Stroker running hot

[vwtipeii]

You should also put your thermostat back to the 195F (I assume that is the stock temperature).

Art also brought up the issue of a shroud and I don't think you answered. That is very important in drawing air through the radiator.

The engine fan is pulling in air. The shroud is the stock shroud I have always used. Stock engine fan and stock engine fan clutch.

[vwtipeii]

We are trying to identify what is making it run hot on climbs and at elevation. I think the extra heat and higher compression lead to the pinging with the 91 octane.

[vwtipeii]

Let's dispell the myth that "strokers" run hot. That logic immediately places any Chevy small block above 265 cid into the "stroker " category as they are all longer stroke versions within the same block design. Therefore any 283, 327, 350 or 400 must run hot. Any engine with too little air flow, poor circulation, low coolant pressure, too lean, too rich or with an incorrect timing curve will run hot. The 4.6/4.7 "stroker" was originally built by VAM in Mexico as a stock motor - therefore it's not really even a "stroker". Rant over.
It's interesting that the power comes back at sea level. It's very logical due to the density of the air. But what strikes me is the MAP sensor should be reducing the pulse duration to the injectors only proportional to the density of the intake air pressure. It's perfectly normal to have a power loss due to less air density at a higher altitude, but it almost sounds like it is leaning out too far. If it isn't reading correctly due to a vacuum leak on either end of it's hose/tubing or it's not getting a full 5 volt input, the output will cut off your injectors too soon and you can run lean. It may also just be malfunctioning.
I recall you had throttle position sensor issues before. You may want to check the TPS positioning again. The TPS also plays an important role in the system. If the ECU thinks the throttle isn't open as far as it really is, it will also run lean.
Now for sheer opinion... I am not a fan of pusher fans. The reasoning is that they disturb the air flow into the radiator fins. At low speed, it's probably not an issue, but at freeway speeds, the air has to get around the fan and it's guarding before going into the fins to dissipate heat. With a puller fan, the air is already through the fins before having to get around the fan, but by this time, it's the fan's problem to move the hot air away since it already did it's job in the fins. Doesn't the grille disturb the air first? Yep. But why compound the issue?
Flatout had a very good point. The 4.0 block and head trap air when first filled. Make sure your system is FULL.
Another (and the dumbest) thing I've seen is a weak radiator cap. I've had two brand new ones fail on two different rigs. If they don't hold pressure, the water isn't pressurized against the tubes or block to dissipate heat. Everything was new, pump radiator and cap. The motor was flushed, timing was right, fuel wasn't too rich or too lean and they went straight to red. Changed the cap and everything settled back down.

i have also put in a new MAP sensor and new TPS in February. That fixed some other things as the old TPS was only a year old and was failing. I hope both are still working properly.

[Zoobi]

Maybe I missed this in your post but I want you to clarify something. When exactly does it run hot and what temp? For example; It runs around 190 then when sitting at a light it creeps to 250 then goes back when I accelerate. That for instance is a common fan related problem. It runs about 210 on freeway then goes to 250 when pulling hills then cools off when leveling out. The more exact your details are the easier it is.

Your radiator is what gets rid of the heat. Radiators are generally overkill for most engines. Your airflow and coolant flow are critical. You said your running the stock fan and clutch If those are bad you will run hotter at low speed and stops then cool off once you get moving. If your fans are working but you have no air flow because of things blocking the front of the radiator you will normally run hotter at speed under load and you will hear your fan running hard.
Rust and muck in the cooling system will cause big problems if its bad enough. Rust will be caused by poor coolant mixture corroding the block and head or a block that was left to rust outside for a few years then not properly cleaned before building the engine. As far as Ive seen once the block starts to rust flushing gets out the flakes but will not stop it from continuing. Ive seen this issue on many cars for many years. Ive heard you can get something to add to coolant to stop it but have never seen any actually work.
If you have mud looking substance that comes from coolant reacting to something like mixing 2 incompatible coolants.

You stated you have a high flow pump. I cant comment on those in the inline motors because I never ran one but Ive see instances where they flow the water too fast at higher speed and cause over heat. I ran a high compression 258 with an 80 over bore with the stock water pump, 190 thermostat and clutch fan with no issue high speed or low speed.

You have also stated that when it runs hot you let off and it cools when coasting? If that's true does it do that at any speed just being under a load? That symptom was with a couple of vehicles I've worked with that had cams set retarded. One was indexed wrong and the other was ground wrong. Block and head issues will cause this issue also. Some of them will pass a chemical block test and still be bad.

As you have seen everyone here has given you different things that can cause this and all of them are possible, especially if you have multiple issues. Start with easy stuff first. Clean coolant system, put proper thermostat in, make sure the radiator and condenser fins are not covered with dirt and are not bent over.

