HOLLEYS ARE DODGY

[DYNOED250]

FOR ME ITS EFI, WHY BOTHER WITH CARBS BUT I LEARNT SOMTHING TODAY BOUT HOLLEY CARBY SIZES AND HOW THEY MEASSURE THE CFM RATEING.
WHEN HOLLEY FLOW A 2 BAREL CARBY ITS FLOWED AT 5 INCHES OF VACCUME TO GET THE 500 CFM.
BUT WHEN THEY FLOW A 4 BARREL ITS ONLY AT 2.5 INCHES OF VACUME

WE SAT DOWN AND MEASSURED THE ID OF A 500 EACH BARREL WAS THE SAME SIZE AS A 750 FOURE BARRREL, SO IF U TAKE THIS INTO CONSIDERATION AND FLOWED A 500 AT ONLY 2.5 INCHES OF VACUME IT WOULD ONLY FLOW 375 CFM IF FLOWED AT THE SAME VACUME AS A FOURE BAREL.

I WAS TOLD THIS BY AN ENGINE BUILDER GUY, SO TAKE IT ANY WAY U WANT. BUT I THINK HIS RIGHT.
I MEAN A 500 DOESNT HAVE VENTURY AS BIG AS A 1000CFM FOUR BAREL DOES IT.
I MAY BE WRONG BUT CHECK IT OUT

JUST INJECT IT PEOPLE CARBYS ARE FOR VICTA'S EFI MMMMM YUMMY
STILL HAVNT GOT MY HEAD FLOW FIGURES FOR THE MOTOR THAT DIED UP HIGH. I DECIDED TO LIVE WITH THE 290 IT MADE , I JUST WANA DRIVE IT BEEN 2 YEARS OF THE ROAD.

 

[xctasy]

Bang on. They used 3" and 1.5" for the flow of 2 and 4-bbls. Confuses the heck outa everyone when you tell them a 500 cfm 2-barrel carb is smaller than a 390 cfm 4-barrel. Just divide the 2-bbl cfm by 1.4, and you get the carby flow by the same standard.

Carbs are ancient, but injection requires a good IT expert to sort the set up. Even if you follow the manual, you have to learn all the rules, and it gives you enough adjustability to do bad things if your not on to it. Especially intergrated ignition and fuel systems.

I deal with some aspects of Information Technology, and I hate the fact that you can't predict how long a modification is going to take, and what extra stuff you need. With EFI, you really better off seeing the bank manager, and getting enough coin to make it work.


If your a 'tight a$$' who can read bookes then a carb will do nicely.

In another 10 years, EFI will rule, until then, I'll stick with the Detriot Leakers.

 

[DYNOED250]

THE COST OF A DECENT FOUR BARREL CARB THESES DAYS IS ENUF TO GET AN AFTERMARKET COMPUTER. MY INJECTION SET UP COST BUGGER ALL

INJECT FUEL ONLY COMPUTER $300
EFI 400 HP BOSCH FUEL PUMP $260
INJECTORS $470
ASSORTED WIRING, SENSORS $100
SURGE TANK $120
CUSTOM INTAKE FREE :>

FOR THE COST OF THAT AND THE FACT THAT THEERE WERE ONLY LIKE 15 WIRES MABIE A TAD MORE ,MADE THE LOOM UP IN UNDER A DAY. YOU JUST CAN NOT BEAT EFI NO MATTER WHAT YA SAY, THE AIR FUEL RATIO IS ALWAYS GOIN TO BE RIGHT ALL THROUGH THE REV RANGE IF ITS NOT U PUNCH A FEW BUTTONS. COLD MORNINGS STARTS FIRST TURN OF THE KEY, NO NASTY FLAT SPOTS, AWSOME FUEL ECONMONY, NO HOLLEY CAR FIRES. THE LIST IS ENDLESS OF THE ADVANTAGES OF EFI OVER CARB. ONE REAL BIG ONE FOR THE 250 IS EVEN FUEL DISTRUBUTION AMOUNST THE CYLINDERS.
THE COST OF SETTING EFI UP IS COMMING CHEAPER WHILE CARBS ARE ONLY GOING UP

RED LINE FOUR BARLLE $240
HOLLEY 650 DOUBLE PUMPER $ 600 +
HOLLEY BLUE $250
FUEL REG $50

CARB IS STILL CHEAPER ......... BUT GET WITH THE TIMES DONT BE SCARED HAVE A GO EFI IS DA WAY

 

[xctasy]

I'm getting older and more conservative each day, sonny. Should I change to EFI now, and get it over and done with?

