1.92"/1.60" Magnum R/T Cast Iron Heads, here are my initial results:

LIFT-----ASCAST--------PORTED
---------IN/EX----------IN/EX
.200"--135.6/110.4---148.4/111.8
.300"--194.9/154.9---208.7/155.3
.400"--227.4/173.5---243.2/189.1
.450"--233.9/177.3---252.5/194.6
.500"--239.4/179.4---255.6/197.7
.550"--244.9/180.8---259.1/199.8
.600"--245.0/181.8---268.4/201.2
.650"--245.0/181.8---276.0/203.2
.700"--241.5/183.2---281.2/203.2

I still have some chamber work to do, so I expect #'s can be just a hair better on the Ported Cylinder.

Not bad for a 1.92" valve. The ported .300" intake flow is the highest # I have ever seen out of any SB head ever on my flowbench. So to say the low lift is good, would be an understatement.

The exhaust is ok for what it is. MP IMO goofed up and put a magnum short turn in it instead of the true W2 turn. That coupled with a smaller and improper port exit shape will not allow it to flow quite with a true W2 head in the high lift #'s.

I'd like to see a 2.02" version to see what the difference in flow would be exactly.......

Overall, I think this may be one of the best SB cylinder heads on the market today for the $. Mancini has them for $429 each bare. The advantages of these heads may be too numerous to list, but here are some hightlights:

8mm I/E valve stems...
63 cc CLOSED chambers (good for flat tops and Quench motors)
Stock Exhaust Bolt pattern
10 bolt Magnum Valve covers, with MILLED VC rails (ie. NO LEAKS)
Re-enforced decks with external stiffening ribs
The intake port Valve Job, out of the box was in my opinion, probably the finest VJ I have ever seen on any head EVER. I sat there and stared in bewilderment when I looked at it. 6 angles, and every cut is the perfect width, perfect angle etc. BLEW ME AWAY for a MP part right out of a box. These heads are cast at the same foundry as the new W-2's, but I have had a pile of new W-2's in my hands and whoever did the VJ on these heads is not who is doing the W2 stuff. Absolutely no reason you could'nt bolt these heads on and run right out of the box.
And my favorite:
TRUE Hardened exhaust seats installed from the factory. NOT induction hardening. These are actual pressed in Hardened seats..... not only are they hardened, but the shape of them was created for airflow. ie. they are a rounded seat right up to the 45* seat. I have never seen seats like these before. Perhaps Dwayne etc. can shed more light on them? As soon as I saw the exhaust seats when I pulled the head out of the box on Thursday I was blown away.

I can't say enough good things about these heads. I still am in LOVE with the Large Port Commando for an Aluminum street head, but these have the Iron field covered. They will never flow as good as a W2 due to the pushrod pinch restricion, but there are more things to think about when trying to make power than absolute raw flow #'s. The short turn on these heads is an excellent design once again right out of the box, Brett will love how much the short turn angles down AWAY form the common intake wall. Whoever designed this head at MP, was earning their $ on this project. It took very little reworking or moving of metal from the short turn, (or anywhere for that matter) to get the #'s you see above. I am going to try to play with the short turn a little on another cylinder, but I think All I can do is hurt low lift flow from here.

OH and BTW for those of you who's minds are churning, YES these will bolt right on an LA block, you will just have to pushrod oil the rockers with an AMC lifter and run a Magnum intake manifold.

And Patrick, don't even bother asking for intake runner volumes as I hav'nt CC'd it yet. Good God I only got the head 2 days ago LOL But I know you will want to know that, and CC'ing it is in my plans if I ever feel like it here tonight.



















I think these will make "moparheads"'s little 348" stroker motor scream.

The 1.92 ints are only $374 from mancini, the 2.02s are $439, I got the 1.92s 9 months ago for $329. I'm very happy.

I'm no head expert but the friend that helped me do some minor porting was freaking at the quality of the valve job as well.

Those prices are from the latest mancini newsletter. Says Prices good thru september 31, 2003?

Those as cast #s are pretty decent. Alot better then the E-brocks(which is what I've got ) which have the 2.02 intakes of course. Interested to see what the 2.02 R/T's will do.

Looks good to me, should wake up any S/B, the factory installed hardened inserts sound like a great idea.

When I have the hardened inserts installed I use a specific cutter for the blending, have to roll the edge to the right shape, sounds as though Mopar has figured this out

The as cast exhaust flow is off the charts at 0.600"! 268.4!

