Distributor advances too much

I brought my '74 Super Beetle to the VW shop and had new points
installed, valves, timing, idle and mixture adjusted. The mechanic
showed me that my distributor was advancing the spark 43 degrees at
maximum rpm. He told me that for my dual vacuum 1600 engine the maximum
advance should be 34 degrees and that I was overheating the engine. The
only thing he could do for me was to plug the advance hose and adjust
the timing to get 27 degrees maximum advance at maximum rpm.

I would be driving with a distributor with only centrifugal advance. I
drove my car with a 009 but went back to a dual advance distributor.
With the 009 the car couldn't go up hills. I notice that he made the
timing adjustments with the retard hose still connected. Shouldn't he
have removed and plugged the retard hose?

Thank you

azazel scratch wrote:
> I brought my '74 Super Beetle to the VW shop and had new points
> installed, valves, timing, idle and mixture adjusted. The mechanic
> showed me that my distributor was advancing the spark 43 degrees at
> maximum rpm. He told me that for my dual vacuum 1600 engine the maximum
> advance should be 34 degrees and that I was overheating the engine. The
> only thing he could do for me was to plug the advance hose and adjust
> the timing to get 27 degrees maximum advance at maximum rpm.
>
> I would be driving with a distributor with only centrifugal advance. I
> drove my car with a 009 but went back to a dual advance distributor.
> With the 009 the car couldn't go up hills. I notice that he made the
> timing adjustments with the retard hose still connected. Shouldn't he
> have removed and plugged the retard hose?
>
> Thank you
>
>

He should have plugged the advance hose before doing the all in
mechanical advance test.
During cruising conditions on a level surface your total advance(Mech
and vacuum) should total some 44 degrees or there abouts..

The engine likes to see 28 to 34 degrees under full load and no vacuum
advance..

Seems like your mechanic in charge is not fully into aircooleds..

J.

"P.J. Berg" wrote

Seems like your mechanic in charge is not fully into aircooleds..

J.

Or even into understanding basic vacuum advance, aircooled or not.

Under a load, i.e. driving down the road, vacuum advance GOES away.

Vacuum advance only comes in when you accelerate or rev the engine in neutral.

Cruising down the highway, you just have centrifugal advance.

Your mechanic needs to go to City College and retake Auto Mechanics 101. Problem is, all they teach
now is computerized crap and how to replace parts.

"Karl" > wrote in message
news
>
> "P.J. Berg" wrote
>
> Seems like your mechanic in charge is not fully into aircooleds..
>
> J.
>
> Or even into understanding basic vacuum advance, aircooled or not.
>
> Under a load, i.e. driving down the road, vacuum advance GOES away.

No.


>
> Vacuum advance only comes in when you accelerate or rev the engine in
neutral.

No.
>
> Cruising down the highway, you just have centrifugal advance.

No, again.
>
> Your mechanic needs to go to City College and retake Auto Mechanics 101.

Join him.

Karl wrote:
> "P.J. Berg" wrote
>
> Seems like your mechanic in charge is not fully into aircooleds..
>
> J.
>
> Or even into understanding basic vacuum advance, aircooled or not.
>
> Under a load, i.e. driving down the road, vacuum advance GOES away.
>
> Vacuum advance only comes in when you accelerate or rev the engine in neutral.
>
> Cruising down the highway, you just have centrifugal advance.
>
> Your mechanic needs to go to City College and retake Auto Mechanics 101. Problem is, all they teach
> now is computerized crap and how to replace parts.
>
>

Wrong!!

J.

Karl wrote:
> "P.J. Berg" wrote
>
> Seems like your mechanic in charge is not fully into aircooleds..
>
> J.
>
> Or even into understanding basic vacuum advance, aircooled or not.
>
> Under a load, i.e. driving down the road, vacuum advance GOES away.
>
> Vacuum advance only comes in when you accelerate or rev the engine in neutral.
>
> Cruising down the highway, you just have centrifugal advance.
>
> Your mechanic needs to go to City College and retake Auto Mechanics 101. Problem is, all they teach
> now is computerized crap and how to replace parts.

Cruising at steady speed and very small throttle openings gives you
strong vacuum at the throttle plate, where the vacuum signal for the
distributor is taken. I.e. max advance.

