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Magnum R/T Heads........ Flow Results

Posted By: RyanJ

Magnum R/T Heads........ Flow Results - 09/06/03 08:16 PM

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.
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/06/03 08:55 PM

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.
Posted By: RyanJ

Re: Magnum R/T Heads........ Flow Results - 09/06/03 09:01 PM

Quote:

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.




Where are you seeing this? This is the price I just found on their website:

MOPAR - Cast Iron Head Casting (1.92 Int. - 1.625 Ex.)

SOLD INDIVIDUALLY


MOPP5007140$429.95

http://store.yahoo.com/chucker54/martcyhe.html
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/06/03 09:15 PM

Those prices are from the latest mancini newsletter. Says Prices good thru september 31, 2003?
Posted By: d4rt

Re: Magnum R/T Heads........ Flow Results - 09/06/03 10:02 PM

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.
Posted By: FastOne

Re: Magnum R/T Heads........ Flow Results - 09/06/03 10:17 PM

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
Posted By: d4rt

Re: Magnum R/T Heads........ Flow Results - 09/06/03 10:50 PM

The as cast exhaust flow is off the charts at 0.600"! 268.4!
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/07/03 12:17 AM

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!
Posted By: 65Dart270

Re: Magnum R/T Heads........ Flow Results - 09/07/03 12:23 AM

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.
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/07/03 01:08 AM

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
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/07/03 01:24 AM

More price info.

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

1.92s P5007140 $353.05
2.02s P5007141 $396.75
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/07/03 01:49 AM

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.
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/07/03 02:49 AM

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

Posted By: RyanJ

Re: Magnum R/T Heads........ Flow Results - 09/07/03 04:17 PM

.......
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/07/03 07:35 PM

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.

Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/08/03 03:03 AM

btt
Posted By: RyanJ

Re: Magnum R/T Heads........ Flow Results - 09/08/03 03:16 AM

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.
Posted By: Clair_Davis

Re: Magnum R/T Heads........ Flow Results - 09/08/03 03:42 AM

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
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/08/03 04:16 AM

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.
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/08/03 12:17 PM

Quote:

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.




That's kinda what I thought later on. I just get greedy sometimes.

Thinking about what I said about flattening out..... I think that is more because the lift figures change to 0.05" increments. If you just look at the 0.1" increments it looks fine. Sorry if I ask dumb questions, I'm still kinda new to head flow stuff.
Posted By: clonestocker

Re: Magnum R/T Heads........ Flow Results - 09/08/03 12:58 PM

Ryan, What kind of HP do you think those heads could support? matt s
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/08/03 02:59 PM

For comparison's sake:

LIFT--R/T AC--------R/T PRTD----MAG PRTD---"596"---"587"---EBRK---COM---W2AC*--W2PRTD*--W5PRTD*
---------IN/EX----------IN/EX
.200"--135.6/110.4---148.4/111.8---132.8/115.6---120.1---135.2---135.2----140.1----121.7-----127.2------146.6/102
.300"--194.9/154.9---208.7/155.3---196.0/156.6---182.9---198.7---197.7----202.5----181.7-----184.1------210.5/145
.400"--227.4/173.5---243.2/189.1---225.0/172.2---225.6---239.8---233.2----246.4----228.9-----232.1------262.9/204
.450"--233.9/177.3---252.5/194.6---238.1/174.3---238.1---253.9---245.0----266.0----248.1-----254.5---------N/A
.500"--239.4/179.4---255.6/197.7---250.5/176.6---241.5---258.4---255.3----277.1----262.5-----273.7------301.9/220
.550"--244.9/180.8---259.1/199.8---257.1/178.0---247.0---264.9---265.7----281.2----268.9-----289.7------309.1/224
.600"--245.0/181.8---268.4/201.2---259.1/180.8---248.8---254.6---274.6----282.9----265.0-----302.2------315.7/229
.650"--245.0/181.8---276.0/203.2---259.1/180.8---N/A----N/A-----279.1----283.0----253.2-----302.2------315.7/231
.700"--241.5/183.2---281.2/203.2---259.8/180.8---N/A----N/A-----283.9----285.3----249.8-----280.0------312.2/232
* taken from Shady Dell Speed Shop site
AC = As Cast
PRTD = Ported
Posted By: patrick

Re: Magnum R/T Heads........ Flow Results - 09/08/03 05:18 PM

Quote:

