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<!-- BEGIN TEMPLATE: ad_showthread_firstpost_start --><!-- END TEMPLATE: ad_showthread_firstpost_start -->Hello everyone,

Looking for some advise, I have a Inline 6 with a 1 barrel carb. I really don't know that much about engines but i was wondering if i could install a 2 or 4 barrel carb on my inline 6? I know I would have to put on a different intake but would it be worth it? and anything else i would have to do to it?


Thanks for helping out
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"Worth it" is something that can only be defined and quantified by you.

Do a lot of reading on this site and this one Fordsix Performance :: View Forum - 240-300 "Big Block" Six Performance.

JMO, there isn't anything a 2v can do that a 4v can't do better including mpg.

 

I agree; I'll also add that if you don't know much about engines, you may be in for a little more than you bargain for because you may have to get a little creative with the throttle linkage, depending on your setup. You also might need to tune the new carburetor with jets and metering rods\power valves. Not for the first-timer. A 4-barrel carb and intake swap on a straight six isn't as straightforward as it is with a V8.

 

Agreed on both. A 4bbl is commonly agreed to simply be better than a 2bbl. A 2bbl needs to be made bigger to give you the power you need, whereas a 4bbl closes off two of them when you're not using them.
For example, if you have a 400cfm 4bbl and a 300cfm 2bbl. When you are driving the 2bbl, you're using the 300cfm all the time. However, when you're driving the 4bbl, you only drive around with 200cfm because two of the barrels are closed, using less power and saving gas. Then when you step on it, and need the power, you have 400cfm.
(I have, at one point, seen a 2bbl that did this. Really interesting. It had a 1 barrel primary and a one barrel secondary.)

As for what fmc400 said, I just did this swap in my engine, and it was a good thing I knew my engine in and out. I've had it for about 4 years and didn't know a single thing about it when I got it. By the time I put the 4bbl on, I knew how every inch helped every other inch make the whole thing tick. When I did the swap, it was easy, and I knew how to reconfigure my engine to accommodate the changes. This is something I certainly couldn't have done when I first owned it.

Unless you're great at engines to begin with, I'd recommend taking some time to learn your engine, how it works, and then plan on the upgrades. They're definitely fun, and you'll get a lot of great help here.

 

Ok here's your options...keep the 1 bbl for low end torque, 4bbl for high speed. a 2 bbl is pretty much impractical since no one makes a 2bbl intake, and the adapters just funnel everything into the small 1bbl hole.

 

How the spit does a 4BBL hurt low end torque?

 

A 4bbl just doesnt have as good torque as the 1bbl. It takes too much to get it going. It's like putting a 850 cfm carb on a 302. The bigger the carb, the higher up in the rpm range the torque curve moves.

 

That doesn't make any sense to me. I'm trying to wrap my head around it but it seems backwords. How would providing MORE fuel HURT power?

I understand how having no backpreasure can hurt low end torque but this seems strange. Very interesting!

 

A bigger cam usually moves the peak tq and hp up higher in the range and that isn't saying that one is losing tq and hp at the lower ranges either.

So how does one move the tq and hp band higher in the range with a 4v carb? If anything, there will be an increase in tq and hp across the band plus a bit more range one didn't have with the 1v carb.

 

A lot of people thing you lose bottom end torque because the peak torque is at a higher RPM. This can be the case if one puts in a particular cam, but not generally.
For example:

Stock: 255tq @ 1400 RPM
Upgrade: 300tq @ 2000 RPM

However, when you're at 300tq at 2000RPM, you very well could be making something like 260 or 270 at 1400, which is higher than stock. So, even though your peak torque is at a higher RPM, (which gives the appearance of loosing bottom end torque) you very well could be making even more than you used to all throughout the power band.

My new 4bbl makes way more low end torque than the 1bbl.

 

He was asking about changing the carb and intake only. If you just slap on a big carb and intake it will hurt the bottom end. Dont ask me how, thats just the way it works. Just like slapping on a set of big tube headers and 3" duals will kill your bottom end torque. You have to change intake, carb, cam, improve your ignition, headers, and good free flowing exhaust to balance everything out. Remember, an engine is a big air pump, sucking in more air does no good if it has no where to go.

 

Holy crap, that is alot of great advise!! Im not going to do anything real soon, probably at the end of summer, 4v and intake it is!!!!!!! maybe headmans headers also.Thanks for all the info

 

Headers are a good idea too, or even EFI manifolds. Time for some 50 series flowmasters too!

 

Yeah, most poeple say that the EFI manifolds work better than headers for making low end torque.

 

Dunno about that but they will last the lifetime of the truck in most cases. With how difficult it can be to instal headers I would prefer to have something that will last a loooong time.