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360 pros n cons #2771009
05/04/20 09:11 AM
05/04/20 09:11 AM
Joined: Apr 2007
Posts: 1,390
CA.
RAY1969CARS Offline OP
pro stock
RAY1969CARS  Offline OP
pro stock

Joined: Apr 2007
Posts: 1,390
CA.
Hi guys
Pros and cons when it comes to building a regular 360 flat tappet motor
360 pre-magnum roller motor
Or the 5.9

Which one would you build and why what are your reasons

Re: 360 pros n cons [Re: RAY1969CARS] #2771016
05/04/20 09:35 AM
05/04/20 09:35 AM
Joined: Feb 2003
Posts: 8,660
A
Andrewh Offline
master
Andrewh  Offline
master
A

Joined: Feb 2003
Posts: 8,660
I guess it would depend.
but in general the 5.9 is a better motor overall.
cheap in the yards, no oil issues with modern oil.
parts stores still have everything and small parts can still be gotten cheap at the yards.

where it becomes tricky is how much hotrodding you want to do to it, and if you want to keep efi, or just go carb.

EFI intakes are not very plentiful for the 5.9, and the one or two out there are not very cheap.

there are knock off ones for the carb intakes, so it isn't that big a deal.

hot rodding with efi, also is a bit problematic. Narrow window of cams unless you start going into programmable setups.

Re: 360 pros n cons [Re: RAY1969CARS] #2771020
05/04/20 10:00 AM
05/04/20 10:00 AM
Joined: Jan 2003
Posts: 11,894
Benton, IL.
D
DaveRS23 Online rolleyes
Special needs idiot
DaveRS23  Online Rolleyes
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Joined: Jan 2003
Posts: 11,894
Benton, IL.
What are your goals? If performance is important, then the Magnum heads are the way to go. And you can do that with either block style.


Master, again and still
Re: 360 pros n cons [Re: DaveRS23] #2771040
05/04/20 10:39 AM
05/04/20 10:39 AM
Joined: Jan 2003
Posts: 20,356
Eagle, Idaho
Neil Offline
The Doctor is in.
Neil  Offline
The Doctor is in.

Joined: Jan 2003
Posts: 20,356
Eagle, Idaho
New engine has a roller cam.
New engine has to run an electrical fuel pump.

LA engine has been around longer and the cylinder head selection is better for a high hp engine build (W2 heads etc.)

For a mild street car I'd do the 5.9 with a carburetor.

Re: 360 pros n cons [Re: Neil] #2771063
05/04/20 11:43 AM
05/04/20 11:43 AM
Joined: May 2019
Posts: 6,176
nowhere
S
Sniper Offline
master
Sniper  Offline
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Joined: May 2019
Posts: 6,176
nowhere
400hp out of a mostly stock Magnum is easy, even the 5.2L version.

Cam swap and a good 4bbl intake is about the limit of the hard parts needed. Of course you will need to tune the carb and the timing, but that's any build.

360 takes more work and costs more to get to 400.

Re: 360 pros n cons [Re: Sniper] #2771093
05/04/20 01:28 PM
05/04/20 01:28 PM
Joined: Apr 2007
Posts: 1,390
CA.
RAY1969CARS Offline OP
pro stock
RAY1969CARS  Offline OP
pro stock

Joined: Apr 2007
Posts: 1,390
CA.
I heard the magnum heads are prone to cracking is that because the engine temperature is much higher in newer cars with the same thing happen that running 160?

Re: 360 pros n cons [Re: RAY1969CARS] #2771097
05/04/20 01:42 PM
05/04/20 01:42 PM
Joined: Jan 2003
Posts: 20,356
Eagle, Idaho
Neil Offline
The Doctor is in.
Neil  Offline
The Doctor is in.

Joined: Jan 2003
Posts: 20,356
Eagle, Idaho
Magnum heads can crack between the valve seats.

Last edited by Neil; 05/04/20 01:42 PM.
Re: 360 pros n cons [Re: Neil] #2771183
05/04/20 07:09 PM
05/04/20 07:09 PM
Joined: Mar 2006
Posts: 9,791
MI, usa
dvw Offline
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dvw  Offline
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Joined: Mar 2006
Posts: 9,791
MI, usa
The roller cam and more precise factory machining makes the Magnum a better choice. The heads do crack but seldom leak. We've used them. New heads available cheap
https://www.ebay.com/itm/BRAND-NEW-Dodge-Magnum-Chrysler-Jeep-5-2-5-9-V8-Mopar-318-360-Cylinder-Head-PAIR/312749010022?hash=item48d14b2c66:g:9~AAAOSwYNRcbyAq
Doug

Re: 360 pros n cons [Re: dvw] #2771278
05/04/20 11:58 PM
05/04/20 11:58 PM
Joined: Jan 2003
Posts: 3,122
Auburn WA
Dave_J Offline
master
Dave_J  Offline
master

Joined: Jan 2003
Posts: 3,122
Auburn WA
The Magnumn 5.9 has a lot of plus's over the old Commando style 360. Even a base 5.2 will put out about the same usable power than a stock 360.
The oiling ports on a mag are larger so the oil pump does not have to work as hard saving power.
The heads flat out outflow Commando heads. Even some mild ported Commando heads will not flow as much as stock Mag heads.
The Mag head have a much better quench shelf so you get higher compression with the closed chamber but the quench helps with the 'PING' too.
Even if you use the same Cam spec's, a roller will have less friction to save HP

The mix of parts are so easy too to Hybred some combos.


