First real run since rebuild-long

[jimfoo]

I am copying some of this from what I sent to my Rover Mailing list, then will add on.
Well, I took my first long trip since the rebuild. I went with Peter Hope and a couple Disco owners to scout out new trails for this years Nat Rally. These were over in Grand Junction, so the trip consisted of around 500 miles, and climbing 2 passes. I did fine going out, but the temp still was a bit high, getting to 230 on the climb up to the Eisenhower Tunnel. The east side of Vail pass was no problem at 220 degrees. I was able to do the speed limit up both, and could have gone faster, but would have heated up more.
We did several trails , Rattlesnake Canyon, Bangs Canyon and Coal Canyon. Rattlesnake was almost a non-trail, more like a dirt road, so it won't be a rally trail. We ran this one as it has the highest concentration of arches aside from Arches NP in Utah. However we found that you can only see them from a hiking trail. It was around 100 degrees, so we didn't feel much like desert hiking. So we went to Bangs Canyon. This trail is probably a 7 out of 10. It has a lot of long steep hills, sometimes with rocky sections. The Rover did great on this other than running 230 degrees uphill. The torque seemed better, although it almost seemed like my gearing was lower. I thought suffix a and b had the same low range, but I'll have to check TeriAnn's site. We camped both days in the Bangs Canyon area, which was nice as almost no one was out there. The next day we met Keith Tanner at Starbucks , where I gave him a header for Basil. We then headed for Coal Canyon out of Palisade. It was a little cooler out that way, and I don't think the temp got much above 210, but the hills weren't quite as long, and there was a good breeze blowing. This trail had a road following a wash in a deep ravine, with a lot of the wash also being drivable. There were numerous side trails going up the steep canyon walls. At least 2 of them stopped at excellent views overlooking Palisade from the mesa top. We had to drive back home, so only explored for about half the day. With a little in town driving, 1/2 day trail, a lot of highway, and a tank which now leaks where the filler meets the tank, I was getting 24 MPG. I was running 230-240 degrees most of the way back, but it is almost all uphill. I got to 250 on the west side of Vail pass, and Pete was getting high oil temps, so we both stopped to cool down once. Once I started back up, I decided to see what I could do going up. I got up to 61 MPH, still accelerating, but the temp was back up to 240, so I backed off. I have a couple ideas I want to try to see if I can keep the temp under control. I'm sure the hot weather didn't help any though.
I have pictures up at: http://forum.solihullsociety.org/cphoto/index.php Click on Colorado Trails, then Rattlesnake Canyon, Bangs Canyon and Coal Canyon to see the trip.

The engine had great response off-road, even without my manual vane control, so I may remove it. The intermediate spring governor mod was no problem with such a heavy vehicle on the pavement, but I had to be a little more careful off-road, especially in 1st low range as it was almost a little jumpy, quickly picking up revs after you pass 1500 RPM. Even idling downhill, once past 1500 RPM it would speed up enough to have to use the braakes. As long as I wasn't above 1500, it would hold the truck back just fine. It is drivable that way, but you just have to be more aware. It does seem to fuel better at higher RPM's. I'm not sure if the percieved better low RPM torque is a function of possible gearing changes, advancing the timing, a VNT turbo, the governor mod or the rebuild, but I like it.
What I didn't like is the temps I was running at going uphill. I could floor it to pass a truck, going from 65 to 80, and the temp would rise almost as fast as the boost gauge. I'm not sure if heat travels through the head this fast, or if the HG is leaking, but when idling, I get NO bubbles in the overflow, and I am running an open system with the Evans coolant. So if the HG does leak, it only does it at higher throttle. I am questioning if my fan is maybe too weak as it seems like my much smaller IC fan moves more air. I may also put a valve on the heater line as whatever flows through it never sees the radiator, so could become significant at higher temps. I could also move the IC from in front of the rad, but don't have many places to put it. I had to put my oil filter under the rad as there was no room for it in the engine compartment. On my way up Vail Pass, the bracket for my actuator had all the vibration it could take, and it broke off, giving me uncontrolled max boost. So I removed the vane control cable and just ran with them open. I reached 15 PSI @ 3000 RPM, full throttle with open vanes on my GT1749V at 10000' elevation. I'm wondering if I should try to tighten the head bolts a little more(ARP). Maybe the torque specs are for the 1.6 and the 1.9 might need more?
Any thoughts on any of the above?

[Otis2]

Your oil temperatures are suggestive that your oil "cooler" on this engine is just the stock water/oil heat exchanger.

I would expect much better results if you got rid of that thing, and replaced it with a sandwich plate for an air-cooled oil cooler.

I've considered doing that with my AAZ.  Supposedly the Trans-Dapt oil cooler sandwich adapter (part # 1313) will fit an AAZ.  The spike for the oil filter uses 3/4 - 16 threads, the same as many U.S. Ford engines.

But you already have a remote oil filter adapter on there, so maybe it's possible to plumb an oil cooler radiator into that same oil circuit without doing much else.  The only trick would be trying to mount a thermostat.  You don't want the oil cooler to work when the temps are below 180 F, but you don't want to interrupt the circuit to the oil filter below 180 F either.  So to have both the oil cooler radiator and the remote oil filter on the same plumbing circuit could be a bit tricky.

[jimfoo]

I already have 2 air/oil coolers mounted behind the radiator, with a thermostat in the adapter.  The temps I have listed are WATER temps. I do have the stock one in the mix, but only to adapt the adapter to the filter. It has no water lines to it. Thought it might make a great hot water heater for showers while camping.  

[Otis2]

Wow, that seems crazy high for water temps.  That's why I assumed you were talking about oil.  250 F, jesus christ.

Just curious, what are your oil temps once the water temps shoot up that high?

