MOPARS STAGE VI HEADS

[carbkid]

JUST PURCHASED SET OF ALUMINUM STAGE VI HEADS ANYONE HAVE ANY EXPERIENCE WITH THESE CARBKID

[Cudaloco]

I've been wanting a set, but I figured if I go with a new set of heads (I've got 908's now)I wanted something with an angled plug to bring it in the bore centerline....like the new Max Wedge StageVI. Did you get the standard or the new MW? Keep the rest of us informed on how they do, no matter which set you went with!

[Christopher]

My understanding is that these heads are no better flow wise than a stock set of 906's.I also understand that they need to be ported and the bowl area blended then they really come alive.They are a good set of heads.I also like the fact that they don't need alot of expensive parts that the Indy's do.

[carbkid]

CUDALOCO, I got the standard straight did not know about MW's till Mopar Nats but I did get them bran-new inthe box with valves for under 1400 off the internet mopar alley classifieds. Serno heads will bowl port them to flow close to stock B-1's. Need to find out cc,s to work with my 13;1 forged pop up's. I read you can mill them to at least 76cc's straight plugs will work well with my pistons w/plug notch in dome. I want to take advantage of high compressions awesome power burst.

[sanborn]

We worked a set of these several years ago with good success. Our application was oval track, yours is probably different. The location of the spark plug dictates a different approach. Use .000" deck height (with billet steel rods). Mill .100" to get the CC to about 75-76. Just clean up the combustion chamber (equalize CC), Use a dome height of .100" and closely match the dome to the combustion chamber. Use minimum valve reliefs, .040" intake and .100" exhaust clearance. This will get you in the 13.5-14 to 1 area. In the exhaust port, raise the roof .200" and form into a "D" shape. Do not touch the floor other than clean up. The port width should be 1.800". Very carefully raise the port roof in the guide area, remove as much of the guide as possible without removing strength. Use a 1.800" valve. Flow will be in the 240-250 CFM area @ 28". In the intake port, plug the oiling passage between the intake runners using an aluminum bar, oil the rockers externally. Press a stainless tube (.015" wall) into the pushrod holes and epoxy in. After porting, The divider between the ports will be .125" and will extend out to the stainless tube. Maximize "line of sight" to the valve. Again, do not cut the floor, just smooth and blend. Raise the roof about .200" all the way to the valve pocket. You will spend a lot of time removing material around the guide, but this is very important to flow. If you cas afford offset Jessel Rockers, you can widen the port even more. We used 2.200" intakes. The intake flowed 340-350 CFM @ 28". We used offst dowel pins to get the valve centerline to bore centerline. Your engine will want a 1050 dominator. We ran 32-34 degrees advance. We also modified the water flow to help cool the exhaust valves and seats. Drill a 5/8" hole between the center exhaust valves in both block and heads, restrict the flow at the back of the block with a freeze plug with a 1/2" hole drilled in it. The ports do not stall so you should be able to use .750" or more lift. Because ours was an oval track application, we used only a .680" lift for better valve spring life. These heads love RPM, plan to turn your engine 7800-7900 RPM with good power. Use either aluminum main caps or 4 bolt caps. Our engine with the heads modified as described produced 745 HP.

[Rue]

Hi dude's talkin about MP Stage VI Heads, I have a pair to put on my 440. The heads I have are P4876311. I understand that these can be bolted on to an RB without the spacer package. (at least that's what the guy said) The ones I purchased were still in the box and I had the keepers and retainers upgraded to 10 Deg types and springs upgraded for use with the P4120663 camshaft.

I have ordered P5249506 Stage VI porting template kit. In the MP Performance Catalog it states that these particular heads are "Street Stage VI" ... what does this mean? Is there differences between the Stage VI's ie. apart from the Max Wedge types etc.

I havn't a clue as to what this things goin to go like ... its goin into a backhalve 68' Dart with 5.14 gears, 4 Link and 16x33 Slicks. It's got H-Beam 4340 Rods, top and bottom Stud Kit, Holley HP950DP, M1 and MSD7AL2 etc. It should tip the scales around 3200lbs when completed. I would love to hear from others who have similar combo's. I live in New Zealand and MoPars are kinda thin on the ground here. But what one's there are here - are 'KickButt' Chryslers - no worries. Thankyou.

