Help - Search - Members - Calendar
Full Version: Fuel supply Hose ID
914World.com > The 914 Forums > 914World Garage
Joe Ricard
So I have some confidence in my carb tuning and hotrodding ability. She's pretty frigging fast now.
So here is what my sypmtom is. Runs great on the idle jets and will pull to 6 grand on the mains. I can hold it wide open to 120 MPH But not long a few seconds or so. tends to lean out by glancing at the gauge.

Engine just flat shits and gits on the Autocross course.

when I let off and get back to normal cruising the carbs will spit on the idle jets until what seems like the bowls fill back up then runs fine and will cruise 85-90 all day long @ indicated 13.5 to 12 to 1 air fuel. (narrow band)

Running a CB rotary pump 3-5 PSI through 5/16 fuel line. all filters are new Pressure regulator 3 psi. 40IDF's

I am not wanting to but may have to go bigger on the gas supply to this hopped up 2.0l .500 lift 300 duration cam ported head with stock size valves.

AND my Tangerine header will be on the door step any day now.

Does this make sense or am I just makng excuses for a big Holley pump and 3/8 fuel line.
tommy914
Have you checked the pressure and flow at the carb?
Are the floats set to spec?
Joe Ricard
Yes I know what I'm doing and no I'm not an idiot. wacko.gif
The only other thng is I might have some kind of sharp bend in the hose as it goes around from tank to pre-filter pump and through the body. I think bestto go with bigger ID hose with thicker wall thickness so it don't kink and will resist half collapsing making a turn.
Need to put it up in the air soon anyway so I'll go peeking up in the access hole. Pumps in front inder the tank.
Tom Perso
Believe it or not, my friend had the SAME setup on his hot 2056. It would pull the same crap, it run run like a raped ape up to 100mph or so, die out, you'd let off and then it would come back.

Do you have a pressure regulator that has the rotary dial? If so, throw it in the dumpster.

If your pump runs at 3-5psi, just dump the pressure regulator. The IDF's can take that.

That's what my friend did and it ran great afterwards.

I dunno, but I'd give it a shot... confused24.gif

Tom
TimT
5/16 hose is plenty to support the power your are making.. the problem is elsewhere

I dont know, but do 914s have strainers on the outlet side of the tank? if so that could be loaded up with crap.

QUOTE
Do you have a pressure regulator that has the rotary dial? If so, throw it in the dumpster.


agree.gif

along with those clear glass gas filters that used to be popular
Tom Perso
Yup, 5/16" is plenty. I fed my 2270 with Weber 44's with 1/4" line.

I even ran that crappy rotary dial pressure regulator, but I had a Holley red fuel pump. Those run 12 - 15psi (I think), and I think those regulators need a healthy pump running to them to make them work at the specified pressure.

Weber 44's will run for quite a while with the fuel that is remaining in the bowls. It's amazing you *can* run them out of fuel... laugh.gif

As for the filter, those clears ones do suck too. I like the healthy big metal ones. They are sturdy and are BIG.

Tom
Joe Ricard
The clear glass one's suck? Not to doubt you guys but why is that? Ok that's an easy fix. I will stop by the FLAPS for a big metal one.
Nope using the Holley pressure regulator. There was one of them dial regulators on the Cool Blue Teener. POS flew pretty far into the weeds when it locked up and nearly burnt up my engine.
Tom Perso
Early riser, eh??? wink.gif

I'd take the pressure regulator off since you've got the CB pump and see what it does. In fact, just turn the pump on and let it fill the bowls and see if it overfills.

If not, take the car out for a short drive and see how it does.

If it passes test, go out and rip on it.

Tom
Joe Ricard
If memory serves me well I put the regulator on because it was spilling over.
It may have been just because I thought I needed it. IDONNO.

Funny thing about fuel pumps. There was a pump in a guys car that we all know and love. Parts dealor had it marked as carb fuel pump. So it must be good right.

So I get a call that both carbs are messed up and flooding the engine..... idea.gif

One maybe not both. Anyway put a pressure gauge on it and the 20 PSI gauge pegged put a regulator on it and the gauge still pegged. Even tried to crank down on the adjustment. Nope that was one strong FI pump I don't care what he box had written on it.

