400 block with 440 crank article

[Oldschool]

Thanks guys, this is certainly food for thought.
I know that a 426 is just a ego thing but I would love to have one nevertheless. However, having ordered a XV stage II suspension kit now, I have to look at total cost and just how deep I really want to be in a 72 Charger. The 400 would certainly be the best bang for the buck and if I really like the car down the road, could do a 426 later.
Someone give me some clues on heads and camshafts.
I will probably go with a Tremic 5 speed since I love to shift gears.
Thanks again for all the help.

Bill,  if you are gonna want a Hemi eventually, why spend $5-$12K on building up a wedge and then spending the money on the Hemi also later?       Just do the Hemi the first time and use the money that would have gone into the wedge build-up towards the Hemi.  The "trick" to great Hemi performance is to put plenty of cubes under those high flowing heads.  They make mucho power when done correctly.  You can take a look at my combo here:

http://www.cuda-challenger.com/cc/index.php?topic=16505.0

When I am asked the HP of my normally aspirated engine I ALWAYS use the dyno numbers.  It made 776 HP at 6000 rpm.  It also made 703 lb/ft torque @ 6000 rpm. The dyno pulls only went up to 6000 rpm.
That ain't bad, BUT.....................  that isn't the true HP output of this engine...  bear me out here..  When raced on the 1/4 mile I shift @ 6800, not 6000.  The formula to figure out what the HP at 6800 is this.  Take the torque (703) and multiply it by the shift rpm of 6800.  This gives you 4780400.  You then divide that by 5252.  That gives the HP at the new rpm of 6800.  That is 910 HP @ 6800 rpm.  So  HP= Torque X RPM divided by 5252.  Even though the formula is pretty accurate, I only use the dyno numbers.   The formulas are here:


http://www.ajdesigner.com/phphorsepower/horsepower_equation_trap_speed_method_horsepower.php


 But even if the formula is off a little, a nearly 900 HP fire breathing 528 CI normally aspirated Hemi ain't too shabby. Street driven, pump gas car.  If you need more info, PM me and I'll share the little knowledge I have with ya...  Oldschool         

[Bill Howell]

Oldschool, Emal sent.

[v8440]

Hold up a second.  To figure hp, you need to multiply torque at a given rpm BY THE RPM AT WHICH THE TORQUE OCCURRED.  You can't just pick some higher rpm and multiply by that, using the torque obtained at a lower rpm.  The torque has almost certainly fallen somewhat between 6000 rpm and 6800.  Hell, I can see the torque curve heading downward by 5700 plain as day in your dyno sheet.  Your hp could still rise beyond what it was at 6000, as long as torque fell more slowly than rpm rose.  But, to just say "well, it made 703 ft/lbs at 6000 so I'll just multiply the 703 ft/lbs by 6800 since that's where I shift", no.  It doesn't work that way.

I'm not trying to insult you, it's just that if you did it the way I understood you said you did it, it's not valid.

[Oldschool]

Hold up a second.  To figure hp, you need to multiply torque at a given rpm BY THE RPM AT WHICH THE TORQUE OCCURRED.  You can't just pick some higher rpm and multiply by that, using the torque obtained at a lower rpm.  The torque has almost certainly fallen somewhat between 6000 rpm and 6800.  Hell, I can see the torque curve heading downward by 5700 plain as day in your dyno sheet.  Your hp could still rise beyond what it was at 6000, as long as torque fell more slowly than rpm rose.  But, to just say "well, it made 703 ft/lbs at 6000 so I'll just multiply the 703 ft/lbs by 6800 since that's where I shift", no.  It doesn't work that way.

I'm not trying to insult you, it's just that if you did it the way I understood you said you did it, it's not valid.