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




that was ported....

you read my mind Ryan, well, it's kinda nice to see intake port CC comparisons, too to get an idea of port velocity, especially if one is using these on a small motor (:

I assume you used a 4" bore plate? are the exhaust numbers without a flow tube?

horsepower? if you're using a cam in the .600" lift range, I'd say you'd support ~550 max HP.

ryan- you also forgot to mention magnums have a 1.6 ratio rocker standard
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/08/03 05:42 PM

Quote:

you'd support ~550 max HP


Posted By: d4rt

Re: Magnum R/T Heads........ Flow Results - 09/08/03 05:51 PM

Quote:

Quote:

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




that was ported....






I was just giving Ryan a friendly ribbing for a minor typo. The 268.4 that is the ported intake flow at 0.600" was over in the exhaust category with the "as cast" numbers. He seen it and fixed it. All is good. Once again those are some impressive heads. Both as cast and ported. Wish my E-brocks flowed like that out of the box.
Posted By: RyanJ

Re: Magnum R/T Heads........ Flow Results - 09/08/03 05:59 PM

Quote:



you read my mind Ryan, well, it's kinda nice to see intake port CC comparisons, too to get an idea of port velocity, especially if one is using these on a small motor (:

I assume you used a 4" bore plate? are the exhaust numbers without a flow tube?






I never flow exhaust with a tube, well OK, a few times and when I do I will ALWAYS mention the #'s are with a tube. Only times I want to flow with a tube, is to get a better idea of true percentage of exhaust flow for cam selection.

Yes 4" bore.

Still Hav'nt CC;'d it yet LOL. I know I'm lazy..... either that or I just find CC'ing heads is a PITA LOL.

Volume does'nt always tell EVERYTHING about velocity. Look at a W5.... Large runner (~215-220 CC ported), and probably has best velocity across the short turn of any SB head out there (59*) You can tell this head has good velocity by the Low lift #'s it put up. Generally it takes big velocity to make big #'s at low valve lifts.
Posted By: RumbleVid

Re: Magnum R/T Heads........ Flow Results - 09/08/03 06:04 PM

Actually, the stock magnum rockers that I've checked have been 1.67-1.68 to 1. But offset that fact with the 59 degree lifter angle and it's pretty much a wash so you might as well spec. lobes using the 1.6 figure.

Posted By: patrick

Re: Magnum R/T Heads........ Flow Results - 09/08/03 08:11 PM

Quote:

Still Hav'nt CC;'d it yet LOL. I know I'm lazy..... either that or I just find CC'ing heads is a PITA LOL.

Volume does'nt always tell EVERYTHING about velocity. Look at a W5.... Large runner (~215-220 CC ported), and probably has best velocity across the short turn of any SB head out there (59*) You can tell this head has good velocity by the Low lift #'s it put up. Generally it takes big velocity to make big #'s at low valve lifts.




true about the port volume, but generally speaking, if you have a port flowing 240CFM with a 165cc port and a port flowing 240cfm with a 220cfm port, it's pretty easy to figure out which port will yield crisper throttle response and overall streetability. no biggie, although it will be curious to see if these things are alot larger than a standard magnum. anyone know how the aluminum magnum heads compare to the stock iron and R/T's?
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/08/03 08:21 PM

boxcar, I'm curious, when I checked the 3 set of magnum rockers I have here (at the valve) I get more like 1.56 to 1.57 average ratios, I am assuming you are just checking the pure rocker ratio to get your rather high figures? And that the severe lifter angle and the higher than rated "rocker" ratio cancel each other out and net about a 1.6 at the valve????

Just trying to sort out all the different info out there floating around about the magnum heads/valve gear, it seem like everyone I talk to tells me something different
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/08/03 09:51 PM

OK what about cam recommendations? I'm thinking a fast ramp hydraulic like a Hughes or Comp XE.