Anyway sort of side tracked. I'll do this stuff and see what it does. Thanks Tom. beerchug.gif
Tom Perso
As a side note, I always put my fuel pump on a dedicated switch and relay. That way, I can run the carbs empty if I need to do work on them, instead of trying to dump the fuel out of them into a container.

Later,
Tom
watsonrx13
OK Joe, let me explain the fuel pump issues to you....... poke.gif
Joe Ricard
Whaaaaat? I was only saying I know this guy rolleyes.gif

Driving it yet?
bd1308
pitch the regulator....

b
watsonrx13
Yep, drive it around the block, then back to the shop.

No insurance coverage yet. I can't afford the regular insurance, so I'm trying to get the 'classic' car coverage. I've contacted several vendors and they have requested pics. When I sent them in, they refused coverage because 'it appears that the car isn't completed.' Well yea, all I have left to do is paint the outside. So, if anyone is going to get the 'classic car' insurance, I would recommend getting a great paint job first, then fix any interior, engine, suspension later. I guess it doesn't matter if the car runs, stops or has any interior, just as long as it looks good.

Anyway, hope you get the car figured out...

-- Rob
Joe Ricard
You could always rent out that extra room you got. lol2.gif Or start selling off them extra car parts. wink.gif
tommy914
QUOTE (Joe Ricard @ Dec 19 2005, 07:15 PM)
Yes I know what I'm doing and no I'm not an idiot. wacko.gif

Joe,
I wasn't implying that you were an idiot.

These are just things I would double check.
What PSI are you seeing at the carb after the regulator?
Is the flow rate at the carb equal to the rating of your pump?
Is there a little screen at the weber carb fuel inlet that may be clogged?
Is the full open position of the float (empty bowl) at spec?

my .02


Joe Ricard
QUOTE (tommy914 @ Dec 20 2005, 08:40 AM)
QUOTE (Joe Ricard @ Dec 19 2005, 07:15 PM)
Yes I know what I'm doing and no I'm not an idiot. wacko.gif

Joe,
I wasn't implying that you were an idiot.

These are just things I would double check.
What PSI are you seeing at the carb after the regulator?
Is the flow rate at the carb equal to the rating of your pump?
Is there a little screen at the weber carb fuel inlet that may be clogged?
Is the full open position of the float (empty bowl) at spec?

my .02

3 PSI
Tough to measure max flow of the carb whilst hauling down the road under full load. Sitting still the carbs are filling up the desired level no problem.... Need a Dyno cool_shades.gif
Screens are clean in carb inlet
Floats are set to desired wide open spec sumpin like 35mm Got written down in the book.

Don't intentionally get snippy but sometimes it just happens.
tommy914
Joe,
It sounds like we need a way to figure out if the flow rate at the carb is being restricted. Can you measure the flow of the pump unrestricted at the tank, then compare that to the flow rate at carb inlet? Then remove/replace regulators, filters and line kinks until they are the same?

Oh, and let us know what you find out. I am running that cheap dial regulator and glass filters too. biggrin.gif
mikelsr
Joe,
I have dellortos on mine and I bought a manual for them. In the manual they talked about increasing the flow to the carb at the inlet so they just drilled out the inlet. Just a thought.

M
Joe Ricard
If I remember correctly the inlet valve design is about the same. Interesting approach, I would bet it won't take much of an increase in diameter. As long as the needle seat still shuts it off. idea.gif
Need to go spelunking 1st step. Maybe there is a cone (pylon) still wedged up in there somewhere. lol2.gif

Last Cone Hassan hit was wedged so tight under the car I had to have him rock back and forth whilst pulling with both hands and getting my feet up against the tiar.
tommy914
I would check AirCooled.net for a larger Weber needle and seat if you think that is what is constricting the system.
Joe Ricard
Well I started withthe easy stuff. inspecting the routing of hoses in the engine compartment.
One possible culprit (MAYBE) was the loop and droop ofthe supply hose to the regulator. So I got it straightened out. time and heat make the radious tighter.
Second I replaced the regulator with a "T"
I found one of my early mistakes or maybe just an over sight. the inlet fitting to the regulator were 1/4" ID I had it on my list to get better ones but somehow dropped track on that one.

Carbs are not running over but.... are not running the same as before @ idle Which means I might be on the high edge of fuel pressure. Gauge got ruined in the storm so I need to get another one.

Have I mentioned lately how much Hurricanes SUCK.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2024 Invision Power Services, Inc.