5.2/5.9 H.P build guesstimate

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Slantsix64

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Sup guys, so this is my new build I have a cheaper way of going with a ready core 5.2 magnum in my yard, or just find me a 5.9

Car is a 67 Abody, manual steering brakes, 904 trans go shift kit 2800 stall converter 3.55 and 3.91 gears available. Long tube headers Rpm Air Gap and a 750 Holley Vacuum secondary

Camshaft I have a used Howard’s grind, .503/533 lift @50 221/225 intake 274 exhaust 278

Two questions, will this work well with my 5.2 block or should I source a 5.9?
Also how much H.P are we looking at, trying to get in the 375-400 Range lol
 
Sup guys, so this is my new build I have a cheaper way of going with a ready core 5.2 magnum in my yard, or just find me a 5.9

Car is a 67 Abody, manual steering brakes, 904 trans go shift kit 2800 stall converter 3.55 and 3.91 gears available. Long tube headers Rpm Air Gap and a 750 Holley Vacuum secondary

Camshaft I have a used Howard’s grind, .503/533 lift @50 221/225 intake 274 exhaust 278

Two questions, will this work well with my 5.2 block or should I source a 5.9?
Also how much H.P are we looking at, trying to get in the 375-400 Range lol
Richard gets 350 hp out of a stock 5.9l longblock with 4bbl headers and a 212 cam, I would say the 5.2l would get similar. The 380hp crate engine gets 400 hp with 230 cam so your cam is about in between so I'd say should maybe get the 375 hp.

The 5.2l is gonna need about 500-600 more rpm and higher stall and about a half a ratio deeper gear to perform similar as a 5.9l. So that's up to you if that's fine.

Here's a basically 400 hp 5.2l (318 with magnum heads)

https://www.motortrend.com/articles/mopp-0409-318-engine-build/

And here's a 400 hp 5.9l

https://www.motortrend.com/articles/mopp-0303-360-crate-engine-buildup/

And here's the 350 hp 5.9l

 
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How bout this. I’m the process of a 360 magnum swap on my 69 dart. Similar specs with a milder cam.

We could meet this fall somewhere in LA and see whose car is faster.
 
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How bout this. I’m the process of a 360 magnum swap on my 69 dart. Similar specs with a milder cam.

We could meet this fall somewhere in LA and see who’s car is faster.
Always down for that! I already know a couple spots in the SGV
 
Richard gets 350 hp out of a stock 5.9l longblock with 4bbl headers and a 212 cam, I would say the 5.2l would get similar. The 380hp crate engine gets 400 hp with 230 cam so your cam is about in between so I'd say should maybe get the 375 hp.

The 5.2l is gonna need about 500-600 more rpm and higher stall and about a half a ratio deeper gear to perform similar as a 5.9l. So that's up to you if that's fine.

Here's a basically 400 hp 5.2l (318 with magnum heads)

https://www.motortrend.com/articles/mopp-0409-318-engine-build/

And here's a 400 hp 5.9l

https://www.motortrend.com/articles/mopp-0303-360-crate-engine-buildup/

And here's the 350 hp 5.9l


How much can I bore the 318 to? I know it won’t be much but if I can get into the 330 CI range I’ll be happy
 
How much can I bore the 318 to? I know it won’t be much but if I can get into the 330 CI range I’ll be happy
A 30 over is 323, 60 over will be a 328, as for max overbore you'd have to get it sonic checked.
 
A 30 over is 323, 60 over will be a 328, as for max overbore you'd have to get it sonic checked.
I know with the .533 lift I will run into issues, would I be having to trim the valve guides? I already have the Hughes retainers and springs
 
Richard gets 350 hp out of a stock 5.9l longblock with 4bbl headers and a 212 cam, I would say the 5.2l would get similar. The 380hp crate engine gets 400 hp with 230 cam so your cam is about in between so I'd say should maybe get the 375 hp.

The 5.2l is gonna need about 500-600 more rpm and higher stall and about a half a ratio deeper gear to perform similar as a 5.9l. So that's up to you if that's fine.

Here's a basically 400 hp 5.2l (318 with magnum heads)

https://www.motortrend.com/articles/mopp-0409-318-engine-build/

And here's a 400 hp 5.9l

https://www.motortrend.com/articles/mopp-0303-360-crate-engine-buildup/

And here's the 350 hp 5.9l


I now own the magnum crate engine Holdener was using for testing. With the 212/218 cam and an rpm air gap it now makes 365.