These heads
3.58" stroke cast MP crank
9.5-10.0 compression
Performer RPM intake
Holley 3310
3.91's
'68 B body
3800 converter
Posted By: patrick

Re: Magnum R/T Heads........ Flow Results - 09/08/03 10:57 PM

you looking for streetable manners, good vacuum? what block?
since you're making a stroked 'teen, I'd look at an '85 up block and a hughes HER2836AL roller, meeself, maybe the HER3644AL, if you want an off the shelf grind, and reuse the stock lifters. the wide LSA should give decent idle/vacuum at idle. or contact scott brown for a roller cam.

if you're using an older block, and you want good street manners, comp XE268 or XE275HL, or a hughes HEH 2328 AL or HEH 2832 AL for off the shelf, or again call scott brown at straightling performance.
Posted By: TC@HP2

Re: Magnum R/T Heads........ Flow Results - 09/08/03 11:04 PM

Ya know, after seeing so many people slamming MP for parts quality, it is real nice to see a post about something they have not only done right, but exceeded expectations on.
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/09/03 12:14 AM

Quote:

Ya know, after seeing so many people slamming MP for parts quality, it is real nice to see a post about something they have not only done right, but exceeded expectations on.




Totally agree here!
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/09/03 03:24 AM

Good street manners need not apply. No vacuum accessories on this car. Manual brakes, manual steering, no AC, etc.... This is my fun car that I drive some on the street, but like to take to test-n-tune / grudge racing almost weekly. I can deal with some not so friendly street manners to have great straight line performance. This is a 68 block, and, so far, I don't really want to do the roller thing. Although, it doesn't seem like a big deal to put roller lifters into an old block though. Just need 3 holes drilled and tapped in the lifter valley to hold the lifter retention spider. Heck you could probably JBWeld some bosses in there to do that. Unless there are differences I don't know about. (wouldn't be surprised.)

-James
Posted By: RumbleVid

Re: Magnum R/T Heads........ Flow Results - 09/09/03 05:15 AM

360Dust, yeah they cancel each other out to end up at around 1.6. The lifter bank angle gives up around .010 lobe lift. Were you checking with a solid lifter? Moparhead, the stock hyd. roller lifter anti-rotation hardware needs the top of the lifter bosses milled flat, in addition to the "spider" mounting bosses. I've been running a set of ported R/T's on my 408 for a couple of years now and have been very happy with them.
Posted By: 4speeds4me

Re: Magnum R/T Heads........ Flow Results - 09/09/03 09:51 AM

Quote:

Quote:

Ya know, after seeing so many people slamming MP for parts quality, it is real nice to see a post about something they have not only done right, but exceeded expectations on.




Totally agree here!




Me too...with a caution...This isn't the only thing MP has done right, but quality control has a tendency to SUCK! Joe Blow buys a Crate motor and it's got so many issues it has a standing offer from the Jerry Springer Show, and then Joe Schmo buys one and it runs so hard he's winning races like there's no tomorrow.

I really hope these heads don't turn out to be another one of those cases...
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/09/03 01:38 PM

Quote:

the stock hyd. roller lifter anti-rotation hardware needs the top of the lifter bosses milled flat, in addition to the "spider" mounting bosses.




Ahh, didn't know that. If you are having machine work done to the block, couldn't they just set it up and mill 'em off flat?
Posted By: AndyF

Re: Magnum R/T Heads........ Flow Results - 09/09/03 04:25 PM

Sounds like a good head. So a couple of questions: There doesn't seem to be a lot of Magnum intake manifolds on the market so isn't that drawback to using these heads?

Also, given the intake limitations, is this head a better head for a stout street small block than the large port aluminum commando heads?
Posted By: RyanJ

Re: Magnum R/T Heads........ Flow Results - 09/09/03 05:21 PM

Quote:

Sounds like a good head. So a couple of questions: There doesn't seem to be a lot of Magnum intake manifolds on the market so isn't that drawback to using these heads?

Also, given the intake limitations, is this head a better head for a stout street small block than the large port aluminum commando heads?




Large Port Commando is still my favorite "street" type SB head. It is head and shoulders above everything else in terms of flow and quality of casting. Only drawbacks it has are the W2/5 race rocker setup and they are more $ than a Magnum R/T or a set of E heads.


OH and here are the new #'s hot off the flowbench, on the left is the intake #'s from before and on the right is a mirror port with the short turn layed back more as I had discussed previously.....

LIFT----OLDPORT-----NEW
.200"---148.4-----137.3
.300"---208.7-----202.5
.400"---243.2-----242.2
.450"---252.5-----248.4
.500"---255.6-----256.0
.550"---259.1-----265.0
.600"---268.4-----273.3
.650"---276.0-----279.1
.700"---281.2-----285.7
.750"---N/A-------288.8

Did exactly what I expected, lost low lift and traded it for gains in the high lift.

