Maximum temperature for homemade engine .

[minh-thanh]

Hi All !
Maximum temperature for homemade engine
What is the maximum temperature we should maintain for a homemade engine ?
Thanks

 

[stevehuckss396]

I don't know for sure but I would think it would be inline with a full size engine and maybe lower. Coolant boils at the same temp big or small. Aluminum warps and other things fail independent of size. I had a boil over once. Superized me because it didn't seem that hot but guess what?

 

[Brian Rupnow]

These small engines, running under no load, don't run as hot as you would expect. About 180 to 200 degrees Fahrenheit.

 

[minh-thanh]

Thanks for the comments.
Maybe I take the temperature of a full-size engine as the standard
I am looking for a way to cool the engine but not too much affect the cold start of the diesel engine, but also make sure the engine runs for a long time without overheating.

 

[colby15642]

All compression-ignition engines like to be hot, as in 200 degrees F. In fact most engines like to be that hot as long as you're not degrading the lube oil or paint.

 

[minh-thanh]

All compression-ignition engines like to be hot, as in 200 degrees F. In fact most engines like to be that hot as long as you're not degrading the lube oil or paint.

An issue worth noting
Thank you !

 

[Peter Twissell]

Full size guidelines, equally applicable to models, are 150C max for aluminium heads, 180C max for iron.
As Brian says, small engines tend to run cooler, due to the scaled ratios between surface area and volume.
90 to 100C is a good place to be.

 

[Bentwings]

Thanks for the comments.
Maybe I take the temperature of a full-size engine as the standard
I am looking for a way to cool the engine but not too much affect the cold start of the diesel engine, but also make sure the engine runs for a long time without overheating.

You might look into motorcycle radiators my hon had a pair from his dirt bike that we used as oil coolers for his sand buggy. They are aluminum and pretty easy to mount . I welded brackets on ours .

 

[rickhann]

I would think that the desired max temp would be around 212 F for a Hit&Miss. That would be why the old engines had a open water tank surrounding the cylinder casting. When running under a load the water would boil.

 

[minh-thanh]

Thanks for the comments !!

 

[stevehuckss396]

These small engines, running under no load, don't run as hot as you would expect. About 180 to 200 degrees Fahrenheit.

The single cylinder and Hit Miss engines that may be true but the V engines 4, 6 ,8's its a real problem. I have had boil overs from running too much. At the engine shows people want to see them run and builders want to show them running. You have to be aware of that. The hit miss guys start them up 5 minutes before the show opens and shut them off 5 minutes after the door closes. Engines like that have no worries about it.

 

[rickhann]

If you have problems with boiling over, perhaps you should replicate the automotive practice of pressurizing the cooling system and running 50/50 antifreeze. 50/50 antifreeze boils at 223 F and a standard 15 Lb pressure cap raises the boiling point by 45 degrees F. If you still have boiling problems then I would look into a bigger radiator. Horses for courses!

 

[stevehuckss396]

If you have problems with boiling over, perhaps you should replicate the automotive practice of pressurizing the cooling system and running 50/50 antifreeze. 50/50 antifreeze boils at 223 F and a standard 15 Lb pressure cap raises the boiling point by 45 degrees F. If you still have boiling problems then I would look into a bigger radiator. Horses for courses!

And then end up with a radiator so far out of scale that it looks like the engine is at the drive in theater. Just need to run it less and be aware so it wont over heat. Its more of an operator error thing.

 

[Bentwings]

And then end up with a radiator so far out of scale that it looks like the engine is at the drive in theater. Just need to run it less and be aware so it wont over heat. Its more of an operator error thing.

Also check into the waterless automotive coolants these seem to have considerably higher boiling point . We used this in a supercharged hot rod that had continuous cooling issues problem solved . In another Streetrod we switched to a double pass radiator this solved most of the issues but we finally went to a triple pass radiator this is not a big improvement over the double pass but with the waterless coolant and the extra pass it was enough to make the car drivable about anytime or temp . We actually made the triple pass conversion ourselves. It took a bit of cutting and TIG welding the aluminum radiator but it did work . You will have to look this up as to how this is done . Circle track racers use these as pretty standard practice . That’s where we got the idea and process for conversion . The radiator needs to be spotless clean inside to weld or brand new . We used a new one after experimenting on a used one .

 

[Bentwings]

I’ve been to various farm shows and seen hit and Miss engines that run all day on a gallon of water some use an addition gallon if they sit out on the open range, according to owners .

 

[stevehuckss396]

Also check into the waterless automotive coolants these seem to have considerably higher boiling point .

I use water wetter. Close enough.

 

[Jasonb]

Depends really on how hard you are running the engines, some of the performance aero engines had the bore leaning back slightly to compensate for the forward facing side of the cylinder expanding less than the back which did not see much airfow.

Exhausts can get hot too like this Nemett Lynx