The beginning

A

AF upgrade

New Member
After some twenty years of "kids", I have a chance to do my thing...an Auto Forge AF kitcar, a 90's kits, some fifty kits sold, lotus/spyder chassis, high spec, and some fitted with the beautiful little V8s....That's where I'm taking this.
Conundrum...three engines to choose from, a 1970's 42517303 unit, a 10A, and/or an 11A.....I gather the latter two are ok with unleaded fuel, as per the American market (I've been reading some posts), so one of these then, the 10A or the 11A......
The 11A is in bits, having been partially dismantled, cleaned up, albeit some ten years ago.....can I mix and match some of the 11A with the 10A components, ie 10A bottom end, heads off the 11A, and strangely the carbs off the early 42517303 (10.5 1CR).....They're the only carbs I've got.....otherwise I have an 8 pot injection head system - can't think where I got that from......

So yes, to get off the starting blocks, which unit to go for....? All opinions and pointers appreciated....

cheers, Will
 
Best available heads will be SD1 - bigger valves, flow better. Even better are 10 bolt types. In my experience 10.5:1 CR are more peaky than 9.25:1 CR, but require better fuel. Late blocks with thicker braces across the valley are stronger. Read all the available books - Hammill etc on what to look for.
 
Hi, The 425 engine is P6b, depending on its age the rear oil seal will be either rope or lip, if the engine number is at the rear by the bellhousing it will be rope seal and if its by the dipstick it will be lip seal. the 10A and 11A are SD1, being manual or auto respectively one of the differences will be the spigot bush size. The carb differences will be HS6 (side float chamber) and HIF6 or HIF44 (integral).

What do you mean by 8 pot injection heads? Do you mean injection manifold or pipes in the exhaust ports?

Colin
 
10A sounds ideal, especially if you have the exhaust manifolds, and they will fit in the car.
 
colnerov said:
Hi, The 425 engine is P6b, depending on its age the rear oil seal will be either rope or lip, if the engine number is at the rear by the bellhousing it will be rope seal and if its by the dipstick it will be lip seal. the 10A and 11A are SD1, being manual or auto respectively one of the differences will be the spigot bush size. The carb differences will be HS6 (side float chamber) and HIF6 or HIF44 (integral).

What do you mean by 8 pot injection heads? Do you mean injection manifold or pipes in the exhaust ports?

Colin
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I've got sitting there one of those heads which has eight vertical tubes in two rows, I believe its an injections system?? I'm told the SU's are a simpler way forward, which is my principle aim; get it together, and done, then tweak as I learn its performance. The P6b unit has 1970 stamped on the inlet manifold between the carbs, which I was hoping to fit these onto the 10A....which will obviously suit the 5 speed box, thanks
 
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