The problem with "internet " diagnosis is most of us have checks we do automatically and don't think about them. The info given over the net is really too vague to be precise. The more exact your posting is the easier it is to eliminate what wont be causing it.
Whats going to really suck is if it turns out to not have anything broken but the combination of the winch, ac condenser and what ever you have for other coolers in front are limiting your air flow causing this problem. Those will normally show up at higher speeds also

Sorry about the long post. Hope it helps

Scott

[jonah]

I think you should get a true wide band Air/Fuel gauge and see what you are really running at. I was battling overheating on my new motor and found that in mid throttle while climbing hills put it into the 13.7-14 range and it would get hot. My motor likes to be at 13 or under to run right, especially with any load. I thought 14 wasn't lean enough to cause overheating but as soon as I added more fuel to that part of the map the overheating went away. With Robert saying he thought your injectors at stock pressure were marginal for fuel delivery on the stroker you may just be leaning out a bit under certain loads and throttle positions.

I have this:
http://www.amazon.com/Innovate-Motor...=innovate+lc-2

[6spdYJ]

I can't believe I didn't think of this before... I'll trade you your overheating 4.7 straight across for a 4.0 with no cooling issues whatsoever. It only has 197,000 miles too! I hate seeing you go through so much hassle

[vwtipeii]

All great feedback And you are so kind with your offer 6 speed! I may take you up on that in the future.

Well... I dropped the YJ back off at Brother's and asked Haik to fix the cooling issue or else I would send him back to Armenia. He personally worked on my YJ driving her up and down the road to the top of mount baldy and back a bunch of times. Before driving her a bunch he:

1. Flushed the Heater Core until the rust stopped coming out (that is the source of the rust)
2. Flushed the rest of the cooling system (sent the new griffin radiator out for super flushing)
3. Removed a non high flow water pump that was supposed to be a high flow water pump and installed an actual high flow water pump.
4. Installed a 180 degree thermostat.
5. New coolant.

After that he ran the Jeep up and down Mt. Baldy...and... she still ran hot...still pinged all over the place. Then he:

1. Adjusted the timing, time and time again until basically there was no power to try to stop the pinging and over heating...
2. Finally noticed there was some "play" inside the distributor.
3. Put in a new distributor and adjusted timing.

Ran her up and down Mt Baldy again...she ran cool as could be with AC blowing cold. I picked her up yesterday and did the same thing before finally driving her home and washing her... I actually drove her home the whole time with the windows up and AC on...something I have NEVER done before in my lil YJ. I am finally satisfied with the motor and the way she is running.... I washed her and even waxed her! I was soo excited I did the big no no and even put tire wet on her small tires!!





The true test will be the 4th of July...high sierra's again... wish me luck!

[jonah]

Working out the bugs. Glad to hear she is running again!

[ROBERTK]

I think you should get a true wide band Air/Fuel gauge and see what you are really running at. I was battling overheating on my new motor and found that in mid throttle while climbing hills put it into the 13.7-14 range and it would get hot. My motor likes to be at 13 or under to run right, especially with any load. I thought 14 wasn't lean enough to cause overheating but as soon as I added more fuel to that part of the map the overheating went away. With Robert saying he thought your injectors at stock pressure were marginal for fuel delivery on the stroker you may just be leaning out a bit under certain loads and throttle positions.

I have this:
http://www.amazon.com/Innovate-Motor...=innovate+lc-2

My post are just ignored I think by Brett anymore at least for years.
But I have recommended d this twice before. Still say this is the Most important gauge for a vehicle with a stroker motor.

I have a 10.6 comp ratio 4.7 that I run with 110 and 91 oct. 50/50 Mix and have ran many races in deserts and hills now without once getting above 200deg.

I run a thick 2 row rad. A 190 deg t stat. Flow cooler fan clutch. Grand cherokee fan clutch. And the stock auxiliary fan on a 195deg tstat on switch. You don't seem to take what I recommend with much merit. But this stroker has been flawless.

Wide band I watch. Temp or rpm or oil psi is all lower degree of importance compared to a/f ratio!

[daniel_buck]

ah, right on Brett! Glad to hear the over heating seems to be taken care of!

[aw12345]

My post are just ignored I think by Brett anymore at least for years.
But I have recommended d this twice before. Still say this is the Most important gauge for a vehicle with a stroker motor.

I have a 10.6 comp ratio 4.7 that I run with 110 and 91 oct. 50/50 Mix and have ran many races in deserts and hills now without once getting above 200deg.

I run a thick 2 row rad. A 190 deg t stat. Flow cooler fan clutch. Grand cherokee fan clutch. And the stock auxiliary fan on a 195deg tstat on switch. You don't seem to take what I recommend with much merit. But this stroker has been flawless.

Wide band I watch. Temp or rpm or oil psi is all lower degree of importance compared to a/f ratio!

Skeeter rather throws money at his lil Jalopy than listen to good sense, other than that the boy does now how to cook at camp and carries a lot of usefull stuff in the back of that thing, oh yeah he is pretty good for lighting up the night sky too