Retired, US ARMY 1973-1994
ASE mechanic, Electrical 1994-1997
Retired GTE/VERIZON/FRONTIER 1997-2015


Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.

03 Suzuki Burgman 650(Burger King) Scooter
65 Formula S Cuda
78 Little Red Express Truck
98 Buick Regal (wifes car)
Re: 360 pros n cons [Re: Dave_J] #2771436
05/05/20 01:39 PM
05/05/20 01:39 PM
Joined: Jan 2011
Posts: 15,713
Central Florida
larrymopar360 Offline
Stud Muffin
larrymopar360  Offline
Stud Muffin

Joined: Jan 2011
Posts: 15,713
Central Florida
I owned two MP Magnum 360/300hp crate engines and put lots of miles on them. Never a problem with cracking heads. Only issues was some leaks in gaskets, probably poor assembly.

Flat out the best engine for the money I ever had. The 300hp/375tq seemed very underrated. It was a tire shredding torque monster but smooth idling and quite a sleeper. Someday I'd like to assemble the parts and build one again since MP does not produce them anymore.


Facts are stubborn things.
Re: 360 pros n cons [Re: Dave_J] #2771506
05/05/20 05:00 PM
05/05/20 05:00 PM
Joined: Apr 2007
Posts: 1,390
CA.
RAY1969CARS Offline OP
pro stock
RAY1969CARS  Offline OP
pro stock

Joined: Apr 2007
Posts: 1,390
CA.
Do they share the same oil pan ?

Re: 360 pros n cons [Re: RAY1969CARS] #2771530
05/05/20 05:53 PM
05/05/20 05:53 PM
Joined: Jan 2003
Posts: 3,122
Auburn WA
Dave_J Offline
master
Dave_J  Offline
master

Joined: Jan 2003
Posts: 3,122
Auburn WA
Originally Posted by RAY1969CARS
Do they share the same oil pan ?

Yes. But the Mag 5.2 and 5.9 have a dinky 4 quart pan. But they both use the 360's small rear main hump. For a center sump use a 360 car pan.

You can also use the timing chain cover for the mechanical fuel pump if you get a long snout roller cam or a Hughes Engines adapter for the eccentric.

Last edited by Dave_J; 05/05/20 05:56 PM.

Retired, US ARMY 1973-1994
ASE mechanic, Electrical 1994-1997
Retired GTE/VERIZON/FRONTIER 1997-2015


Posting cheap tech help (CRAP) here since Nov 97, 1000's of posts, some may be good.

03 Suzuki Burgman 650(Burger King) Scooter
65 Formula S Cuda
78 Little Red Express Truck
98 Buick Regal (wifes car)
Re: 360 pros n cons [Re: Dave_J] #2771715
05/06/20 08:17 AM
05/06/20 08:17 AM
Joined: Jun 2008
Posts: 1,822
Colorado
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denfireguy Offline
top fuel
denfireguy  Offline
top fuel
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Joined: Jun 2008
Posts: 1,822
Colorado
I wanted to keep the classic look but use fuel injection. I reused the timing cover but not the fuel pump. I used a 360 oil pan and oil pump. On top, I used CH318B cylinder heads that are Magnum based but have LA intake bolt angles. They are new castings that so far do not seem to have the Magnum cracking issue.The intake is an Edelbrock 4 BBL with a Holly Terminator TBI. If they were out then, I would have used a FI Tech. Spectra in tank fuel pump pushes the gas,
This all started with a 5.2L out of a Dodge van that I paid 500 for. Just the roller cam itself made it a no brainer.
Craig


2014 Ram 1500 Laramie, 73 Cuda
Previous mopars: 62 Valiant, 65 Fury III, 68 Fury III, 72 Satellite, 74 Satellite, 89 Acclaim, 98 Caravan, 2003 Durango
Only previous Non-Mopar: Schwinn Tornado
Re: 360 pros n cons [Re: denfireguy] #2771884
05/06/20 06:50 PM
05/06/20 06:50 PM
Joined: Jan 2003
Posts: 8,473
Candler,NC / Myrtle Beach, SC
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JDMopar Offline
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JDMopar  Offline
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Candler,NC / Myrtle Beach, SC
Just an FYI for those who may not have heard......Engine Quest is no longer making the CH318B heads. They still make the stock Magnum pattern though. If you want to use an LA intake on new EQ heads, you will have to buy the CH318A's and drill them for the LA pattern. There is a guy on FABO who made a drilling jig, and is kind enough to let people use it and just ship it to the next person in line that needs it.

Re: 360 pros n cons [Re: JDMopar] #2772028
05/07/20 09:47 AM
05/07/20 09:47 AM
Joined: Jun 2018
Posts: 350
Mequon, WI
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gzig5 Offline
enthusiast
gzig5  Offline
enthusiast
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Joined: Jun 2018
Posts: 350
Mequon, WI
LA intakes can be used on Magnum by re-drilling the heads with the mentioned templates or some shops can set it up in the mill. LA heads can be run on Magnum blocks if you use a valve train that lubricates the rockers up through the pushrods. It just depends what you are trying to accomplish. There seems to be more parts selection for LA style.







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