Are you sure your radiator is not plugged?  Maybe shoot it with one of those infra-red heat sensor guns to make sure it's all flowing well, and not partly blocked.

There are lots of people around who report high oil temps with AAZs mounted in heavy applications (eg. Vanagon/T3), but if they have good radiators, then water temps are not usually a problem.

[jimfoo]

I don't have an oil temp gauge. The rad is brand new, but I don't know how it compares size wise to what was stock on an AAZ equipped car. My truck also weighs about 3500 lbs, so is quite a bit heavier than a stock VW.

[deepmud]

What are the rev's you are running, Jim? I know with small tires my temps would climb rapidly to 220 (where my non-Evans coolant was about thru doing it's job).

I wish there was more information available as to how MUCH hotter you can run the engine with Evans - but my gut says the long term limit will be your oil - if you run sythetic you can run hotter, and 250 may be ok. 250 is crazy hot for normal coolant, but it seems like cast iron and aluminum would be ok with that as long as the system was still doing it's job - in normal coolant I'd expect hot spots and run-away localized heating in the head, which is where the warping usually comes from.

The boil point of Evens is what? 380? Is that at sea level?

[jimfoo]

about 2900 RPM @ 65 MPH, obviously higher at closer to 75

[deepmud]

that's not that crazy an rpm - less than 3000 sounds pretty good - with my 35-ish Baja Claws (more like 34" measured) and about a 5.20-ish  final drive stock-suzuki drive ratio I was getting about 3300-ish at 65mph - but with temps in the 70's and fairly flat driving my coolant would run about 215.

I think comparisons to the Vanagons are good - they are heavier but have lower mechanical friction losses(small, narrow tires, no solid axle 4x4 drivetrain), and similar aerodynamics(barn door). Does a Vanagon have a larger radiator than a Quantum or Jetta diesel? Bigger/faster water pump?

[jtanguay]

what kind of thermostat are you running?? what temp?? did you try swapping for a cooler one?

if i were you, i would run little resistored led's from the thermoswitch on the rad (assuming you're using the VW rad...) so that you could see if the thermoswitch is reading the right temps on the opposite side.  I had the same problem that you are describing with my car.  my t-stat was only opening about half way, and around 95-100C which wasn't cool at all.

good luck!

[jimfoo]

VW stat that I modified to close off the internal passage a little sooner to send more water to the rad sooner. I did this after my first heat problems. I checked it in water and it works correctly. Air temps in Grand Junction were at least 100, GPS said 41 C on one trail. Vail pass was cooler, but at least in the upper 70's. The stat is an 87 C one. After looking at fans, mine seems low on the CFM for similar sized ones.

[jtanguay]

maybe you should source out one of those mk3 dual fan setups? that way the whole rad has air moving over it.

[Otis2]

I am questioning if my fan is maybe too weak as it seems like my much smaller IC fan moves more air. I may also put a valve on the heater line as whatever flows through it never sees the radiator, so could become significant at higher temps. I could also move the IC from in front of the rad, but don't have many places to put it.

I don't see how the fan should have much to do with it, if the temps are climbing that fast on the highway.  60 + mph of vehicle speed should provide all the airflow Jim needs, even if the fans shut off completely.  

If the temperature was only spiking on low-speed, high-load, 4x4 crawling, then would I suspect the fans to make a big difference.

Jim, are you saying that you have no heater core, but you just connected the two heater hoses together directly?  That would definitely reduce flow to the radiator.  It would be better to cap those hoses off, if you are not running a heater core.  

If you are running the heater core, then as an experiment, crank on the heat & heater fan, and see what happens to your water temps.  That would be like adding temporary extra radiator capacity.

Deepmud,  the Vanagon radiator is much bigger than the VW car radiators, but it uses the same water pump as the cars.  I have about the same top gear ratio as your Suzuki, with my standard Vanagon 4-speed trans.  So I spin my AAZ at 3275 at 65 mph and 3800 rpm at 75 mph, even though my tires are already 2" greater diameter than stock (stock is only 25.5").  I don't have a calibrated water gauge, just the factory VW one, which never goes beyond the half-way mark on the highway, so I assume my water temp is just fine.

[jimfoo]

I don't see how the fan should have much to do with it, if the temps are climbing that fast on the highway.  60 + mph of vehicle speed should provide all the airflow Jim needs, even if the fans shut off completely.  

If the temperature was only spiking on low-speed, high-load, 4x4 crawling, then would I suspect the fans to make a big difference.

Jim, are you saying that you have no heater core, but you just connected the two heater hoses together directly?  That would definitely reduce flow to the radiator.  It would be better to cap those hoses off, if you are not running a heater core.  

If you are running the heater core, then as an experiment, crank on the heat & heater fan, and see what happens to your water temps.  That would be like adding temporary extra radiator capacity.

Deepmud,  the Vanagon radiator is much bigger than the VW car radiators, but it uses the same water pump as the cars.  I have about the same top gear ratio as your Suzuki, with my standard Vanagon 4-speed trans.  So I spin my AAZ at 3275 at 65 mph and 3800 rpm at 75 mph, even though my tires are already 2" greater diameter than stock (stock is only 25.5").  I don't have a calibrated water gauge, just the factory VW one, which never goes beyond the half-way mark on the highway, so I assume my water temp is just fine.

Well, there was a tailwind on the highway, so airflow wasn't what it could have been. I was hot on some trails, and going uphill on the highway. I do have 2 heaters actually, but the bigger one is drawing air from the engine compartment, which is quite hot to begin with. I guess I'll start with the easier stuff and work my way up the list. I'm just glad that even revving it, I don't see any bubbles in the coolant. Just what are the dimensions of the Vanagon radiator?