E894CC2A-E9DA-4934-BB04-4C717C473EE9.png
 
Two questions, will this work well with my 5.2 block or should I source a 5.9?
Also how much H.P are we looking at, trying to get in the 375-400 Range lol
That's a great cam for a 5.9 hi-torque engine, or
not bad in a 5.2, but you'll need to get the Dcr up to about 8/1. That will run great the 2800/3.91s , altho it will pull any gears with the 5.9; and even down to 3.23s with the 5.2; which I'm not advocating for, jus-saying..
In a 5.2
For street;
horsepower means almost nothing, because 275 is already enough to burn thru two gears in your small-tub chassis. So unless you're willing to spend say $2500 or MORE, on the back end, 400 hp is, IMO, an unrealistic target, and way overkill. I mean, think about it; 65 mph in Second gear with 3.55s, is like 4700; for a 5.2/400 hp combo, this rpm is at the bottom of the power curve, and you won't get to peak power 'til around 75/80 mph. and with 245s in the back, there's a good chance they'll still be spinning over half way thru Second ..... So, if yur gonna run 3.55s, then you want power at 4700, and, you ain't even gonna get close to 400@4700 with 318 cubes, no matter what street-friendly cam you put in it..
But if you already have the cam for say a 5200 peak, which you do, just run it but with the 3.91s for best street performance. This will make 65mph to be about 5150, which is, right on the money..

>As is almost universally recommended; Forget chasing a big overbore for street power, you'll never feel it. Bore the teener out, the minimum it needs to go for the holes to be round without taper.
>For best results with iron heads, you'll need 8:1 Dcr, and a tight squish, in the window of 030>040. This will likely require an Scr of 10/1; flat-top pistons, and closed-chamber heads; so the Magnums are a good start..
>IMO the 750carb is also overkill, but if you already have it, just bolt it on, and use the 3.91s, it'll be fine ..........
>Before you start anything, Figure out what Scr you need to run, with chosen top-end, and see if you can even get pistons close to that . The biggest complaint I hear from the Teen-Crowd, is finding off-the-shelf pistons. If you gotta go custom, then it will most likely be cheaper to just grab a 5.9 short.
Happy HotRodding
 
If you look at the dyno curves provided, the 350 hp 5.9l makes about 330 hp @ 4700 rpms, 400 hp 5.2l makes about 340 hp @ 4700 rpms, 365 hp 5.9l makes 355 hp @ 4700 rpms and the 400 hp 5.9l makes about 380 hp @ 4700 rpms, if you notice the 5.2l ain't doing so bad plus you should be running deeper gears with a 318 so it would be revving higher in rpms and in hp at 65 mph.

Plus in the 4900-5000 rpms the 318 is making the same power as both the 350 & 365 hp 5.9l and still makes usable power to 6200-6500 rpms 400-393 hp if one chooses to rev up there if not it's still makes similar power at 5000 rpms as the lower hp 5.9's. Not trying to get you to build the 5.2l it's up to you, the really only reasons to run the 5.2l you already have it and more importantly if you want higher rpm power and are fine with the possible side effects if not build a 5.9l but no reason not to build a 400 hp 5.9l if you look, its basically make better power every where except above 6000 rpms.

Some seems to think more power only happens at the top end of the power curve forgetting it can add through out especially mid curve 3000-4500 rpms where like someone pointed out you'll spend a lot of your time at full throttle.

Mopar 318
RPMHPTQ
3,000190332
3,500241376
4,000286376
4,500321375
4,900357382
5,000363381
5,500388371
6,000398348
6,200400339
6,500393318

Mopar Performance 360 cid 380 hp rated

RPMTQHP
2500380.6181
3000402.9230
3500415.1277
4000437.8333
4100439.5343
4500437.1375
5000416.3396
5400398.6409
5500388.6407
6000343.9395

1721978676491.png


1721978709489.png
 
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Sup guys, so this is my new build I have a cheaper way of going with a ready core 5.2 magnum in my yard, or just find me a 5.9

Car is a 67 Abody, manual steering brakes, 904 trans go shift kit 2800 stall converter 3.55 and 3.91 gears available. Long tube headers Rpm Air Gap and a 750 Holley Vacuum secondary

Camshaft I have a used Howard’s grind, .503/533 lift @50 221/225 intake 274 exhaust 278

Two questions, will this work well with my 5.2 block or should I source a 5.9?
Also how much H.P are we looking at, trying to get in the 375-400 Range lol

The MP crate engine, 360/380 hp is basically a stone stock long block with a Hyd roller cam of 230@050 on the intake and .513 lift. These engines dyno’d constantly over 400hp.

