field trials

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

friel01

friel01

10 Year 15 Year 20 Year
Joined
Nov 16, 2005
Threads
38
Messages
422
Location
Tucson, az
Continuing the test runs of my new truck. Have been driving it all over town, no issues, and finally got my 18" drop hitch, so today I installed the trailer brake controller, and hitched up the Airstream (1961, Overlander, 26ft), and took it on a test run up to Superior and back. Just wanted to see how it would do towing and in particular towing uphill.

As soon as I hooked up, I could sure feel the trailer back there. That is interesting since with an 80 series, you really don't feel it on flat ground, but you sure feel it up hill. But this one felt it right off. The airstream is pretty easy to tow actually, it tracks nicely, and isnt that heavy (maybe 3500lbs dry).

So hopped on the US60 eastbound and headed for Superior. Even though I felt the trailer more, I had no trouble going highway speeds. It did make it run about 10 degrees warmer (but it has barely been running 185 without the trailer, so 195 is not too bad).

Going up the hill to Gonzolas Pass, it definitly did not slow as much as the 80 series. But it did warm up faster than the 80. I dont know if that is just the smaller radiator I am forced to run (compared to the 80), or other factors. But although it stayed in a safe enough range, I was not happy with the climbing temps (and this was a nice day, and I have yet to burden it with AC, which only increases my worry for the future). So I made it to Superior no issues, made it back just as good. Need to think about the temp issues and see if there is some resolution... Any ideas?
DSC00898.webp
DSC00900.webp
 
No suggestions, but that is a classic setup. Congratulations.
 
Not sure I have any real ideas but I LOVE the set up. When I saw your great truck at the meet the first thing I said when looking in the engine bay was ....wow then there isn't a shroud and everything is REALLY close. I think the way things are set you aren't using large parts of the radiator due to the fan being so close without a shroud. I am NO expert and I am sure Kevin will have some more technical input.
 
great-looking truck :cheers:

do you have space for a selectable pusher fan ?

that's what I use, since I do not have a shroud, either (this project has moved up on the priority list since today :D)

Jeg's used to have a "slim-line" type, but I am sure other major suppliers do, too
 
yeah, no room for a shroud, or I should say, no room to place the fan back at all to alow the shroud to duct. I could block off the non, fan parts, but doesnt seem like that would really move the air to the fan. I do actually have these rubber spacer rings that came witht eh spal fan to hold it 1/4 inch off the radiator to create a seal to the radiator and increase the pull. And no extra room in the front for a pusher fan either. I have heard/read that at highway speeds electric fans can actually restrict airflow and several hotrod shops sell switches that monitor your speed sensor and automatically turn off the electric fan above 60pmh.

But it runs so darn cool without a trailer. Like amazingly cool.

I was thinking maybe taking it to AZTPI (who do a lot of lt1 and ls1 conversions and talk to them. It seems to idle a bit high, and perhaps havingthe ECU computer flashed to modify idle, timing, transmisison shift points etc with their experienced hands might make it run cooler under heavy load.
 
I replaced the stock grille mesh with some from Ace that mounts closer to the bezel, clearing enough space for a pusher fan :hillbilly:

and then I mounted my sombrero decal onto that (with ducttape no less :hillbilly:) - hardly anybody ever notices that the mesh pattern is not exactly OEM :hillbilly:
 
I squeezed a bit of extra room out of my grill too, but I used it the space with a AC evaporator, and a transmission cooler. So thr eis still no pusher fan room.

And not to discount the discussion of a shroud (because I am far from an expert), but the more I think about it, if it were a shrouding issue, I would expect that to manifest itself at low speeds/ sitting still, not at highway speeds. And as I said, it runs so cool at low speeds that at first I didnt believe my gauge was working, so I actually ran it in my garage with the cap off and a thermometer stuck in the fluid to make sure the thermostat was opening properly and that the gauge was in fact telling me the truth.

Another thought, maybe it isnt able to move anough air OUT of the engine compartment at speed?
 
maybe I missed it, do you have a 2F or a 350 motor ?

I know nothing about 350 conversions :meh:
 
Howdy! You may need to upgrade the water pump. Summit offers several brands that are supposed to give you 30% more flow, but you can go directly to Flowkooler.com and buy the same thing for about 1/2 the price. I am running one, and I am very happy with it. John
 
No room for a shroud for the engine fan. Too bad, that would help.

Another trick for that engine bay is to shroud the front side of the radiator top and sides between the grill and radiator. Keeps the hot air from the engine being pulled through at low speeds. But you're already cool there.

Pusher fan too as others have said.

Stock Radiator? Cross flow is better, aluminum better yet.
 
It is an aluminum cross flow radiator. The biggest I could fit in the rather tight confines of an fj40 between the headlight buckets. I hate to be argumentative, but I dont think a shroud will do anything for me at high speeds, and at low speeds or sitting still I have no problem.

Anyone ever fab up a scoop between the lower frame rails to catch air and direct it up into the radiator? There is so little actual airflow room in hte bib, maybe catching some more and redirecting would help.
 
I would lean towards more airflow and not more coolant flow. If coolant passes thru the radiator TOO fast it doesn't have time to cool down and so you're just dumping very hot coolant back into the engine. That's my 2 cents anyway.
 
Gotta agree with Ray K. Which brings the question of what temp thermostat are you running?

And that idea of getting the air out of the engine bay at speed is something to consider. The hood louvers would take care of it I think, but more flow thru is better.

Are there big hot headers in there?
 
Are your hoses collasping at high RPM?

Fan are designed to work with a shroud otherwise the air fly off the tips and makes them very inefficent. At speed you could be introducing air into your engine compartment from undrneath and producing engine compartment presure and not getting the flow you think you are.

Pushing hard up a hill with my supercharged 80 would have problems with heat with a Ron Davis Alm radiator and it was all about the fan being a POS.
 
I'm runing a low temp thermostat (I think it is 160 degrees). And again, I tested it with the cap off and a thermometer int he coolant, and it started flowing right on at 160).

Phil, My fan is a Spal, the highest pull rate I could get in the slim porfile version (didnt have the room for more). It doesnt have a shroud inthe traditional big metal thing that covers the whole radiator except for where the fan is sort of sense, but it does have these rubber spacers that seal the fan frame to the radiator so that the tips of the fan do not loose the air flow like you were mentioning.

I dont know about the hose collapsing, that might be a possibility, my top hose is pretty long, it could be collapsing I suppose... will have to pull my hood off to find out though, and even then not sure I will be able to tell. Interesting idea though.
 
195 doens't really sound bad at all.... My 06 2500hd runs around 200 all the time and thats from the factory. Equipped with a 6.0.
A ls1 is going to run better at a little higher temperture honestly.

As far as I know an Ideal temperature for an ls1 to make horsepower is 210* Obviously your not racing so you don't care if the temperature is lower but if its running under 210 I wouldn't change a thing as it would be pointless.

If it doesn't spike over 230* on climbs your defiantly fine as far as damage goes.

Most factory thermostats open around 190 on high performance engines.
 
You must log in or register to reply here.

Share this page

Back
Top Bottom