Cam selection 400 70 Dart.

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I know this has been beat to death but being a new guy here I didn’t want to jump on another’s post.

What I’m working with …

400 with a 383 forged crank

KB 240 pistons.

Approx 9 to 1 compression.

452 heads will be opened on the cheap, because I’m cheap.

Stock rocker set up.

HP iron manifolds matched to the heads, I have them.

8 ¾ rear with 323 gears because that’s what have.

I want..

A street car, cruise control & AC

4 speed auto to cruise at 70 at less than 2K rpm, thinking 200r4 lock-up 2500 stall?

FI fuel injection.

So I’ve been reading here about the 6400 cam and keeping good spread on lobe separation for FI and iron manifolds. I currently don’t own a cam or an intake that’s the part I was looking for some help with opinions on. Thanks in advance!
 
A cam in the low [email protected] duration with a stock or Edelbrock Performer (or like) intake. Or a Holley Street Dominator, which is a low level single plane intake.

What FI unit?
 
I ran a Crane HMV278 in my 400 with basically the same specs. I really liked it as a street cam. It was 222/234 duration at .050 and 467/494 lift. It had a 114 lobe separation so it idled well and produced good vacuum. It had a slight lope at idle. With a 750 Holley and 1 3/4 headers, it made 415 HP and 450 TQ on an engine dyno, and ran high 12's in my cuda with 3.91 gears, slicks and open exhaust. The same cam is sold under the Summit brand name, except they show the specs 1 or 2 degrees different.
 
lets see if I can post a couple

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the little hole kept getting bigger so we added some scrap pipe
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added a little here
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sub frame connectors added in made the stripes
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And thanks Guys for the cam input
 
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Checking on the cams recommended I'm thinking the overdrive with a 3.23 gear might be setting the interstate cruise rpm too low for the engine to be happy? So saving a couple hundred on a gear set might be not the way to go. Maybe 3.91?
The plan was on the engine was to do exactly what IQ 52 said to do but it didn't play out quite right. Pulled a supposedly good running motor out of the poison ivy. Pulled the pan bearings looked good. good news! Pulled the heads. not so much, big ridge, the motor had been stuck at some point, and broke loose. Pistons measured .120 down the hole. Good deal on the KB's good deal on the forged crank. I figure the new pistons should fit .020 down the hole a steel .020 gasket. The 452's are the unknown so that where the guessing part come in. Approx 9 to 1 compression?
My last car that ran good was in the late 70's (alway a 4 speed stick) so I think maybe this overdrive want in the equation is messing me up.
 
The biggest problem to the overdrive and figuring the cam spec is the cruise in O.D. The cam can suddenly be a bit to big for the RPM in the final drive. This is where you must figure out is a street beast or cruiser n the final out come. IMO, your not going to need a ton of cam to be quick in the street.

You could allways keep the compression low and the cam mild so you can add a supercharger later......
Just food for thought....
 
rumblefish360 said:
The biggest problem to the overdrive and figuring the cam spec is the cruise in O.D. The cam can suddenly be a bit to big for the RPM in the final drive. This is where you must figure out is a street beast or cruiser n the final out come. IMO, your not going to need a ton of cam to be quick in the street.

You could allways keep the compression low and the cam mild so you can add a supercharger later......
Just food for thought....
Click to expand...
Yes, what you say makes sense. I'm hoping the "never quick enough" fever doesn't take hold again.
 
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I'm running 4.56's with the overdrive and a 28" tire. That puts me sat about 2500RPM at 60mph. I'm pretty happy with that RPM. But in retrospect I wish I had went with a 4.30 or 4.10 because I'm about 500RPM past peak HP going through the traps in the 1/4 mile.

easiest thing to do is to go the tech pages at RMS and use the calculator there. Decide where you want to be at cruise RPM.

Personally I think you'd be VERY happy with the 3.91's and they'll work fine at the strip too.
 
roccodart440 said:
I'm running 4.56's with the overdrive and a 28" tire. That puts me sat about 2500RPM at 60mph. I'm pretty happy with that RPM. But in retrospect I wish I had went with a 4.30 or 4.10 because I'm about 500RPM past peak HP going through the traps in the 1/4 mile.

easiest thing to do is to go the tech pages at RMS and use the calculator there. Decide where you want to be at cruise RPM.