I'll be sticking with my original short turn shape on the next 6 cylinders.....
Posted By: RumbleVid

Re: Magnum R/T Heads........ Flow Results - 09/09/03 05:26 PM

Any LA intake can be used on the magnum heads. they just need to be modified a little. I have an airgap on mine at the moment.
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/09/03 05:52 PM

Here's a shot of my modified rpm air-gap with r/t heads.

Hard to see but I was able to use a 318 throttle bracket and 318 1 piece kickdown linkage. With the small pedestal washers I made and bending the mounts on the throttle bracket from 45 to 90 degrees and some bending of the kickdown it works great. Saved on buying a lokar.

See attachment

Attached picture 399804-94210011.jpg
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/09/03 06:13 PM

Pic?

nevermind still getting used to the attachment thing.....
Posted By: 65Dart270

Re: Magnum R/T Heads........ Flow Results - 09/09/03 07:51 PM

Looks great, now all I need are the Magnum R/Ts...and the Air Gap...
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/09/03 08:03 PM

Here's another attachment. Note no freeze plugs on end of head, dry threads all the way around.

Attached picture 400011-54340005.jpg
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/09/03 08:04 PM

How did you modify the intake for the vertical bolts used on the Magnum heads?
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/09/03 08:09 PM

Quote:

How did you modify the intake for the vertical bolts used on the Magnum heads?




7/8" aluminum tubing, a bandsaw, a drillpress, and JB Weld.
Posted By: ChrisLib

Re: Magnum R/T Heads........ Flow Results - 09/10/03 02:33 AM

Quote:

Here's a shot of my modified rpm air-gap with r/t heads.

Hard to see but I was able to use a 318 throttle bracket and 318 1 piece kickdown linkage. With the small pedestal washers I made and bending the mounts on the throttle bracket from 45 to 90 degrees and some bending of the kickdown it works great. Saved on buying a lokar.

See attachment



I have been having a heck of a time getting the kickdown on my truck "just right",It has a crate motor and those darned vertical intake bolts, makes the angles all screwed up on the K/D bracket. Do you have any more pics of the K/d brkt?
Posted By: Clair_Davis

Re: Magnum R/T Heads........ Flow Results - 09/10/03 04:24 PM

I’m going in reverse with my intake… Magnum M1 EFI going on to my LA heads. Granted, this is to make my life easier on the EFI project, but I’m planning a Magnum R/T upgrade in the not-too-distant future. This way, I’ll be able to re-use the same intake for both sets of heads. FWIW, it appears after drilling the first hole, that there’s plenty of meat for two sets of bolts, and that the only thing that really got changed on the intake casting was the addition of vertical bosses for the Mag bolts. The funky angle that the LA intake bolts are set at is still cast in to the base of the intake, so that when you drill new holes, the heads of the bolts will sit flush with the surface of the intake. Near abouts as I can measure, this angle is 7.5 degrees UP from perpendicular to the intake face of the head. Anyone have a REAL number for this?
Also, while poking around trying to find an internet source for this data, I found a place that makes what appears to be an RPM knock-off that has BOTH intake bolt patterns on it. Google for “Dodge Magnum intake manifold bolt angle”. If I can find the real link this evening, I’ll post it.

Clair
Posted By: worthywads

Re: Magnum R/T Heads........ Flow Results - 09/10/03 11:41 PM

Quote:

Quote:

Here's a shot of my modified rpm air-gap with r/t heads.

Hard to see but I was able to use a 318 throttle bracket and 318 1 piece kickdown linkage. With the small pedestal washers I made and bending the mounts on the throttle bracket from 45 to 90 degrees and some bending of the kickdown it works great. Saved on buying a lokar.

See attachment



I have been having a heck of a time getting the kickdown on my truck "just right",It has a crate motor and those darned vertical intake bolts, makes the angles all screwed up on the K/D bracket. Do you have any more pics of the K/d brkt?




I don't have any more pictures, but one thing I ended up doing (and you can see it in the picture, shiny chrome nut) is on the slotted rod that attaches to the carb I added a nut/bolt/washer to allow additional "lengthening" of the kickdown. It wasn't long enough as is and that was my simple solution.

The only modification to the bracked was bending the 2 mounting tabs from 135 degrees to 90 degrees. It's a 1970 318 bracket. And yes the angles aren't pretty.

