TT5.9mag
Two atmospheres are better than one
I’m glad you are considering it. I don’t think I’ve seen a set of stock magnum cast heads ported someone with your background or experience. I’d like to.
factory magnum head replacement options
- Thread starter 393foureyedfox
- Start date
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How do these heads compare to the cast iron head Speedmaster sells.
TT5.9mag
Two atmospheres are better than one
I have no idea. I didn’t know speedmaster had a cast head.
Specs
| Brand: | Speedmaster |
| Part Number: | PCE281.1773 |
| Part Type: | Cylinder Heads |
| Cylinder Head Style: | Bare |
| Cylinder Head Material: | Cast Iron |
| Cylinder Head Finish: | Natural |
| Combustion Chamber Volume (cc): | 62 cc |
| CNC-Machined Combustion Chamber: | No |
| Intake Runner Volume (cc): | 179 cc |
| Exhaust Runner Volume (cc): | n/a |
| CNC-Machined Intake Runner: | No |
| CNC-Machined Exhaust Runner: | No |
| Intake Port Shape: | Standard Magnum |
| Intake Port Location: | Standard |
| Exhaust Port Shape: | Standard Magnum |
| Exhaust Port Location: | Standard |
| Spark Plug Style: | Standard |
| Comp. Valve Job: | No |
| Intake Valves Included: | No |
| Intake Valve Diameter (in): | 1.920 in. |
| Exhaust Valves Included: | No |
| Exhaust Valve Diameter (in): | 1.625 in. |
| Valve Springs Included: | No |
| Damper Spring Included: | No |
| Retainers Included: | No |
| Locks Included: | No |
| Valve Stem Seals Included: | No |
| Rocker Arm Studs Included: | No |
| Rocker Arms Included: | No |
| Rocker Arm Nuts Included: | No |
| Guideplates Included: | No |
| Valve Cover Mounting Style: | Perimeter Bolt |
| Accessory Bolt Holes Drilled: | Yes |
| Intake Valve Angle: | Standard |
| Exhaust Valve Angle: | Standard |
| Valve Guides Included: | Yes |
| Valve Guide Material: | Cast iron |
| Valve Seats Machined: | Yes |
| Valve Seat Machine Style: | 3-angle |
| Valve Seat Material: | Ductile iron |
| Steam Holes Drilled: | No |
| Oiling Style: | Through pushrod |
| Machined for O-Ring: | No |
| Heat Crossover: | No |
| Quantity: | Sold individually. |
| Calculator | Compression Calculator |
Description
Chrysler 400:Intake - Fel Pro 1216
Exhaust - Fel Pro 1414
(May need a small amount of trimming)
Chrysler 318 - 360: (PCE281.1773) Cast Iron
Intake - Mopar #4876049
Exhaust - Mopar #MS95480
Chrysler 318 - 360: (PCE281.1654) Aluminum
Intake - PCE349.1010 or FelPro 1213
Exhaust - SM3275 or Felpro 1413
HEAD GASKETS
The PCE281.1776 4-cyl. head is designed around an OEM head gasket. Use Mopar # P4452006. We recommend you use Fel Pro head gaskets under our Speedmaster PCE281.1728, PCE281.1731 & PCE281.1733 heads. Use Fel P5ro #1009 or 1105 (big bore) On Speedmaster PCE281.1773 we recommend the Fel Pro #519SD ( on Magnum Engines), or #1008 (on LA-series Engines). For the new Speedmaster PCE281.1654 Aluminum heads, we only recommend using Speedmaster PCE348.1010 or Felpro #1008 head gaskets.
HEAD BOLTS / STUDS
For the PCE281.1776 4-cyl. head, use ARP #241-3701 (bolts) or #241-4701 (studs), and follow ARP"s recommended torque values. Also, make sure you follow the OEM torque sequence! For the PCE281.1728, PCE281.1731 and PCE281.1733 use Speedmaster head stud kit PCE279.1018. Torque to 65lbs. using high pressure Moly lube on the threads and under the heads. The Arp #"s for the Big Block 440 heads are #145-3609 (bolts) and #145-4206 (studs) For the Small Block Chrysler heads, use Speedmaster PCE279.1017 head stud kit and torque the heads to 65lbs with Moly Lube.
SPARKPLUGS
For the 4-cyl. Chrysler head, use the following: Autolite 65, or AP65 Champion RN12YC or 3405 NGK GR4 or GR4GP
For the V8 Chrysler heads, the following is a small list of spark plugs you can use: NGK - BCPR6ES, R5671A-7, R5671A-8 Autolite - 3923, 3924, AR3933, AR3934 Champion - RC12YC, RC10YC4, RC9YC3
Remember that you need a COLDER plug when you make more power, ie. N2O, turbo and Supercharging
replicaracer43
Grumpy Old Man
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Same castings
replicaracer43
Grumpy Old Man
- Joined
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This is a china magnum head, same castings regardless of who you buy them from. This particular head was just a spare "R&D" head, and the 2.02 port was a really quick seat cut, multiple angles, bowl opened up, and 15 minutes of port work. It's been a few years, but I recall it being in the 270s cfm range at .550 or close. Could have been .500 lift.
