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Tri-Power, Dual Two's or ??? Intake

926 views 4 replies 3 participants last post by  M&M CUSTOM 
#1 ·
I happen to have the rebuilt carbs here to make up the necessary flow and feed needs for my cadillac 500 engine in either a three one barrel (these were from 250 inch engines and all match), a dual two barrel (these were from late '70's 350 inch truck engines), or have I gone over the deep end?
I can get the aluminum cheap and trade some spare parts for a local welder to make up a custom intake for cheap too. Or make it myself out of steel for a no cost experiment.
If I were to go with the three-ones setup how should the runners be divided (single runner with 8 branches of equal length??)
The dual-two would look extremely different in a tubular crossram configuration.
I have the limited experience with multi-carb set-up on Honda and Yamaha motorcycles, and inline six engines.
So why leave my newest stock intake equipped big block alone if I have the big money part of this sitting in boxes on the shelf?
I would even consider a crossram four-one barrel.
That just requires I retune a carb already set up for my 292 engine.
HMMM!!!
 
#2 ·
My Apologies for posting this topic THREE TIMES,
if anyone noticed it last night.
I had a very unresponsive connection to my server, and impatience got the best of me.
But hey impatience comes more readily at 1:40 am.
I then rebooted the computer a half hour later and got the other two changed to something that was on my mind that I wanted to know about anyway.

<img src="graemlins/nono.gif" border="0" alt="[nono]" /> <img src="graemlins/spank.gif" border="0" alt="[spank]" /> <img src="graemlins/crash.gif" border="0" alt="[crash]" /> <img src="graemlins/spank.gif" border="0" alt="[spank]" />

[ April 19, 2003: Message edited by: M&M CUSTOM ]</p>
 
#4 ·
I don't remember the specs on you Cad motor, but most want something in the 800-1000 CFM range. 1 and 2 bbl carbs are rated at 3" pressure drop. A 4 bbl is rated at 1.5". I'm thinking the 1 bbl 6cyl carbs where 170cfm. 3 would get you 510 @ 3". Not all that much.... I think there where 4 sizes of the big bolt pattern Rochester 2 bbl. The biggest being 300 cfm. The venturi changed size for the different cfm ratings. Throttle bores stayed the same.

I think, if it was me, I would try a cross ram 6 single style setup. Two logs to mount carbs with four runners crossing to feed the cylinders. The longer the runner, the more torque you would make at low rpms. Run the motor off the two center carbs and bring in the outside ones with a progresive linkage. You would only need chokes on the center carbs. Idle circuts on the outside carbs may be a problem as well. Six carbs feeding idle fuel would be a bunch. Dan
 
#5 ·
This engine I plan on being a warmed over stocker.
500 inch engine, comp cams 268H w/ 218* duration-.490" lift @ .050", headers into dual exhaust.
And am now thinking 4 carbs up the middle of the manifold with each feeding two cylinders.
These carbs will only have to feed 125 inches each, so my thinking is the 1G's will suffice.
This engine by the measurements could hold four edelbrock 1400 series carbs but I wont go that big because the engine doesn't need that much carb for my intended useage.
Warmed over stock.
This engine still has the original 80 pound cast iron intake and Rochester 795 cfm carb, and is impressive in stock form.
 
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