| View previous topic :: View next topic |
| Author |
Message |
RBL
Alfa Sprint
Joined: 30 Mar 2003
Posts: 162
Location: Leicestershire
|
 Posted: Wed May 14, 2008 2:32 pm Post subject: fuel return pipe? |
 |
|
I have Dellorto 40 carbs on my 1.7 8v engine. There is a fuel return pipe on the right hand carb - Does it have to go back to the tank? Is it needed at all?
If the standard mechanical fuel pump is only 3-4psi (correct me if I'm wrong) once the float chambers are full and the needle valves are shut, there's no chance of flooding (assuming they're adjusted correctly). So is any sort of fuel return needed?
I routed mine to the main fuel line just upstream of the pump (I didn't want to return it to the tank due to the distance in a mid-engined car). But at the weekend I was getting some fuel starvation because I think the pump was sucking fuel from the return pipe - the heat probably didn't help either.
So - get rid of return pipe all together?
_________________
Porsche 550 spyder replica with Alfa Sprint 1.7 engine |
|
| Back to top |
|
 |
john 33_16v
16 Valve
Joined: 27 May 2005
Posts: 1406
Location: herts, uk
|
| Posted: Wed May 14, 2008 3:11 pm Post subject: Re: fuel return pipe? |
|
|
| RBL wrote: |
So - get rid of return pipe all together? |
Yep.
On my Dads Minari running 1700 8v with twin dellortos we blanked it off at the carb. Basically there is a stub of the tube with a bolt pushed in and a jubilee clip around the end.
Never had any probs, and i think this was done on the advice of Minari themselves at the time.
John
_________________
If it aint broke, fiddle with it until it is!
- - - - - - - - - - - - - -
93 33 16v Mirtle Met
08 Fiat Grande Punto Exotica Red
90 Yamaha FZR600 Genesis- Silky white/red/blue |
|
| Back to top |
|
|
Oggie
Green Cloverleaf
Joined: 06 Mar 2008
Posts: 811
Location: Whitehill
|
| Posted: Wed May 14, 2008 8:06 pm Post subject: |
|
|
I agree with john, block it off its not needed, mine is blocked and never caused any fueling issues.
_________________
PHAT 33 |
|
| Back to top |
|
|
RBL
Alfa Sprint
Joined: 30 Mar 2003
Posts: 162
Location: Leicestershire
|
| Posted: Thu May 15, 2008 7:56 am Post subject: |
|
|
Thanks, that's what I'll do.
_________________
Porsche 550 spyder replica with Alfa Sprint 1.7 engine |
|
| Back to top |
|
|
BigAl
P4
Joined: 06 May 2003
Posts: 2995
Location: U.K Surrey
|
|
| Back to top |
|
|
rsfruitbat
Alfa Sprint
Joined: 13 Jun 2007
Posts: 241
Location: Kidderminster
|
| Posted: Thu May 15, 2008 4:36 pm Post subject: |
|
|
I know its a bit extreme but I found it helped if you were sat in traffic a lot. i.e. waiting in a queue to start a stage. Putting the fuel return pipe back on helped reduce fuel vaporisation. In normal circumstances though never found it did a lot.
Regards rsfruitbat
_________________
Alfa 33 rallycar series 1
1399cc 16V
red / white / blue |
|
| Back to top |
|
|
RBL
Alfa Sprint
Joined: 30 Mar 2003
Posts: 162
Location: Leicestershire
|
| Posted: Fri May 16, 2008 10:18 pm Post subject: |
|
|
Yes, sitting in traffic in hot weather could be the only problem. The car doesn't get used in traffic though unless I'm unlucky and get stuck in a motorway jam or a queue in or out of a car show. Hmmm, perhaps it does see traffic! We're off to the Classic Le Mans this year so that should be a good trip!
I'll try it though and see how it goes.
Thank, Rich
_________________
Porsche 550 spyder replica with Alfa Sprint 1.7 engine |
|
| Back to top |
|
|
|
