Bob da builder
|
| posted on 2/11/04 at 09:56 AM |
|
|
1360 xflow, bit thirsty!
hey up,
im running a 1360 xflow with Kent BCF2 cam, twin 40`s and its costing me a small fortune in fuel..... does anybody have any views on the below and how
it will give me better MPG....
just run single 40 DCOE, will it still be just as thirsty?
run standard downdraught carb, but with cam will this be insufficent fueling?
any other ideas...... dont realy fancey a different engine, what mpg are people getting out of a standard 1300 xflow in a locost?? im less bothered
about go and more about mpg!!!
if i cant get the mpg up to mid 30`s then im gona have to sell the kit as its costing me a small fortune!!!!
cheers for your time
bob 
|
|
|
|
|
Bob da builder
|
| posted on 2/11/04 at 09:58 AM |
|
|
p.s. if any body has a standsrd 1300 xflow that they want to p/x for mine then then i may be interested!!
spec:
1360cc, Kent BCF2 cam, twin 40`s, full rebuild / recondition 2000 miles ago (may 04) poss electronic iginition 70bhp on the rolling road
bob
|
|
|
barrie sharp
|
| posted on 2/11/04 at 11:12 AM |
|
|
Bob i think its the twin fortys that do it mines the same on a bog standard 1300 drinks like a fish but i do have to be first from the lights and rev
it through towns
the cars looking good" a blind man would be pleased to see it"
''stop press'' the blind mans seen it said "it felt ok"
|
|
|
timf
|
| posted on 2/11/04 at 11:15 AM |
|
|
have you had it set up on a rolling road
it does make quite a difference to consumption when they are set up correctly
|
|
|
Bob da builder
|
| posted on 2/11/04 at 11:23 AM |
|
|
hey up.
barrie, i agree it must be the webbers. but as you say do have to be 1st off the lights, and she does fly, and the noise of the webbers......
bliss!!! but the wallet....
i have had it set up on the rollers and the mpg went down!!! before it was running very lean, now i would say a bit rich, barrie, do you get flames
out of the exhaust?? when i boot it it lookes more like a diesel with all the black smoke!! poss the pump jets are too large, but think that will have
little effect on MPG... maybe i should try a different rolling road and see what they can do......
the plan is to use the locost as my single car, make a hard top... but first need to sort the fuel out, 20k miles per year at 18mpg will be a
killer!!! 
cheers
bob
[Edited on 2/11/04 by Bob da builder]
|
|
|
barrie sharp
|
| posted on 2/11/04 at 11:30 AM |
|
|
Yea i get a bit of poping when driving but no flames and usually a large bang when i turn off!!
the cars looking good" a blind man would be pleased to see it"
''stop press'' the blind mans seen it said "it felt ok"
|
|
|
psylsph
|
| posted on 2/11/04 at 12:10 PM |
|
|
Temperature
What sort of temperature are you running at? My 1300 had no thermastat when I bought it so was running cold in the winter, thus increased fuel
consumption.
Stuart
|
|
|
MikeR
|
| posted on 2/11/04 at 12:22 PM |
|
|
at a guess with twin 40's you're running without a vacum on the dizzy, this will really upset fuel economy. Either change back to a
downdraft and fit a vacum or ..... get mega jolt (ignition side of mega squirt).
these should help !
Although something tells me mid 30's economy isnt' going to happen if you race from the lights.
|
|
|
JAG
|
| posted on 2/11/04 at 12:54 PM |
|
|
My first thought is get rid of the Dizzy and replace with a 3D ignition system - like the Megajolt.
This should give an extra 6-8mpg - maybe more depends upon how bad your current set-up is.
