Re: magnum heads on an LA short block
[Re: barrakudaman]
#788611
08/30/10 08:23 PM
08/30/10 08:23 PM
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Joined: Nov 2004
Posts: 3,544
Syracuse,NY
CompWedgeEngines
master
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master
Joined: Nov 2004
Posts: 3,544
Syracuse,NY
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Works great, especially with a Edelbrock head. You need to be paying attention to pushrod clearance, make sure you have the right head gaskets, and you'll need the right pushrod oiling lifters. Really a simple, effective set up.
RIP Monte Smith
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WD for Diamond Pistons,Sidewinder cylinder heads, Wiseco, K1 rods and cranks,BAM lifters, Morel lifters, Molnar Technologies, Harland Sharp, Pro Gear, Cometic, King Engine Bearings and many others.
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Re: magnum heads on an LA short block
[Re: barrakudaman]
#788613
09/02/10 01:04 PM
09/02/10 01:04 PM
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Joined: Sep 2007
Posts: 738
TN
'84 D150 Shorty
Pickup Man
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Pickup Man
Joined: Sep 2007
Posts: 738
TN
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Quote:
anyone have anything bad to say about this idea? 
Nope! Sounds like a great idea! I am scrounging together the parts for this swap myself. I am lucky in that my engine is a roller cam LA block already, so I can directly swap in the Mag lifters and pushrods (for the through the PR oiling). I'm gonna use stock Mag heads outta the wreckin yard, and swap in the GM 3.1-3.3 beehive springs 
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Re: magnum heads on an LA short block
[Re: '84 D150 Shorty]
#788614
09/02/10 01:21 PM
09/02/10 01:21 PM
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Joined: Apr 2007
Posts: 2,826
NY usa
540challenger
master
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master
Joined: Apr 2007
Posts: 2,826
NY usa
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Quote:
Quote:
anyone have anything bad to say about this idea?
Nope! Sounds like a great idea! I am scrounging together the parts for this swap myself. I am lucky in that my engine is a roller cam LA block already, so I can directly swap in the Mag lifters and pushrods (for the through the PR oiling). I'm gonna use stock Mag heads outta the wreckin yard, and swap in the GM 3.1-3.3 beehive springs
DOn't forget that the factory V10 magnums use 1.7 rockers instead of the 1.6 that V8 rockers cheap upgrade 
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Re: magnum heads on an LA short block
[Re: 540challenger]
#788615
09/02/10 01:31 PM
09/02/10 01:31 PM
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Joined: Sep 2007
Posts: 738
TN
'84 D150 Shorty
Pickup Man
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Pickup Man
Joined: Sep 2007
Posts: 738
TN
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Quote:
Quote:
Quote:
anyone have anything bad to say about this idea?
Nope! Sounds like a great idea! I am scrounging together the parts for this swap myself. I am lucky in that my engine is a roller cam LA block already, so I can directly swap in the Mag lifters and pushrods (for the through the PR oiling). I'm gonna use stock Mag heads outta the wreckin yard, and swap in the GM 3.1-3.3 beehive springs
DOn't forget that the factory V10 magnums use 1.7 rockers instead of the 1.6 that V8 rockers cheap upgrade
Not sure how good an idea that would be...the mag heads already are a step up with 1.6 rockers vs. 1.5 rockers on stock LA heads. Per a discussion with Patrick, the cam guru, the mag heads are limited on the amount of lift you can run, and 1.7 rockers seem like they would be a tad too much unless you were using a stock cam...right?
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Re: magnum heads on an LA short block
[Re: '84 D150 Shorty]
#788616
09/02/10 01:36 PM
09/02/10 01:36 PM
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Joined: Apr 2007
Posts: 2,826
NY usa
540challenger
master
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master
Joined: Apr 2007
Posts: 2,826
NY usa
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Quote:
Quote:
Quote:
Quote:
anyone have anything bad to say about this idea?
Nope! Sounds like a great idea! I am scrounging together the parts for this swap myself. I am lucky in that my engine is a roller cam LA block already, so I can directly swap in the Mag lifters and pushrods (for the through the PR oiling). I'm gonna use stock Mag heads outta the wreckin yard, and swap in the GM 3.1-3.3 beehive springs
DOn't forget that the factory V10 magnums use 1.7 rockers instead of the 1.6 that V8 rockers cheap upgrade
Not sure how good an idea that would be...the mag heads already are a step up with 1.6 rockers vs. 1.5 rockers on stock LA heads. Per a discussion with Patrick, the cam guru, the mag heads are limited on the amount of lift you can run, and 1.7 rockers seem like they would be a tad too much unless you were using a stock cam...right?
correct even with the 1.6 you have to watch out once you get around .500 lift, You will/should get the guides cut down. All depends on your combo but the 1.7 rockers is another option out there. 
