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Carb size for 512 stroker

TexasRoadRunner68

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I am in the process of building my 512. About to pick the block up from the shop. It will be getting a 10.4:1 512 kit from 440 Source, topped with trick flow 270s and an Indy single plane. I’ll either be putting in my Hughes roller cam or the 713 lunati voodoo cam. It will be in a 4 speed car with 3.54s.

Is an 850 going to be too small on this motor? I would assume a 950 is the way to go?

Ideally I would like to find one of the old Barry grant race demon carbs with the RS sleeves. I have a 995 Dominator demon RS , but the intake I was able to find is for a 4150 carb.

CE8053B7-B5BC-4169-B512-16F85AE64932.jpeg


82A5F77A-2572-4222-AD89-582E132232A8.png
 
What are you going to do with the car? Full drag strip, low E.T., or street cruiser? If its for all top end, high RPM, the 950 would be your choice, but for street use, the smaller carb will be more responsive for better low end power. Its all about the jetting, more than the cfm of flow.
 
My opinion mirrors the above post except that because you chose a single plane intake that probably doesn't
fit under the hood, you're going to race the car. In that case you'll need 1100cfm or there abouts.
 
You have a dominator? Get a 4500 to 4150 adapter, and try it!
As said above, your intake probably requires a scoop, so the extra height of the adapter probably won't matter.
 
My opinion mirrors the above post except that because you chose a single plane intake that probably doesn't
fit under the hood, you're going to race the car. In that case you'll need 1100cfm or there abouts.

It’ll be mainly for street duty, but I would like to be able to track it. I wanted max wedge heads, since they make a noticeable amount more HP and torque everywhere under the curve per engine masters. Unfortunately they do not make an intake for the low deck (I think there are 2-3 options total) that clears the stock hood. I will not be cutting my original. I’ll probably just go with a fiberglass hemi scoop hood.
You have a dominator? Get a 4500 to 4150 adapter, and try it!
I have heard the adaptor will cut flow through the carb significantly compared to even a 4150, but I have no experience with them personally.
 
I have an adapter, but I haven't used it yet, don't have enough motor yet to need a dominator. When I do, I'm gonna compare my M1 dominator manifold to a team g with the adapter. I have read that a bbc 4150 with adapter made more hp than the same manifold flanged for a dominator.
I'd still give it a try, that's what a dyno is for.
 
You have a dominator? Get a 4500 to 4150 adapter, and try it!
As said above, your intake probably requires a scoop, so the extra height of the adapter probably won't matter.

I have heard the adaptor will cut flow through the carb significantly compared to even a 4150, but I have no experience with them personally.
Thanks to 33 IMP, you've now heard the proper information.
20220928_080702.jpg
 
For performance, the 4150 size seem to only go to around 950-1050 cfm, but these are the Holley HP, Quick Fuel, and a few others. I'm fairly sure none have a choke, so you would need to give the throttle some input until the engine warms up. In the Charger, I used an old 1,000 cfm Holley HP on both my 451 stroker, and then on the 500" stroker and it worked good.
I have a Quick fuel 1050 E-85 carb that was on the 500" stroker that ran good too, but the E-85 messed up my filter and now I need to clean the carb out.
Because the E-85 needed cleaning. I put a FiTech 1200 PA EFI unit on the car just to see if it would work with a large cam and low vacuum. I don't think it flows as much, but startup and drivability is much better. I haven't raced the car since putting the EFI on, but so far I'm liking it.

On the 505" stroker in the convertible, I wanted something with an electric choke, so settled on a smaller cfm carb. Ran it a few years before switching to the Edelbrock XFI (TPI type) EFI, with FAST 2.0 Controller.

If something your going to race, then the large carbs will be the way to go, but they are almost as expensive as the lower cost TBI EFI units from Holley and FiTech.

I'm willing to sell the QuickFuel 1050 E-85 carb and a Holley ultra street avenger 770 carb that are nearly new for $300 less than retail.

Reference photos:
Quick Fuel Q-1050-E85 Quick Fuel Q-Series 4-Barrel Carburetors | Summit Racing $1,092 Retail, sell for $792
Holley 0-86770BL Holley Ultra Street Avenger Carburetors | Summit Racing $745 Retail, sell for $445
 
I’d use a 4150/1050 AN carb. It’ll have good response and work well. You’re not going to over carburete a 512.
 
1664382630849.png
here's the height of Indy intake on a B block using 2in carb spacer
 
Yes. I know you mentioned wanting to fit under your hood so I was just wanted to add picture for reference. Plus if you went with a dominator this would put you in ballpark of the height
 
Yes. I know you mentioned wanting to fit under your hood so I was just wanted to add picture for reference. Plus if you went with a dominator this would put you in ballpark of the height
Awesome. That’s definitely helpful. I will be buying a fiberglass hood with either a cowl or hemi scoop. I just need a ballpark of how tall it needs to be.

Im sure I’ll have a better idea once the motor is in the car.
 
We dyno'd my 512 with Indy Max Wedge heads with my 850 DP, 692 HP, with a trick Holley 950 694(no tuning), a 1150 Dominator (no tuning) 696 HP. Overall height is an issue.
 
We dyno'd my 512 with Indy Max Wedge heads with my 850 DP, 692 HP, with a trick Holley 950 694(no tuning), a 1150 Dominator (no tuning) 696 HP. Overall height is an issue.
That's interesting! It confirms the test EM did, comparing a "1050" 4150 to a same-size Dominator. I was surprised. They made almost exactly the same power. (I was SURE the dommy would win!).
 
I have gone to a 1050 Dominator. It definitely makes more power, and I haven't done any tuning on it. I still am amazed the Holley 950 we tried didn't do better.
 
I have gone to a 1050 Dominator. It definitely makes more power, and I haven't done any tuning on it. I still am amazed the Holley 950 we tried didn't do better.
Was it a "real" 950, or a 750 holley that they hung a 950 name on? (They did that, you know).
Throttle size and venturi bore makes a difference.
 
Was it a "real" 950, or a 750 holley that they hung a 950 name on? (They did that, you know).
Throttle size and venturi bore makes a difference.
This.

“950s” can be anything from 840 cfm to 1000 cfm, depending on the above.
 
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