Over the winter I rebuilt the top end of my 1980 shovelhead new pistons and rings. I've ran it a couple of times and am wondering if it's running to hot. It's running around 235 to 260 degrees F. I'm using 20w50 weight oil. What is the ideal temp for a shovel to run.

 

What temp are you referring too....oil, head, exhaust? If it's oil then yes your running waaaaaay tooo hot.

 

Before you freak out, use another temp guage. Mine ran about 185-190 on a hot Texas day, with no oil cooler. Look at your plugs. Are the electrodes white or chocolate. If they are white, you could be in a lean condition, which will cause overheating.

 

It's the head temperature I'm looking at with a temp gun. The plugs are not white but more of a gray to light brown color.

 

I always liked to know whats going on inside the motor. Oil temperature and plug readings are the best way, IMO. Measuring the head temp is ok, if you have a baseline. But remember the motor is disipating heat to the outside, to be cooled by the wind blowing around the motor, and could vary quite a bit, depending on the outside temp, winter vs. summer, idling vs. city driving vs. highway driving.

 

Okay, so oil temperature is what I should be looking at not so much the temp of the heads.

 

I like watching the oil temp. Oil is more consistant in it's temp. I mean, it's not like I watch it all of the time. Just occationally, mostly in situations like heavy traffic where overheating can cause damage to the motor. You don't need to be a temp hawk. The motor is going to heat up. If you are using a good oil, you should be running around 200, without a cooler. A little less with one. You don't want your oil too cold either. It will only work right if it is up to temp. Otherwise, you'll be running molassas through the motor, causing strain that can wear out the low end quicker than it should. Remember, as the oil heats up, the less pressure you will have at idle. That's a whole different subject.

 

Well first thing I'd change to a straight 50W or 60W oil if I where you . Anything pre Evo was designed to run straight heavy oil not the multi grades out now , depending on where you live 70W is common in the summers to keep a Shovel happy if your still running hyd. lifters and any upgraded cam . Double check to make sure oil is getting to the upper end , Ive seen a bit of thread tape blocking a fitting on the rocker oil lines a few times and getting hot is a sign . Next timing issues can make a new motor heat way up fast and it's good to run the carb a little on the fat side till you've got break end miles under you and it helps keeping the engine cooler . Good luck

 

Got an oil temperature gauge and took her out for a ride 70 degrees outside. After about 30 mins checked the temp and it was 189 degrees. Rode back home and checked again oil temp was around 192 degrees. Next days of I'm going to change oil and run straight 50 weight.

 

Sounds like it is running about right. Is your motor fresh, meaning recently rebuilt, or is it a seasoned motor? If it is fresh, go ahead and run a multigrade oil, I preferred Castrol 20w50. If it has more than it's share of miles, a straight grade is ok, but nothing higher than a 50w.
(This is going to open up a can of worms) If your motor is new, top and bottom, Mobil 1 V-Twin is a excellent choice.