How's it going guys?
I am beginning to gather parts for a project down the line a bit, and I found a carb for a helluva good deal, $250 for carb, intake mani, K&N filter kit and velocity stacks.
(I am buying it from a friend, so it is not too good to be true lol)
I am planning on building a NA BP 4 port 13b (Turbo housings with probably an s4 rotating mass)
-The carb is a OER 45mm DCOE side draft
Is that carb too small? and if so can I bore it out/ modify it to make it pro?

I searched and I didn't really find too much that helped me.

Any info is greatly appreciated!

Thanks

 

A 45 DCOE feels just like a stock carburetor, on a stockport 12A.

Two 45DCOEs is probably closer to right.

 

id go for at least a 63 if not more or dual carbs. My Fiat engine runs dual 63 and its only a 1.8 4cyl. If anything i go for the Holley setup

 

Damn seriously?

any carb recommendations or mods I can make to it?

 

Id go for the Holley 4 barrel setup that racing beat sells http://www.racingbeat.com/FRmazda1.htm you will have to get a better fuel pump that cn handle 6 psi through the entire rpm range but i would go with this and if you need more later holley sells hop up kits and bigger carbs will prolly fit is you need even more.(like if you ever get a bridge or peripheral port.

 

Im so sorry i got my facts wrong i just looked like an idiot my dual carbs on my fiat are 36 dcoe your 45 is still low for the motor though maybe a racing beat 48 or 51 i still prefer the holley. Once again im sorry for giving you the wrong info.

 

haha I was gonna say dual 63?!

Couldn't I go with larger venturis and jetting in the 45 though?

 

it might run really rich because it might not pull as much air in as it needs. might be able to get it bored out but try the jets and venturies but be warned venturies are expensive.

 

a 45 dcoe is too small for a 13b with stock ports, unless you want a daily driver with good driveability and only decent power. But that doesn't sound like what you are going for. for a full bridge? no way. Even if you buy the biggest venturis you can find, it will be to small. A 48 or 51 dco might work. Or an ida or idf 48 or 51.

look up wackricer, or hyper4mance. They have experience with carbs on ported engines.

but the 45 dcoe will never get you what you want out of a full bridge on a 13b.

 

Go with Webber 48mm DCOE side draft

 

i agree. for a bridge, i wonder if the longer side draft style manifold is too long also. seems like a 48IDA/holley would be a better choice (arguably the 48IDA is too small too)

 

There is a lot wrong with that statement, in actual concept.

Carburetors don't pull air, they meter fuel. They rely on the speed of the airflow through the venturi to pull the fuel out of the fuel bowl.

Sizing a carburetor is getting the speed through the venturi to an optimal balance, and tuning is a matter of changing the fuel jets, air bleeds, and emulsion tubes to provide the proper amount of fuel for a given velocity (airflow) through the venturi.

It's very simple in concept but, like most simple things, there are a lot of interrelated variables that will make your head hurt if you think about them a lot.

Like - a more efficient booster design will allow a larger venturi to be used without sacrificing low-flow fuel quality. I have seen a carb with a seriously crazy looking setup - the booster looked like it was just a tube stuck into the middle of the "venturi". I put that in quotes because there WAS no venturi. I asked the car's owner and he said yeah, it looks like it shouldn't work at all, but it actually worked very well.