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  #21  
Old 08-24-2018, 12:40 PM
rapom rapom is offline
230 Tornado
 
Join Date: Aug 10, 2016
Location: Toledo, OH
Posts: 22
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I have a similar issue with my 79 chief. I have a new radiator, thermostat, and a clutch fan that seems good. Mine will also overheat, but only at idle or very slow speeds. I even installed a 14” spal pusher fan on the condenser which gives me nice and cold a/c sitting in traffic. It stabilizes the temp. But I still think it runs to hot.

The 360 has about 130,000 on it and the water pump looks original, so my next idea is to install a flowcooler water pump and a Robert Shaw thermostat to get my idle water circulation up.

In your case you may what to try adjustable homemade front spoiler under your front bumper.

A heavy duty fixed blade fan is another option.

A four core radiator from champion, may be better. May have to source one from an old mopar application.

Water wetter in your antifreeze is supposed to help.

I bet the front spoiler would work but would take away your stock look. A lot of oem’s use them because cars now have smaller grills and need that extra low pressure in the engine compartment at higher speeds.
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  #22  
Old 08-24-2018, 12:58 PM
Ristow Ristow is offline
 
Join Date: Jan 20, 2006
Location: The Great Googley Moogley Midwest.
Posts: 16,958
the flowkooler pump is a joke. it usually scars up the timing cover with the rivets on the gimicky backing plate,so you put 2 gaskets on which i leak maker.


if your motor won't cool with a standard issue water pump and thermostat you need to find the reall reason why.


all the spoiler does on these is hide the front shackles. the spoiler wasn't used until later years.


the fan creates the low pressure zone.
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  #23  
Old 08-24-2018, 10:03 PM
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68glad 68glad is offline
350 Buick
 
Join Date: Jun 01, 2006
Location: stayton,oregon
Posts: 1,041
Quote:
Originally Posted by Ristow
Flex fans are a joke


100% agree especially wheeling offroad. Fan thinks your going 65mph and blades flatten out but really only going 5mph. Never again.
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  #24  
Old 08-31-2018, 01:35 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
Ok, so I finally had time to look at things a bit. I moved the trans cooler out of the way just to take that out of the picture, because the previous owner had it mounted in front of the condenser at an angle, meaning it was leaning forward. I was afraid it was creating a deadspot right behind it that was affecting airflow into 1/3 of the radiator (its a big cooler). I test drove it with the cooler out of the way, and no change. I did notice that the previous owner did put a flex fan on there, so I am now looking for a stock-type non flexible fan to mount, with the addition of a fan clutch. Anyone have any ideas on where to look for a stock fan? Im going to look at a few FSJ websites soon.
Im still suspicious though, as to why there is such a fast and drastic climb in temperature once I turn on the A/C. The compressor clutch isnt working all that well, as I recently noticed. It appears to be getting stuck sometimes when I switch on the A/C. I know it cycles on and off, but there is a constant scraping noise coming from it, and like I said, it stopped several times and I had to tap on it to release it so it could spin again. Maybe the compressor (the original one bolted back on after the motor swap by the previous owner) is on its last legs in addition to the clutch not working well is causing a lot more resistance than it normally should?
So for now Im looking for a factory style fan to which I will attach a clutch to, and looking at a new A/C compressor clutch.
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  #25  
Old 08-31-2018, 05:18 PM
gpcl16 gpcl16 is offline
232 I6
 
Join Date: Apr 02, 2016
Location: California
Posts: 117
The compressor putting extra load on the engine could have something to do with it. Do you notice a big drop in RPMs at idle when turning the AC on? Assuming you're running a carb, the idle speed would drop quite a bit if there was a heavier than normal load from a faulty compressor or blockage in the AC system. A slight drop 50-100 RPM would be normal.

Also just how much hotter are we talking here? Are you running an aftermarket gauge that shows you the actual temp or just a stock gauge with no numbers? Oftentimes stock gauges do not have a linear movement of the needle, in other words, there might be little difference between 180-205 then suddenly it climbs much faster after 205. You might only be running 5-10 degrees hotter which I would think is normal when running AC on a hot summer day.
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  #26  
Old 08-31-2018, 09:27 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
I havent really noticed what kind of an RPM drop there is, whether its at idle or cruising. Thats something I'll have to watch for.
While tooling along with the A/C off, it stabilizes at 195-200, and that is with the interior (stock) gauge at the 3/4 mark, and the aftermarket underhood gauge giving me that reading of between 195-200. I installed the underhood gauge so that I could get some actual numbers. Once I switch on the A/C, the A/C works just fine, but the coolant temp very quickly rises to 220, then continues to climb to 230. Yesterday I was testing things out again after moving the trans cooler out of the way, and as it was sitting in a parking lot at idle with the A/C still on, the underhood gauge climbed to about 240 in about 5 minutes. So at that point I just turned it off and let it sit until it cooled off.
As soon as I get a day off here coming up, I want to do a compression check, check the timing, and make sure the carb is set decently. But mostly I want to check the compression to ensure there isnt a leaking head gasket.
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  #27  
Old 09-01-2018, 09:00 AM
wiley-moeracing wiley-moeracing is offline
350 Buick
 
