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What's the biggest draw back of the 400?

Started by 73chgrSE, January 24, 2008, 05:16:41 PM

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What's the biggest problem with these stock "smog motors" from the 70's?

crappy heads (low compression)
5 (25%)
intake manifolds
0 (0%)
exhaust manifolds
1 (5%)
cam too mild
1 (5%)
they need more cubes, ie. stroker
0 (0%)
combination of all these
9 (45%)
other please explain
4 (20%)

Total Members Voted: 20

73chgrSE



Nacho-RT74

if ppl wants to find ANY drawback about 400 would it be low compression and cast crank, and both have easy solution

AND compression is nothing related with heads... is simply PISTON HEIGHT

heads are the same than earliers.

cams... nothing wrong really.

intake... they are spreadbore, so theorically BETTER.

exhaust, same than earliers.

Cubic inchs MORE WITH THAT STROKE LENGHT ?, come on, 383s are the same stroke and less cubic inches

so, get KB 240 pistons ( for example ) or any custom made, and will get more juice than a 383 due the cubic inches, however nobody complaints about 383!
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

John_Kunkel

QuoteAND compression is nothing related with heads... is simply PISTON HEIGHT


:iagree: The pistons are the source of the low compression, the heads used on the 400 flow as well as any 383 head so a HP400 with the same compression and cam as a HP383 should perform as well (or better) than the 383.
Pardon me but my karma just ran over your dogma.

Nacho-RT74

once I told... 400 are a charcoal piece ready to be a diamond!... and doesn't need to be millionaire!
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

hemihead

The 452 heads are the same heads as used on  later 440's . It's all pistons as stated above . Cams were miserable . Ground with emissions in mind .
Lots of people talkin' , few of them know
Soul of a woman was created below
  Led Zeppelin

Ghoste

Would they have also had a less aggressive timing curve built into the distributors with the emission thing in mind?

supserdave

Some had the lean burn system, which was pretty much a POS from what I've heard. I don't know if the dizzy's were differetnt, I know the lean burn ones are?

Ghoste

I was more wondering if they had tighter springs in the advance.

firefighter3931

The biggest complaint with 400 ci engines would have to be the lack of compression which really crippled the power output. The 400 has the largest bore (4.34) ever put in a BB mopar engine and makes a killer foundation for a stroker type build. The large bore with a 3.75 stroke crank has lots of power potential and revs like a smallblock due to the light rotating assembly.  :2thumbs:


Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

Nacho-RT74

Quote from: Ghoste on January 24, 2008, 10:28:57 PM
Would they have also had a less aggressive timing curve built into the distributors with the emission thing in mind?

If they have, no big deal, is not engine guilt
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

Ghoste

It's really just a question that occured to me when hemihead mentioned emissions.  It would go hand in hand with egr and many of those other good things.

my73charger

Question for Ron.  I have often wondered what the result would be if you bolted a twin turbo to one of these engines?  Of course I would want to change out the cam, intake, manifolds etc.  You would probably also want to go with some forged pistons to.

dukeboy_318

Quote from: firefighter3931 on January 24, 2008, 11:22:29 PM
The biggest complaint with 400 ci engines would have to be the lack of compression which really crippled the power output. The 400 has the largest bore (4.34) ever put in a BB mopar engine and makes a killer foundation for a stroker type build. The large bore with a 3.75 stroke crank has lots of power potential and revs like a smallblock due to the light rotating assembly.  :2thumbs:


Ron

yep, i cant wait to get my stroker done :D, now if your talking twin turbos, you're gonna have to beef the bottom end up alot, not to mention run an external oil line.  one of the guys i ran around with back in highschool tried putting twin turbos on his Z28, took him for ever to get it right, but he didnt beef the bottom end or rotating assembly and after a few months on the street, it snapped a connecting rod and sent it out the bottom of the block :icon_smile_blackeye:
1978 Dodge Power Wagon W200 4x4- 408 stroker/4spd
1974 Dodge Dart Swinger. 440 project in the works.

Nacho-RT74

Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

firefighter3931

Quote from: my73charger on January 25, 2008, 08:30:41 AM
Question for Ron.  I have often wondered what the result would be if you bolted a twin turbo to one of these engines?  Of course I would want to change out the cam, intake, manifolds etc.  You would probably also want to go with some forged pistons to.


Like any motor, the 400 will make lots of power when boost is applied. Using good cylinder heads really helps get the air in/out and of course you need good parts to keep it all together.  :Twocents:



Ron
68 Charger R/T "Black Pig" Street/Strip bruiser, 70 Charger R/T 440-6bbl Cruiser. Firecore ignition  authorized dealer ; contact me with your needs

my73charger

Thanks Ron & Dukeboy.

I wouldn't mind launching at the track like this guy:

http://www.youtube.com/watch?v=lkGFjX3deVM

hemihead

Quote from: Ghoste on January 24, 2008, 11:43:25 PM
It's really just a question that occured to me when hemihead mentioned emissions.  It would go hand in hand with egr and many of those other good things.
I believe the springs were a little heavier . The Lean Burn System was acceptable when new but after some miles wasn't really all that great .
Lots of people talkin' , few of them know
Soul of a woman was created below
  Led Zeppelin

Ghoste

As bad as the Lean Burn turned out to be, I still can't fault Chrysler for trying to come up with something that was a good idea on paper.  They just didn't have the technology yet to make it work and when you think about the modern efi and powertrain control computers, Mopar was way ahead of their time with the idea.  Can't hit a homerun everytime but I won't kick the home team for trying.