Hi, I am thinking of sticking some twin 40's on my mechnical headed 1.3 engine, so already single carb'ed and with a crossflow design. I have had a look for a definative guide but have found nothing yet, is there anything? I have found lots of useful information, but its been split all over threads. Is the just one central location? Also I am assuming i am I am not the first person to do this, so does anybody have any guide setups for the carbs? I know a lot will depend on the actual spec of the engine, but there must be a good starting point for me somewhere? Many thanks in advance Mark
What car are you putting the engine in? The Weber Haynes manual has lots of sample jetting setups, but not for a modded 1300 golf. Mine's in one of the cars or I'd have a look for you. I think you'd need to have an idea of the spec of the engine to get anywhere near.
It's going in an early polo Standard engine in these, will have a manifold, maybe headwork and a cam too. Was looking for a guide to basic installation, so I can get everything set up and then take it somewhere for fine tuning
The basic engine spec will determine the power potential, which in turn will define the choke size needed as the starting point. Once that is sorted a basic start up jetting choice can be established. In general, a fast road type engine making say 90hp, will use 28mm chokes, 115 mains, 160 air's, F15 or F16 tube's, 35 pump's, 45F11 or F14 idle's, 4.5 aux vents. That would be a fair starting point for the jetting, along with turning the idle screws fully in, then 1 to 1-1/2 turns out and balance from there.
I wasn't totally sure what you meant by the guide to installation... You'll need carbs, manifold, linkage, fuel pump, fuel filter, fuel pressure regulator. Alfa did a 1300 8v twin cam lump in the 60s and 70s that had 100ish BHP on twin 40s - amazing what you can do with a proper cylinder head design I'll add the jetting specs for that from the Haynes Weber manual, in case it helps - it might give you an idea of what you'd need to start with on a higher spec 1300 lump. I'd really recommend picking up a copy of the manual if you can. They do come up on ebay in the UK. The stripdown / rebuild and setup pics and guides are very useful. If you can't get one in SA (am I right in thinking you're in SA?), then drop me a PM and I'll see if I can help.
Thanks for the info, got some of what I needed from reading a lot of tgreads here, plus above has cleared up a few things too. Not in SA but Surrey!!! Will pick a copy of the Haynes in the next week or so and get reading :-) Basic current spec of engine is 1.3 hh engine with pertberg carb running 55 massive horses. Plans are to just perk it up a bit, something with a bit more go, 85 bhp would be nice. Want to try and keep the tuning simple for now, until I rip it all out and replace it with a tuned G40 engine Cheers
Stick with the old skool 1272...cool engine! Or the later 1390 8v is a great choice for a small engine swap...I've just pulled one apart...great potential...excellent head in std form.
I was close then! lol If you've got a direction you want to go in longer term, maybe you should try to do things that will be compatible with the later engine. For example, if you went for aftermarket management rather than carbs and all the other bits, you'll get more power now, but still be able to use it on a G40 lump, by remapping it. Again, if you buy a lumpy cam you won't be able to use it with a forced induction engine, as a lairy cam will just bleed off the boost. As Jon already said, it's expensive the first time you put a carb setup together, and reconfigure the carbs to suit your engine.
In case you're still going for carbs... jetting spec from an Alfa 1300 Junior - around 100 bhp. Not bad for the 1960s! http://www.carfolio.com/specifications/models/car/?car=37004 28mm chokes 4-50 Aux Venturi 112 mains 0.50 F11 idle F16 Emulsion 210 Air 0.60 Starter 0.35 Accel Pump 0.60 Accel Bleed 1.50 needle valve If you do go ahead with the carb madness, I hope that helps
Still working on this (was put on the back burner) just wondering what kind of fuel pumps i will need for this? Car the engine will be going in, was carb fed (single pierburg) and now has been converted to run a G40 lump..... can i just use the G40 fuel pumps or will i need to convert back to carb base and then run a facet pump?
I've a similar setup in mind for my 79 small block mk1. I've a 1300MH block, ported and polished head with a piper 272 cam, dbilas inlet manifold and delorto twin 40's. I'll be running it on programmable ignition with ford edis and coil and dta ecu.
There was a feature in Performance VW years ago that had a white MK2 Golf with a 1300 and twin carbs with a wacky cam etc. I'm sure that made 105bhp I can't quite remember, it was my friends mag. I've been trying to find the back issue for sale but I don't even know what issue I'm looking for; I'd love to read that article again. Anyway, if you can track it down it may give you some insight. Alex.
Webers use a low pressure pump. Plenty out there, your basic 'Facet' is a cheap, if noisy, option. Don't forget to add a filter on the inlet. Jon
