The Stovebolt Site Forums The Shop Area Engine Shop Dual or triple carbs. on a 250

I have a 1970 6cyl. 250 and I can't decide which would be better?Two or Three. I'm not looking for performance,it's a stocker, just looks and driveable.Using either Offenhause 5414 or 5415 intake,also what carbs to use? and split exhaust.If I go 3, will it run ok on 1 with the others being secondaries? Any ideals will help . Thanks

if you run 3, you could go the progressive route, like you said, and have the 2 outside carbs as secondairies. this gives you performance when you step on it, but keeps the stock-ability when you're just cruising on the middle main carb.
also will help keep the mpg's down.

personally, i like 3. the more the better. :p .

.later days.
.desperado.
.sam.

Beware of triple carbs due to linkage problems (?) and possible firewall clearance problems on some trucks. Check it out before you throw down your money and yes, do the exhaust manifold too.

67-72 chevys have qite a bit of room under the hood but make shure you check the brake booster clearing the third carb

Wow, thanks guys for the info. It's going in a 37 Chevy 1/2 ton, so I can make it fit. I think I'll go the 2 route for clearance.Now what carbs to use? Thanks again

i love the look of those stromberg 97's. the hot rodder's journal did an artical on two rat rods that had 235's in them. one of them was running two strombergs.

they look cool at least, i dont know about performance tho. i know theyre $$$$$

Hey , 3 fit on the '39 ............


More is not enough !!!!

3 small ones atomize fuel better than 2 medium ones or one fat one! How well it runs depends on what you choose to install and how you adjust it.
That, and 3 looks cool!!!!

My father, who unfortunately is no longer with us, was a serious old school chevy guy and he swore by multiple carbs with progressive linkage. That third carb makes a big difference at higher revs.

Boo

Hotrod, heres a link to my '37 with three carbs and headers.
http://www.stovebolt.com/gallery/hand_joe_1937_01.htm

I made the whole set up. I have since removed it due to poor running when the weather turned cold, no heat under the manifold. I also made a manifold to hold these three carbs that bolts to the stock exhaust. It ran much better due to the under carb heat and the ability to hook up the choke. It still needs some rejetting to get it just right.

Don't go to small on the carbs. Use a center or main carb big enough to handle the engine alone. The engine will use what it wants from the other two. Mine are to small and it takes all three just to make 240 cfm. One original Monojet flows more air than two of my Corvair units. Joe

not trying to steal this post, but what would be better. 3 one's hooked pregressively? or 3 one's hooked direct? for gas mileage, performance, ease of contruction, etc.

thanks.

.later days.
.desperado.
.sam.

Hi all, Well I bit the bullet and bought a Offie. 2 manifold, and a set of Dual split headers from Landons ( really nice)and I just got 4 rochester 1 barrels (B)s I hope I can make two good ones from them.Ihope I did the right thing on just 2 instead of 3 intake??!! Also Joe, your 37 truck is really Cool! Thanks for all the info guys! and Sam, I would use progressive linkage with your 3s.

Just for the ease of adjustment, progressive would be better, but it really shouldn't make much difference if everything is set up correctly.
Try and find three carbs with the same ID numbers. There are so many different ones out there that look the same but are different inside. Run one at a time on a stock intake till you are happy with it, then switch to the next one till you have all three running equal. With all three at once, its very hard to tell which one is acting up. Jetting should be just the same with all three.
Be prepaired for alot of tuning and fine adjustments. Don't settle for all most! Joe