Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

[cecho]

Does the 4 BBL carb on a Chevy 305 generate any more power while accelerating out of the hole than a 2 BBL carb? It seems to me the extra power wouldn't come into play until at a higher RPM, but carbs aren't really my thing. Fuel injection makes a lot more sense to me.

 

[Bondo]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

Ayuh,.... That ole Qudra-jet was a Fine carb in it's day,...

If in Good shape, it still is a Good carb...

A 4bbl. carb on a motor, is 'bout 20hp better than the same motor with a 2bbl. carb...

Efi costs a fortune to retrofit, 'n is a Waste of gas money...

 

[cecho]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

I'm wondering if the 4 BBL gives the engine any extra horses below 2500-3000 RPMs. I was thinking there wouldn't be any difference until higher RPMs. As much as I would love to add EFI, I understand it's not worth it at all. I'd rather put that money towards a new 350... not that I'm planning to do that.

 

[Tail_Gunner]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

Unless you have efi on the boat its not a good ideal. Here is a area where marine is truly different than automotive..night and day. In the end you do not want to run above 13/1....carbs can do that for about 2000 less.

 

[cecho]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

When you say 13/1 do you mean 13:1 air/fuel ratio?

 

[Augie56]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

I have the Mercruiser 228 setup. My engine makes excellent compression and is tuned well. I'm not going to exaggerate because I don't have much else to compare it to, but I do notice that I have no problem planing quickly, no matter the amount of fuel and people/gear, whenever I want to. She just goes.

Also, there is NO HESITATION in accelerating from cruising (say around 2000-2500 RPM) to WOT when you put the remote down. The sound and feel of that 4 barrel opening up is sweet music.

When I looked for a boat, I knew I wanted three things in my I/O : 8 cylinders, 4 barrels, and a black outdrive.

 

[cecho]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

If I have any power problem I guess the first thing to do would be to put the 4 BBL intake and carb on in place of the 2 BBL versions... or maybe a torque shift prop.

When you're in the hole and trying to get on plane are the secondaries open? If not than I would imagine the 2BBL and 4BBL version of the same engine would perform nearly the same way while accelerating from in the hole and getting onto plane.

What size boat and prop do you have that 228 in?

 

[dan t.]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

On a q-jet the primaries are smaller than a 2 bbl, this gives you better throttle response at low rpm,also better fuel mileage as long as you stay out of the secondaries. At wot the secondaries are open but the air valves are closed until there is enough rpm ( read air flow) to pull them open.

 

[greg82255]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

A few years back, I had a Merc 898 chevy 305 and I did a swap from the stock 2bbl carb to a Holley 4 bbl/Edelbrock performer intake. Cost me a lot of $, and I painted it so the motor looked cooler, but I didn't get much noticeable power out of it. Maybe a mph or 2 on the top but not better throttle response.

 

[Tail_Gunner]

Re: Chevy 305 (198 HP 2 BBL Carb) VS (228 HP 4 BBL Carb)

When you say 13/1 do you mean 13:1 air/fuel ratio?

Yes and that's pretty lean. If your not in saltwater look at the air gap intake (eldobrok) that will help off idle response.