Overheating problems?

[Atrus96]

When doing semi slowish trail riding is the overheating problem really that bad? Is there anything I can do to help it? Is the wr as bad and if its not as bad why? I searched and really didn't find what I was looking for. Thx for any insight. Speaking of an 06 - 07 450 specificly.

Edited January 25, 2010 by Atrus96
Added year

[Gunner354]

Evans Npgr. Been using for a couple of years. Runs cooler and the motor will NOT boil over. Same stuff Zipty racing sells at half the price.

[ranchopower]

Evans Npgr. Been using for a couple of years. Runs cooler and the motor will NOT boil over. Same stuff Zipty racing sells at half the price.

EVANS problem solved

Javier

[Gunner354]

A friend had a CRF 450 that would boil over like crazy try the Evans. Never boiled over again.

[grayracer513]

Before choosing the Evans, understand that it does not make the engine run cooler, it simply raises the boiling point. In fact, at temperatures below boiling, it doesn't cool as well as plain water (no coolant or coolant mix does). So if you have an abnormal amount of heat build up, it won't be cured by the coolant.

It is, however, also true that coolant that is boiling will not cool anything, so boiling needs to be avoided one way or other. If the cooling system is in good condition, and it's just a matter of going too slow for too long, the Evans may be what you need.

Personally, I would try a 1.6 bar cap (23 psi) and a mix of 50/50 propylene glycol coolant and water, and if that didn't do it, go with the Evans.

[ranchopower]

Before choosing the Evans, understand that it does not make the engine run cooler, it simply raises the boiling point. In fact, at temperatures below boiling, it doesn't cool as well as plain water (no coolant or coolant mix does). So if you have an abnormal amount of heat build up, it won't be cured by the coolant.

It is, however, also true that coolant that is boiling will not cool anything, so boiling needs to be avoided one way or other. If the cooling system is in good condition, and it's just a matter of going too slow for too long, the Evans may be what you need.

Personally, I would try a 1.6 bar cap (23 psi) and a mix of 50/50 propylene glycol coolant and water, and if that didn't do it, go with the Evans.

I hope I dont offend, I am not trying to, trying to teach new tricks and help making more time to enjoy our equiptment.

Conventional coolants have a narrow operating range IMO, anything over 220 and conventional coolants fail to deliver efficient heat transfer due to the water content turning to vapor, So with that said most people would agree running an engine at 230F 240F will damage the engine.

Well that could be true using conventional coolants, most coolants advertise boiling between 250F/275F at 230F the coolant is lost most its% of heat transfer capabilities and the temps will run away.

I dont believe an engine will be damaged running at 250F as long as the cooling system is transfering heat to the radiator and the oil is capable of the higher temperatures.

turbine jet engines have sump oil temps in the 300/500F+ range regularly

and use oils that withstand those temps.

I may be talking to a brick wall here, but I am not copy pasting this info, I have done my own research and spent my money in this direction and I am not going bacwards, ever again.

Javier

[DieselSJ]

turbine jet engines have sump oil temps in the 300/500F+ range regularly

and use oils that withstand those temps.

And what exactly does that have to do with the discussion here? It isn't like anyone here is using those oils, so what is the point?

And if you don't think that 250 degrees will do damage (regardless of whatever coolant you use), then you haven't gotten an engine that hot yet.

[ranchopower]

And what exactly does that have to do with the discussion here? It isn't like anyone here is using those oils, so what is the point?

And if you don't think that 250 degrees will do damage (regardless of whatever coolant you use), then you haven't gotten an engine that hot yet.

LOL! I have plenty of experience learning what works and what dont.

http://www.ranchopower.com/wp-content/uploads/2009/12/Picture-3882.jpg

I broke this gauge when I lost all my coolant from a branch that took out my lower hose, I drove it home 15 miles no coolant!

http://www.ranchopower.com/wp-content/uploads/2009/12/Picture-006.jpg

nice to be able to get places without boilover.

Javier

[Family Man]

If your keeping the revs up in a technical slower section it will boil over.

[Chas_M]

If your keeping the revs up in a technical slower section it will boil over.

It's not so much the revs as it is the excessive clutch slipping. Note that there will be an increase in coolant flow rate with a moderate increase in RPM.

The sure fire way to limit overheating is with a fan installation.

[Gunner354]

My temp. strips tell me Evans runs cooler not hotter under normal conditions.

[grayracer513]

... anything over 220 and conventional coolants fail to deliver efficient heat transfer due to the water content turning to vapor, So with that said most people would agree running an engine at 230F 240F will damage the engine.

Well that could be true using conventional coolants, most coolants advertise boiling between 250F/275F at 230F the coolant is lost most its% of heat transfer capabilities and the temps will run away.

And if you don't think that 250 degrees will do damage (regardless of whatever coolant you use), then you haven't gotten an engine that hot yet.

All modern automobile engines operate in a coolant temp range that begins at 200 ℉ and is not considered overheated until it reaches 255 ℉. The reason it isn't considered overheated is because that temperature is not high enough to boil a 50/50 ethylene glycol/water mix under 16 psi of pressure, and as I said earlier, a liquid cooling system will continue to work as long as the liquid stays liquid.