Join Date: Feb 15, 2010
Location: arizona
Posts: 976
can you place a box fan in front of the radiator while running with the a/c on and see if the temps drop or stabilize. That will show if its a airflow issue or something else. will help to narrow it down. Is your radiator cap functioning correctly?, I feel your pain here in phoenix area.
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  #28  
Old 09-01-2018, 12:13 PM
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babywag babywag is online now
out of order
 
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Location: Land of froot loops and cukcoo-nuts, CA
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Quote:
Originally Posted by AZChief
I did notice that the previous owner did put a flex fan on there, so I am now looking for a stock-type non flexible fan to mount, with the addition of a fan clutch. Anyone have any ideas on where to look for a stock fan?

Not a FSJ fan but I have an 18” 7 blade fan off a roadmaster.
IIRC the stock FS Jeep fan is 19”?
I stole/used the clutch on my Jeep so it should work/bolt up.
Shoot me a PM if you’re interested.
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  #29  
Old 09-01-2018, 02:48 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
I dont believe its an airflow issue at this point. I had the grill assembly off when I relocated the trans cooler out of the way, so I was able to clearly see the condition of the fins on the radiator, which were great because it was just recored (3-cores). The A/C condenser fins were in good shape as well, very little debris to clean out, and I straightened a few of the fins that needed it, and none of the fins seemed brittle or corroded, so Im ruling that out.
Aside from replacing the mechanical fan and adding a fan clutch, and replacing the A/C compressor clutch as well, Im going to look into the basics first, to include a compression check to ensure that I dont have combustion leakage into the cooling system, as well as a check of the ignition timing and fuel mixture.
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  #30  
Old 09-01-2018, 04:12 PM
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letank letank is offline
AMC 4 OH! 1
 
Join Date: Jun 03, 2002
Location: San Francisco
Posts: 3,818
Time to get an infra red thermometer, also known as non contact thermometer and measure the temp difference between the input and output of your radiator hoses.
If the engine is really cooking the coolant, you may need a better cooling system for those bored over 401...
21" fan from a dodge RV with 9 blades can be in your future, I read that it seems that the flow is not restricted, but in the end it is how much heat can the radiator extract, and how much flow to remove heat is designed in a specific system


Otherwise if it is really running lean, time for an oxygen sensor and have real data at various rpm.


Too much advance while crusing will increase the temp of the engine, and as usual always look for the cheapest solution to solve a problem!


post a pict of your shroud and fan combo please


I am running a 9 blade 17" fan and fan clutch out of a 560SL mercedes, FSJ fan on left side. Why, it is aluminum and 1 lbs lighter... more HP for my dinosaur.




and the result



and the bottom view, you need the opening to prevent a vacuum effect that will impede the airflow


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Last edited by letank : 09-01-2018 at 05:15 PM.
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  #31  
Old 09-01-2018, 06:03 PM
wiley-moeracing wiley-moeracing is offline
350 Buick
 
Join Date: Feb 15, 2010
Location: arizona
Posts: 976
You should have a shroud that goes all around the fan so it creates maximum pull through the radiator itself.
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  #32  
Old 09-02-2018, 01:33 PM
rapom rapom is offline
230 Tornado
 
Join Date: Aug 10, 2016
Location: Toledo, OH
Posts: 22
I think your high speed temp. problem will be fixed with this mod. I found that you can do to your thermo clutch. I did it and while I really wasn't overheating at highway speed. It still made a big difference and at 65mph I'm at only the halfway point on the temp gage where I was at the 3/4 point before the mod.

http://www.stl-vettes.com/65vette/co...tch_adjust.pdf

I found this link looking for a heavier duty thermo clutch that would come on earlier or at lower rpm's.

For cooling a stock 401 a 18" 7 blade high pitch 3-1/4" pitch like out of a 1977 caddy el dorado with a 472 v8 seems to be adequate matched to the stock shroud especially with a 180 mr gasket or robert shaw high flow thermostat. (stock fan is 16-7/8" or 17" 7 blade with a hair under 2-1/2" of pitch, another fan is from a 1981-1986 Cadillac with the 4.1L v8 it is 7 blade an 18 inches also with similar pitch right at 3" and moves a lot of air) i moved the MORE motor mounts up almost an inch since i have a 1" body lift to clear the 18" fan in stock shroud. Since i was going for a flat belly pan with my clocked dana 300 things needed to be shifted little any ways i re=drilled the more mounts 7/8" up and 3/8" for ward sliding the motor slightly ahead helped with valve cover clearance at the fire wall, moving it up allows you to continue using the stock radiator shroud.

I used a Hayden Severe duty fan clutch #2797 (buick with the diesel in the early 80's on some models like napa i had to notch the holes just a smidge to clear the bolts into the water pump but on a summit model i didn't, it was slotted deeper with universal slots). Also these fan clutches need some adjustment they like to engage at 210-220. Read this article about thermostatic fan clutch adjustment

I run 30% dextron synthetic coolant and 70% Distilled water with a 180* mr gasket high flow thermostat. Iw as running a 4 core brass radiator but recently on ebay there were some aluminium radiators for $139 + shipping another $30 called champion aluminium radiators, 3 row (3- 5/8" tubes) that are down flow and bolt in. for the price a good deal and seem to be providing good results for me.

