fuel economy W/ dual 40's

[Moisabamf]

my friend just got a 510 with a 32/36 and is interested in going 40's.

what kind of fuel economy do you guys get

they would go on an L20B with headers and 2.5 inch exhaust

what you guys think?

[datzenmike]

Does it have a stock cam? That's a way lot of intake and exhaust for a stocker.

[808DA6]

Hehe. Pardon the non-constructive comment, but the term "40's" and "economy" look funny together. Its like putting Godzilla and King Kong in a room w/ priceless, fine China.

 

Not to deter though. I'm going to throw some 40's on mine and was kinda wondering the same.

 

-Brian

[banzai510(hainz)]

I get about 20-22 with mine 40 mikunis& cam

but I have 3.7 Suby diff

 

about the same as my 521 with a 32/36weber(but the truck has the low 4.375 gears!!!!!!!)

[racerx]

Hehe. Pardon the non-constructive comment, but the term "40's" and "economy" look funny together. Its like putting Godzilla and King Kong in a room w/ priceless, fine China.

 

Not to deter though. I'm going to throw some 40's on mine and was kinda wondering the same.

 

-Brian

 

 

Yeh, I am with you like Jumbo Shrimp, Oxymoronish or Military Intelligence or government efficiency..people, people, can't have your cake and it too. How's this for an idea, if the 510 is not a daily driver then who cars how many miles a gallon you get. I know quiet a few dimers in the Bay Area and they take their car out maybe once a month!

[banzai510(hainz)]

If gas keeps going up Im going to pull off my dual carbs and put my DGV carb back on and sell my Yellow 510 convert

[Guest jaimesix]

If gasoline is a concern and the engine is not a monster modified powerplant, consider a single sidedraught. I purchased on E Bay AU a single 40 Dellorto with a cross flow single sidedraught Lynx manifold.

 

I have not used it yet, but I will on my 710. A single well tuned Dellorto ( Solex, Weber , similar ) and the benefit of a cross flow Lynx manifold will add power without excesive juice.

 

A 38 DGES downdraught Weber is about the same size as a 40 sidedraught , but more direct flow. A 32/36 Weber has less cfms that any of the aformentioned carburetors.

 

I will test the difference in my 610 ( L20B) I will use it with the 38 DGES on a cannon manifold for a while, then try the 40 sidedraught on the Lynx to determine the actual difference.

 

But for those using twin sidedraughts, try a single sidedraught instead.

 

Jaime.______________________________________________________

 

Jaime.______________________________________________________

[banzai510(hainz)]

Jaimessix,

I have a 38DGES and Im impress with them(not used right now)

I had it installed on a camed L16(521)and was great but if on a hill and had to pop the clutch I could kill it(stall out). Maybe loss of vaccum to fast with both buterflies open . I would figure this be best on a camed L20. as my carb was jetted for a Landcruiser.

 

another reason is my L16 in my Banzai car has blowby which stick bad inside the car. But car runs STRONG. really STRONG> So I was think of hooking a spare 32/36 Weber using the matchported stock L16 intake and use the PCV and valve cover tube to aircleaner to keepit from stinking and just run this motor till it dies(well really STINKS to much).

 

I have a Built spare L18 and new bottom end L20 which to use latter.

 

If the gas milage increase isnt all that then Ill stick with my L20 build and put the sidedrafts I have on now and just say Fuck it.

 

But anybody getting 25/30mpg with a 510?

I have a Suby 3.7 and I get about 21/22 already with the sidedrafts.

 

To put a DGV on to get 23/24 isnt worth it

 

Jaimesix

PM me with your thoughts.

Ill be back tuesday

[zhent]

I'm getting 26MPG city with an L18 and Weber DGV, though I still intend to put my 38mm SUs on this motor. I also daily drive the car, so mileage is somewhat important, though I was only getting 20MPG in my 240sx, so I'm used to shitty mileage...

[Guest jaimesix]

Jaimessix,

I have a 38DGES and Im impress with them(not used right now)

I had it installed on a camed L16(521)and was great but if on a hill and had to pop the clutch I could kill it(stall out). Maybe loss of vaccum to fast with both buterflies open . I would figure this be best on a camed L20. as my carb was jetted for a Landcruiser.

