A Lazy Afternoon of Air-Cooled Fun

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Lanval
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Post by Lanval » Sun Aug 16, 2009 1:51 pm

I have a confession to make: sometimes, I think Colin might be lying to me. Oh, not about the little stuff, like the nature of man, or the importance of socialized health care, but the big stuff, like whether an air-cooled vanagon can cruise around at 70 mph without overheating and risking death by thrown rod or seized engine.

Now, there are are conflicting data here; on the one hand, Colin is a master at the air-cooled art, and can spot a crappy rebuild at 30 yards; he can see through your lies about constant care, and fix crappy running with a single screwdriver. Therefore, he should know.

On the other hand, there is my vanagon, which has never done anything to suggest that what Colin claims is possible is actually possible.

So: after Colin's visit a couple of weeks ago, the van seemed to be running as well as it ever has, I decided to give it a stress-test; unlike government stress-tests mine was real and actually measured performance. I woke up early and drove to Vegas and back on the same day, starting at 7am and returning around midnight (I blew a couple of hundred bucks in the afternoon while waiting for evening). Here are some observations from that trip:

AM ~ running reasonably in the 380's on the way to east Riverside. Heat up the pass, ran at 400-410 going up hill, cooled way down on the backside. Oil temp stayed happily in the 110 C. range. (to convert C. to F. just double for approx value.) Speed on this section was 60-65 until the hill.

Ran from 390-410 across the desert, oil temp again happily in the 110C. range. I attributed the higher range to higher ambient temps. Not too hot that day, mid-90's or so at the world's largest (non-working) thermometer. Speed on this section was 55-60. Mostly 55.

I waited at Baker and had tacos for lunch, allowing the engine to cool before the big pass. Whoa baby! I had to drive 30mph in 3rd or sometimes second to keep the head temps under 430 F.! Oil temp an unhappy 128-130 C. all the way up.

Cooled off during the run down into Vegas, ran at 400/120 C. in traffic in Vegas.

I started the return trip at 6:30pm, by which temperatures had just started to cool. My question was: "will cooler ambient temps at night affect running temperature"? Answer = no. The same or higher on the return trip. Driving 55-60 kept the head temp at 410-430 all the way back, regardless of speed (during this section I discovered that the head temps would drop 6 degrees per 5 mph drop in speed). Higher for uphill, lower for downhill (headtemps in the 265 range on the downhill into Baker!). Oil temp stayed at 110 C if it was relatively flat, jumped to 120-130 C. going uphill. The later it got, the more stable oil temp was at around 110.

***************************

The underlying issue is practical: I want to take my vanagon to Oregon in November for Thanksgiving, but I want to make sure that 18-20 hours of driving each way won't result in an unplanned stop at Go Westy or the Buslab.

The current answer seems to be: "Are you a gambling man?" which, after my brief but expensive stay in Vegas, I am not. But I'm still stuck with the fact that Colin knows these engines better than anyone I've ever heard of, so how could he be so wrong?

The answer is, I think, that he is not. In fact, I suspect this proves his point better than anything, given a couple of facts and some thinking. First, the head temps came up gradually, and stayed high, regardless of ambient temp. It got cool enough in the desert (I started using the heater around 10pm ~ and yes, it works. At least up front) that I would've expected the 40-50 degree difference to show, but it didn't. Given that, I suspect a developing vacuum leak affecting temps.

When Colin was here, he suspected a leak on the passenger side intake manifold, but if it was there, it was slight. It may have progressed under serious driving.

Colin probably won't remember, but when he was here last year (three months after I had the engine built) he saw that:
1) They hadn't hooked up the air-flappers
2) The air flappers were broken on the driver's side (where it directs air through the oil cooler)
Since this can't be fixed without taking the engine apart it has remained that way. I now suspect that the flap is not correctly set. It's neither open nor closed, but some in-between point. While driving around the relatively cool coast here in OC, it doesn't make a difference, but in real heat, it needs to open up but can't.

Some other thing may be at issue; the quality of the rebuild is an unknown; it doesn't leak a single drop of oil (unbelievable, but true), but several issues that Colin has spotted suggest sloppiness in the work of the guys who did the engine. So who knows what else is less than optimal.

******************************

All in all, this run was both dispiriting (does my van ever not need work?!) and enlightening (if my relatively poorly built and maintained engine could handle the toughest of tough, then what will it be like if I learn to build and fix the engine right?!).

Colin was telling the truth, I think; now it's for me to learn to listen to the engine and give it what it needs to do the job. I've got a few months til Thanksgiving, and more VW parts at my disposal (new and used) than anyone in this country (I live about 5 miles from Rimco, for example), so I'll see what I can do.

