[T3] Diagnosis help for a badly running 1971 VW 411

[Sean Bartnik]

> On Aug 14, 2019, at 11:17 AM, Jim Adney <jadney at vwtype3.org> wrote:
> 
>> On 13 Aug 2019 at 21:18, Dave Hall wrote:
>> 
>> The Type 3 dual carb engine overproduction has definitely been confirmed
>> as being used mainly in the Type 2.  It was also used as an industrial
>> engine. 

Confirmed by who? I don’t think this is correct and I’ve certainly never seen or even heard of a Type 3 engine ever being installed in a Bus. 

> Which brings up the question: What did VW have to do to the bus body to 
> get cooling air into the Type 4 engine? Did they have to lengthen the body or 
> just shorten that shelf behind the engine?

I think the latter, Jim. There were some cosmetic changes made in the Bus body for ‘72 (bigger D-pillar air scoops, big taillights) which coincided with the introduction of the Type 4. While the Type 4 engine was the only engine in USA Buses from ‘72 on, in many other markets the Type 1 engine remained standard with the Type 4 engine as an option. 

> Did they make airducts in the body 
> or just seal the engine, top from bottom, and let the engine suck from the air 
> above?

No air ducts in the body. As far as I know the Type 3 is unique among air cooled VWs in that regard. 

The Bus with Type 4 engine just has tin and a seal to seal the engine to body like Beetles. The D-pillar scoops admit fresh air to the engine compartment and the hot air is dumped underneath. 

The body cutout for the engine is definitely larger in ‘72 and later Buses. Later Buses with Type 1 engines have massive expanses of tin. 😄