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Re: magnum heads on an LA short block
[Re: 5spdcuda]
#788618
09/02/10 02:59 PM
09/02/10 02:59 PM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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technically, these aren't ball stud rockers, they are a pedestal mount, and a carryover part from the old AMC 290-401 engines.
on my OEM mag heads, I could run about .530" lift before I started getting into keeper to seal clearance issues, but the GM 3.1/3.4 springs will coil bind well before that. anything over .480" at the valve, check real close with those springs.
if you're buying new springs, get some junkyard 2.2" retainers and hughes 1110 springs, that'll give you about .040" more lift capacity than the 3.1L springs/retainers. they have near identical spring rates, but the hughes will have another 40+ lbs of seat pressure.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: magnum heads on an LA short block
[Re: barrakudaman]
#788622
09/03/10 12:00 AM
09/03/10 12:00 AM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
I am looking at a set of edlebrock performer rpm heads with 1.6 roller rockers and a comp cam XR265 hydraulic roller cam .506" - .506" lift, 216^-224^ duration at .050". The guy wants $1,100 for all this. not sure if its a steal but it does sound like a deal. 3,000 miles on them he said. Im not sure if i will actually use this cam for my stroker motor. i have to do some more research 
sounds like a good deal....over in the race forum, a guy ran 13.6 in the quarter with that cam in a stock long block 318 mag with an eddie RPM air gap intake in a 3400 lb volare....
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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Re: magnum heads on an LA short block
[Re: 5spdcuda]
#788623
09/03/10 09:09 AM
09/03/10 09:09 AM
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Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
patrick
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 16,123
Grand Haven, MI
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Quote:
Patrick I've read many of your posts over the years and I have nothing but respect for your views. I simply disagree in this case. True they aren't a ball stud head in a technical sense of the word, but for all practical purposes they are and non-adjustable to boot. Don't forget puny 5/16 studs versus 3/8 on Eddys. Eddys also accept most aftermarket Chevy rockers. Factory magnums also limit your choices regarding intake manifolds. Sure heads and manifolds can be redrilled, but not for free. The Indy/RHS magnum style head can be had with LA manifold bolt holes and shaft style rockers. Plus they claim to have fixed the crack prone areas. By the time you fix all the things that need to be addressed on a set of used factory heads you can buy a new Indy/RHS head cheaper. Judging from what I've read they flow better too. Lastly he is putting them on a stroker which tells me that this probably isn't a quick and cheap "ring and bearing job". Why after building a good foundation try to "cheap out" now. The top half of the engine can definitely make or break you power wise. Put a good top half on the engine and let the stroker realize it's potential. No offense intended, this is after all just my opinion.
not offended in the least....it all depends on one's budget and realistic performance needs. my OEM mag heads that I scored for free weren't cracked when checked at a machine shop. beings it was going to be in a daily driver with a cam and spring pressures that aren't super excessive (.316 lobe lift, ~150lb seat pressure, and ~330 or so open), OEM rockers have been running fine for over a year.
comparably prepped 1.92 OEM magnum heads vs. 2.02 la heads, the magnums are probably worth ~15-20 HP & 15-20 lb ft due to better chamber and port velocity, even if you equalize compression ratio (IIRC Jesse lackman did this test with some dirt track motors)
all I know is my mag headed 318 runs darn hard, with a 208@.050 roller cam, it runs as hard as my old LA360 with a comp XE262, while returning nearly 20% better fuel economy.
the manifold thing is overblown...redrill to LA, or sell your LA and buy a magnum M1, air gap, or crosswind....I spend $15 to redrill mine.
as far as ball stud vs. pedestal, the design of the pedestal mount (having the pedestal with a through bolt), you don't NEED a larger bolt than 5/16", because it's just in tension, taking very little potential bending loads due to friction at the fulcrum (the pedestal takes that, loading the bolt in tension), a ball stud, the stud does potentially take bending load. one nice thing with the pedestal mount is, even though they're non adjustable, you can easily shim them if you need to fine tune the fulcrum height due to valve jobs, etc.
if you do feel the need to switch to adjustable/chevy style rockers, there are options, one being drilling the 5/16 holes to 3/8 or 7/16....the other being special studs, the 3rd being hughes' jesel style shaft mount rockers....
I agree, if you don't have good, crack free OEM heads, you're better off going aftermarket....but, personally, I like the idea of using a magnum/chevy type rocker gear if you're looking at roller rockers over the LA shaft mounts.. there's just too many choices of good quality than a comparable LA rocker system, and if you are on a budget and using stock rockers, the magnum rockers seem to measure much more true (if anything a touch OVER 1.6) than LA rockers (which routinely measure at ~1.4)
Last edited by patrick; 09/03/10 09:17 AM.
1976 Spinnaker White Plymouth Duster, /6 A833OD
1986 Silver/Twilight Blue Chrysler 5th Ave HotRod **SOLD!***
2011 Toxic Orange Dodge Charger R/T
2017 Grand Cherokee Overland
2014 Jeep Cherokee Latitude (holy crap, my daughter is driving)
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