I also changed to a synthetic motor oil 20/50 found i shed another 5 degrees across the board in engine temps.

Consider Evans NPG if you are having major cooling issues, check into it if you are really diggin for a different option to cooling. heard alot of good results i pondered looking at it in my jeep but so far the caddy fan with the ultra cheap aluminum down flow radiator seems to be sufficient

Last edited by rapom : 09-02-2018 at 01:49 PM.
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  #33  
Old 09-02-2018, 02:50 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
Thanks for all the input. Ive got a lot to cover as soon as a day off from work shows up, but Im really anxious to dive into this some more. As soon as I get more info on whats going on, or if something works, Ill be back on here right away!
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  #34  
Old 09-04-2018, 10:29 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
Compression check turned out fine, lowest number was 134 and the highest number was 145. So no indication of combustion gasses blowing into the coolant somewhere. Checking the timing and carb tomorrow.
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  #35  
Old 09-06-2018, 05:55 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
So here's the latest update for those who haven't gotten bored and moved on to other posts.
I checked the timing yesterday, and low and behold, found the timing at what I can best estimate at about 6 degrees retarded. The timing marks on this new timing cover I put on do not show any marks for retarded timing, The first arrow starts with TDC. So by looking at the spacing of the advanced timing marks, 6 degrees retarded is where it was at. Im not going to waste my time wondering why the previous owner had it set there. I went ahead and set the timing to 5 degrees advanced(yes, vacuum advance disconnected). So, Im not saying that is the be-all cure for my problem, but that sure does explain what was happening!
I checked the idle fuel settings and they were set in too lean, so I adjusted that in conjunction with the idle speed. The vacuum is strong and steady now as well.
I didnt get to test drive it yet, as I was pulling apart the exhaust to make sure the heat riser valve wasnt blocking the flow, and one of the studs sheared off. I am going to leave out the heat riser valve, replace all four studs, button it back up with some new seals, and give it a run. That wont happen until next week due to my schedule, but I will post the results. Later.
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  #36  
Old 09-06-2018, 08:03 PM
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rang-a-stang rang-a-stang is offline
304 AMC
 
Join Date: Oct 31, 2016
Location: Camarillo, CA
Posts: 2,339
My 79 Chief with a 401 really liked 10 degrees static timing at idle....
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  #37  
Old 09-07-2018, 11:15 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
Did you encounter any detonation with ten degrees advance, or was it good? What other mods do you have, parts and/or tuning?
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  #38  
Old 09-08-2018, 10:03 AM
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rang-a-stang rang-a-stang is offline
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Join Date: Oct 31, 2016
Location: Camarillo, CA
Posts: 2,339
None. Stock except for headers, no cat, and single 3" exhaust.
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  #39  
Old 09-08-2018, 02:51 PM
AZChief AZChief is offline
230 Tornado
 
Join Date: Aug 16, 2018
Location: AZ
Posts: 17
How does that 3" exhaust work for you, did you get a little more power out of it? The stock exhaust, especially the 'Y' pipe up front, doesnt look great at all, the flow cant be very good. I've already thought to myself that I'd be improving that in the future. Maybe 2 1/2" head pipes with a nice transition 'Y' into a 3" feeder into the muffler, good flowing muffler, and then maybe a 3" tailpipe. I bet that would wake up this engine.
I'll test drive it first to see if the adjustment in timing solved the hot condition, and if it runs well, maybe I'll bump the timing up a little more to see what I can get away with. Thanks.
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  #40  
Old 09-08-2018, 03:41 PM
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rang-a-stang rang-a-stang is offline
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Join Date: Oct 31, 2016
Location: Camarillo, CA
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Love it.

When I bought my rig, it had stock 360 exhaust with a plethora of exhaust leaks. I had the cat back made first becuase I have to pass CA smog. As soon as the cat back was done, I took it home, removed the manifolds, stock y-pipe, and cat and put the headers on, drove it back to the shop (open headers ) and had the new Y-pipe made.

I have Hedman headers for 79 and down, they flow into a 3" Y-pipe, down the passenger side of the truck into a Borla single 3" inlet, single 3" outlet, up over the axle and dumps out the stock location. The whole exhaust fits up in the chassis (my factory muffler hung below the chassis, as does the cat) so I gain a slight amount of ground clearance with it.

When it is running stock manifolds, cat, and 3" back it sounds totally mellow, and there was almost no noticeable difference in power. When it is running headers, no cat, and 3" exhaust there is a HUGE power difference, it sounds a bit raspy, and throttle response is noticeably better. In my opinion, exhaust should be the first upgrade to one of these. I would like to run a 3" high flow cat but CA says that is not legal.

Here are 2 threads I started regarding my exhuast:
http://www.ifsja.org/forums/vb/showthread.php?t=182656
http://www.ifsja.org/forums/vb/showt...hlight=exhaust
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