Your cam choice will make more torque down low and give up some power up top. If your going to stay with your cam choice, your going to need to do one or the other of, porting the OEM heads or moving to aluminum heads. The Edelbrock Magnums are the choice here. The better higher flowing cylinder heads will allow more HP and extend the RPM range a tad bit.

Use the 5.9 over the 5.2. It’ll have more torque and make more HP.

Another note, the crate engine used a M1 single plane. The Edelbrock RPM is capable of meeting the HP goal with more torque. A spacer under neath the 750 carb would be great if it fits under the hood. MoPar also used 1-3/4 headers.
 
I second what @rumblefish360 says.

If you can spring for the 5.9 you should.

The 5.9 will make more torque/power at every point on the curve.

Carefully consider cam spec with the converter and gears you're planning on running. Aftermarket cams paired with highway gears and low stall converters is a recipe for a dog.
 
Going to go with the 5.9!!

this is my set up
5.9 Magnum Stock heads stock compression 9:1
A904 3000k stall
3.55/3.91 gears
Tube headers
Rpm Air Gap
750 3310 Holley
67 barracuda

Looking into the best camshaft trying to stay right under .500 lift aiming for 400hp @ flywheel

These are my choices I came down to Oregon camshaft regrinds

#1169 220@ .50 282/282 duration at .498/498 lift

#1408 224/230 @50 276/282 duration at .480/.480 lift


Really like the number 1408 grind the split duration probably will sound nasty lol

What do you guys think?
 
I think you’re going to be (IMO at least) 20 hp short with the 1408 cam and stock heads. Referred to the Mopar crate engine for guidance. They listed as a 380 horse 360 with a larger can and a single plane. I wouldn’t use the single plane since the RPM will perform as well with a lot more torque. But the camp or the heads. Didn’t say what size to run. Mopar ran their crane three 8360 with one three-quarter headers.

This engine with a hydraulic roller cam of 230° at 50 for the intake is notorious to 400 hp or better consistently.
 
I think you’re going to be (IMO at least) 20 hp short with the 1408 cam and stock heads. Referred to the Mopar crate engine for guidance. They listed as a 380 horse 360 with a larger can and a single plane. I wouldn’t use the single plane since the RPM will perform as well with a lot more torque. But the camp or the heads. Didn’t say what size to run. Mopar ran their crane three 8360 with one three-quarter headers.

This engine with a hydraulic roller cam of 230° at 50 for the intake is notorious to 400 hp or better consistently.
Rumble, do you think I should try a hotter cam, or would that cam be the ticket with the stock magnum heads being the limiting factor?
 
Going to go with the 5.9!!

this is my set up
5.9 Magnum Stock heads stock compression 9:1
A904 3000k stall
3.55/3.91 gears
Tube headers
Rpm Air Gap
750 3310 Holley
67 barracuda

Looking into the best camshaft trying to stay right under .500 lift aiming for 400hp @ flywheel

These are my choices I came down to Oregon camshaft regrinds

#1169 220@ .50 282/282 duration at .498/498 lift

#1408 224/230 @50 276/282 duration at .480/.480 lift


Really like the number 1408 grind the split duration probably will sound nasty lol

What do you guys think?

Now that I think about it, contact Hughes Engines and get their trick spring and lifter kit, which allows for more than 500 lift.
Check out Charlie Servedio on YouTube and scroll down to where he does work on Magnum heads. I myself appearing a video with him on Magnum heads and then later on sent in his heads to be ported and he shows the results of what can be done. But does lack And lift to achieve the minimum horsepower number that stated at 400 hp.
 
Rumble, do you think I should try a hotter cam, or would that cam be the ticket with the stock magnum heads being the limiting factor?
The stock magnum heads do have a flow limitation, and a lift where they start giving up. Find the video I was talking about. A slightly hot a cam would be the ticket in my opinion. And don’t be afraid of lift, however, let’s not go crazy.

To be honest! Finding a copy with something very similar to the Mopar cam in the 380 hp 360 engine would be an excellent way to go. No shame copy cat engine building because it’s just simply paying homage to the original design and builders of it.
 
Oh! The 3000 stall will work with a 230 at 50 hydraulic roller cam.
 
