251 replies to this topic

[CanadianMiniFan]

Read your whole thread, you're an inspiration, and I wish you the best of luck in doing this. Should be a sweet ride when it's done. V12 is cool.

[Bungle]

isn't a 32/36 weber a progressive carb ?

i had one on my camper, they run one barrel on idle and part throttle and the other barrel opens up for full throttle

the what you have plumed in the manifold wont work


+ stay away from the cheap empi weber copy's

[chairchild]

yups, it is indeed progressive Mr Bungle - the secondary starts to open when the primary is 2/3rds open. There is a weber of a similar size that opens both at the same time, but they're not as common and cheap to find

If you look in the second picture of the carbs, you can actually see the linkages that control them - all I need to do is modify that part, to open them both simultaniously, rather than be on a delay




And cheers for the support CanadianMiniFan - Seems that now I've actually got the engine, people are starting to take me seriously

[Bungle]

but aren't the 2 barrels of a different size ?

carb porn

[Dog]

Why progressive?

Why not go IDF?

[Bungle]

they are a progressive carb but he wants to modify them as a 2 barrel carb

[Dog]

But, still why progressive?

Go and spend some moolaa and get IDA's

[chairchild]

because I'm poor as sin, and because it's something different

And I know that they're different sizes (the name 32/36 kinda gives it away ) But if you look at that scribble, it's not divided into 2 ports per carb barrel - 4 throats are fed into a miniature plenum type affair, with one carb feeding that.

Thats the downside to that quick scribble - it doesn't show the height, so here's a better one!



and dont forget - the only reason for me changing in from progressive, to simultanious, is to avoid the annoying ignition timing requirements of the progressive setup that I've read about

[Down&Out]

this is looking great

[Dog]

So shall I put a warning in the local paper to al ford owners, that own a older generation ford then




There carbs might go walkies....

[Bungle]

and dont forget - the only reason for me changing in from progressive, to simultanious, is to avoid the annoying ignition timing requirements of the progressive setup that I've read about

what is the annoying ignition timing requirements of a progressive carb ?

i ran one on my stock camper with no problems

allthough my new delli's give me loads more power

[chairchild]

This is one of the bits i read about them:

WEBER 32/36 DGV (all MGB's 1963-1980)
While a very reliable carb/manifold set up, a disadvantage with this carburetor is the fact that the primary venturi accounts for two thirds of the throttle open position (no CFM* figures are given for this position) with the secondary venturi becoming active in the final one third of throttle movement. This carburetor requires excessive initial ignition timing advance to avoid stumble on take off (if the ignition timing was retarded, we would have to open the primary throttle plate to obtain the necessary idle; this would expose the progression bleed holes which in turn would require that the idle mixture be leaned to compensate for this richer mixture condition. The end result being very little progressive richening upon further throttle opening, especially at snap throttle and so the stumble). Carburetor can be modified to allow the primary & secondary throttle plates to open simultaneously plus modifications to the progression circuit and accelerator pump.

But after further thinking, I might just leave them stock - these will only be on a for a year or so before I get a fapping huge supercharger plonked on there anyway!

[chairchild]

Another update on the "planning" side of things only I'm afraid - nothing mechanicals been done again


I'm no longer going to go N/A, or even supercharged, as I'm now fully commited to going turbo Not even going to go with carbs and a dizzy anymore, as you can use megasquirt for injection, and two edis6 units (with a bit of jiggery-pokery) to run near faultless ignition!

The only reason, I will admit though, for deciding to go this route, is because after stripping down the manifolds of their maze of hoses, pipes, solonoids, and wires - it turns out that the damned mechanical dizzy NEEDS them to get anything close to a decent idle!

The engine (being of the HE type) needs virtually no advance at full throttle, loooooads at cruise, and only a smidgen at idle - which would explain why the builder of "jagged edge" (that v12 bike) found it was a PITA to get warmed up!



but thankfully, someone's already managed to get a V12 running on the jolt/squirt setup already, and found out the major hassles already

[Bungle]

but thankfully, someone's already managed to get a V12 running on the jolt/squirt setup already, and found out the major hassles already

i'm sure you will be able to find some more

[chairchild]

lol, trust me - if this bloke hadn't have put up the circuit diagram, and the program to run it - I'd still be trying to find ways to get the standard dizzy to run normally!

What it does, is remember the output of the megajolt, for 60 degrees of crank rotation. So what it sends to one EDIS unit, it sents an identical signal, at the correct time, to the secondary one! It's a bloody clever way of doing it, and saves having to buy a second megajolt

The injection is relatively easy - it just runs the two banks seperately, which is exactly how the standard setup ran. But I may even give the standard ECU a go, and see if it's possible to tweak it - if only because it then means I dont have to spend much more!

I'll be using all the standard manifolds, injectors, throttle bodies, and control rods - I'll jus be adding the pipework for a couple of turbos and intercoolers!

And a few pictures...

here's jobe as he was today



The poor little mite!


Now, here's that jag's wheel for size, and in the correct location, so the diff cage will miss the rear bench




And yups, this is pretty much the exact width the rear is going to be! (from the floor that is, it's only leaning because the floor was uneven!)