There is no particular risk of engine damage at that temperature under normal conditions. Under a continuous 50-60% load condition, the piston crown runs about 550 ℉, exhaust valves can run at 1500 ℉, and typical combustion chamber temps will be in the 5000 ℉ area. The creation of heat and its conversion to mechanical energy is what an engine is about, and it actually works against the process to draw off too much of that heat with a cooling system. That's why contemporary thermostats are set so high.

The water in a coolant water mix will vaporize, but not at 220 ℉ under pressure generally. If the pressure is increased to the 20-22 psi area, it's even more prone to stay liquid. The main thing is that the liquid in contact with both the heat source and the radiators remains liquid. Once any sort of boiling takes place, there's no longer any fluid contact with the part to be cooled, and temps skyrocket. Absent boiling, runaway temperatures only occur when heat is being produced at a rate higher than it's being carried off, and that, in this case, is simply from a lack of air moving over the radiators.

It's not so much the revs as it is the excessive clutch slipping. Note that there will be an increase in coolant flow rate with a moderate increase in RPM.

The sure fire way to limit overheating is with a fan installation.

Heat from the clutch adds to coolant temperatures only in a very indirect way, as the clutch is mostly cooled by oil, and the oil transfers relatively little heat to any part of the engine directly cooled by the cooling system.

The fan, though, really is the solution to the problem that prompted this thread, since it's mostly an air flow issue.

[ranchopower]

If I use a coolant in all my vehicles that has a lifetime fill, runs at low pressure, stops cooling system corrosion, for the rest of my life, I will not be spending money changing out blown hoses from 16+PSI and spending money when my cooling system boils over to replace coolant loss and best of all I wont be spending money doing routine coolant changes every few years along with clogged radiators and leaking water pumps.

I am done with that whole TRAP!

been there done that I GOT THE T-SHIRT!

Javier

[grayracer513]

"Lifetime fill". I remember that one from DexCool.

[Wikki]

LOL! I have plenty of experience learning what works and what dont.

http://www.ranchopower.com/wp-content/uploads/2009/12/Picture-3882.jpg

I broke this gauge when I lost all my coolant from a branch that took out my lower hose, I drove it home 15 miles no coolant!

http://www.ranchopower.com/wp-content/uploads/2009/12/Picture-006.jpg

nice to be able to get places without boilover.

Javier

My friend had the same thing, he broke his water pump cover in a crash and we didn't relize till we got back to camp he rode 45min with no coolant. The next day we stoped to rest where he crashed and found the pump cover pieces. I figured major damage but we replaced the cover filled it up and it still runs fine to this day. I just don't know how this is possible.

[DieselSJ]

LOL! I have plenty of experience learning what works and what dont.

http://www.ranchopower.com/wp-content/uploads/2009/12/Picture-3882.jpg

I broke this gauge when I lost all my coolant from a branch that took out my lower hose, I drove it home 15 miles no coolant!

http://www.ranchopower.com/wp-content/uploads/2009/12/Picture-006.jpg

nice to be able to get places without boilover.

Javier

So what does a picture of a broken gauge prove?

We got one of our race engines so hot that it melted the rubber around the oil fill cap and a couple of the freeze plugs literally fell out of the block. After it cooled off it actually fired up and ran again. Pulled it apart and the cylinder walls were blue. Wasn't boiling over though. Pfft. Again, just because the coolant can go up into some extremely high temps without "boiling over" does not mean it is a good idea.

[FinchFan194]

When I am on a really slow trail and feel like my bike is starting to heat up I am sure to try and build those RPM's every chance I get even if I have to pull the clutch in and crack it a time or two. To me the key is to get the coolant moving.

[Atrus96]

Dexcool is nasty nasty stuff I used to work in the. Auto industry and have seen its effects

[ranchopower]

Dexcool is nasty nasty stuff I used to work in the. Auto industry and have seen its effects

No disrespect to you or anyone working in the auto industry, but I know for certain that when a vehicle comes in for a coolant change, It is never done by the book.

Mechanics/service managers dont give a flip if the coolant is completely removed and replaced but they sure do charge like they did.

I am certain some service shops have a coolant flush machine and the chanches are better getting a better job done.

But the horror stories on dex cool are most likely mixing coolants

Javier

[grayracer513]

But the horror stories on dex cool are most likely mixing coolants

Javier

Having spent more than 20 years working with end-to-end power trains in GM and Chevrolet dealerships as a certified master technician and shop manager, let me say simply that the statement above is wrong.

For one thing, there is no particular problem mixing Dex-Cool with EG or PG coolants, other than doing so reduces it's change interval to 2 years or less. The real problem is that Dex-Cool oxidizes like crazy in the presence of air, and ANY leak in the cooling system ends up causing major build-ups of sludge in the systems, resulting from corrosion accelerated by metals exposed to air and vapors in the presence of Dex-Cool. Because owners look only at the recovery bottle, and never open their cooling systems to see if the level is up, the level can easily be 3 qts down before it shows as a hot engine.

Flushing the system reasonably well and refilling it with EG or PG coolants solves the problem.