Oh! The 3000 stall will work with a 230 at 50 hydraulic roller cam.
Rumble! Here’s what I been looking at
Grind#1357 230/236 @.50 284/290 duration at .515 lift, I’ll probably have to check valve to piston clearance, I’ll probably end up using a thicker head gasket when I swap them back on that would probably help, also I would advance this camshaft 4 degrees.
 
Rumble! Here’s what I been looking at
Grind#1357 230/236 @.50 284/290 duration at .515 lift, I’ll probably have to check valve to piston clearance, I’ll probably end up using a thicker head gasket when I swap them back on that would probably help, also I would advance this camshaft 4 degrees.
Always check piston to valve clearance just to make sure that you didn’t screw up the cam installation. The actual valve lift, while a concern is more of a troublesome thing even with low lifts, because the cam is installed by mistake 2 or 4 degree off by way of a multi slot crank and/or can gear.

The cam used by MP for the 380/360 had a .515 (IIRC) intake lift. So far, the cam you listed looks like a copy of that MP cam. Though not all the information is there. You should be able to find the specs of the MP cam easy enough.

Adding in a thicker head gasket is a looser on torque and HP. It does little if not actually nothing for piston to valve clearance. Retain the stock thickness or less for keeping everything the cam is supposed to offer in power.

Advancing or retarding the can move the power band slightly in favor of one attribute and the detriment of another. I would suggest seeking out Dino results of moving the cam around rather than rely on someone’s opinion and their seat of the pants Dyno. These things (opinions) are often not accurate and only a few people can actually pick up the differences. I would advise to install the cam straight up as it supposed to be to start with and then mess with it later.

I’ve witnessed these Mopar crate engines run mid to low 12s at the track with a few guys dipping into the Levans. Although that time does require a dedicated stripped out vehicle designed only for the strip.
 
Always check piston to valve clearance just to make sure that you didn’t screw up the cam installation. The actual valve lift, while a concern is more of a troublesome thing even with low lifts, because the cam is installed by mistake 2 or 4 degree off by way of a multi slot crank and/or can gear.

The cam used by MP for the 380/360 had a .515 (IIRC) intake lift. So far, the cam you listed looks like a copy of that MP cam. Though not all the information is there. You should be able to find the specs of the MP cam easy enough.

Adding in a thicker head gasket is a looser on torque and HP. It does little if not actually nothing for piston to valve clearance. Retain the stock thickness or less for keeping everything the cam is supposed to offer in power.

Advancing or retarding the can move the power band slightly in favor of one attribute and the detriment of another. I would suggest seeking out Dino results of moving the cam around rather than rely on someone’s opinion and their seat of the pants Dyno. These things (opinions) are often not accurate and only a few people can actually pick up the differences. I would advise to install the cam straight up as it supposed to be to start with and then mess with it later.

I’ve witnessed these Mopar crate engines run mid to low 12s at the track with a few guys dipping into the Levans. Although that time does require a dedicated stripped out vehicle designed only for the strip.
Your right! I’ll probably use the play dough method, should I just reuse the factory gasket torqued to spec because it’s probably way more thinner than the replacement I will use,. that way if I have clearance with that gasket I should be fine with the after market one.
 
Richard gets 350 hp out of a stock 5.9l longblock with 4bbl headers and a 212 cam, I would say the 5.2l would get similar. The 380hp crate engine gets 400 hp with 230 cam so your cam is about in between so I'd say should maybe get the 375 hp.

The 5.2l is gonna need about 500-600 more rpm and higher stall and about a half a ratio deeper gear to perform similar as a 5.9l. So that's up to you if that's fine.

Here's a basically 400 hp 5.2l (318 with magnum heads)

https://www.motortrend.com/articles/mopp-0409-318-engine-build/

And here's a 400 hp 5.9l

https://www.motortrend.com/articles/mopp-0303-360-crate-engine-buildup/

And here's the 350 hp 5.9l


It is worth mentioning the 280h cam selected for the 318 build will be a dog on the bottom end if you don't follow the rest of the build and the compression up.
Years ago we used that in a 350 chebbie with stock low compression pistons and a stock converter in an 81 pontiac grand prix with 373 gears. Dead off the line. My 360 with much less cam and equally shitty compression destroyed it drag racing in route 8.
Something arrund the comp 262h probably would have been better for our application.
And the 350 has the advantage of cubes.
 
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