostat.
fooger03 is offline   Reply With Quote
Old 12-12-2013, 12:30 PM   #16
Junior Member
iTrader: (2)
 
Join Date: Nov 2013
Posts: 90
Total Cats: 5
Default

Quote:
Originally Posted by fooger03 View Post
What kind of thermostats are you using? Do they have "slick 50" stamped on them? I've never had a problem that was fixed by replacing a thermostat - I have replaced many thermostats, using different temperature ranges, different flow-through hole sizes, etc., and they have never fixed the problems; they have only ever shifted the symptoms. I know of *one* person who has had a thermostat fail on them *one* time.

Thermostats really are the one good *solution* to thermal issues with your engine and cooling system; they are rarely, if ever, the problem.

Engines love thermostats; get that engine a thermostat.
Lol @ the slick 50 comment. I know there have been reports of some of the Stant ones failing. I had a thermostat fail closed once which is pretty rare. For reference I had been using the same OEM Mazda tstat for about 5 years until it failed.

Usually they fail open but in the event that the car overheats, the wax element inside the thermostat can get stuck closed and you'll see temps starting to climb.
Raisin is offline   Reply With Quote
Old 12-12-2013, 12:31 PM   #17
Junior Member
iTrader: (3)
 
Join Date: Apr 2010
Location: South Bay, CA
Posts: 354
Total Cats: -2
Default

Quote:
Originally Posted by fooger03 View Post
Thermostats really are the one good *solution* to thermal issues with your engine and cooling system; they are rarely, if ever, the problem.
This. Depending on if you have a heater core in the car still, look into how to route coolant piping without a heater as well. This might cause issues if not done properly.
comradefks is offline   Reply With Quote
Old 12-12-2013, 06:17 PM   #18
Moderator
iTrader: (11)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 15,673
Total Cats: 1,561
Default

Attached Thumbnails
Engine temps vs. wear-cylwallwearvstemp_640x480.jpg  
sixshooter is online now   Reply With Quote
Old 12-13-2013, 02:08 PM   #19
Senior Member
iTrader: (6)
 
Join Date: Jun 2010
Location: San Rafael, CA
Posts: 1,125
Total Cats: 41
Default

Good timing for this thread. I have not been running a thermostat and just replaced my motor with a stout build. New thermostat is on the way. Do most of you guys run 180's?
k24madness is offline   Reply With Quote
Old 12-13-2013, 02:45 PM   #20
Elite Member
iTrader: (2)
 
fooger03's Avatar
 
Join Date: Jan 2009
Location: Columbus, OH
Posts: 4,132
Total Cats: 187
Default

180 or 190 here - put a 160 in at one point to try and correct problem; the engine and oil simply warmed up more slowly, and the problem remained unchanged. 180-190 is probably the sweet spot.
fooger03 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 12-13-2017 10:04 PM
Changing from 460cc to flow force 610cc in diypnp 90 Turbo MEGAsquirt 19 10-19-2015 04:23 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 12:15 PM.