PRH
Well-Known Member
Seems like I recall “Moparofficial” buying a pair of SM magnum heads, and what they initially sent him was two heads that weren’t a matching pair.
I’m pretty sure there was a thread on it…….. with various stages of prep.
I’m pretty sure there was a thread on it…….. with various stages of prep.
Cast iron can look so pretty after being ported. Thanks.
PRH
Well-Known Member
393foureyedfox
Well-Known Member
BINGO!
Thats the problem I am suspecting. Noticed a 'miss' to it recently, showing signs of a burnt valve on driver's side. Once I get it apart, I would bet there's a crack in that same combustion chamber. I don't want to put yet another set of 'rebuilt' magnums on it. So it looks like I have few options. Find and rebuild a set of older EQ's, buy the newer chinesium EQ's of questionable quality/durability, or pointlessly shell out $2K for edelbrock aluminum heads for a totally stock cruiser car.
From what I've read, the old EQ's didn't have freeze plugs on the ends like magnums and new EQ's do. The problem is, when walking through a junkyard, you cant see the ends of the heads to tell what it has because there's so much crap bolted over the front of the heads. Any other tips on how to identify a set while on a complete motor. There's an old junkyard near me full of 50+ years of accumulated cars and trucks, maybe there's a set in there.
393foureyedfox
Well-Known Member
anyone got any tips/pics on how I can identify an old set of non-china EQ's still on a truck or van?
393foureyedfox
Well-Known Member
They made/make them in both LA and magnum intake patterns.
It's easy to tell the EQ new zealand from the china head when theyre off the motor. The problem is, you can't tell them apart when still on the vehicle due to all the accessories being bolted over the front of the head....unless there's some way to tell otherwise.
I reaaaaaaaaaaaaaaally don't wanna have to resort to the china casting.
It's easy to tell the EQ new zealand from the china head when theyre off the motor. The problem is, you can't tell them apart when still on the vehicle due to all the accessories being bolted over the front of the head....unless there's some way to tell otherwise.
I reaaaaaaaaaaaaaaally don't wanna have to resort to the china casting.
replicaracer43
Grumpy Old Man
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I have never seen the china versions with the LA bolt pattern.
The reason I wondered is this is the recommended gasket. I Dont use this gasket but it’s an LA Gasket right.
replicaracer43
Grumpy Old Man
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Yeah, and maybe they DO offer them in the LA pattern now, I have no idea. All I have seen up till now is the magnum pattern.
StreetSleeper
Well-Known Member
Please expand on that statement sir-was looking to try a set on a roller 318 instead of using the 302/741 roller heads.
TT5.9mag
Two atmospheres are better than one
When the eq heads moved overseas to China (from Australia) the quality went away fast. I actually don’t even think they are even the same casting but I could be wrong on that. There are plenty of threads here showing how bad these are ootb, just do a search. That’s not to say they can’t be made to work, but the cost for the machine work often outweighs just buying a better set of heads to begin with, and on top of that you have to find a machinist willing to grind on cast iron.
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StreetSleeper
Well-Known Member
I got mine assembled with everything $700 shipped years ago. Planned to go through them and then have a machine shop check them out as well.
Just bought two 318’s
A 1967 LA BLOCK with the forged crankshaft for $50 with some old/used/unused-by-me big block 346 heads and a 1990-non-magnum-roller-318 tpi top-to-A500 for $600
Was going to build both 318’s for a pair Mopars that would be setup for daily driving.
Michael Harrington
Well-Known Member
I bought a pair of Chinese heads from the same source "318 will run" did. Vega Parts and Cores. The pros? My machine shop said the guides/clearances were correct, the valve job great and quality of components very good. I had them cut down the valve guide for clearance to accommodate a higher lift cam. The cons? The ports as cast/delivered do not have the dimension and clean shape that the design intends. I remedied this by a common sense port job- the goal being restore the proper shape and have nice clean contours and surface finishes. Obviously- the bottom pic is the as delivered condition.
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If they go on sale this year for 40% off and IF they come with LA manifold bolt pattern I may buy a couple sets to play with. I’m not a very bright man.
Bobzilla
Well-Known Member
The Speedmaster heads do not have LA pattern intake mounting. The thread PRH linked is a good read on those heads and if I remember correctly, the two heads @MOPAROFFICIAL received initially were a little different, so he sent one back to get another one so they did match. I assume that means there is two foundries in China making them, or at least two sets of tooling.
I think some shops are drilling the LA pattern and selling them when they offer the current EQ castings but I have not seen any in person yet.
DumpsterFire
Well-Known Member
Between the valves? I wouldn't worry any about that
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