[Vwdiesel] Why #3

[Doyt W. Echelberger]

At 03:59 PM 9/7/2005, you wrote:
>In a message dated 9/7/05 8:35:06 AM US Mountain Standard Time, 
>doyt at buckeye-express.com writes:
>
>
>>My take on that.........Those little diesels are basically high RPM engines
>>that aren't meant to be run slow under heavy load, like truck diesels. So,
>>it is fairly risky to lug those little diesels, and it is harder to lug one
>>that is moving a Jetta or Rabbit.....Rabbit/Jetta weight and wind
>>resistance at 65 mph just doesn't compare to that of a Vanagon.
>
>
>I would almost buy that if I hadn't driven a N/A diesel vanagon.  The 
>gearing is such that you really can't lug it.

We started out trying to explain Andrew's observation: "Every blown up 
vanagon diesel that I have heard about tossed rod #3.  Why is it always 
#3?  Is that the same for Rabbit/Jetta   (you don't hear about those
very often-vanagon diesel rod tossing is pandemic)?"

One thing for sure is different about Rabbits and Vanagone, regardless of 
who is shifting gears. the Vanagon diesel is ALWAYS moving about 4,700 
pounds of vehicle, which is at least twice the weight of my old Rabbit, 
curbing at about 2,100 pounds.

Over the same number of miles, the Vanagon diesel will have done more than 
twice the work than the one did in my Rabbit.

So, maybe total lifetime workload has something to do with it.


......................and I must add that if I'm not careful, I_ can _lug 
my Rabbit (2,100 lbs)  or my Jetta (more than that). But not very often. I 
have to use my judgement about when to change gears. Hills, load, wind 
resistance all change and the little diesel is doing all the work. It 
doesn't tend to bog down very often in either car. They are quire "peppy" 
in my opinion.

I'll bet those Vanagon drivers can't say the same thing about their diesel 
Vanagons (being "peppy.")

So, I have to entertain the possibility that using the same mill to push 
around about 4,700 pounds and who knows how much load of wind resistance 
adds up to more_ opportunity _to lug, and unquestionably more actual total 
work over the same number of miles.

Chances are high that the Vanagon diesel runs at higher speeds its entire 
life, compared to the diesels in the Rabbits/Jettas.

And possibly the resonance of vibration is different under such different 
lifetime speeds/loads......metal fatigue?

If #3 is usually the first to fail, it seems reasonable to expect it to 
fail  more frequently in engines that do twice the work and run  at higher 
RPMs over a lifetime than those in the Rabbit.

Again, I'm just trying to use reason to explain some observations. (Amateur 
reasoning at best.)

Doyt

>  The 4-speed maxes out at about 60 MPH.
>
>Andrew