My background is Lp gas set-ups. I'd love to use an EFI system to inject propane, but its worse of than carbs at the moment.

Totally agree about Fuel/air ratio. Theres a lot of safe gaurds.

 

[DYNOED250]

Funny u should say u were thinking bout injectiing propain me and my work mates were talking bout the same thing. u would have to have the injectors heated ,,, and it would prob still freeze the injector up. at least there would be no need for a gas converter.
air temp would be cold as 2 which would kixk arse. but i dont know how u would inject it in any other for,m other than a liquid. gas expands a hudge amount when it changers from a liquid to a gas, so only very small amount of gas would b need ed. but i dont know only had a litle experance with gas.
mabie direct injectionm intoi the combustion, chamber using a diesel style injector using the electrionic system they have now to fire the injector. that would stop it freezing up, nothing like combustion to melt ice.
these are all ideas but i know they prob wouldnt work but i have thought bout it

 

[George]

Hi,
I agree on EFI!! I swapped from a carby to efi and was amazed at the difference. Even without being dynoed, the engine is responsive and powerfull without all the problems of carb setups. I found it very easy to tune on the road with a laptop.

In regards to LPG efi, I have heard of people inserting an efi fuel pump inside the main LPG tank to further increase the pressure of the gas in the lines. This ensures the gas doesn't vapourise before it gets to the injectors. I am not sure if it is hooked up with a return line and regulator!?
The return line would eliminate heating of the gas in the engine bay.

If done like this, there is a posibility of using standard fuel injectors and freezing should no be a problem as vaporisation occurs after the gas exits the injector. BUT who knows for sure??

This system would be great with turbo's...Intercooler for each cylynder.

See Yah

 

[addo]

I'm sure it's feasible on a daily (EFI LPG). Perhaps a little more trigger happy than regular fuel, but not outright iffy. Heating blankets/shrouds on the injectors could help the icing problem, I'm sure.

I also believe there's a reason or two it's not been done.

 

[Anonymous]

George,

http://members.iinet.net.au/~disco/LPG1.jpg
http://members.iinet.net.au/~disco/LPG2.jpg
http://members.iinet.net.au/~disco/LPG3.jpg

looks like it can be done with a regular gas tank, an inline fuel pump in a loop, and one fuel rail if you're going for straight gas

 

[George]

Hi Disco,

Thanks for the info. I had heard but never seen or read about it.

This is very interesting....I am getting excited...Will I try something like this next?...Perhaps another dodgy backyard special?? :idea:

I dont think it would be that hard to setup. The pump in the tank and return line is the scary part

Does anyone know what the octane of LPG is these days?

I like it

 

[xctasy]

105 RON. It was about 112 RON in the early 80's.

 

[TCSTEVE]

Dudes you can run more than just holleys on 250's. Iv'e seen webbers and of course the tripple weber set up all have gone hard as shit. Also off of the 6's only to clear this shit up.
1969 XY GT 351 CARB---14.3 second passes
2003 NEW FORD GT
smaller motor--4.6 litre
30 years of knowledge/experience later
Higher horsepoer figure
E.F.I---14.1 second passes
Plus the horsepower winners at summernats etc are (mostly) carb proves that EFI is catching up so dudes run whatever you want and prove yourselves out on the track!!

 

[Anonymous]

I hate Holleys!!!!!!!!!!!!!!!!!
I was getting 12mpg out of a 2.7 fitted with a Holley 350. Same car with a Weber can get 30mpg!

 

[Anonymous]

INJECT FUEL ONLY COMPUTER $300

was that new? got any more info or a website?

 

[DYNOED250]

THAT WAS SECOND HAND , I HAVNT BEEN ABLE TO FIND A WEB SIGHT EITHER, THERE AN AUSTRALIAN BASSED COMPANY, , THERE IS A EM1 EM2 AND ME THINKS EM3 NOW, THE EM1 AND EM2 ARE VERY SIMILAR BUT THE EM2 DOES IGNITION, BOOST RETAIRD, AND LOTS OF STUFF.
I JUST HEARD OF A BLUE BIRD GETTING SOLD FOR 350 WITH AN EM2 IN IT DAMMMMMMM