Maybe that will help.
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/16/03 02:01 PM

OK, you guys have convinced me to switch from my mildly ported 2.02 j heads to Magnums on my mildly built stock short block 360. I found a complete set of 98 R/T heads with 30K on them.

What do I do about pushrods for a hydralic cam?
Anyone make them for this conversion?

Are the stock roller cam springs adequate for my XE 268H cam reving to about 5700 RPM?
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/16/03 02:23 PM

FIRST AND FOREMOST!

Dakota R/T & Durango R/T trucks DID NOT come from the factory with these heads! They have standard Magnum heads, a different cam and different computer configuration than standard trucks.

Now:

Special hydraulic pushrods
Designed to allow the use of magnum heads and
standard magnum rockers on standard 1967-91
"A" short block/engines.
5007477 Magnum head on standard "A" block-set of 16
(7.625") $38.50

This is from Moparts Racing

Make sure your lifters are AMC style lifters. If they have the little holes in the cups to let oil pass throught to the pushrods and eventually to the rockers. I know the last set of CompCAMS lifters I bought had the holes as well as the same part number for an AMC.

-James

Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/16/03 04:00 PM

Good point on the standard Magnum heads. Is this worth doing with standard Magnum heads? My combo is stock 360 (low comp) with XE268 Hydrailic cam, wieand intake and Demonsizzler TQ plus TTI headers and 2.5 exhaust. I currently run J heads with 2.02/1.60 and home bowl port. I shift at 5600 rpm. I figured the compresiion gain would be worht the swap?
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/16/03 05:10 PM

Posted By: patrick

Re: Magnum R/T Heads........ Flow Results - 09/16/03 07:09 PM

Quote:

Good point on the standard Magnum heads. Is this worth doing with standard Magnum heads? My combo is stock 360 (low comp) with XE268 Hydrailic cam, wieand intake and Demonsizzler TQ plus TTI headers and 2.5 exhaust. I currently run J heads with 2.02/1.60 and home bowl port. I shift at 5600 rpm. I figured the compresiion gain would be worht the swap?




stealth or action plus? if it's the action plus, I'd go with a stealth or RPM/air gap. with the magnums, I'd do a good 3 angle job and a little bowl port/cleanup as well. you'll gain alot on the compression, and you'll get the same flow with a smaller valve/slightly smaller port, which should really help low end torque.
Posted By: dogdays

Re: Magnum R/T Heads........ Flow Results - 09/16/03 07:46 PM

"AMC style lifters" This sounds like a hard-to-find part, doesn't it?
BUT
If you go to the lowbuck auto parts store and ask for a hydraulic lifter for a 318, unless all you get is a blank stare, or a hydraulic roller if the person behind the counter knows what a lifter is, you will in all likelihood get a 2011 lifter. This is the "one size fits all" lifter which works on both AMC and Mopar applications, and is in fact the "AMC-style lifter" that is needed for the Mag head conversion.
What's my point? Almost every aftermarket 0.904" diameter lifter that you will ever see is the "AMC-style lifter." They are actually hard to avoid if for some reason you do not want the little hole in the cup on top of the lifter! I did some market research on this last year and if you can find the no-hole lifters they cost about twice what the other lifters cost. So if all that is holding you up is the lack of an "AMC-style lifter" you don't have an excuse any more.

R.
Posted By: Anonymous

Re: Magnum R/T Heads........ Flow Results - 09/17/03 04:57 PM

It's actually an older Weiand intake that I haven't been able to identify. It has a spreadbore configuration like an Action Plus, but large runners like the Stealth. I like it because it has large runners but I can run my TQ without an adapter plate.
Posted By: patrick

Re: Magnum R/T Heads........ Flow Results - 09/17/03 05:07 PM

if it's got 360 sized ports, I'd keep it then...
Posted By: WilliamHall

Re: Magnum R/T Heads........ Flow Results - 09/17/03 06:14 PM

Does the 360-380hp crate motor use RT Heads?
Posted By: StricNine

Re: Magnum R/T Heads........ Flow Results - 09/17/03 06:19 PM


WilliamHall: No, it uses regular Magnum heads.


David
Posted By: BBR

Re: Magnum R/T Heads........ Flow Results - 09/24/03 06:51 PM

btt for some guys asking questions
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