Wow that's cool! I haven't had much time to let it soak in, but I am really happy with what I see so far! Yee Haw!

Ryan, moparhead wanted me to give you a new address when you ship those heads back, so that we make sure they get picked up in case he isn't home when they come....

Awesome numbers, though. I guess my mind is made up about heads for my 360.

Hi, Ryan. My friend who ported the 915s on my 340 also has done a set of those iron R/Ts for his Dakota. I'll have to check his numbers now, but his truck screams! He also was impressed. His biggest problem (he runs a Magnum hydraulic roller motor) has been getting RPMs out of the lifters. I think I have him talked into trying the Crowers, as they claim to have the high RPM problems resolved. We'll see. Good job!

-Allan

More price info.

https://secure.earnhardt.com/mymoparsearch/index.php3

1.92s P5007140 $353.05
2.02s P5007141 $396.75

This head to me seems like it would be awesome for those small bore strokers(ie. 4" crank 318 based engines). With those kind of flow numbers out of the small valve head I would think shrouding wouldn't really be that much of a concern. Now if only someone would step up and make a reasonably priced stocking piston for the combo.

from mopar performance page:

P5007140 Magnum R/T Cylinder Head - Machined for 1.92" intake / 1.625" exhaust valves.
P5007141 Magnum R/T Cylinder Head - Machined for 1.97" intake / 1.625" exhaust valves

.......

Ok I have let it soak in a bit. And did some literal cutting and pasting with your previous Mag flow numbers and some of your others (Commando, Ebrock, 596) from the past. All I can say is WOW! that low lift flow IS awesome! Heck out of the box they are flowing as well as Valcuda's 596's and just a touch behind a ported Magnum.

Now: Do you think adding a 2.02 valve would really blow the lid off the low lift numbers? Gettin' greedy here....

They seem to have a sort of bizarre (to me) flow pattern. Low lift is awesome, mid lift is good and high lift jumps way back up there. It sorta goes flat at .450 to .550 then takes off again whereas a lot of your other numbers from various heads tend to plateau at higher lifts. A more linear looking flow pattern. Is there any way to boost those mid numbers? I don't know much about porting heads and flow characterisitcs, but is seems odd that it would flatten out and then pick up again. Or is it the port is SO good at low lift that it makes the mid flatten out? Again, maybe I'm getting greedy......

Rhumba..... I can already hear the 349 running!

BTW - I got this set on Ebay for a Buy-It-Now price of $550. The last auctions I had been watching for R/T heads have all ended in the $500 range for 2 heads. Bargain stuff.

btt

For what you are doing (349") I don't think I want to even mess with a 2.02 in these heads. I still have some playing to do with the short turn shape, so We'll see where that leads to, but 208 @ .300", I really don't want to screw up that low lift...... Maybe you don't understand how good 208.7 @ .300" is on my bench...... B3Strokers W5's with a 2.08 Del West valve and 30* BC were "only" in the 205 range...... When I saw 208.7 pop up on the calculator I was quite a happy man.

Moparhead,
What has it cost you to put together complete heads? I've been watching those auctions off and on, and the guy seems to have a line on quite a few pairs at that price. I'm assuming (going from faded memory) that the Mag's use specific valve springs... locks & retainers for sure. Are the Mag RT's OK with lifts over 0.510" without any work to the spring seat area?
FWIW, these heads appear to ROCK on my Desktop Dyno 340. I thought it was pretty healthy for a low-compression engine (8.5:1, Crane HMV272 cam, 2.02/1.60 valves, pocket-ported heads similar to Steve D's in an old MM article). That configuration gives 348 HP @ 5500, 380 lb-ft @ 4000. Using W8's flow numbers, the as-cast heads give 377 HP @ 5500, 390 lb-ft @ 4000 (392 @ 4500), and the ported heads give 390 HP @ 6000, and 394 lb-ft @ 4000 (397 @ 4500). Between the flow, the bigger lift numbers, and the extra half-point of compression, that's a healthy 29 HP and 12 lb-ft bolt-on gain. Plus, it will let me bolt on my Magnum M1 EFI manifold without tweaking the bolt holes... Hmmm...
Clair

I used Hughes springs (1110) and retainers (1276), with MP keepers (p4529218), seals (p5249661) and valves (p5249875/6). With the MP retainers I was only getting a 1.595 installed height. With the hughes I got 1.64 without touching the spring seat. The hughes springs are good to .620 lift.

Springs $76, retainers $62, seals $8.28, keepers $13.92, valves $170.72.