Here are the pictures that BruceG provided for the AEG 347 on the 12A661 P2 casting.

There are no visible differences between the P and P2 castings in a photo comparison.  The markings are cast differently on the P manifold, 12A 661 on a raised pad with the P below it.

Bruce, does your manifold have MOWOG or any other markings on it?  The P casting has MOWOG upside down on the back of the balance tube.

S&M Minis - thanks, have emailed photos to you.

BruceG

BruceG, No photos yet.  If you want to e-mail them to me I can post.

Here's what's come up on your manifold via this thread and direct e-mail I've received.  There were two different 12A661 castings, a "P" and a "P2".  At this point it's not clear what is different about the castings other than the P/P2 designation, pictures are still coming in.  From each of those castings there were two different manifolds made; the ones stamped 1004 which had only the PCV valve boss drilled and tapped (for 998 Coopers), and the ones stamped AEG347 which had both the bosses drilled and tapped (for Cooper S).  All four variations have been identified and I think we have pictures of all four coming.  The 12A661 variations are: P 1004; P AEG347; P2 1004; P2 AEG347.  If anyone has both the P and P2 castings could you put them side by side and see if there are any obvious differences?

And not a pedantic response at all.  The chart will have some major changes made to it based on the impressive and helpful input I've received.  I have to get some real work done first, so please bear with me.

Trying to be helpful, not pedantic, but I have a manifold with 12A661 P2 casting marks, and AEG347 stamped, the only 12A661 P2 in the most excellent chart is stamped 1004. Both vacuum ports are drilled. I don't know the origin of this manifold. I will try to post a pic, but have had not been able to recently.

My RAC paper about the evolution manifold is dated 1st March 1968.I think this fits in with Spitz AEG 573 manifold.

Tulka

MOWOG marked.
AEG573   6" between studs

1130cc, 12g295, SW5 cam, LCB, Twin 1¼ SU's, CA spec.

I am making zero progress on a couple of reports that clients are expecting tomorrow, but the distraction has been terrific!

There's a post on the Vintage Mini Racing Board where the member describes the manifold xcc has posted a picture of (original number ground off and AEG 179 stamped in its place) and he further states that the manifold is original to his 1071 S (i.e., the first S model).

This is pure supposition, but I would propose that BMC modified the casting cores for the 12A309 manifold (997/998) to include a brake booster vacuum boss when the 1071 came out.  If the boss was drilled and tapped for a booster on an S installation (see xcc's picture) the casting number was changed.  If the boss wasn't drilled and tapped (for a 998 Cooper installation) the number stayed as-cast (see Tulka's picture).

Does anyone have a AEG 179 with the numbers cast in?  Or did it go from this grind and stamp approach straight to the 12A661 casting with two vacuum port bosses?

This is an original C-AEG489 from above, BA82357 might be the drawing or mould.

 Tulka

Somebody on the night shift forgot to change numbers?

 Tulka

XCC, That is the original Cooper S manifold with a brake booster takeoff but no smog valve port.  I haven't seen one of those in a long time and was afraid they wouldn't surface in this search.  The stamped number is interesting.  Thanks much.

Also, Cheleker sent me an e-mail with a few numbers we haven't seen so far.  I'll get his stuff in the mix shortly, but wanted to recognize his contribution.  He also seems to be slightly ahead of me for the number of duplicates of a manifold that nobody is ever going to want!

How about an AEG179 - stamped into it and a "P" below cast into it. Tapped for one fitting, no fitting rings but a place for them, 6" on center w/ 1 1/2" openings.

Randy,

Photos sent. Carbs and linkage are attached. The only marks are on the bottom.

meb

Sunday Morning Post - Part 3 of 3

I forgot to mention in post 2 that the MG 1100 manifolds have a slight taper cut on the carb side of the throat.  It's only 1 1/4 inch at the carb mounting face, not 1 1/2 inch like the Cooper manifolds.  It's really just to clean up the opening, not a performane mod.

Now for one that's just so damn cute - an adjective I hate, but you could almost make this one into a piece of bling.  It's off a Turner (a Sprite based sports car) with a 948 engine and is made for H1 carbs, the 1 1/8 inch size from the first Bugeyes.  I have an H1 Bugeye manifold somewhere, and the Turner manifold is much shorter.  It will fit on a Mini and I've been saving it for that 60's era street racer 850 I'll build "someday".  This one apparently uses divine intervention to keep it positioned on the head, neither stud nor ring mounts.  I don't know who cast it but it looked very original on the Turner (the owner swapped it for a Sprite HS2 manifold), so I just call it a Turner.

