I probably am crazy but here goes.

I have been a fan of dual carb setups for a long time dating back to my performance VW and Porsche days.

I'm looking at building a perfomance 300ci with most of it's power in the mid-range for my street-rod 1953 F-250 truck. I'm thinking of a .478 lift/.270 duration cam and triple Weber 45 DCOE side-draught carbs. So long as I build the head accordingly and run a header, is this too crazy of a setup for a street engine?

Looking for intelligent feedback/criticism not flames.

Thanks guys.

- JT

 

the 300 isnt really a performance engine, crane makes a cam for the 300 and the carb should do fine if u dont over do it.

 

Nope, I don't think so. I'm also a fan of Weber carb setups. If you offroad a lot, there's something about the properly tuned & jetted Weber carbs that just don't let that engine stall. A few of my machinist friends say that it's the large amount of vaccum that the I-6 makes. I was going to do the same thing, but with a single 48 DCOE mated to the fuel injected upper intake. The I-6 seems to love long intake runners and high velocity flow, vice direct carburetion for some reason. I'd say, if you do a lot of offroading, keep the cfm's down with a few multiple throat DGES or IDF upright carbs mated to the lower FI intake manifold. This way you can have your cake & eat it too. The smaller throat size is going to be a little more condusive to higher velocity charge and you can keep your torque while boosting the HP. It seems like 3 DCOE carbs mated right to the engine would be great for a "high revving" application, but what is high revving in an I-6? 3500 rpm? Right now I'm working on taking a stock I-6 manifold and chopping of the single throat port of the intake and mating a motorcraft 2100 from a 390 to the intake. A friend of mine uses this same setup on his I-6 with FI exhaust manifolds, a 240 head in a 1 ton flatbed that regularly tows nearly 20,000 lb of whatever it is that machinists tow... Good luck with the Weber setup however you do it & post some #'s when you get done.

 

According to my machinest, the upper end for a 300 is around 8000 rpm. Just because you don't build an engine for a particular RPM doesn't mean it can't go there.


-=Whittey=-

P.S. 3500 isn't even high for stock, never mind modified.