Personally I think you'd be VERY happy with the 3.91's and they'll work fine at the strip too.
Click to expand...
What is RMS?
The cruise is easy 2K give or take a little.
The iron manifolds and the FI is the banana peel for me. Thats where I'm not following the lo-po recipe that I originally intend to do.
 
RMS is Reilly Motorsports. Bill Reilly is the owner. He makes and sells the AlterKation as well as many other Mopar suspension/braking related products.
 
I appreciate the help. This Cam stuff make me dizzy.
thinking one of these two
summit 6400
Cam Style:Hydraulic flat tappet
Basic Operating RPM Range:1,500-5,000
Intake Duration at 050 inch Lift:214
Exhaust Duration at 050 inch Lift:224
Duration at 050 inch Lift:214 int./224 exh.
Advertised Intake Duration:288
Advertised Exhaust Duration:298
Advertised Duration:288 int./298 exh.
Intake Valve Lift with Factory Rocker Arm Ratio:0.444 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio:0.466 in.
Valve Lift with Factory Rocker Arm Ratio:0.444 int./0.466 exh.

Lunati 701
  • Advertised Duration (Int/Exh): 256/262
  • Duration @ .050 (Int/Exh): 213/220
  • Gross Valve Lift (Int/Exh): .454/.475
  • LSA/ICL: 112/108
  • Valve Lash (Int/Exh): Hyd/Hyd
  • RPM Range: 1000-5500
  • Includes: Cam & Lifters (#71977PR-16)
Both seems really inexpensive for cam and lifters. The Summit a little scary cheap. Hopefully it's not imported, that would settle it quick for me.
 
I think both of those cams will disappoint the hell out of you but the 2nd one of those 2 would be my choice. In addition I'd never throw a summit cam in an engine to save a few bucks.
 
roccodart440 said:
I think both of those cams will disappoint the hell out of you but the 2nd one of those 2 would be my choice. In addition I'd never throw a summit cam in an engine to save a few bucks.
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Of the two the Lunati is most probably a better choice.

Sometimes these stupid tests of mine come in handy. Here is the 6400 in action in a 400.

The slug 400 on the dyno.
 
IQ52 said:
Of the two the Lunati is most probably a better choice.

Sometimes these stupid tests of mine come in handy. Here is the 6400 in action in a 400.

The slug 400 on the dyno.
Click to expand...
I actually printed that recipe and was going to use it. But as I stated above the plan changed a little. Had to buy pistons so why not get a set perched a little higher in the bore? Also after the plan, iron manifolds came into the picture, they were donated to the build by a friend, I want to use them because it will make him smile, and that’s worth the hit on the TQ/HP numbers to me. Fi, thinking I can be at the beach in 2 hrs or at 5000 ft in 3hrs. The manufacture states 1 unit will cover a 250- 600 hp. So here I am poking around asking guys that play with cool stuff everyday this question. Based on the amount I drifted from the original recipe which cam???

Nope sharing what you’ve learned isn’t stupid. If left to the folks that do the opposite we’d still be living in caves. If you’d care to wade in on this I could get a jar of North Carolina goodness headed your way.

And Another.

· Advertised Duration (Int/Exh): 278/288

· Duration @ .050 (Int/Exh): 216/226

· Gross Valve Lift (Int/Exh): .455/.470

· LSA/ICL: 112/108

· Valve Lash (Int/Exh): Hyd/Hyd

· RPM Range: 1800-5500

· Includes: Cam Only

Part Number: 10211005
Previous Part Number: 10305LUN
 
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I've had great service from Lunati recently, and an engineer friend with a (very precise) cam measuring apparatus just measured the little baby flat/solid Voodoo cam (235/243 at .050) I'm putting in a 457 and it checked out surprisingly awesome as far as manufacturing consistency, so I'm inclined to speak favorably of them. S/F.....Ken M
 
EchoSixMike said:
I've had great service from Lunati recently, and an engineer friend with a (very precise) cam measuring apparatus just measured the little baby flat/solid Voodoo cam (235/243 at .050) I'm putting in a 457 and it checked out surprisingly awesome as far as manufacturing consistency, so I'm inclined to speak favorably of them. S/F.....Ken M
Click to expand...
Thanks good to hear, I 'll give that a go. Contacted comp cams, they never replied?
 
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