Finally are a pair of Sprinzell stub manifolds for H4 carbs.  The balance tube is a rubber hose.  Sprinzell Sprites were very fast numbers in their day and I'm assuming the S1000 number means they are for a Sprite 948.  They won't fit on a Mini.  I got these off the "Flounder", a Mini-based rear engined car, in a swap for a standard Sprite setup.

That's all for now.

Sunday Morning Post - Part 2 of 3

Now for posers and red herrings.  Start with three variations of the MG 1100 HS2 manifold.  The earliest ones have no vacuum ports and stud mount, laters have have ports and ring mounts.  One of the vacuum ports is angled.  Each of these three have different numbers cast/stamped.  I'll put the numbers on the chart.

These really aren't all that bad if you are using HS2s, the balance tube opening is much less intrusive and probably disrupts airflow less than the Cooper manfolds.  The heat shields were either one piece or two piece.

Compared to a Cooper manifold the balance tube is smaller diameter and doesn't overhang on the ends.  The 1100 is 1/4 inch longer from face to face and the carbs are mounted on a shallower angle.

Carb spacing is 1/2 inch narrower on the 1100.  The curve in the manifold isn't really that severe. 

Here's a red herring - an MGB manifold narrowed to fit the A Series port spacing.  A 1960's budget racer mod.  It will fit on a Sprite but not a Mini.  I bought it for the carb set, kept the manifold for the novelty value.

More in post 3.

Sunday Morning Post - Part 1 of 3

Yeah, what is it with intake manifolds that makes them so interesting?  Just a chunk of aluminim with no moving parts, but I can't resist.

Great stuff coming in.  Here's where I can use more detail, followed by some pics spread over several posts.

Good Times (Or Nick), meb, Tulka - Can you provide full pics (i.e., show the whole manifold) of the HS4/HS6 manifolds, there seem to be several variations of casting marks.  I have yet another one that I'll show below.

Good Times - Have you ever seen AEG 490 used as a part number, or is that from the casting number on your manifold?  BMC/BL often (but not always) had the part number one digit off of the casting number.  I've never seen 490 used as the part number.

Tulka - Excellent info. on the Mk. II & III stuff - My manuals only cover Mk. I.  Could you also provide full pictures of your 12A 308 with the ring mounts?

MacDhaibhidh - Your the only one that has chimed in with a 12G2463.  Could you provide the missing info on the chart and maybe some pictures.  Tulka has identified it as a Mk. III S.

I will update and repost the chart next week.

Now for the big pile o' stuff - the pile doesn't include any duplicates.  I already posted 12A 308 individually.  (My wife walked by while I was taking this picture.  She stopped making disparaging remarks decades ago!)

First is AEG 347, possibly the most common.  This one has been mildly polished on the carb side so the factory machining marks aren't real visible on the taper.

Next is "my" C-AEG 489 dual pattern HS4/HS6.  I bought this 10 or 15 years ago from one of the major US vendors.  The only marking on it is 12G2464.  No foundry marks (e.g., MOWOG, VAF, etc.)  The exterior of the casting isn't quite as good as most of the others I have, like an 8 out of 10.  Was somebody doing knockoffs?  This one has been heavily modified, it originally had the locating ring groves on the cylinder head side.  Note that neither of the vacuum port bosses was drilled or tapped - aftermarket?

More on the next post.  These tend to crash when they get too long.

I also have a BA82357  AEG490  manifold for 2 x HS6 S.U,s with 6" centers. This is a 4 stud pattern with 2 drilled & tapped top outlets & the stud for the throttle cable fitting. note this one reads 490 not 489 @ the end.

Sold it this week to Nick for $50 & he has photo,s

From parts list AKD5312 (Mk1&Mk2);

I have a 12G 2463 if you want any info on it. I wish it was the correct one for my 69 Cooper

Speed's Expensive........How Fast can you afford to Go??   

meb, Thanks for the info.  Since you didn't state otherwise, I'm assuming those are the only markings on your manifold.  The physical description matches what's already on the chart, but with different markings.  Looks like there might be several versions of the HS4/HS6 manifold, at least as far as the markings go.

RJM