360 magnum horsepower guess

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Brooks James

Brooks James

VET, CPT, Huey Medevac Pilot
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Guesstimates on 360 magnum
Stock heads/block/pistons/rods/crank
650 double pumper
Knock off air gap intake
340 exhaust manifolds
Mp distributor
Msd ignition
Cam 498/512 lift 274/286 duration
Appropriate valve springs from Hughes

Hoping for 330-340 horses
 
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Yea probably in the 340+ish range if the heads are setup for the cam i.e. springs that can handle it.
 
MP's 380hp engine had 501/513 hyd roller with...I don't remember duration. but that figure was with a 750 carb and headers. and a single plane intake.
 
dano said:
Yea probably in the 340+ish range if the heads are setup for the cam i.e. springs that can handle it.
Click to expand...
Forgot got good valve springs from Hughes
abdywgn said:
MP's 380hp engine had 501/513 hyd roller with...I don't remember duration. but that figure was with a 750 carb and headers. and a single plane intake.
Click to expand...
 
Brooks James said:
Guesstimates on 360 magnum
Click to expand...
I'll guess low at maybe 300,
But be warned;
at 9.2Scr, the bottom end, sub 3000, will be on the weaker side. That cam, if on a 114+4 would like 10.7 Scr.. On a 108+4 wants 10.1; both, to make about 160psi cranking pressure.

That 284 cam pushes the power up to something like 5400, so you may need, additionally, a hi-stall TC and more rear gear to take advantage of the power, else with 3.23s you won't get to it until 5400= more than 74mph in 1.45second gear.
With no other changes to your basically stock long-block, your engine should make more torque at sub-3000rpm with a cam sporting an earlier closing Ica. You may not need it or want it; just saying.
The good news is, you didn't start with an 8/1 360LA, which would be worse.
300/320hp is still a gaggle of giggles when combo'ed up nice.
 
A bone stock, cam and all, 360 magnum with a intake swap and a set of headers will make 320 if in good condition
 
AJ/FormS said:
I'll guess low at maybe 300,
But be warned;
at 9.2Scr, the bottom end, sub 3000, will be on the weaker side. That cam, if on a 114+4 would like 10.7 Scr.. On a 108+4 wants 10.1; both, to make about 160psi cranking


That 284 cam pushes the power up to something like 5400, so you may need, additionally, a hi-stall TC and more rear gear to take advantage of the power, else with 3.23s you won't get to it until 5400= more than 74mph in 1.45second gear.
With no other changes to your basically stock long-block, your engine should make more torque at sub-3000rpm with a cam sporting an earlier closing Ica. You may not need it or want it; just saying.
The good news is, you didn't start with an 8/1 360LA, which would be worse.
300/320hp is still a gaggle of giggles when combo'ed up nice.
Click to expand...

the cam lsa is 113
I’ll be running 3.91 ratio rear
100 shot of nitrous which should help solve any low end torque problems
3500 street converter
Distributor will be set up initially with
33-34 degrees all in by 2500
 
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Brooks James said:
Guesstimates on 360 magnum
Stock heads/block/pistons/rods/crank
650 double pumper
Knock off air gap intake
340 exhaust manifolds
Mp distributor
Msd ignition
Cam 498/512 lift 274/286 duration
Appropriate valve springs from Hughes

Hoping for 330-340 horses
Click to expand...

here’s the 380 hp crate engine makes 409 hp, guess knock of 20 or so hp since you got manifolds.

0418C435-D2E8-4AE6-9BCB-DC15614C4166.jpeg
 
Nice! It's refreshing to see someone select the proper converter and gear to match the cam. What is it going in and what size of tire are you going to run on it?
 
That thing is going to be Zinging RPM. I had the same set up and it was fun until driving on the highway.
 
crackedback said:
That thing is going to be Zinging RPM. I had the same set up and it was fun until driving on the highway.
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1st Dart had 340 w/4.56's and F60-14's. It gets on your nerves after awhile of highway driving...nothing that a good stab with the right foot doesn't take care of.
 
abdywgn said:
1st Dart had 340 w/4.56's and F60-14's. It gets on your nerves after awhile of highway driving...nothing that a good stab with the right foot doesn't take care of.
Click to expand...
I know that it will the fartherest I will drive it will be car shows within about a 60-70 miles radius
Mostly to Old Town in Orlando which
Is about 45 minutes away
It is going to be a sleeper other than the wheels it will look stock
The exhaust will thru chambered mufflers with not much lope as the cam is lsa 113
 
A 3.55 gear would have you running at 2900 rpm at 61 mph accounting for 1/2 inch of tire growth at speed. 3.91 gears will have you at 3200 rpm at 61 mph. 3.23 gears will have you at 62 @ 2700. I would look into getting a set of the largest diameter highway tires that will reasonably fit on some 15 inch wintertime rims to run during the highway trips.
 
I did the tire swapping business for a few years. From the max of 28"" to a 24.5 is about the same as from 3.91s to 3.45s.
So; with 3.91s and 24.5s , 65=3490
and with 28s; 65=3050; both at zeroslip
poorman's overdrive.
 
AJ/FormS said:
I did the tire swapping business for a few years. From the max of 28"" to a 24.5 is about the same as from 3.91s to 3.45s.
So; with 3.91s and 24.5s , 65=3490
and with 28s; 65=3050; both at zeroslip
poorman's overdrive.
Click to expand...
 
335-355 hp depending on the tune

Imo If it was a real 9.5 and the heads were a solid 220cfm ...about 395-400hp would be my guess
 
Alright, so what if someone takes this same exact setup but goes just a little deeper. What if they spend some time gasket matching the heads and spends some time on a good home port/ polish job, and get it to a true 60cc chamber with a .039 headgasket coupled with some longtube headers. What might the power expectations be then?
 
Justin Sykes said:
Alright, so what if someone takes this same exact setup but goes just a little deeper. What if they spend some time gasket matching the heads and spends some time on a good home port/ polish job, and get it to a true 60cc chamber with a .039 headgasket coupled with some longtube headers. What might the power expectations be then?
Click to expand...
With the same cam? You might see some more numbers, but I dont think it will be a drastic difference.
 
The good home port and polish job is the deciding factor. Good as in using the MP templates or good as in maybe Mopar official would have some guidelines to follow to maximize flow at those lifts?
 
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