Zenith Manifold

[SoCal'beaming]

Hi All ... Looking for this particular intake mani. with the port for the brake servo. ... Any help or leeds much appreciated!

.... Thanks, David

 

[twautomotive]

$50 for the manifold or $100 for the carbs and the manifold plus shipping. Tom

 

[SoCal'beaming]

PM sent Tom ... Thanks

 

[alpine_64]

David it's the series 3 manifold.. toms setup is ideal....but...on the carbs.. check the numbers as they could be the GT carbs which have the leaner jetting for the larger air cleaner.

 

[SoCal'beaming]

David it's the series 3 manifold.. toms setup is ideal....but...on the carbs.. check the numbers as they could be the GT carbs which have the leaner jetting for the larger air cleaner.

Michael ... What are the numbers I should look for, ... Ideal for?? ... I have a Bat+Wing set-up that I just acquired and was planning on running it on my "62 .

...... David

 

[alpine_64]

Michael ... What are the numbers I should look for, ... Ideal for?? ... I have a Bat+Wing set-up that I just acquired and was planning on running it on my "62 .

...... David

David, don't have them off the top of my head... @bernd_st might do... And iirc someone posted the Zenith parts numbers from the Parts book..

They may have been WIA not WIP iirc?

 

[SoCal'beaming]

Thanks Michael ... I'll ask Tom for the numbers and do some digging around for the info. ... unless someone chimes in and saves me the finger work .....

 

[husky drvr]

unless someone chimes in and saves me the finger work .....

Well, don't know the unit numbers - should be in the parts manual. Jetting is in "General Data" of WSM 124.

Those carb bodies do seem to display as WIA-3 series, and might be correct for s3-GT.

Hope this helps,

 

[bernd_st]

Unfortunately my Zenith parts schedule ends with late Series II while the WSM 124 doesn't state the telltailing 4 - digit numbers. Need to check my notes again, but I have something like 1763 or 1812 in the back of my mind for a Series 3 (Sports & /or GT)...

 

[SoCal'beaming]

Thanks Guys! ... Looks like a correct pair of 36 WIA-3's ... numbers are ... 1800 386 F and 1800 387 R

.... David

 

[husky drvr]

excerpt from parts manual:

 

[SoCal'beaming]

excerpt from parts manual:

View attachment 34151

Thanks for that conformation ... My 'ol laptop does not like to pull up lengthy pdf. files ... makes it sleepy!

............... David

 

[twautomotive]

Alpine 64 wrote - David it's the series 3 manifold.. toms setup is ideal....but...on the carbs.. check the numbers as they could be the GT carbs which have the leaner jetting for the larger air cleaner. Is this because the paper air filter flows less air than the rock strainers?

 

[SoCal'beaming]

Alpine 64 wrote - David it's the series 3 manifold.. toms setup is ideal....but...on the carbs.. check the numbers as they could be the GT carbs which have the leaner jetting for the larger air cleaner. Is this because the paper air filter flows less air than the rock strainers?

Tom .... I believe it's not just the air filter element, it's the hole Batwing contraption that's more restrictive ... and finding the air filter for it has been a challenge so far ... it's an ODD size (AC -A 2435) though I have found newer versions that will probably work better than the original. Baldwin makes one very close, but K&N has some better ones that might flow better and can be cleaned and reused.

........ David

 

[bernd_st]

Is this because the paper air filter flows less air than the rock strainers?

From theory yes - less flow with the batwing setup plus the 29mm venturis requiring smaller main jets to achieve proper mixture. I never had the chance to actually drive a twin Zenith S3 with batwing filter housing though. However Rootes must have had a certain motivation to design & offer this setup. This could have been:

- Better filtering-> specifically for certain export markets
- Less induction noise - > GT's were intended to adress the more luxury oriented clients
- More low end torque
- Better fuel economy

Perhaps a nice package somehow for more comfort oriented customers, while me definitely prefering the sports pedigree

 

[husky drvr]

Tom .... I believe it's not just the air filter element, it's the hole Batwing contraption that's more restrictive ... and finding the air filter for it has been a challenge so far ... it's an ODD size (AC -A 2435) though I have found newer versions that will probably work better than the original. Baldwin makes one very close, but K&N has some better ones that might flow better and can be cleaned and reused.

David,

You should realize the GT's 1600 engine would only require less than 125 cubic feet of air per minute, the engine itself was NOT tuned for maximum power (3GT's power rating was lower than 3ST), and the "batwing" and air filter were designed for placement and intake noise reduction, then you should realize those carbs are probably not tuned leaner due to airflow restrictions. The overall tune is one that allows the WIA3's power valve to cover the jetting to provide a more economical, tractable, and less noisy automobile. A daily drivable car more aligned with the day's thought of "GT", comfortable and sporting while not annoying.

 

[bernd_st]

Don, you absolutely hit the point.
Referencing to that table at least the Max torque was not improved over the Sports Version. We would need to see the actual curve over the whole RPM range to really compare the low end response. Think there were also graphs in the respective period motoring magazines. BHP significantly reduced as expected...

 

[SoCal'beaming]

Just came across this ....

 

[bernd_st]

A great find indeed! Wonder how much quieter it really was compared to the sports setup...

 

[SoCal'beaming]

A great find indeed! Wonder how much quieter it really was compared to the sports setup...

Here's the whole article https://www.sunbeamalpineowners.club/magazine_pdfs/1963MarchAutocarSeriesIIISportsandGT.PDF