Mild 360 Magnum Build

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I’m going to give these magnum heads a bit of a cleanup.... any input? Anyone, anyone....
 
Cam finally made it to Canada...

1193194D-09E5-446D-9DEA-EF1746296F1C.jpeg
 
Retro-Fit Hydraulic Roller. Good high performance street cam with slight lope. Works with all power acces- sories. Fair idle.

  • Advertised Duration (Int/Exh): 276/284
  • Duration @ .050 (Int/Exh): 210/218
  • Gross Valve Lift (Int/Exh): .492/.492
  • LSA/ICL: 112/106
  • Valve Lash (Int/Exh): Hyd/Hyd
  • RPM Range: 1200 - 5200
 
Still waiting on the EQ heads... ordered them bare.
 
rumblefish360 said:
Not necessarily. That depends on the height of the piston.

It is but not by much. The exact amount will vary as the LA engines did not always come with a uniform Deck height. The magnum was much better at this.
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I think positive height on a magnum engine comes from a Keith Black 107 piston, and probably not from a Speed Pro H116P piston -gathered from following the SBM forum here for 6 or 7 years, but I am a noob myself. Those silvolites look better than the Speed Pro H405P pistons.
 
IIRC, the difference in slug height between the KB-107 & the Federal-Mougal 116 is .001 in the KB favor.
 
Rods are resized and ARP bolts in... the bottom end will start going together soon
 
Going to start the assembly of the bottom end this weekend, one thing I would like to order up is the roller lifters...should I just get new factory ones or does anyone have a recommendation?
 
I bought some melling stock replacements from the local parts store. They’ve held up fine in my engine.
 
I also re-ordered the factory units. There a bit heavier then others, but it is still a low RPM street engine.
 
I will get factory ones st the local dealer... it’s my first magnum. Thanks guys
 
And the pistons ended up about 50 down the hole for the guys that are interested in that sort of thing...
 
1994redram said:
I bought some melling stock replacements from the local parts store. They’ve held up fine in my engine.
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Ended up with melling rollers.. no deal to be had on factory parts dealer wanted twice the price
 
67autocross said:
Ended up with melling rollers.. no deal to be had on factory parts dealer wanted twice the price
Click to expand...

Those lifters will be fine. Any update on the EQ heads? What are your plans on those?

I just pulled my magnum out to upgrade to a larger cam and edelbrock heads. It made 304hp & 342 ft lbs on a chassis dyno with a fresh out of the box and untuned demon 750, pump gas 91, and 104° weather. That was with 2.02 1.62 EQ heads and a 218/222 @.050, .539/.549 cam. Should have been 360-370 HP at the flywheel.
 
The EQ heads are on order but have not shown up yet... I’m thinking of a 2.02 or 2.05 valve on the intake and some clean up. I read somewhere that the airgap intake flows around 255 ... so I was going to get the magnum heads to flow in the same range...keep in mind this is based on nothing more than my own ideas and not based on any scientific evidence
 
67autocross said:
Ended up with melling rollers.. no deal to be had on factory parts dealer wanted twice the price
Click to expand...
I believe the factory lifters are in fact Melling lifters. When I rebuilt my 89 roller LA block I examined the factory lifters I pulled out and replaced with Melling, they were identical. Mind you this is an LA roller pre Magnum. FWIW, they work awesome on my .580 lift cam. I've run it safely to 6350 rpm.
 
I’m kind of shooting for 375hp in the low 5000rpm range on 87 octane with this build... of course I take it to the best Dyno in town to help achieve my results
 
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