Colin, thanks for making me think for myself.

Cruise on, and I'll see you next year; even if by then you're helping me pick out a transporter, or build a new engine.

Best,

Michael L

As a final note, I'll add that Colin will say I am a gambling man. Why? I did this whole trip with NO oil pressure indicator. The line is shorted somewheres and I haven't fixed it yet... Sheesh. Oil pressure is for "Worried Willies" ~ "damn the torpedoes" I say.

ML

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blatzer
Getting Hooked!
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Post by blatzer » Sun Aug 16, 2009 3:56 pm

nice neat trim awning set up you got there- how about some closeups where it hooks to the van
good post, as well!
Enlighten the people, and tyranny and oppressions of body and mind will vanish like spirits at the dawn of day.
Thomas Jefferson

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Amskeptic
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Post by Amskeptic » Sun Aug 16, 2009 11:57 pm

Lanval wrote: AM ~ running reasonably in the 380's on the way to east Riverside.
the pass, ran at 400-410 going up hill,

Ran from 390-410 across the desert, oil temp again happily in the 110C. range. I attributed the higher range to higher ambient temps. Not too hot that day, mid-90's or so at the world's largest (non-working) thermometer. Speed on this section was 55-60. Mostly 55.

Baker big pass. 30mph in 3rd or sometimes second to keep the head temps under 430 F.! Oil temp an unhappy 128-130 C. all the way up.

return trip at 6:30pm, by which temperatures had just started to cool. My question was: "will cooler ambient temps at night affect running temperature"? Answer = no.
Doesn't seem too far out of the ordinary cooling flaps duly noted. 6:30PM is maybe cooler to us standing at 5' -6' above the pavement, but the pavement itself may still be higher.
Just for my learning, did you try holding 3rd at cooling fan optimum of 3,800RPM or so, which is 50 to 55 in 3rd?
Colin
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

Lanval
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Post by Lanval » Mon Aug 17, 2009 1:35 pm

Colin,

I did try it, on the way up out of Baker ~ I dropped down to 2nd to get the RPMs up while not forcing the engine to push more; it didn't seem to have any effect, but I suspect that I didn't give it enough time.

I've noted before that it takes a couple of minutes for the oil temps to come down after spiking, if the driving is otherwise normal (i.e. not coasting down a steep hill).

I agree the temps out were ballpark OK. The way back though, should have been the same or better (given lower temps ~ it was in the 60s by the time I hit Barstow), but in fact were higher.

I'll check around and see what's going on. Come Dec, we'll be moving (not being a student, I can't stay in student housing forever) and with any luck, I'll have a garage. If that's the case, and I still have the van, I may drop the engine and discover how to rebuild an engine myself.

Best,

Lanval

Addendum:

Colin, given the numbers I'm reporting here, do you think we're safe to go North in Nov? I'm planning to take 101 (I've never done the coast from Santa Barbara to SF), so we'll go a bit slower, and the temps should be more reasonable... we'll have a more substantial load though.

I should add ~ going TO Vegas, I carried a full load of water. On the way back I dumped it. Still hotter; I still think that there's a leak, but we won't know til I stick my head in there.

ML

reluctantartist
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Location: Bloomington, IN
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Post by reluctantartist » Thu Aug 20, 2009 9:34 pm

Lanval,

You can fix that flap without removing the engine. I had to get at the seal for the oil filter mount last year so I removed the cooling fan housing with the engine still in the car. It will take you a good part of the day to remove it, fix it, and put it back in.
82 Westy

Lanval
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Post by Lanval » Sun Aug 30, 2009 7:30 pm

Reluctant,

Are there any obvious starting points, or should I just start unbolting stuff in the general vicinity of my goal, and go from there?

Do any of the manuals give a decent exploded view? I'm thinking/hoping the Bentley does...

Lanval

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Amskeptic
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Post by Amskeptic » Mon Aug 31, 2009 2:42 pm

Lanval wrote:Reluctant,

Are there any obvious starting points, or should I just start unbolting stuff in the general vicinity of my goal, and go from there?

Do any of the manuals give a decent exploded view? I'm thinking/hoping the Bentley does...

Lanval
Rear tins, remove screws between housing and upper cylinder covers, alternator wiring, blower assembly, fan belt, fan bolts, heat exchanger covers (I'd remove the heat exchangers as well) keep alternator bolted to fan housing, fan housing nuts, and remove carefully.
Colin
BobD - 1978 Bus . . . . . . . . . . . 112,660 miles
Chloe - 1970 bus . . . . . . . . . . . 206,845 miles
Naranja - 1977 Westfalia . . . . . 112,885 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 1991 Lexus LS400 . . . 78,899 miles

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