Itinerant Air-Cooled

asiab3 wrote: ↑

Sat Mar 03, 2018 4:03 am

Remember that the factory had to get all four cylinders exhaust through the catalytic converter as well; that wasn't possible on the slightly-better-flowing (according to STF) 72-74 collector muffler setup.

Except that is exactly what VW did with the Federal air-cooled Vanagon exhaust, where they returned to the much simpler integrated manifold+heat exchanger, terminating in the same trapezoidal flanges used in the 72-74 exhausts. For which I am now even more grateful, having read Colin's tribulations with Naranja's plumbing. I mean, three days? I'm exhausted just reading about it.

But then, after having redesigned for elegant simplicity on the air-cooled Vanagons (well 'cepting the Cali emissions ones), they went to the opposite extreme on the water-cooled ones, as you've pointed out. One wonders at the design battles that must have taken place in VW's engineering departments back then.

Mr Blotto wrote: ↑

Fri Mar 02, 2018 8:07 pm

A) don't you scratch your head sometimes and wonder why the old German engineers couldn't think of a more elegant way to let that engine breathe while giving the cabin some heat? It IS an engineering feat, but far too many parts and changes in directions in that system.

B) I am surprised to see that you are taking Naranja on another lap. Still working the kinks out, or do you find it easier to work out of?

a) I can envision the engineers trying to come up with an emissions-certified engine. And this whole idea to exit the manifolds *forward* then turn the exhaust around gave us shivering Americans some nice long exchangers for some excellent heat, all the while gathering up the exhaust to enter the catalytic converter. Here, an illustration from twelve years ago, '72-'74 upper right, Naranja & Co. lower right, and lower left ... when Volkswagen said "screw off, California, now you're pissing us off" :

http://i187.photobucket.com/albums/x133 ... gine44.jpg




b) I am taking NaranjaWesty on this lap to bring it up to 9.5/10ths. We're only at 8/10ths. Did I mention that NaranjaWesty is the second nicest late-model bus in the country to drive? It is. The overall experience is not as tight as the BobD, but it is the most civilized highway VW I have driven. Since the first lap with NaranjaWesty was slightly inconvenient, I'd like to try a trouble-free joyful lap.
Colin

Amskeptic wrote:The interior surfaces were smoothed you know for better air flow at 8,000 rpm. Then everything was scrubbed in the sink with hot water and Dawn:

Do you think these protruding interior weld blobs help restrict the airflow into the classic "Gutless VW Exhaust Restriction" category, or do you think it only helps at extreme RPM? (What color Dremel stones did you use? I'm two orange stones deep and not even through the first U-pipe…)

Robbie

asiab3 wrote: ↑

Tue May 22, 2018 9:42 am

A) Do you think these protruding interior weld blobs help restrict the airflow into the classic "Gutless VW Exhaust Restriction" category, or do you think it only helps at extreme RPM?

B) (What color Dremel stones did you use? I'm two orange stones deep and not even through the first U-pipe…)

Robbie

a) I am not so interested in the "restricted air flow" aspects to weld blobs as I am interested in consistency between all cylinders' exhaust paths out, and I am highly interested in avoiding incandescent hot blob spots (especially in combustion chambers as you might remember when I attacked the raised edges of the exhaust seats and the sharp edges in Chloe's combustion chambers).

b) I used cutting wheels first, they make it easy, then I grind a bit for finish. Oh shall you wash well . . .
ColinInTexas

A) Ah, yes, we don't want one side of the engine flowing more than the other. I speculate that could show up as a nervous AFM wiper.

B) The mountain of shavings that came out of each surprised me. There will be much rinsing and scrubbing; no exhaust reversion getting any of this garbage in the combustion chambers.

Robbie

Jivermo wrote: ↑

Wed Feb 21, 2018 6:16 pm

At one point, Colin said to me, “Remind me, never to start the Itinerary with a three day stop, never, ever, again.”
Nah, I’m not gonna remind him. It was a lotta fun.

You sure didn't, either. This time February 14-18, it was a four-day marathon for me and even longer for you, and we all had a commensurately whole lotta boatload even more fun.

https://itinerant-air-cooled.com/viewto ... 78&t=13769