445 stroker carb?
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Fleet Mechanic
Joined: Jun 2011
Posts: 1,804
Likes: 5
From: Southern California
I am not a carb expert so take it for what it is worth.
I was running a 670 cfm Street Avenger on what I thought was a 400 cu in motor, but once I tore it down learned that it was only a 351 cu in. The carb, once I had tuned it, ran wonderful with great throttle response on the street.
I am now in the process of building a 437 cu in stroker out of it. I used one of the online VE/CFM calculators to find a ballpark figure to work with for carb size, which ended up being around 630-640 cfm at 100% VE at 5,000 rpm. When I was talking to T. Meyer putting my engine package together I asked his recommendation on carb size and he said to run a 750 cfm.
I started looking at carbs and liked the QFT SS series carbs for the features I got at the price point. The only problem is, they only have a 735 cfm and 780 cfm carb in the 750 range so I called up QFT and explained my build and goals. I explained to the tech that I wanted good throttle response, but at the same time I didn't want to leave anything on the table by going with too small a carb and gave him the figure I got out of the VE/CFM calculation. The tech recommended the 735 cfm carb to me stating that it was going to be a better option to run on the street due to the fact that it was flowing about 680 cfm on the front end, close to the CFM number calculated. I ended up purchasing the 735 cfm carb.
Unfortunately, I am still waiting on custom parts from Tim so I cannot give any insight into whether or not it was the right choice or not on a running motor, but I figured I would give you a little information on my thought process for selecting a carb and maybe it would help you select yours.
PS - The QFT carbs are a nice looking unit.
Street Carburetor 735 CFM VS
I was running a 670 cfm Street Avenger on what I thought was a 400 cu in motor, but once I tore it down learned that it was only a 351 cu in. The carb, once I had tuned it, ran wonderful with great throttle response on the street.
I am now in the process of building a 437 cu in stroker out of it. I used one of the online VE/CFM calculators to find a ballpark figure to work with for carb size, which ended up being around 630-640 cfm at 100% VE at 5,000 rpm. When I was talking to T. Meyer putting my engine package together I asked his recommendation on carb size and he said to run a 750 cfm.
I started looking at carbs and liked the QFT SS series carbs for the features I got at the price point. The only problem is, they only have a 735 cfm and 780 cfm carb in the 750 range so I called up QFT and explained my build and goals. I explained to the tech that I wanted good throttle response, but at the same time I didn't want to leave anything on the table by going with too small a carb and gave him the figure I got out of the VE/CFM calculation. The tech recommended the 735 cfm carb to me stating that it was going to be a better option to run on the street due to the fact that it was flowing about 680 cfm on the front end, close to the CFM number calculated. I ended up purchasing the 735 cfm carb.
Unfortunately, I am still waiting on custom parts from Tim so I cannot give any insight into whether or not it was the right choice or not on a running motor, but I figured I would give you a little information on my thought process for selecting a carb and maybe it would help you select yours.
PS - The QFT carbs are a nice looking unit.
Street Carburetor 735 CFM VS
Thanks for the right up and link. Im thinking I should give Barry a call again and see what his POV is. After all he is mr 445.lol
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Fleet Mechanic
Joined: Jun 2011
Posts: 1,804
Likes: 5
From: Southern California
On the holley cfm chart it claims I should be good with a 770... But I tend to overthink things and id hate to get a 770 then have it end up me needing the 870. But im sure im overthinking this again haha
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Fleet Mechanic
Joined: Jun 2011
Posts: 1,804
Likes: 5
From: Southern California
But yea if it wasn't ever going to be used to tow, I throw one heck of a cam in this thing and raise holly hell on the streets haha. But unfortunately I cant.... Maybe ill turn the 390 in my 59 f100 into a 445 someday, that one is for racing and weekend cruising only soooo that just might have to be on the list for a few years down the road
Posting Guru
Joined: Jan 2005
Posts: 1,051
Likes: 0
From: Douglas, Georgia
In Barry's defense, if you told him you wanted that 470hp you quoted, I could see him talking about a bigger carb.
My take? a 445fe never spinning over 4500rpms, a smaller carb will be just fine.
I have a Quickfuel SS 735cfm VS and have no problems at all with it.
My take? a 445fe never spinning over 4500rpms, a smaller carb will be just fine.
I have a Quickfuel SS 735cfm VS and have no problems at all with it.
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