2.5 260 temp?

[Jay Smith]

Ken,

Side and top of the block temps you are correct but the rear of the head at the spark plug region I will have agree to disagree , that area WILL get up as Marles said up too the 170 ish range , I've shot that area will heat gun and seen temps much higher in that area than the block and the top of the head where water is more apt to circulate away from combustion temps,thanks.

Jay

[peedeerooster]

Thanks for the help. And do understand why those temps would be influenced up by combustion temps. This has answered my questions and I appreciate it.

[Ziemer]

In that case you will see temps upwards of 170 degrees.

Is this normal though, or only after a hard WOT run on a hot summer day?

My temp sender is at the back of the head, like most others have indicated, and I rarely see the gauge go over 150. During the summer it reads between 130-140 (cruising) and after a hard run it'll peak around 150 ish but after a minute or 2 of idling its back down in the low 100's.

[us1]

Is this normal though, or only after a hard WOT run on a hot summer day?

My temp sender is at the back of the head, like most others have indicated, and I rarely see the gauge go over 150. During the summer it reads between 130-140 (cruising) and after a hard run it'll peak around 150 ish but after a minute or 2 of idling its back down in the low 100's.

I said "upwards of" meaning up to a max of 170. 150 is good too. It depends how hard you run it. After 1 hour at 9600 RPM my F1s are running 170 head temp 140 water.

[fastcheckmate]

i think normal temp is what the question was about. i have never seen a head temp at 170 on a 260 lake motor running wot or not.

QUOTE:
After 1 hour at 9600 RPM my F1s are running 170 head temp 140 water.

i could understand why this temp is 170. thanks.<!-- / message --><!-- sig -->

[us1]

Point being up to 170 will not hurt a motor. Running wide open for a few miles can produce these figures even in a lake boat. It all depends on your tunning and how hard you run it.

[Jay Smith]

Has allot to do with how much compression your running too. Not only does compression generates large HP its also generates HEAT in large amounts too... Thanks

regards,
jay

[us1]

Jay, you know whats funny. In our 2.5 Mercury 260 HP powered off road race car we run water temp at 180 degrees and head temp is 210 to 220. There is less cylinder/piston ware and straighter cylinders in that motor than any boat motors I have ever seen.

[Jay Smith]

Maybe the even constant heat keeps the metal from getting thermolely shocked with the ambient cooler lake water....

Who knows John....

Jay

[Fish]

Another idea...

I carry a cheap infra-red temp gauge in my tool bag. I can point it at any place on my motor a tell what the temp is on the heads at each cylinder, any spot on the block, you name it. The thing is pretty cool and pretty accurate. I have grown to trust a head temp gauge kinda like a fuel gauge; good for a general idea, but if I need to know what I got, I want to be more specific.

here is the gauge if anyone cares.
http://www.sears.com/shc/s/p_10153_1...rd=thermometer

[us1]

Another idea...

I carry a cheap infra-red temp gauge in my tool bag. I can point it at any place on my motor a tell what the temp is on the heads at each cylinder, any spot on the block, you name it. The thing is pretty cool and pretty accurate. I have grown to trust a head temp gauge kinda like a fuel gauge; good for a general idea, but if I need to know what I got, I want to be more specific.

here is the gauge if anyone cares.
http://www.sears.com/shc/s/p_10153_1...rd=thermometer

I love those things.

[Jay Smith]

Fish,

That was what I refering to in an earlier post ( heat gun ) They work great and keeps them "pinkys" from getting burned.. I use it everyday when engines are running on the run stand checking for even heat displacement...You can tell in just a second if somethings wrong...

Jay @ JSRE