| pig-pen |
Wed Feb 12, 2014 4:54 am |
|
Hello. I know I have seen this before, but no amount of searching is giving me the answer... and all my bookmarks seem to have gone....
anyway, I understand the theory of boost referencing the carb... bit everyone is doing it on a holley or something.
I want to do this on a solex, can any one explain the 'power valve' circuit on a solex to me?
Is there a vacuum reference under the throttle butterfly? I need to plug this right? and tap into the body with a line from the pressure / vacuum side of the charger.
Will be using a draw through roots, with any cheap solex that I can get a 28mm venturi into
thanks in advance
Martin |
|
| demon1018 |
Thu Feb 13, 2014 2:38 am |
|
| If its draw through , why do you need boost reference? Ive done some v8 turbo cars with carb boxes sobthe carb was pressureized and had to use a regulator that upped the fuel press for every pound of boost but never did anything with the carb. Changed jets but thats about it. On a draw through yourr sucking the air through the carb just as it does without the turbo .it just makes more air get sucked through. The carb works as intended. But im no expert!!! |
|
| pig-pen |
Thu Feb 13, 2014 6:31 am |
|
yep. totally hear you, but boost referencing the accelerator pump is a good idea if you can.
This is different to using a FPR and so on to deliver the carb more fuel as boost increases.
It combats the difference in pressure either side of the charger, correctly referencing the accelerator pump to the manifold pressure, not what is going on under the throttle butterfly, meaning the motor will not lean out under acceleration.
But...
As most SOLEX operate their accelerator pumps with a lever then this is a bit of a moot point I guess unless I find one that does use vacuum.
One thing my research has shown me is that it was possible to get 3 different stages of accelerator pump, #2 - normal #3 - rich #4 - lean.
does anyone know where I might get a '#3 - rich' pump as they are recommended for chargers.???? |
|
| pig-pen |
Thu Feb 13, 2014 6:32 am |
|
yep. totally hear you, but boost referencing the accelerator pump is a good idea if you can.
This is different to using a FPR and so on to deliver the carb more fuel as boost increases.
It combats the difference in pressure either side of the charger, correctly referencing the accelerator pump to the manifold pressure, not what is going on under the throttle butterfly, meaning the motor will not lean out under acceleration.
But...
As most SOLEX operate their accelerator pumps with a lever then this is a bit of a moot point I guess unless I find one that does use vacuum.
One thing my research has shown me is that it was possible to get 3 different stages of accelerator pump, #2 - normal #3 - rich #4 - lean.
does anyone know where I might get a '#3 - rich' pump as they are recommended for chargers.???? |
|
| modok |
Thu Feb 13, 2014 6:59 pm |
|
pig-pen wrote:
I want to do this on a solex, can any one explain the 'power valve' circuit on a solex to me?
Ok sure, first find a carb that has a power valve.
Vw solex carbs, PICT/kadrons/type-3, ect.... do not have power valves.
you could add one but these are cheap economy carbs, not worthy.
Find a two barrel progressive with a vac secondary, these were common on four cylinders of the late 80's. |
|
| Joel |
Thu Feb 13, 2014 7:17 pm |
|
modok wrote: pig-pen wrote:
I want to do this on a solex, can any one explain the 'power valve' circuit on a solex to me?
Vw solex carbs, PICT/kadrons/type-3, ect.... do not have power valves.
The 31pict3 carbs as fitted to Aussie and Euro 1300dp do.
Its mounted beside the idle jet, I've got one on one of my spare engines.
The 30pict3 as fitted to 70s 1200s also had the same thing.
Given that Martin is in the UK and 70s 1300 and 1200s were common there its probably the carb in question, they are a power jet rather than a power valve which is probably where the confusion is coming from. |
|
| modok |
Thu Feb 13, 2014 7:23 pm |
|
ah, yes that is probably why.
too small tho |
|
| pig-pen |
Fri Feb 14, 2014 1:31 pm |
|
| yeah... it was that. now going to go renault5 gt turbo blow through solex so its all kinda academic. |
|
Powered by phpBB © 2001, 2005 phpBB Group
|