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
|
|
|
Bob da builder
|
| posted on 2/11/04 at 01:26 PM |
|
|
hey up.
im running a 82 deg stat i think, poss 88...
running a fiesta bosch electronic dizzy with vacume advance (muct check the advance is working ok!) which is tapped into cylinder No.1 inlet.
even if im not booting it, say a run to a show still getting 20mpg......
think the best will be to start from scratch and set up everything again and use a different rolling road and see where i am at with that......
how do your reckon things will improve with just a single weber??
cheers bob
|
|
|
timf
|
| posted on 2/11/04 at 01:44 PM |
|
|
quote:
Originally posted by Bob da builder
running a fiesta bosch electronic dizzy with vacume advance (muct check the advance is working ok!) which is tapped into cylinder No.1 inlet.
nooo big problem the vacum advance is being pulsed by the 1 cylinder its much better to plumb the advance line into all four runners but be sure to
use one way valves to prevent the runners from being connected
|
|
|
MikeRJ
|
| posted on 2/11/04 at 02:05 PM |
|
|
quote:
Originally posted by timf
nooo big problem the vacum advance is being pulsed by the 1 cylinder its much better to plumb the advance line into all four runners but be sure to
use one way valves to prevent the runners from being connected
If you use one way valves the advance mechanism will operate only once...the first time the engine is started!
You can join the port runners together using small bore tubing or using restrictors to ensure the bulk gas flow between the runners is very low.
|
|
|
Bob da builder
|
| posted on 2/11/04 at 05:15 PM |
|
|
cheers guys....
will address the vacume, will take a draw off each inlet..... and get it back onto the rolling road.
as for the exhaust.... well the note has changed... louder im not too sure but def different, that and the flames are burning my wheel arch paint!!!
is a 300mm (12inch) flame the norm...... thourght not!!! but does turn heads!!!!
take it easy
bob
|
|
|
MikeRJ
|
| posted on 2/11/04 at 06:18 PM |
|
|
The big problem is using a long duration cam in a small engine. Trying to calibrate the carbs accurately for the RPM range in which the engine is
running "off the cam" ranges from difficult to impossible, and the engine inevitably ends up running very rich under these conditions.
FYI, a single DCOE 40 flows enough for a 1360 up to about 8000RPM with the largest venturis. The higher gas flow may make calibrating the carb easier
(and you don't have to worry about balancing!)
Is the distributor still running the stock advance curve? Chances are it's miles away from what your engine needs now.
|
|
|
Bob da builder
|
| posted on 3/11/04 at 09:30 AM |
|
|
hey up.
the dizzy is stock bosch from a d reg fiesta.
so im assuming that a single weber will also be more reliable as well, now after 1500 miles since the rolling road they are already off ballance
so does any body have a single x flow - 40 inlet manifold for sale?? / p/x for twin 40`s on inlet.?
can i take the vacume off opposite pairs of inlets? i.e one cylinder on on intake and the other on exhaust stroke?? (say cylinder 1 and 2?)
cheers
bob
|
|
|
Bob da builder
|
| posted on 3/11/04 at 10:51 AM |
|
|
ok.... more stupid questions...
how do you reckon this will run....:
if i sack the webers off and use a double choke 32/36 down draught weber and keep the ignition as it is and take a vacume off the inlet as per
normal....
will it run ok or like a bag of nails?? and how do you think the mpg will be affected?? just a bit conserned that the cam and diff carb wont be too
happy together??
realy wish that i had done some more research into engine set ups and mpg before spending so much money on what i have!!!
cheers
bob
|
|
|
David Jenkins
|
| posted on 3/11/04 at 11:50 AM |
|
|
I've read quite a few 'experts' who said that the Weber downdraft carb is the best option for a fast road cam and general road use.
Plenty of go, easy to set up, reasonable economy.
I'm biased - that's what I've got on by 1600 x-flow! Pretty lively...
rgds,
David
|
|
|
jollygreengiant
|
| posted on 3/11/04 at 02:44 PM |
|
|
The other thing that helps fuel economy is driving style. Don't move the throttle so much, adjust speed with gear rather than throttle
possition. Each application of the throttle give 4 squirts of fuel (one per cylinder) as opposed to a single or twin choke down draught wich usually
only give a single squirt of fuel. I used to run a 1660cc Xflow & that used to give me 30mpg on a run, about 25mpg over all.
