Fuel Pressure

All

What is the fuel pressure I should be running for dual Solex 40mm carbs on a 1600cc motor? is it 2.5???

Thanks

Todd

Lower than 2.0.

1.5 is good.

Can anyone advise the name and source of the "quiet" fuel pump...not the Facet brand ? Thanks...

Todd.....1.5 lbs for kadrons.

David.... The cb performance rotary pumps are nice and quite and are around 60 bucks with filter. They work great.
Mike

Any rotary pump or a Holley blue pump (or equivalent.)

A quality fuel pressure regulator with a pressure gauge is a nice idea. Removes that last question mark in the system.

CB performance has a nice rotary pump that quite a few of us use.

This is it:

http://www.cbperformance.com/catalog.asp?ProductID=577

Personally, I think 1.5 lbs. is a tad low, even for Kadrons. I would bump it up to at least 2.5 lbs. or a bit more. The pilot valves can certainly handle it.

I've found the CB pump, at 3.5 lbs. to be just right for most applications onhere, and if you want to run pressure lower than 3.5 lbs, get an adjustable regulator to go with it and dial in whatever you want and it'll stay there.

todd if these are the stock solexes on a 356 engine ? they should be at 3 psi. bill

i agree with Gordon. I run 2.5 PSI with a FPR with dual 44 IDF's, but the size of the carbs is not important - too much pressure will overfill the float boal of any carb and make it run uber rich (/be a fire hazard)

there are essentially two fuel pressure zones. carbed engines and FI.

Probably one of the leading experts on Kads

http://www.lowbugget.com/main_page.html

Ok. thanks Everyone. Next question. Does anyone have a picture of a normal speedster with dual carb set up and where they actually had room to put this? I am finding it hard to believe this is going to fit on the hose line between the fuel pump and the T bar conecting the two hoses going to the carbs...

Electric fuel pumps should be mounted as close to the gas tank as possible. IE: on the pan behind the front end beams.

Here is a quote from one of the Kardon Gurus at lowbudget.com.....Read the section about fuel pressure...



Poor performance:
Is the timing correct? I do not recommend setting your timing at idle or static. This is just for
getting it to start and should be set afterwards with a timing gun set at full advance.
Are you still using a 009 distributor? click here for more info Kadrons like vacuum advance.
Is the idle & main jet the correct size for your combo? Notice its "combo" and not just motor size! The numbers stamped on each jet can be wrong. You should call us for a set of our indexted jets.
Did you adjust the mixture?
Is the motor new? if so it may take up to 1,000 miles to seat the rings. So at this time there will be low vacuuim.
Check for high fuel pressure. Kadrons like lower than 2.00 psi. max.(1.5 is good)
A stock fuel pump can produce over 4lbs of fuel pressure.You may need a regulator.
Check for fuel pressure spikes. Some fuel pumps pulsate and this can cause a problem.
Is your float still afloat?
Do you have the correct venturies?
Are the plugs fouling? use only good plugs like NGK

1.5 lbs. is nice if you have new, clean fuel filters (you DO have more than one fuel filter, don't you? Or at least a single BEFORE the pump?) but once the filters start to accumulate crud, that 1.5 lbs. will trail off and you'll quickly begin to experience fuel starvation.

So, you can certainly run a 1.5 lb. fuel supply and clean/replace your fuel filters every oil change, or you can run the pressure up a pound or two and change your fuel filters every other year or so.

It's up to you.

I still stand behind the CB Rotary pump for Solex/Kadron carbs at 3-3.5 lbs pressure. And most of the VW pumps I've used over the years typically run 3-4 lbs. pressure, although the mechanical pumps typically pulsate a bit too much for my taste (plus, they're at the wrong end of the fuel circuit).

How cN it be mounted close to gas tank when it has to be arter the pump and the pump is on the engine?

Todd, there seems to be a bit of confusion on your part. I'm not exactly sure about your question in the post directly above this however... If you install an electric fuel pump you should install it under the car, as near to the gas tank as feasibly possible. The reason is that electric fuel pumps like to "push" fuel rather than "pull" fuel.. If you choose to install an electric pump, most people remove the mechanical fuel pump that's mounted on the engine case and then install a block off plate to cover the hole created by the removal of the mechanical fuel pump. Most people mount the electric fuel pump somewhere on the front suspension beams

You'll need to do some re-routing of your fuel line in that it's "nice" to have a fuel filter both before and after the electric pump. Electric pumps don't like dirt in their "innards" and your carburetors don't like dirt in their interior. In my opinion, the 2 filters are a "must" I hope this helps to explain your dilemma. And, by the way, the filter between the electric pump and the "T" that feeds the carburetors can be installed anywhere. Most like it to be visible from the engine compartment to make it easier to check and replace.

He might be referring to a regulator versus a fuel pump.

As per Jeff's statement: If you're installing a fuel pressure regulator and persist on keeping the mechanical fuel pump, you'll have to do some fuel hose modifications. Mount the regulator to the inside compartment. Run fuel line from the Mechanical Pump "out" to the pressure regulator "in" then to the "T" fitting feeding both carburetors.

If you choose "wisely" to install an electric pump, then do basically the same, Mount the pump and filter/s to or near the front suspension beam then mount the regulator to the firewall/inside engine compartment etc. then to the "T" fitting.