You'd be better off with physically smaller carbs (ICTs or baby Dells). Dell 40s will do the job fine, but they're going to be expensive. If you're moving to twin carbs, don't forget to factor in the cost of all the other bits: linkage, filters, fuel lines, etc. It soon mounts up.
Expensive ? I guess that's a relative thing...... so far the full resto owes something approaching £12k so in terms of expense if it's going to cost a little more to make it flexible and reliable so be it. If the motor was old it would be binned in favour of a breathed on type 4...... but it just seems wrong to pull the little lump when it's fresh.
You're going to struggle to fit twin carbs and manifolds with the engine in. I daresay it's possible, but I wouldn't want to do it.
Why not just enjoy your van. It goes. Its reliable. Ok its slow up hills, but that's normal isn't it. My tintop is lightweight inside with its bespoke ply interior, but it still slows down up hills. I am ok with that. Instead of modifying the engine at unknown cost with no guarantee it would be much better, I would put the super higher octane petrol in the tank. I use the more expensive stuff in my van and the mgb and they like it, smoother engine, improved performance. Some folks go much further and put in a Subaru engine etc. Then its no longer the classic van it was.
I have twin kadron 40's and achieved a 56bhp on the rolling road. Ive got a pic of the curve i can post so you can see how much the torque improved. I have yet to meet a hill that i cant climb in 3rd gear. I may slow down to 35 to 40 but she does pull nicely with all the gear on board.
ha ha i can only do the after. I do know its a huge improvement on the pulling power. No real difference in cruising speed just in the time taken to get there. As a single carb she would cruise behind lorries but would need planning to overtake and a nice gap. With the twin 40's i can keep up with traffic and overtake nice n easy. Where are you? Im in northampton but do get about. Perhaps you can drive mine to get a feel.
Because that's a personal choice - I'm choosing not to make. I've no desire to make it into a flame throwing hotrod or swap in a modern lump, but if there is something that I can do to add a little more grunt then it's happening. As for with no warranty that spending the money will bring results....... I'm not talking about modifying the latest jap box - this motor was about when God was in short trousers - I'm positive that within the collective experience of the air cooled world there is knowledge of sure fire ways to improve the pulling ability of this motor without breaking the bank .
Just be careful not to spend cash on a half arsed solution and then have to do a proper job later anyway.
Well my office is in Rugby and im always over that way. Im sure a nice cold cider at a brewery to suit us both would be good ;-) You may feel that its not hugely different to yours and choose to stay as is, but im posative you will feel it. Plus its got a nice growl, when you put your foot down, from the cone filters
The thing is, IMHO, all these small changes, though they do add noticeable power, don't add anywhere near enough to make it drive in the unfussed way you'd really like. Sell the 1600 turnkey for top dollar while it's in good condition and go big capacity type-4. That's what you really want ( I can tell ).
I like the bit I was shown by Scott at SGS Aircooled .....where the cracks in the cylinders caused by the turbo boost and nitrous turn into little cutting torches and eat the cylinder heads too...
I have bigger pistons so a 1641 motor and i live in the lake district so have to cope with hills like kirkstone pass which it manages to do it in second and a bit in third. for more normal hills it might go down to third and a normal cruising speed of 60
Can I give you a shout some time in September...... between now and then I'm pretty well stuffed for time? Would be good to meet up and swap notes!
