32/36 Dgav Or 38 Dgas

[tractor]

when you look at manufacturing quality of the manifolds from wot I have seen from other suppliers Dasnt is the top Dog

[Gusty]

Managed to get the Dellortos running a lot better today after I put the old fuel pump back on! I'm hoping I can get it to the rolling road now. Thanks all

[Bob Tucker]

They dont need high pressure...anything between 4-5 psi will work fine.

Any more can overpower the float valve causing rich running

[Gusty]

Hi,

 

Just the old mechanical one.

[Longboarder]

The dell'ortos must be balanced as a first step. Bob, I wouldn't run them at over 3psi unless I knew they were in very good nick and I had a monster engine. The choke mechanism is poor and needs to be disabled in the off position. It also helps if the accelerator jets are balanced but the adjustment nut/threaded rod is very fragile. These are things that you can do before fiddling with jets/chokes/etc that can get it drivable so you can get to a rolling road. I assume you have already part stripped the carbs to make sure they are a matched pair with all the same variable jets/emulsion tubes/chokes/etc and that the float heights are correct and needle valves in good condition. If not, do it soonest and repair any faults before going on a rolling road.

I loved my dell'ortos on my old pinto.

 

Nigel

Edited April 13, 2016 by Longboarder

[Gusty]

Hi,

 

Stripped them, new gaskets , needle valves, set floats to 15mm ,8.5 gram floats. Cleaned and blew all the crap out. Need to balance them now then have a play with idle mixture screw. Definitely going in the right direction now .

 

Cheers

 

New diaphragms as well . Plus all jets etc are matched

Edited April 13, 2016 by Gusty

[Bob Tucker]

Hi Nigel,

I'm sure you are right.

Just going by my own experience, a Facet square block pump

running at 5PSI feeding twin Dellortos seems to run OK.

But it is a 200 bhp redtop, maybe it would be too much for 120ish HP pinto.

[Longboarder]

Your experience is more than mine. I found mine used to flood on a facet with no pressure regulator. Probably needed an overhaul and new float valves. Switched back to the mechanical pump and it ran fine again.

I did work on a friends twin 45 pinto hood that was producing 150bhp and it seemed to run fine at 2psi until he turned it up to 3psi and it ran much better at full chat. So it was suffering from fuel starvation at 2 psi. Tried it up again to about 4psi and it flooded.

 

Nigel

[Gusty]

How many psi is the mechanical pump? Managed to balance the carbs today and runnng even better now. Bit more tinkering and should be there:)

 

Cheers

Edited April 14, 2016 by Gusty

[Bob Tucker]

The big difference between a mechanical pump & an electrical one

is that the leccy one pumps at the same rate all the time.

The mechanical one pumps more as the engine increases revs

& needs more fuel.

But that's about flow not pressure......(Here we go....floodgates open again....)

Maybe I'll fit the Filter king & see what 3psi does....

Any tinkering rather than put it up for sale!!

[Gusty]

Hi,

 

Do you need a fuel pressure regulator with a mechanical pump? It seems to be running even better now as the cam timing was retarded. A few degrees of advance and it revs well without bogging down or spluttering. Another play tomorrow and should be there or there abouts.

 

Cheers

[tractor]

mechanical pump doesn't normally need a regulator but if you think its flooding the carbs then put one on at least then you have control over pressure

[Guest 2b cruising]

Hi,

Do you need a fuel pressure regulator with a mechanical pump? It seems to be running even better now as the cam timing was retarded. A few degrees of advance and it revs well without bogging down or spluttering. Another play tomorrow and should be there or there abouts.

Cheers

Was this under load or just revving in neutral.

If so you might find a total difference when actuall running on the road.

About the pressure on mech pumps.

It is down to the spring pressure that closes the valves in the pump.

If the pressure is at running psi, the valves seal on there seats. If over this pressure, the valves will not seal therefore no pumping takes place until the pressure is lower than the spring pressure on the valves.

Hope you can understand my gibberish, even I can't at times.

[Gusty]

Thanks for the replies. Yes it does flood the carbs. I've set the float height to 15.5mm with new needle valves and it still drips a bit. No where near as bad as before though. I saw a Sytec reg for £25 on eBay . Any good?.

 

Cheers

 

Ken it was revving in neutral. I couldn't get much out of it before now it revs freely

Edited April 25, 2016 by Gusty