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Discussion Starter #1
hey guys
so I am considering putting a new offy intake on my 250 but I am debating between either dual single barrel's or I know a lot of people do a Holley 390. I am wondering what the pros and cons are for performance, mpg, reliability and anything else you can think of. my uncle who has been part of the car scene for a while and has a lot of knowledge, said that he thought the dual 1bbls would better suit a 250
 

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They also make a triple 1bbls setup that looks pretty cool. I'm working on getting a 4brl setup because I don't want to have to deal with progressive linkage and all the little stuff you need to deal with on the setups like them. But make no mistake, they look super cool and are nice once you get them dialed in. You also have to consider if your gonna run heat to the manifold?
 

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- - - - can't go any better than this (all new parts - back in 2012) .



Holley 390 cfm 4bbl # 0 - 8007 (just looked @ summit = NOW priced @ $ 606.00 . . . . . new . . . . . WOW !
OFFY 4bbl intake # 5416 . . . @ summit - new - = $ 385.00
Fel - Pro intake / exhaust gasket set . . . @ summit - new - # MS-9786 = $ 11.00
. . . . or . . . . better intake / exhaust gasket set (much thicker - better seal ) .
RemFlex Gasket set - Chevy 6 - part # RFL - 2034 . . . @ summit = $ 43.19

Then . . use " Twisted 6 " . . . OFFY intake "base - plate" (too turn your carb , where it sits facing
"forward & back - like a normal 4bbl carb " . . . . . . worth every penny , (y)




contact : t6performance : for current price .

carb & intake bought new : March 2012 @ summit :





I installed this Holley carb . . . . . . . and . . . . . . have had too remove it once - to adjust the
electric choke . . . . . . right out of the box . . . . installed back in Sept - 2016 .
and, I CAN get over 21mpg . . . . (if I drive like a good-boy) .

over & out ...................... jim
 

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They also make a triple 1bbls setup that looks pretty cool. I'm working on getting a 4brl setup because I don't want to have to deal with progressive linkage and all the little stuff you need to deal with on the setups like them. But make no mistake, they look super cool and are nice once you get them dialed in. You also have to consider if your gonna run heat to the manifold?
I recently swapped out the dual Weber 38/38 setup on my six cylinder to a single 4-bbl setup using a Q-jet. It is much easier having everything on common shafts with no balancing and linkage adjustments necessary. You also get the Q-jet sound as a bonus...
 

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I recently swapped out the dual Weber 38/38 setup on my six cylinder to a single 4-bbl setup using a Q-jet. It is much easier having everything on common shafts with no balancing and linkage adjustments necessary. You also get the Q-jet sound as a bonus...
Hi Mike . . . . . you have a picture of that swap (I just (the other day) saw your dual carb picture) .
You Still doing th' "swap" . . . . . I like it .

jim
 
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That's a good looking setup you got Jim. Thanks for sharing it.

Smee78 . . . . . . . Thank you , very much . . . . ;)

jim
 

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Thanks, Mike . . . . . I was looking yesterday . . . and saw u'r bottom picture .
That's looking good = Q-jet carb . - simple -

Thank you .
 
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Discussion Starter #11
Wow all those set ups look really great so I guess what I am hearing is that the 4 barrel is simpler which probably means more reliable and more have done it. What about proformance is the 4 going to give me more power as well?
 

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Well , it should . . . . .

but, hard too say . . . . . How's your motor , now . . . . good shape , run good , have any power now . . . .

see what I mean . . . . just hard to say - without 'seeing your car , seeing u'r engine run , maybe even driving your car = before & after . . . the change .
My 390 carb - - helped my 250 motor , alot . . . . but, my 250 engine ran very good , anyway . (Plus, I had a VERY GOOD 1bbl carb, also ) . . (and, was getting 15 to 17 mpg , before I changed anything ) .

See what I mean .............................................

I, also bought my Holley carb - new from Summit - for about 200 dollars less than
the current price . . . (back in 2012) . (the OFFY intake has also 'gone - up' ) , in price .

jim
 

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Thanks, Mike . . . . . I was looking yesterday . . . and saw u'r bottom picture .
That's looking good = Q-jet carb . - simple -

Thank you .
Simple and cheap. I got the manifold from Ebay several years ago for $180, including the Solex 4A1 carburetor. I had the Q-jet hanging on a nail in my garage so I rebuilt it and it works great.
 

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Discussion Starter #14
Well , it should . . . . .

but, hard too say . . . . . How's your motor , now . . . . good shape , run good , have any power now . . . .

see what I mean . . . . just hard to say - without 'seeing your car , seeing u'r engine run , maybe even driving your car = before & after . . . the change .
My 390 carb - - helped my 250 motor , alot . . . . but, my 250 engine ran very good , anyway . (Plus, I had a VERY GOOD 1bbl carb, also ) . . (and, was getting 15 to 17 mpg , before I changed anything ) .

See what I mean .............................................

I, also bought my Holley carb - new from Summit - for about 200 dollars less than
the current price . . . (back in 2012) . (the OFFY intake has also 'gone - up' ) , in price .

jim
The engine runs really great. The only issues I have have been with my shitty monojet
I more meant compared to the dual single carbs is the 4bbl better as far as proformance
 

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Discussion Starter #15
Simple and cheap. I got the manifold from Ebay several years ago for $180, including the Solex 4A1 carburetor. I had the Q-jet hanging on a nail in my garage so I rebuilt it and it works great.
Yeah good point I will definitely check out eBay to see if I can get a discount
 

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Mr Goble where didyou get/who makes a spreadbore manifold for a BMW 6?! Very interesting swap... always wanted a Jaguar six, they are pretty motors.
 

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Mr Goble where didyou get/who makes a spreadbore manifold for a BMW 6?! Very interesting swap... always wanted a Jaguar six, they are pretty motors.
They're a factory item that came on some euro cars of the late 70's and early 80's as well as some marine engines. The Solex 4A1 has bores that match up perfectly with a Q-jet. Some guys put a square bore carb on these manifolds, but the picture below shows the huge mismatch and disruption of the flow through the manifold.



The Solex four barrel can be found on the following Euro BMW models: E12: 525, 528, 530. E24: 628, 630, and E23: 728 and 730. An E21 320/6 may also be equipped with a version of the Solex.
 

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Interesting reading . . . . Thanks, Mike
 
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