Progressing ever slowly on my historic rally car build.
I am going to use twin HS4 (1.5" /38mm)(yes know can do better with a single etc etc) but this is what I am doing..
The carbies I bought off ebay and came on an AEG573 manifold - which as far as I could make out where mainly for twin HS2. This looks standard (?).
Rather than go to the hassle of modifying thought I get a repro C-AEG489 (12G2464) manifold which were for the HS4/HS6... which has now arrived.
This comes pre-modified aka Vizard.
What surprises me however is the manifold to head port sizes.
The is not much between them on the Carby mounting side - both pretty much around the 38mm mark.
On the head side the 573 is around 34-35mm.
The 489 is only 30mm !
To compound the issue - the head ( a Mk1 AEG163) is heavily ported old school ... and inlets opened up to around the 38mm mark.
Question:
Should I open up the ports on the 489 - and to what size ? (and only has about 6mm of wall at the bottom flange)
or
Work on the 573 ? (this has about 5mm, as well as being more open to start with... )
(There is option 3 there an already ported original 12G2464 manifold that came with the head when I bought it 20 years ago - and currently on another car... but want that for another project...)
Other questions while I am at it...
The Carbs came with #7 needles...
It's +30 bore - so right on the 1300cc and will be running an RE13 and Maniflow LM4 extractors to 1 7/8" exhaust (maniflow) ....
Any thoughts if these are a good starting point needle - or likely to be way off with this combo ??
(and this all started by buying a roof rack !)
ps Anyone have any idea who MM or MLM might be ? (presume they were the ones who ported the head originally... bought it from a bloke in Sydney with a dismantled GT abut 20 years ago)
)