Intake Manifold (113.129 701A vs 4 113.129.701)

[jerry montano]

I've been running the 701A manifold on my 61' 1200 but found that the heat risers are badly clogged with carbon. I bought a used manifold (4 113.129.701) that was said to match my 1200 engine. However, even though the 4 manifold will fit properly on my engine, I notice that the 4 manifold tubing where the fuel/air pass is a smaller diameter than my 701A (small difference). The car runs very nicely with the 701A (apart from no heat riser heat) and I want to know if the 4 manifold will affect performance much, and how I can tell the original applications of these respective manifolds.

Engine number is 5313482 and I'm trying to bring everything to stock specs as much as possible.

Any insight's much appreciated.

_________________
69' Westy
73’ Adventure Wagen Hightop
81’ Westy

[Ojai63dbl]

I think theyre interchangeable with the exception of the brass o-ring into head .

A is 32mm and D is 34 mm I think.

Someone correct me or Ill measure it when i go to garage.

Glutamondo will know this is he is lurking

[ryans]

I believe that, in order to use the smaller diameter one with your heads, there is a special adapter gasket that you will need. It tapers from the head to the manifold.

[jerry montano]

My apologies I accidentally said i had a "D" manifold. It's actually a "4 113.129.701" manifold. There's no letter after the number, but there's a 4 before the VW logo and number (per the pic). I corrected my original post to reflect this.

The manifolds have the exact same specs on the ends that bolt to the heads. But the diameter of the rest of the tubing is different between the two manifolds.
_________________
69' Westy
73’ Adventure Wagen Hightop
81’ Westy

[branston]

Heres the link to glutomodo's post on the subject & showing the adapter ring.

http://www.thesamba.com/vw/forum/viewtopic.php?t=540431&highlight=intake

I've been unclogging pre-heats on 40hp intakes today and been and measured:

701
O/Dia at head = 32mm
701A
O/Dia at head = 32mm
701D
O/Dia at head = 34mm

The diameters actually measure about .25 to .5mm less so the above dimensions are nominal.

Additionally the intake diameter at the flange where the carb sits is not the same as follows:
701 = 30mm
701A = 28mm
701D = 28mm

The adapter ring 113 129 707 is still available from VW Germany:

113 129 707 ring Genuine Part 4.45 €
(from their inventory tonight)

if you go to VW Germanys Kaferbible here:
http://www.vw-classicparts.de/wissenswerft/page2flip/Ersatzteilkatalog%20_Typ_1/#/198

and here:
http://www.vw-classicparts.de/wissenswerft/page2flip/Ersatzteilkatalog%20_Typ_1/#/200

you will see dimensions of the conversion ring against item# part # 113 129 707

let me know if the links don't work

[jerry montano]

Thanks for this very helpful info Branston. I didnt realize the 701
had a larger intake diameter than the 701A. When I compared the two the 701 seems to be the smaller (in outside diameter) of the two. Is the 701 an earlier manifold than the 701A?
_________________
69' Westy
73’ Adventure Wagen Hightop
81’ Westy

[branston]

Jerry, to be honest I never took the time to investigate the subtle differences until you asked. I've had a bunch of inquiries for my refurbished manifolds in the classified ads.

Strangely most were for 40hp manifolds. Anyway I had all three together including a NOS 701 and measured them. I also noticed that the internal diameters varied and measured them too but didn't post the dimensions (I won't be able to add them until the end of the week as I'm out of town from today)

I too was surprised to see the intake carb flange to be larger. In fact the hole in the NOS 701 flange is flared out to 30mm from 28mm within the thickness of the flange. It seems strange that the earlier part number has a diameter to match a later carb. 28mm came before 30mm right?

The NOS 701 intake had VW's inventory tag on it with a 701D number but 701 clearly cast into the aluminum.

I posted a link to he kaferbible. It needs someone with a better knowledge of the parts system to interpret it.

Lastly if you want your old intake refurbished I'll happily do it it for you.

[glutamodo]

[branston]

I guess i just have a faster connection, nevertheless it isn't the fastest and I agree the old site was much better.

I hoped you'd come up with knowledgeable comments and you did. many thanks.

Buying off VW Germany is so simple, an email requesting what you are looking for through their email link, they often get back within 24 hrs. the shipping is a fixed price (the last time 16 euros) and here in 48 hrs. I've spoken with them many times and the are very helpful. The downside is they are partnering with a few compies (ie VW Heritage in the UK) and the NOS stuff is rapidly draining away, 18 months ago I could find almost anything, now it the inventory is littered with Classic VW (wolfsburwest and others) parts sold by VW. and prices have risen.

But it is still the best place for OG VW NOS parts and of course their key cutting service.

Oh and thanks for posting the photos of the compensating rings, never seen one before

[Ojai63dbl]

anyone selling the adapter ring anymore locally in US. Im assuming Id need to buy quite a few to offset the cost of the shipping.

[Ojai63dbl]

whats the contact info for the VW-original parts

[jerry montano]

Just wanted to give an update on my manifold comparison question:

I ended up installing the 4 113.129.701 manifold that has a slightly smaller diameter than the 113.129.701A, since I couldn't clear out the heat riser on the latter. I was afraid that I would lose horsepower with the smaller manifold. For clarification, the "smaller" manifold bolted right on to my heads with no problems or modifications, since they are both 32mm.

The car runs just as nice (if not nicer) than it did with the 701A! I cannot notice a drop in power or performance in any way. Perhaps at these small engine sizes not much difference will happen anyway.

So if anyone happened to have the same question as I did, all other things being equal, a 4 113.129.701 runs just as well (if not better) than a slightly larger 113.129701A on a stock 1200.

Here's a pic of it all put together. And yes, I'll be removing the fuel filter this weekend Also I'm in the process of putting a 28 Pict 1 carburetor with the return spring soon.

_________________
69' Westy
73’ Adventure Wagen Hightop
81’ Westy

[KTPhil]

In general, the single port engines are intake-limited, mainly by the carb size, at higher rpms. The 28mm venturi on a 1200 is at the lower end of what Solex recommends in their tuning guides. so if you notice any difference, it would be at high rpms where VW engines don't normally live (for long, at least!)

VW wanted to allow the car to be driven flat out all day, and so this limitation provided a built-in rpm/power limiter, of sorts.

I went to a 30 carb when I put in a 1385cc big bore kit to avoid restricting the intake even further. But at 1200 should be fine unless you are looking for max power at max rpm.

You might find a little better throttle response at low rpms due to the faster air movement through a smaller pipe, but you'd probably need a dyno to see it. The difference would be tiny.

Check your spark plug appearance if possible (tough with today's gas) and see if the difference calls for any slight rejetting of the carb.