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Discussion Starter #1 (Edited)
So I am building a 446 sbf:
Dart shp Block 4.125 bore
Eagle 4.170 stroke crank
Ross 14.64:1 custom flat top pistons
Eagle 6.250 forged H-Beam Rods
Lunati camshaft: Duration (Int/Exh): 318/325 ;
Duration @ .050 (Int/Exh): 284/292 ; Gross
Valve Lift (Int/Exh): .728/.728 ; LSA/ICL:
112/106 ; Valve Lash (Int/Exh
AFR 220 Renegade heads good to 800lift
Custom prosystems 1100cfm carb
MSD Grid ignition
Holley electric fuel pumps
Super victor intake with nos fogger (350shot)

Its going in an 89 mustang GT, tublar k member, front and rear coilovers, true coilovers, 10 point cage, 8.8 rear end, 4.30 gears, powerglide with transbrake, 4000 converter, on 275 radials

My goal is to run 5.50's in the 1/8, any opinions?
 

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So I am building a 446 sbf:
Dart shp Block 4.125 bore
Eagle 4.170 stroke crank
Ross 14.64:1 custom flat top pistons
Eagle 6.250 forged H-Beam Rods
Lunati camshaft: Duration (Int/Exh): 318/325 ;
Duration @ .050 (Int/Exh): 284/292 ; Gross
Valve Lift (Int/Exh): .728/.728 ; LSA/ICL:
112/106 ; Valve Lash (Int/Exh
AFR 220 Renegade heads good to 800lift
Custom prosystems 1100cfm carb
MSD Grid ignition
Holley electric fuel pumps
Super victor intake with nos fogger (350shot)

Its going in an 89 mustang GT, tublar k member, front and rear coilovers, true coilovers, 10 point cage, 8.8 rear end, 4.30 gears, powerglide with transbrake, 4000 converter, on 275 radials

My goal is to run 5.50's in the 1/8, any opinions?
Any Windsor engine with that many cubes built for racing needs as big of a head that will fit on it. I see the heads as being the obvious bottleneck here... especially if you're also going to try and spray a bunch of nitrous through it. The heads are on the extremely small side for what you are wanting to do, and if you're wanting to put some power down, that's what you'll need to address.
 

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i have been told, for turning RPM that on a 9.5" deck anything more than 4" stroke is diminishing returns. i would personally probably limit it to 4.100 stroke.
 

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I agree the heads are the bottleneck. On my 460 SBF, I have the flow numbers below from my heads and they are the limiting factor. If they had better flow, I would be able to get a bit more out, but valve size are maxed out. (Could still tweak the cam and squeeze a bit more out).

Current Bullet cam (solid roller):
Gross lift: .755" intake, .740 exhaust.
Duration @ .050: 261/272


Z304 heads worked by Duane Busch.
Intake Flow
.300 lift 224 cfm
.400 270
.500 314
.600 334
.700 342
.800 345

Stock intake valves with 2.02" flowed around 272 cfm @.500, now they are 2.1" with 314 cfm @.500, and the .600" of 334 is awesome

The solid cam will result in .710 lift

Exhaust Flow
.300 lift 171 cfm
.400 206
.500. 233
.600. 249
.700. 261
.800. 265
 

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I have a similar deal, however 4.1 stroke, bigger bore. much better cylinder head and it will damn near run that number on nuts even with this tight nitrous convertor I have. @3100 pounds, on a 235.
 

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I have a similar deal, however 4.1 stroke, bigger bore. much better cylinder head and it will damn near run that number on nuts even with this tight nitrous convertor I have. @3100 pounds, on a 235.
Exactly. The cylinder heads will make or break this type of combo. Think about it, you're feeding 'Big Block' cubic inches through 'Small Block' cylinder heads... Plus, you're trying to move enough air to make big power at close to 8k rpm. You also need room in the port to flow all the nitrous being introduced to the airstream.

It is literally impossible to go 'too big' when choosing a cylinder head for this sort of combination. The current chosen head is far too small. HUGE gains to be had by going with something MUCH larger.

Not a big fan of the cam, either. Not much lift for the amount of duration it has. Is it a crutch to try and use Steel instead of Titanium valves?

