Quick question about engine temps...

[Powerman6766]

Finally got all my upgrades for my Savage 25 and installed all of them.It was about 75 degrees out the night I tuned it.At first we ran a half a tank through it and I did some full speed runs and check the engine temps with a Duratrax infared temp gauge.The highest it got was 240...so i decided to lean the HSN just a tick to see what happened.I think I got it set pretty good becuase after I let the engine cool down to take a break I refileld the tank and start it with a 1 sec push of the roto-start.Anyways I monitered the temps the whole time I was running it and the highest it get was 260 and at one point it even started to drop to 250 even doing high speed runs.I almost ran a full tank of fuel but I shut off the engine and checked the temp once more and it was around 245.MY question was if I started my truck and ran it on a day that was abotu 90 degrees out would the temp be 15 degrees higher than the night I ran it and it was 75?(All temps are in F)

Thanks,
Powerman6766

 

[Rolex]

It wouldn't necessarily go up the same as the ambient temperature, but changes in temp and humidity will change how the engine runs. You seem to be running about perfect right now, but any change in outside temp or humidity will require a tweak on the HSN just for performance.

 

[Powerman6766]

Yeah I think I found a pretty good hot spot on it.Well for that night anyways.Had a little problem with the tranny shifting to soon then not soon enough, but I fixed it and it is running real nice.I can't even hit full speeds on a straight away because I run out of room.I want to go to the old K-Mart parking lot...

 

[JerZ]

What is the perfect temprature you want your engine runing at? Where does the dangerzone begin? Thanx

 

[rossb]

What is the perfect temprature you want your engine runing at? Where does the dangerzone begin? Thanx

Your temps are probably going to vary with the fuel left in the tank. The stock tank tends to lean out the mixture as the fuel level drops. There really is no perfect temp, temps vary with the fuel used, glow plug used, outside air, etc..

You probably want to be somewhere in the 240-270 range. I would keep it below 280 degrees. Mine is currently running great at 255-265 degrees (after 15 consecutive seconds of WOT operation), 20% O-Donnell, Stock R4 medium/cold plug, mid 80s hot & humid outside air, Uniflow mod to keep the fuel tank pressure constant.

Richen up the HSN until you the truck bogs a bit a high speed. Lean it out just until the boggin goes away, and then a hair more. Next move to the LSN, try the pinch test and get it so that after about 3 seconds of pinching the idle increases a bit and it feels like it is about to stall. Release the pinch and the truck should continue to idle normally. After the pinch test is close fine tune the LSN by testing the WOT acceleration from a dead stop. If your LSN is correct the truck should blast off the line with no hesitation after idling for 1-20 seconds (when fully warmed). The motor should load up on fuel if you idle for longer than 20 seconds or so. The initial blast off after a 30 second idle should be a bit rich and the motor should bog a bit until it clears out. It should clear after a few seconds of being wide open.

This should get you very close to perfection.