Stroker running hot

[vwtipeii]

Hi everyone, I am new here. I purchased a 4.8L stroker from factory 505 performance last year. I have been having some issues with it.

Ok... so I have fixed many of the issues (or have had friends and mechs fix) on my lil YJ. I took her out for five days this weekend up to the mountains in Nevada about 100 miles North East of Bishop off highway 6. I was with a group of other Jeeps so I have some reference. The issue... she runs hot when climbing. The higher the elevation. The hotter she gets. I run 91 octane fuel all the time and when the engine gets hot she starts to ping. To avoid the pinging I ease off the throttle and slow down... long story short she was running pretty much all five days in the red or just below the red on highway climbs from 4000 to 8000 feet in elevation. Heck she started getting hot climbing the 405 leaving LA.

Here are what I have done to her cooling system:
1. New Griffin high flow radiator
2. 5 month old high flow water pump
3. New (Friday 160 thermostat)
4. New temp sending unit to the computer and to the gauge
5. Flushed entire system three months ago, Wednesday and again Thursday
6. Added Royal purple "ice" that is supposed to lower the temp by 20 degrees
7. Fan clutch is a year old and seems to be working fine (fan is pulling)
8. I have a small pusher fan in front of the radiator that also seems to be working fine (pushing)

Some things I have noticed is that the coolant becomes a rust color very quickly and there were some chunks of rust sitting on top of the tubes that flow the coolant when you look in the filler of the radiator. The head is about six months old. Engine is about 1.5 years old and has about 5,000 miles on it.

i have a stroker... and strokers are known for running hot. However I should be able to keep up with traffic, not have pinging and not have to run my heater when it is 100 degrees outside. when I drop back down to sea level (I live by the beach) the power comes back and she runs cooler since I am not climbing.

Any thoughts or ideas are appreciated. my YJ is a 94 with OBD 1.

Brett

[the grey ghost]

What kind of elevation and timing are you running?gotta have specs on the engine too, I. E , compression, quench, cam specs, trans and gearing, oh wait I found your prob, 505

[SkauneJohan]

http://www.jeepstrokers.com/forum/viewt ... 7&start=15

look here

[Cheromaniac]

strokers are known for running hot.

Strokers usually only run hot either because the cooling system isn't up to scratch or because the engine's running lean.

]the coolant becomes a rust color very quickly and there were some chunks of rust sitting on top of the tubes that flow the coolant when you look in the filler of the radiator

There's a good possibility that your engine is suffering from excessive internal corrosion (especially the block) and the coolant passages could be obstructed by chunks of rust. I think it would be a good idea to try a chemical agent that's capable of dissolving rust/limescale to flush the cooling system.
You might also want to replace the lower radiator hose if it's quite old, as the spring could have rusted away causing the hose to collapse under the suction from the water pump.

[jsawduste]

http://www.jeepstrokers.com/forum/viewt ... 7&start=15

look here

Which is one of the dumbest cooling approaches I`ve seen in both application and reasoning I`ve seen in a LONG time.

As Dino has already covered. How can you expect the system to adequately do it`s job if the coolant is laced with particulates ? Particulates that are very likely restricting or even blocking the sub standard aluminum Griffin radiator ? Not to mention the reduced heat transfer ability of the coolant itself.

Are you still running the radiator shroud ? Have a big bumper, winch or lighting blocking the radiator ?

Why would you bother with the puller fan ? The extra CFM of the puller is offset by it`s airflow restriction and turbulence.

[Cheromaniac]

At 40+mph there should be enough ram airflow through the radiator to keep the engine cool even if you have no fans at all, so when an engine overheats on the highway the reason isn't a non- or poorly-functioning fan. That said, Brett has a pusher fan in front of the radiator which is restricting airflow and not really serving any useful function, so he'd be well-advised to remove it and anything else (lights, winch) that might be obstructing airflow through the radiator.
I don't have any experience of the Griffin aluminum radiator but if it's a 3-core unit, it isn't going to cool the engine any better than a stock 2-core radiator unless it's at least 25% thicker so that the cores can be wide enough to flow more coolant.
As for Gojeep's upper radiator hose restrictor idea, I tried it once upon a time and it didn't work so it's not something I'd recommend.

[wjtom]

Because its a stroker doesnt mean it will run hot.Stock radiator,high flow stock replacement pump(jeep did this themselves),180 degree thermostat and it runs there all day in 90 degree weather.Who did the tuning?If its 505 it probably has way too much timing.Also what compression is this?By what you described it runs cool at idle but cruising and under load overheats?All this leads me back to a timing issue.ie too much.Any cooling system can only get rid of so much heat.If you have a tuning issue creating more heat than any system can cool you get the problem you have.I have seen this many times where guys change everything in the cooling system only to find out it was a tuning related issue.Usually timing related.

[SilverXJ]

I'll echo what previous posters have said. You need to clean out the cooling system of the rust. Whom did the head or block did not clean it correctly. Or th eblock was left sitting with little coolant, not dried and exposed to air. Rust doesn't help cooling.

,high flow stock replacement pump(jeep did this themselves),

I keep seeing this come up, but the only difference in pumps I have seen has been in late model TJs and WJs where they used an impeller similar to Hesco's. I have never seen a different pump for earlier years not different models.

[wjtom]

Biggest question i see at this point is this a new problem or an existing one.If the motor was free of rust when you put it in and you know this for sure.Then i would carefully check all the grounds on the motor and chassis.The vehicle will try to ground itself through the cooling system.Yes believe it or not you will get voltage readings on the hoses!Ive only seen serious corrosion problems on cherokees to the point the impellers are half gone but i suppose it could happen on others.

[wjtom]

I'll echo what previous posters have said. You need to clean out the cooling system of the rust. Whom did the head or block did not clean it correctly. Or th eblock was left sitting with little coolant, not dried and exposed to air. Rust doesn't help cooling.

,high flow stock replacement pump(jeep did this themselves),

I keep seeing this come up, but the only difference in pumps I have seen has been in late model TJs and WJs where they used an impeller similar to Hesco's. I have never seen a different pump for earlier years not different models.

You are correct. Apparently its 01 and up that got the revised impellers with 8 vanes.Just looked it up on napa for my wj and his earlier one.I stand corrected.