Accelerating: At first, when you touch the pedal, you get6 a sudden rush
of gasoline from the accelerator jet, to accomodate the even bigger rush
of air going in. On top of that you get a strong vacuum signal just as
you step on the gas pedal. Helps kick things in motion. After that, the
more throttle you give, the LESS vacuum there is.

Vacuum is strong ONLY at very small throttle openings. Load or no load.
It's a strict effect of air being sucked through a narrow gap between
throttle plate and carburator body. Small gap, huge suction, FAST
airspeed at the vacuum port. Open the throttle wide open, and the
overall volume of air going in grows, but the SPEED at the vacuum port
actually drops.

At cruising speeds you have very little load, and small throttle
openings, so it's safe to have more ignition advance.

Jan

JimBob wrote:
> "Karl" > wrote in message
> news >
>>"P.J. Berg" wrote
>>
>> Seems like your mechanic in charge is not fully into aircooleds..
>>
>> J.
>>
>>Or even into understanding basic vacuum advance, aircooled or not.
>>
>>Under a load, i.e. driving down the road, vacuum advance GOES away.
>
>
> No.

Contradicting terms the under a load, vacuum indeed goes away.
But cruising around at steady speed is not "under load". That's when you
get the benefit of vacuum advance.


>
>
>
>>Vacuum advance only comes in when you accelerate or rev the engine in
>
> neutral.
>
> No.

Precisely opposite


Jan

Sorry JimBob, you need to go back to 101 also.


"JimBob" > wrote in message news:2_fIe.13676$MO.8339@lakeread04...
>
> "Karl" > wrote in message
> news
>>
>> "P.J. Berg" wrote
>>
>> Seems like your mechanic in charge is not fully into aircooleds..
>>
>> J.
>>
>> Or even into understanding basic vacuum advance, aircooled or not.
>>
>> Under a load, i.e. driving down the road, vacuum advance GOES away.
>
> No.
>
>
>>
>> Vacuum advance only comes in when you accelerate or rev the engine in
> neutral.
>
> No.
>>
>> Cruising down the highway, you just have centrifugal advance.
>
> No, again.
>>
>> Your mechanic needs to go to City College and retake Auto Mechanics 101.
>
> Join him.
>
>

"Karl" > wrote in message
...
> Sorry JimBob, you need to go back to 101 also.
>
>

the sad thing is, you actually believe that. try doing some research, i
won't do it for you. the internet is an abundance of information if you seek
it out. two minutes on google and you will be back here admitting your
mistakes.

I see reading in not high up on your list of things to do today. Not sure where you looked on
Google... but here is one of the 1st links I found doing a JimBob oops I mean a simple search:
http://www.sporttruck.com/techarticl...03/index5.html

Scroll down to the vacuum advance section.....

"Vacuum advance also adds timing to the engine, but it's based on engine load and is controlled by
intake-manifold vacuum. When the throttle is partially open (highway cruising), manifold vacuum is
high. This vacuum signal is routed to the distributor and "pulls" on the vacuum advance canister to
create more ignition timing. As the throttle opening increases, load increases and manifold vacuum
decreases. At wide-open throttle (WOT), manifold vacuum is at or near zero, and the vacuum advance
produces no additional ignition timing."

Hmmm, let's see what I wrote:

Under a load, i.e. driving down the road, vacuum advance GOES away.
and
Vacuum advance only comes in when you accelerate or rev the engine in neutral.

Hmmm, let's see..... I said "under a load vacuum advance goes away" and the link said "As the
throttle opening increases, load increases and manifold vacuum decreases"

Yep, I guess you're right, BOTH the link and I are wrong. Huh?

Get a long piece of vacuum hose and a vacuum gauge. Tee into your ported hose going to the vacuum
advance. You do have one? Or do you still believe a 009 is the greatest thing since sliced bread?
Now go drive your vehicle and watch the gauge. You may learn something.



"JimBob" > wrote in message news:uRwIe.13715$MO.4104@lakeread04...
>
> "Karl" > wrote in message
> ...
>> Sorry JimBob, you need to go back to 101 also.
>>
>>
>
> the sad thing is, you actually believe that. try doing some research, i
> won't do it for you. the internet is an abundance of information if you seek
> it out. two minutes on google and you will be back here admitting your
> mistakes.
>
>