My Combo, Right or Wrong!

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Problem Child

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Here is what I have done. Will someone run it on a desk top dyno and let me know the HP and ET, if it can be figured out. I have it in a 76 Dart Swinger, and will be running 28 inch slicks and a 4:10 gear. The car is stock weight and I weigh a lot........about 250 or so. Thanks

360 bored forty over block is decked and internally balanced
speed pro flat tops balanced 20 thow down in the hole
eagle I beam rods
the heads are from a 98 Durango (59cc's) cut fifteen thow stock size valves
Lunati Bracket Master 2 cam specs Advertised Duration IN/EX: 292/292
Duration @.050 IN/EX: 230/230
Gross Valve Lift IN/EX: .480"/.480" (512 With the Mag rockers)
Lobe Sep Angle 109
RPM Range: 2000-5500
904 trans with MP 2400 stall B&M flexplate
holly 750 duel feed or Predator 950
edlebrock RPM air gap for Mag heads manifold
1 5/8 headers Dynomax mufflers or open
Have a 100/150 NOS kit I would rather not use unless forced to
Well, what do you think? Thanks again
 
I would guess the HP would be 300-330 and the ET in the car and your weight, takeing the car is factory stock with a gear, 13.20-13.60s without the NOS. Then with the NOS mid 11's.



BJR Racing
 
A 750 cfm carb will do ya fine.
Desk Top Dyno info is off due to cam timing and actuall compresion values being off. But it's peak is 374 HP @ 5000 with 424 lbs. of torque @ 4,000. 385+ lbs from 2000 - 5000.
This info is not very accurate to a point. Actual head cc's are an unknown as head gasket bore and thickness, but comp. ratio worked out to be 11.5-1 on the 59 cc head chamber volume.
Cam timing is also off. Do you have a spec card? The program asks for lobe center angle (Cam degress)and intake centerline (Crank degrees) Moving these specs around 2 or 4 degrees on the program will alter results in a big way.
 
Lobe separaration is 109 with a 107 degree centerline
Timing: at .050
EX opens at 46 bbdc
EX closes at 4 atdc
Int closes at 42 abdc
Int opens at 8 btdc

head gasket is standard felpro (.040 I think) dont remember the bore size

Is that better? Thanks again for all your help.
 
Sure does. As off right now, the wifes on he main doing collage work, so I'm sorry it's gonna have to wait a bit.
 
Well, soem Felpros have a much bigger bore, but the std "performance" one is 4.18". IIRC the blue Permatorque is at least a 4.10 bore. (340+.060 over). Using it on a 360 with a 4.04 bore, you'll have a little "extra space". The compression comes to 11ish:1. The heads flow really well after .300, and that cam will use it. I'm thinking it should peak right around 400hp at 5500, and should be able to run on pump premium gas (9.23:1 dynamic compression). Torque should be strong, with a flat curve maxing around 4200. (no calculator or desktop dyno..just my opinion)
 
Problem Child;

The following is the desk tops dyno results. The only thing missing is actual head flow numbers, so the defaults were automaticly entered.

2000 ..145...380
2500...186...392
3000...227...397
3500...274...411
4000...318...417
4500...356...415
5000...381...400
5500...386...368
6000...380...333
6500...360...291

From what I have been reading about this program vs. actual dyno runs are;
A little generous on HP, a little light on torque.
 
First of all,,,thanks everyone. Secondly, If I have this correct, the lower numbers on the left ar HP and the higher on the right torque. If the peak HP was 386 I guess I'm a little disapointed, cause I would like more ( don't we all ) But it will be a good start and I will have to get it finished and to the track to see what real world figures work out to.

Any suggestions on the cam to make more power? I didn't want to spend the money for bigger valves with that cam, so I have what I have for now.

Thanks again guys.
 
Comp cams .507 / .510 hyd 242/246 .050, a good gasket match and a good bowl blend with the stock size valves this cam should be on a 106/114 with a 110 lsa. What part of NC are you in? I'm here in Atlanta, Ga.
This cam and work should put you in the 480HP range and bring the torque up 40 to 60 ft. lbs.



BJR Racing
 
Yes, thats correct on the number listings. I forgot to add it in.
Not for nothing, but your cam is small and I think your comp. ratio is high. But high is good so long as you can feed it and not ping.
I'd do what BJR said. Save the money for nice valves and a minor port job. The car will sing.
 
To be honest, without flow numbers for your heads (not the "general" published ones I was looking at..You need to take into account your castings, and your valve job..) you're kind of tossing darts anyway. I also dont put a ton of faith in algorithms the dynoprograms use. They really generalize too much to make them totally believable. I agree with BJR on the cam, but I dont think you'll ever see the high side of 450hp with stock or even mildly modified factory Magnum heads. I'd say 430hp/430tq with the better cam choice and the rest left alone. With a better set of heads, you could get a bit more from it.
 
rumblefish360 said:
From what I have been reading about this program vs. actual dyno runs are;
A little generous on HP, a little light on torque.
Click to expand...

How can that be?

Horsepower is a straight mathematical calculation of torque times rpm divided by a constant (5252).

By definition if torque is low then horsepower can be nothing but low too.

A dyno only measures torque and rpm. Horsepower is calculated from the formula.
 
I don't know squat about math, but I'll take you guys word for everything. I'll keep the suggestions and see what happens some day ( soon I hope ) when I get her up and running and take her to the track. I guess anywhere from 350 and up will be a nice cruiser, and I have the spray for any wild musky thangs I meet on the street. Thanks again guys

By the way,,,,near Greenville NC.
 
Greenville,NC. thats about 4 hrs. for me. Close enough if you need to send or bring something, that it wouldn't cost a arm and a leg.



BJR Racing
 
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