400 Project
Cargo Master
Joined: Apr 2001
Posts: 2,364
Likes: 3
From: Eustis FL
Originally Posted by danlee
The air flow needed for a 400 cu inch motor at 5500 RPM requires a big carb and high flowing manifold. These do not work well at low RPM, so streetability is reduced.
5500 rpm from a 400 only requires a 650 cfm carb.
(400X5500/3456= 636)
Posting Guru
Joined: Jul 2007
Posts: 1,355
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jajaja dont worry havi, it was "351beast" thread, wasnt it ? my "sorrynes" goes for him, Im just learning about these engines, I have just built a 351 windsor in my life and got better results with a 351m,
and yes trinogt, theoreticly a 400 should easily revvv high and that was my initial question in this thread, thats why I was aiming for a big cam...
and yes trinogt, theoreticly a 400 should easily revvv high and that was my initial question in this thread, thats why I was aiming for a big cam...
Elder User
Joined: May 2002
Posts: 526
Likes: 0
From: Sin City, USA
Originally Posted by havi
Sorry Hollenjoe, didn't mean to piggyback your thread, but I have to say thanks to 73axfalcon.
havi,
If you look in my engine pic folder you will see how the 3 bolt mounts looked and how much smaller the 2 bolt mounts are when bolted on. The 2 bolt mounts were listed a a bronco/f150 mount on e-bay.
Posting Guru
Joined: Mar 2005
Posts: 2,068
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From: western montana
FYI:
with 4 ford 400's in the current jegs engine masters .... we will see 400's that must make great power up to 6000 rpm. And that is with mostly oem parts or readily available parts as the theme this year is based on the engines of the old muscle car era. From what I saw it looked like there are more ford 400's built for this than any other engine.
the competition is based on the best average hp and torque from 2500-6000rpm.
heaven
with 4 ford 400's in the current jegs engine masters .... we will see 400's that must make great power up to 6000 rpm. And that is with mostly oem parts or readily available parts as the theme this year is based on the engines of the old muscle car era. From what I saw it looked like there are more ford 400's built for this than any other engine.
the competition is based on the best average hp and torque from 2500-6000rpm.
heaven
Elder User
Joined: May 2002
Posts: 526
Likes: 0
From: Sin City, USA
Originally Posted by roger dowty
FYI:
with 4 ford 400's in the current jegs engine masters .... we will see 400's that must make great power up to 6000 rpm. And that is with mostly oem parts or readily available parts as the theme this year is based on the engines of the old muscle car era. From what I saw it looked like there are more ford 400's built for this than any other engine.
the competition is based on the best average hp and torque from 2500-6000rpm.
heaven
with 4 ford 400's in the current jegs engine masters .... we will see 400's that must make great power up to 6000 rpm. And that is with mostly oem parts or readily available parts as the theme this year is based on the engines of the old muscle car era. From what I saw it looked like there are more ford 400's built for this than any other engine.
the competition is based on the best average hp and torque from 2500-6000rpm.
heaven
Cargo Master
Joined: Apr 2001
Posts: 2,364
Likes: 3
From: Eustis FL
Wow, four 400's? That is just too cool! But I didn't really want the 400 on the map, just enough to get the aftermarket attention... (And I think we got it!)
I still wanna be able to get these cranks readily! LOL
I still wanna be able to get these cranks readily! LOL
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
Originally Posted by trinogt
Info:
5500 rpm from a 400 only requires a 650 cfm carb.
(400X5500/3456= 636)
5500 rpm from a 400 only requires a 650 cfm carb.
(400X5500/3456= 636)
I am not recommending than someone should over carburate a motor, but maximum power is produced when the pressure drops are minimized.
The difference between running a 650 CFM carb through the traps at 5500 RPM and a 900 CFM carb/Throttle Body with a large displacement motor is the latter motor would still be near peak power and pulling.
With EFI a high flowing intake can be used without significant loss in drivability, unlike a carb.
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Cargo Master
Joined: Apr 2001
Posts: 2,364
Likes: 3
From: Eustis FL
If your engine makes 300 real-world horses, using a 600 cfm carburetor costs you only about 15 hp, at max rpm. Everywhere else in the rpm band the engine will be more responsive with this small carb, the vehicle will feel better in traffic, get better gas mileage, etc. Unless the vehicle is a drag-race only car, the 5% power drop at max rpm is really not very significant - how many minutes a day does your car spend at 10% throttle? How many at WOT? How many at WOT and 5500 rpm?
It's all about the decision in driveability, or if you are going to race only.
I am assuming the truck will be driven a lot on the street, as most Ford trucks should!
It's all about the decision in driveability, or if you are going to race only.
I am assuming the truck will be driven a lot on the street, as most Ford trucks should!
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
Originally Posted by trinogt
If your engine makes 300 real-world horses, using a 600 cfm carburetor costs you only about 15 hp, at max rpm. Everywhere else in the rpm band the engine will be more responsive with this small carb, the vehicle will feel better in traffic, get better gas mileage, etc. Unless the vehicle is a drag-race only car, the 5% power drop at max rpm is really not very significant - how many minutes a day does your car spend at 10% throttle? How many at WOT? How many at WOT and 5500 rpm?
It's all about the decision in driveability, or if you are going to race only.
I am assuming the truck will be driven a lot on the street, as most Ford trucks should!
It's all about the decision in driveability, or if you are going to race only.
I am assuming the truck will be driven a lot on the street, as most Ford trucks should!
Cargo Master
Joined: Apr 2001
Posts: 2,364
Likes: 3
From: Eustis FL
This is from the original poster of the topic:
I thought my info was quite relevant to his question. It was all about streetability.
??
Originally Posted by 351beast
well low-mid range rpms was always what was in sight, its not like im building a ***** to the wall 10 second truck, just a better than average 400, something with alittle giddyup to it, i wouldent think about building a high rpm 400, ever.
??
Last edited by trinogt; Sep 24, 2007 at 11:00 AM.
Postmaster
Joined: Aug 2001
Posts: 4,270
Likes: 5
From: Delaware
Originally Posted by trinogt
This is from the original poster of the topic:
I thought my info was quite relevant to his question. It was all about streetability.
??
I thought my info was quite relevant to his question. It was all about streetability.
??
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