Stroker running hot.....

Well, the downpipe fixed the cutting out issue, but now shes running pretty warm. sitting in my driveway, idling at 2500 rpm for about 10 min, the hoses, valve cover, and intake manifold get HOT to the touch

the temp sensor from the block (now in the HO's t stat housing) was kicking back like 175 ohms, about 220 deg....BUT the IAT was kickin back about 200 ohms, about 200 deg, a few minutes after i shut it off.

According to my narrow band o2 and gauge, its running at the rich side of stoich.... im assuming about 13.5:1, maybe a little richer, if the gauge is right

are these normal temps? it seems really hot to me

btw my temp sensor for the gauge is broken, so i dunno what the number is according to that

I would get a new temp sending unit before you get too worried. My stroker is hot to the touch after it warms up but it never gets hotter than 220 with my electric fan set to kick in at 210. Narrow band A/F guages are junk. I have one and it is less usefull than the tried and true method of pulling a plug to guage A/F. Does your electric fan kick on properly? Replacing the renix era fan with a '96+ fan helps a lot also. Are you running the open or closed cooling system?

open cooling system fan is ALWAYS on, i jumped the connector

i like the A/F gauge just to watch to make sure im not going dead lean at WOT, and it does tell me that, very well

If you are running the fan continuosly and its getting that hot, You have a problem with the cooling system. What kind of shape is the radiator in? How many rows is it? Do your hoses all look good? It's hard to offer suggestions with not very much information but, I would still get a new temp sending unit before you get too worried about it, the 4.0L does very well running at around 220* and the strokers are no different. Also if you are just idling in the driveway there is a lot less air flow than driving so it will warm up.

If it is a new rebuild, it will run hot for the first 100 miles or so during breakin, but the most likely issue is an air bubble. Burp the system by loosening the temp sensor on the rear of the head.

Fix the temp sensor.
PLEASE! DO NOT let a fresh engine idle for 10 min.
Do not let any engine idle at 2500 much less a new one for 10 min.
Let the E fan sensor do it's job. Disable your jumper on it. The fan will last longer. You may get better MPGs.
Reburp the system and take your time doing it. Let her break-in good. Your temps sound about right. LUCK.

the engine and cam are already broken in, she has about 50 miles on her

i see no reason to not let a motor idle, a matter in fact most of the tests at the dealership i worked at, the vehicles were running at 2500-4000 rpm for 15-20 min for the tests to work right (VW, because your gunna ask)

and to break in the cam you have to let it idle at 2000 rpm for 20 min....

its better than idling a slower speeds because the oil pump is spinning faster as well

tealcherokee said:

Well, the downpipe fixed the cutting out issue, but now shes running pretty warm. sitting in my driveway, idling at 2500 rpm for about 10 min, the hoses, valve cover, and intake manifold get HOT to the touch

the temp sensor from the block (now in the HO's t stat housing) was kicking back like 175 ohms, about 220 deg....BUT the IAT was kickin back about 200 ohms, about 200 deg, a few minutes after i shut it off.

According to my narrow band o2 and gauge, its running at the rich side of stoich.... im assuming about 13.5:1, maybe a little richer, if the gauge is right

are these normal temps? it seems really hot to me

btw my temp sensor for the gauge is broken, so i dunno what the number is according to that

Click to expand...

Running the engine at a fast idle for that long WILL cause a lot of heat soak so that's no surprise. Given that the engine's still fresh, it needs to rack up a few hundred miles to loosen up a bit. Then it'll run a tad cooler. The temp. readings that you got from the CTS and the IAT are normal. The 200 deg IAT just confirms that you're getting a lot of heat soak. I suggest you add some insulation to the underside of the intake manifold as I did:

http://www.angelfire.com/my/fan/manifold.html

You'll be amazed at how much cooler the intake manifold will feel and you'll get a significant reduction in underhood temps. It's an excellent and cheap mod. Do it!

very good, when i make my turbo manifold, should i get it ceramic coated, will that help also?

==================================
the engine and cam are already broken in, she has about 50 miles on her
=================================

(IMO) 50 is OK but 200 or so might be even better.
Under the no load or no changing load condition of idle. All moving parts tend to set in one spot on there race, bearing, lobe etc. This lead to an uneven (for lack of a better word) break-in. This kind of break-in does lead to a shorten engine life.
(IMO) A good break-in is done in gear under changing modest speeds and loads. (IMO)
Yes, the factory boys and others do let them high idle for longer times. For some of there test they have no other options but to do it that way.
The truth be known the test would be better if an onboard computer was installed and the jeep driven at a min of 45 MPH for 20 min or more but that ant going to happen.
And they are not going to come out a say. Yes, I want to drag this out so I let your engine idle for much longer then needed. Yes, it's not the best thing for your engine. So sue me.
You will never hear that from a factory boy.

ok, my engine instructor said you break in an engine, 20 min at 2000 rpm for the cam, drive it, bring it to red line in each gear a few time for the rings, keep it under 100 for the first 500 miles

hes been doing engine machining work for about 30 years, he knows his stuff, and no offense, i trust him, and thats how i broke my motor in, and thats how i will continue to break my motor in

driving the jeep around at a steady RPM is terrible for an engine at break in time....

either way, my engine is broken in