hornbm

Well I got my weber setup working rather nicely tonight. However a few things are bugging me. First is fuel pressure. I'm using a GSL-SE fuel pump, connected to a mallory return style pressure regulator. After the regulator I have a Mr. Gasket inline fuel pressure guage.

My guage reads zero at all times no matter how I adjust the regulator. The engine doesnt seem to behave any differently either. I havent driven it yet, but it acts the same in neutral no matter where the regulator is set at.

Next is timing. I made the rathe nice discovery that one of the first gen distribultor's ignitor bumps into the alternator bracket on FC engine. So I stabbed the dizzy in as best I could, and I seem to be running about 10 degrees before top dead center. This is with no vacuum advance. Isnt the leading timing on a rotary supposed to be like 0 degrees, or like 5 after TDC?

I think thats it....

Rotortuner

I have also converted a friends 6 port to carb. it was a 2nd gen though. For the fuel pump i would really suggest getting a fuel pump that is meant for a carburetor. I have had very good luck with the performance facet fuel pumps. I have run them on about 3-4 cars using weber 48 ida carbs with excellents succes. I get them from schucks or napa (dont pay more than $40 should be able to find one for $35). Make sure and get the one that is rated at 4-7 psi. i think they are around 30 gph which is like twice the flow over stock and almost 3 times the pressure of stock 1st gen pumps. When i run these pumps with the IDA's I no longer use a return line and i dont use a regulator because the pressure is nearly perfect for what the webers want.

CJG

427Aggie

You should never!!!ever run a weber 48 above 3psi pressure...the seals in the carb are not meant to take that much fuel. You will blow out the seals and cause a big problem. A return line is nice but not necessary but will keep the carb from varnishing from the fuel that leaks out.

Also on the carb there is a little ear just under where the fuel line goes into the carb...you will see a brass screw that is below that with holes in each..make sure that is safety wired together (trust me if that pin comes out so does the fuel in the float)!

Matt

Siraniko

iTrader: (13)

that BS. I run my 48 IDA in my RX-3 at 6PSI set a WOT. I have no leaks despite my carb cover gasket is cracked since the day I got it. Thats over 5 years ago.

Rotortuner

What are you talking about? The carb doesnt have seals that will blow. It has whats called a neadle and seat to shut off fuel inlent flow when the proper height in the flaot bowl is achieved. webers REQUIRE 5-6 psi.

CJG

hornbm

Yeah my weber book says webers require at least 4PSI. I mean if my guage says zero, and I really have zero, I dont even think the carb would even work at all! What about the timing, how advanced timing should I be running with my setup?

427Aggie

You are correct that there are no rubber seals but there is alot more than a needle and seat to these things.

I run 4 or these on my 427 and there are seals in the carb...you ever pull one apart...the gaskets(or seals) are paper..I run 2.5PSI and thats it...call Pierce or Inglese if you don't believe me they will tell you the same thing and they are the people that sell these...

If you are running 5 PSI do you get alot of varnishing? Or is the carb really clean...varnish is a sign of leaking from the carb...that means gas!

I am telling you what I have seen on the 427's...it may not hold true for the 7's but hey its 1 carb vs 4...I will find out when I put mine on the 7. And did you check to make sure your float pin is safety wired?

Matt

hornbm

Well guys I drove it. And it ran PERFECTLY. I blindley set my fuel pressure, and its dead on. I dont even know what it at. The timing is just fine, and the car halls *****. Sounds like a beast at WOT. I'm gonna have a huge thread with pics on monday so stay tuned.

Rotortuner

If i ran 2.5 psi. i would constantly run out of fuel. I dont get any varnishing. and as long as you have a new needle and seat that works it wll shut off the flow to the float bowl and thats it. the only problem can occur is when you have a crappy neadle and seat that cant hold the pressure then the float bowl will overflow, but usualy wont blow the top cover gasket, it will only dribble through the main aux ventury. Try running 2.5 and i bet you run out of gas fast. I run a BIG 3.3 needle and seat with enlarged float bowl, 5-6 psi. 43mm chokes, 235 main gas jets. this thing dumps fuel. I have run smaller jets with no probs. I think you 427 probably is set up much more conservetively so thats how you get by with less psi. If you read most places though and even the tech manuals that all say 4-6. Jaycee who is a renowned IDA builder for VW stuff sells a neadle and seet that will supposedly hold over 7 psi.

CJG

Rotortuner

here is a link to jaycee:

http://www.jaycee-ent.com/carburatorparts.html

these people say 4 psi. :

http://www.racetep.com/webfuelspark.html#webfuel

These are good neadle and seets too:

http://www.mazdacomp.com/intakesystems.htm

427Aggie

Again thats probably due to the single carb over the 4....if I have learned anything its that every engine is different with these buggers on them. Again just an observation from my 427 so not the 7....I will find out...I run D&G neadles and seats...they have a roller ball in the bottom instead of the crap that came in the carbs..but are heavier as stated int he mazdacomp information which says they use Glass ***** so you can run a higher PSI..

You are right that you are pumping ALOT more fuel than I am I run 37MM Chokes and 165 Main on F7 Emmulsions with 120 Idle Holders and 60 Idles with a .50 Bypass....You can't run the 43MM and get a good running street car...you would have to have your foot in it all the time(which is what these cars did originally with these carbs)

And I keep making comments about the float Pin because I had one come out on the road because I forgot to safety wire it...fuel was pouring out of the float bowl onto the mainfold.

Matt

Siraniko

iTrader: (13)

WRONG AGAIN!!! im running 43 venturies, 75 idle jet, 150 air/230main. my RX-3 is very streetable even on a 4puck clutch and 3500 lbs pressure plate.

427Aggie

Wacky if you read again I was speaking of my cobra which has 4 webers....not the 7's

Matt

hornbm

Well I'm still having a little bit of problems with it, and I think its due to my timing. 10 degrees BTDC. What are the rest of you running?

Rotortuner

10-15 BTDC should be good, then have the trailing firing about 7 degrees behind it. set it at idle and dont run vac advance. This worked pretty good for me.

CJG