 

another reason is my L16 in my Banzai car has blowby which stick bad inside the car. But car runs STRONG. really STRONG> So I was think of hooking a spare 32/36 Weber using the matchported stock L16 intake and use the PCV and valve cover tube to aircleaner to keepit from stinking and just run this motor till it dies(well really STINKS to much).

 

I have a Built spare L18 and new bottom end L20 which to use latter.

 

If the gas milage increase isnt all that then Ill stick with my L20 build and put the sidedrafts I have on now and just say Fuck it.

 

But anybody getting 25/30mpg with a 510?

I have a Suby 3.7 and I get about 21/22 already with the sidedrafts.

 

To put a DGV on to get 23/24 isnt worth it

 

Jaimesix

PM me with your thoughts.

Ill be back tuesday

 

 

Hi.

About the 38DGES stalling, I would check the jets and the emulsion tubes. Since it was geared for a Landcruiser, it probably has been over jeted and over tubed.

 

If your car has excesive blow by , it could have a sticking/clogged PCV valve at the intake manifold. Also bad piston rings allow fumes to return into the engine crankcase, creating blow by.

 

A catch can design crankcase ventilation system instead of the factory PCV system would rid your intake from unnecesary gases that clog and interfere with proper air gas mixture. Using a catch can design crankcase ventilation instead of a PCV ( positive crakcase ventilation ) system will rid your engine of the PCV valve. That port in the manifold is closed.

 

Even if the problem is not a sticking PCV valve, but a piston ring problem or bad cylinder(s) , the catch can design ventilation system will always be of benefit, keeping bad and useless intkae wise fumes from interfering with good mixture.

 

Hope you are having a great weekend. Talk to you when you come back.

 

Jaime.________________________________________________________

[banzai510(hainz)]

well I have acess to a computer today.

 

I removed my 40mm mikunis ans installed a DGV 32/36. I could not get it to idle.I was cheap and tried to reuse the intake gasket. Well the DGV still would not idle. Then the carb sounded like a flute reed. So I replaced the intake gasket with a Felpro and still the carb sounded like a reed. Then I figuire it was the thin DGV carb adpater. I put a med size one on and that solved the bnoise proplem. I still have no idle. ajust the mixture and no help.

Tried to install the 38DGES and the studs are slightly bent so I tried to drill out the 38DGES. That didnt work so I found some new studs. Installed the 38DGES and it flooed out bad(this is a good carb) well maybe cause I had it upside down alot I dont know then I wacked it by the fuel inlet incase the valve was sticking, that fixed that. But only way it would run is if the turn the SPEED screw in more than a few turns and it would just die trying to take off,

. I tried the strter fluid thing and coundt find any increase in RPM so Im missing something. Either these carbs are both bad or Maybe the Cam(475/275) install but the 32/36 seemed to run a little smoother (Not driving around) but no idle either.

 

I got tired of working on it. So my next option is to buy a new DGV instead of used ones which I had.

 

also I find out when I changed the intake.exhaust gaskt that the bottom of th middle exhaust exit was blown out so that madei t smell horrible.Now with the PCV hooked up it was alot better

Jeff Hino has the bigger DGV carb adapter(hell give me) and I always like them as I think they seal better and have a better surface than the others.

I have always had good luck on installing these before just this time hasnt worked out for me.

 

I dont think the cam is too big as I ran a 32/36 with a Scheider 460/270 and it ran like it was stock. Also later put that 38DGES on there with out proplems except bottom hesitation right off idle but went GOOD!!!!

 

PS I had the crank and valve cover OPEN vent using the 40mm MIkunis, NO PCV valve NOTHING!!!!!!!

[Guest jaimesix]

If your car was running fine with the 40s,the problem you have now is strictly carburetion.

What kind of fuel pump were you using with the twin 40's?? Perhaps you have way too much pressure for a single downdraught carburetor. I would check that out. Lower the pressure if it is pump that can be regulated/dialed.

Perhaps that is why you got your 38 flooded. The 32/36 being progressive might restrict the extra fuel pressure a little allowing a little better idle.

The syncroneous barrels on the 38 might add to the over pressure problem flooding the unit faster.

Check that out, let us know.

 

Jaime.________________________________________________________

[banzai510(hainz)]

I have a stock fuel pump. it stopped FLOODING out. think it was on the shelf too long maybe?

 

Jeff will be sending the Bigger carb adapter

 

Ill look for a new DGV if the carb adapter dont work.