Good Luck
 

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So I am building a 446 sbf:
Dart shp Block 4.125 bore
Eagle 4.170 stroke crank
Ross 14.64:1 custom flat top pistons
Eagle 6.250 forged H-Beam Rods
Lunati camshaft: Duration (Int/Exh): 318/325 ;
Duration @ .050 (Int/Exh): 284/292 ; Gross
Valve Lift (Int/Exh): .728/.728 ; LSA/ICL:
112/106 ; Valve Lash (Int/Exh
AFR 220 Renegade heads good to 800lift
Custom prosystems 1100cfm carb
MSD Grid ignition
Holley electric fuel pumps
Super victor intake with nos fogger (350shot)

Its going in an 89 mustang GT, tublar k member, front and rear coilovers, true coilovers, 10 point cage, 8.8 rear end, 4.30 gears, powerglide with transbrake, 4000 converter, on 275 radials

My goal is to run 5.50's in the 1/8, any opinions?

Sounds like a killer sbf
 

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EFI/N2O JUNKIE
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17,206 Posts
So I am building a 446 sbf:
Dart shp Block 4.125 bore
Eagle 4.170 stroke crank
Ross 14.64:1 custom flat top pistons
Eagle 6.250 forged H-Beam Rods
Lunati camshaft: Duration (Int/Exh): 318/325 ;
Duration @ .050 (Int/Exh): 284/292 ; Gross
Valve Lift (Int/Exh): .728/.728 ; LSA/ICL:
112/106 ; Valve Lash (Int/Exh
AFR 220 Renegade heads good to 800lift
Custom prosystems 1100cfm carb
MSD Grid ignition
Holley electric fuel pumps
Super victor intake with nos fogger (350shot)

Its going in an 89 mustang GT, tublar k member, front and rear coilovers, true coilovers, 10 point cage, 8.8 rear end, 4.30 gears, powerglide with transbrake, 4000 converter, on 275 radials

My goal is to run 5.50's in the 1/8, any opinions?
Seems like a lot of duration with not a lot of lift. I am about 30* less on both yet .02 or so more lift........ I am not pushing 350hp of nitrous through the engine anymore with my present combo. Even when I was, I had over 10* less duration and more lift. I never went faster than 5.7's in the 8th, was only running an 8.90 Index Class so never had to push it harder for that.

Heads too small, that is for sure!
 

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So I am building a 446 sbf:
Dart shp Block 4.125 bore
Eagle 4.170 stroke crank
Ross 14.64:1 custom flat top pistons
Eagle 6.250 forged H-Beam Rods
Lunati camshaft: Duration (Int/Exh): 318/325 ;
Duration @ .050 (Int/Exh): 284/292 ; Gross
Valve Lift (Int/Exh): .728/.728 ; LSA/ICL:
112/106 ; Valve Lash (Int/Exh
AFR 220 Renegade heads good to 800lift
Custom prosystems 1100cfm carb
MSD Grid ignition
Holley electric fuel pumps
Super victor intake with nos fogger (350shot)

Its going in an 89 mustang GT, tublar k member, front and rear coilovers, true coilovers, 10 point cage, 8.8 rear end, 4.30 gears, powerglide with transbrake, 4000 converter, on 275 radials

My goal is to run 5.50's in the 1/8, any opinions?
Heads are a choke point.
What does the car weigh?
 

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If you don't have all the pieces already purchased, I would consider a set of fully worked Edelbrock Victor heads... not the Victor Jr's, but the Victor 7721. But, these do not share the same valve angles, etc as standard heads, so you'll need to have pistons, rocker system, etc to match. Some of the canted valve offerings out there would also be nice.
If you've already purchased pistons, etc... The biggest High Port you can find will be the best choice in a 'conventional' cylinder head. Crower makes the best shaft rocker system for those.

I did a search for 'Edelbrock 7721', and BES was the first link that popped up. This is not a personal recommendation for them, just meant to show some basic info and flow potential for the heads.

http://www.besracing.com/cylinder-head-and-intake-packages/cylinder-heads/ford/sbf/bes-edelbrock-victor-7721-heads

http://www.besracing.com/cylinder-head-and-intake-packages/cylinder-heads/ford/sbf/bes-edelbrock-glidden-victor-ii-sbf-heads

http://www.besracing.com/cylinder-head-and-intake-packages/cylinder-heads/ford/sbf/bes-brodix-bf200-neal-sbf

Good Luck
 

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If the converter is decent and 5.50 is your only goal...it should run 5.50 with less than 350. I had a 440"winsdor way back in the 90,s with a vic jr intake and twisted wedge 205 heads go 5.50,s at 3100 pounds on 275 shot in a big shot plate and my cam was only 696"....and tunes were fat as fuck....could have went a lot faster with the tunes of today.
 
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