No insult taken, and you are correct.  I did it from memory and didn't bother to look at the numbers.  The torque on the pulls that I have when the Ray Barton crossram was installed was 686.3 lb/ft at 6000.  That dyno sheet isn't posted, but I have it in my file and went and took a look to make sure.  The HP was 776.8 at 6000.  The torque was falling at a rate of about 25 lb/ft per 800 rpm on a fairly predictable curve.  The HP was climbing at about a rate of 30 HPO per 800 rpm, again fairly predictable.  Anything could happen in those remaining 800 rpm's that are not shown, but the sheet coupled with the rest of the dyno info leads me to believe that the curves would remain fairly constant.  I have port flow data, vacuum, EGT and other data up to 7000 rpm that reflect a constant movement in a certain direction.  Nothing to lead me to believe that there would be a sudden collape of TQ or HP.  If you use the the predicted TQ number at 6800, it would be around 660, maybe a little more or a little less.  SO,   660 X 6800 = 4488000.   4488000 divided by 5252 = 854 HP.  I stated nearly 900, so it is only around 850 based on some pretty solid assumptions.  850 still ain't bad.  I'll take it any time.....        

[v8440]

Ah, I see now.  Yeah, I'd agree that 850 would be a pretty safe bet, based on the rest of the combo.

[Oldschool]

Oldschool, Emal sent.

Back at ya.....   

[heminut]

  If you need more info, PM me and I'll share the little knowledge I have with ya...  Oldschool         

Ya right, little knowledge my keester! You guys don't let this old guy fool you, he's on the ball when it comes to hemis!

[Oldschool]

Bill,

Here is a link to a very short vid of my car.  It was shot by a fellow C-C site member Crcarch.  It is short and all you get is a little idle time and a tiny, quick throttle blip at the end.  Anyway, you kinda get an idea of what it sounds like.  Turn up your sound....

http://video.google.com/videoplay?docid=-5984515808414074693&q=hemi+cuda&hl=en

P.S.  It gets real loud when you stand on the go pedal.....               

[6packCuda]

Oldschool, that car really gets my blood boiling.

[ArcticCuda]

-
I'm driving a 383 cui. with a 4.375 borr  and stroke 3,91 = 470 cui.

That kick a.. 

Really? That's makes really big overbore for your 4.25" block!

[Bill Howell]

Ok, I have decided that if I am going to build a mopar, it might as well have a hemi.
where is the best place to get a good price on a crate motor? I am looking at the 472 Jegs is advertising right now. Also, any crate motors out there with aluminum heads?
I have looked at Indy cylinder heads and really like their stuff but may have to limit my budget too much to buy one of their motors.

[Oldschool]

Ok, I have decided that if I am going to build a mopar, it might as well have a hemi.
where is the best place to get a good price on a crate motor? I am looking at the 472 Jegs is advertising right now. Also, any crate motors out there with aluminum heads?
I have looked at Indy cylinder heads and really like their stuff but may have to limit my budget too much to buy one of their motors.

As has been stated many times here and other sites----be very wary of the crate engines.  They aren't the most quality controlled engines around.  If you are gonna do the crate thing, my advice is to go ahead and order a rebuild gasket set and immediately take the engine when you get it to an experienced Hemi shop and let them thoroughly inspect/correct whatever is not right.   Not all of them have problems, but the ones that do are generally in pretty bad shape when shipped from the supplier.  You wouldn't want to be the guy that sank a ton of money in an engine that failed in only a few miles.   Better be safe than sorry................     Oldschool

[Bill Howell]

That is not good news. Maybe that is why the Indy stuff is so much more money???
Thanks for the advice. OH, I blame part of this decision on you and your video......lol

[Oldschool]

That is not good news. Maybe that is why the Indy stuff is so much more money???
Thanks for the advice. OH, I blame part of this decision on you and your video......lol

Bill----this could be an example of what I was talking about concerning the crate engines:


http://www.cuda-challenger.com/cc/index.php?topic=29872.0


 

[Chryco Psycho]

personally I would gett the Hemi built , it will not cost more & you can get exactly what you want in it