Enjoy.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
|
|
|
MikeRJ
|
| posted on 3/11/04 at 04:21 PM |
|
|
Bob,
Should still go pretty well with the downdraught, but you'll likely sacrifice some top end power. You'll definately have to get it
re-jetted during a rolling road session though, the stock jetting will be miles out.
Are you dead set on keeping the 1300 engine? A 1600/1700 crossflow would produce the same kind of power in a lower state of tune and would be both
more economic and probably more reliable.
[Edited on 3/11/04 by MikeRJ]
|
|
|
ned
|
| posted on 3/11/04 at 04:26 PM |
|
|
stevem has a 1700xflow and says his drinks like a fish on twin 40's, his car is in the 2nd edition book, so it's been around for a while,
drinking away..
Ned.
beware, I've got yellow skin
|
|
|
MikeRJ
|
| posted on 3/11/04 at 07:06 PM |
|
|
Does it have a long duration cam though? They can make things drink fuel as a good chunk of the fuel goes straight down the exhaust when the engine
isn't running up on the cam.
A 1700 with a standard cam and properly set up carbs should be reasonably economic and will have much nicer road manners than a tuned 1300.
The problem with sidedraught Webers/Dellortos is that they can make the engine run surprisingly well even when they are quite a long way off on
calibration.
DCOE's do not make an engine inherently uneconomic (contrary to popular belief), it's just that an awfull lot of them are never properly
set up, and even a rolling road session is no guarantee unless the operator has had plenty of experience.
[Edited on 3/11/04 by MikeRJ]
|
|
|
Stu16v
|
| posted on 3/11/04 at 08:47 PM |
|
|
quote:
Originally posted by MikeRJ
Does it have a long duration cam though? They can make things drink fuel as a good chunk of the fuel goes straight down the exhaust when the engine
isn't running up on the cam.
A 1700 with a standard cam and properly set up carbs should be reasonably economic and will have much nicer road manners than a tuned 1300.
The problem with sidedraught Webers/Dellortos is that they can make the engine run surprisingly well even when they are quite a long way off on
calibration.
DCOE's do not make an engine inherently uneconomic (contrary to popular belief), it's just that an awfull lot of them are never properly
set up, and even a rolling road session is no guarantee unless the operator has had plenty of experience.
[Edited on 3/11/04 by MikeRJ]
Couldnt agree more except for one thing.
quote:
A 1700 with a standard cam and properly set up carbs should be reasonably economic and will have much nicer road manners than a tuned 1300.
My Westy had a 1700 xflow,which was otherwise standard, except it had a GT cam and twin choke weber. And that drunk fuel too...surprisingly poor even
when I tried to drive it carefully...
A careful right foot and a five speed box would go a long way...
Dont just build it.....make it!
|
|
|
paulf
|
| posted on 3/11/04 at 10:31 PM |
|
|
My car has a 1600 engine with warm cam and 1300 pistons, it has a weber 32dft twin downdraught and fiesta electronic dizzy and a 5 speed box. I
normally get about 25mpg which i thought was a bit thirsty but seems about right
Paul.
|
|
|
scotlad
|
| posted on 4/11/04 at 02:13 AM |
|
|
i only get 25-30 mpg from my 893cc!
|
|
|
Bob da builder
|
| posted on 5/11/04 at 09:05 AM |
|
|
hey up guys
cheers for all the advice and ideas......
i still dont have a clue what to do tho!!!, tinker with the xflow or new engine, poss 2.0 honda i-VTEC 50mpg & 200BHP!!!..... or the extreem a new
project!!!
time to do some thining....
cheers again
take it easy
bob
|
|
|
fastavatar.jpg){kind=avatar}
.jpg)