[DartGT66]

I have had the Stage VI's for many years. The chambers were 84-86 cc out of the box. The bowls actually have a lot of material, and it's no wonder that in stock form they do not flow more than the stock iron heads. At the time I got my heads there were no porting templates available, so I ported them without the templates. Later I bought the templates, and they matched the bowls almost perfectly. These heads were first on a mild 440, and were a big power boost over the iron heads. Some other small mods were done at the time, so I can't honestly compare them to the template ported iron heads, anyway the mph went from 109 to 116.5 mph. I think these heads are best oriented for street; there are better racing heads available that need less work to perform. I even think that in a wilder street engine the B1/BS or Indy SR heads are a better choice. Currently the Stage VI's are on a '451' short block; the spacers are history. I just didn't like the idea of spacers in the first place, the intake face angle is only 75 degrees and the spacers form a Z in to the intake port, can't be good to the flow. The angled plugs in some versions of the Stage VI's might interfere with some header designs, so a straight plug version is a safe bet. One of the features I don't like in the Stage VI's is the short valves and the small valve spring assembled height. This means that with high lift cams the spring life will be shorter than with heads with 2" assembled height. The other is the quality of the work, in my case it seemed like someone had drilled the pushrod holes with a hand drill, all were in different angles and places. They worked with a relatively mild cam and 1.5:1 rockers but 1.6:1 rockers and bigger cam needed careful checking and clearancing to be done. I hope Edelbrock can get their BB heads reday really soon, so that we could have well working real bolt on street heads for the BB's for a decent price.

[Belvedere65]

Went from ported 906s, .590 cam, TRW
12.5 pistons to StageVIs,bowls cleaned
up, gasket matched, Ultradyne .640
cam, Ross 12.5 pistons,deck height
.010. Car ran 10.90s @ 121 MPH with old combo & 850 carb. Runs 10.40s @126 MPH now, just shaking it out. Had to add Dominator to wake it up! Harland Sharp rockers hit valve covers on push rod side, changed to Cranes. Intake pushrod holes need clearancing to align with rocker.With more porting ETC. I am sure there is more there.

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BFRACN

[Christopher]

Glad all of this info is here.I have been debating on a aluminum head setup,and you guys gave me all the answers I needed.

[PRO]

The Stage VI(6) head is 78cc's(all are closed chamber).Has 210cc intake runners and are of the raised design,the exhaust port is also raised.You can mill them quite a bit as they have a .450 deck.In aluminum you save 40lbs. and gain 40hp over stock 906/452s.Stock valves sizes are 2.14/1.81. P4876311 needs no int adapter to use stock intakes.Dont confuse this with the "older Stage V(5) head,as it was a stock repacement head w/stock flow.Stage 6 definitely has a flow advantage over stock heads and if you buy P4876186 you gain 12% int and 20% exh flow.If you buy the P5249523 you get 2.18/1.81 valves and gain 20% int and exh flow.Remember the aluminum dissapates heat much better than cast iron so you can gain 1 full point of compression w/o detonation. 10.5-11.0 works well on 92 octane w/these heads.One note though if you have a short duration cam dont exceed 10.5.Go Fast....PRO...

[DartGT66]

Pro, have you measured nay Stage VI's? Mine were 84-86cc out of the box, and I have heard about even bigger chambers. The exhaust ports have been raised more than what the advertisment tells, I once measured the bolt hole distance from the deck but don't remember it. They were raised way more than the 1/8" that the factory tells. I assume you base your 40 hp power advantage to the wedge crate engines? Whenever you read the 'articles' (=advertisments) in the mopar muscle where mr Shepard tells you how good the MP parts are, he always reminds the fact that the Stage VI's have a lot smaller ports than for example the Indy SR heads, 210 vs 260 cc, and therefore a better velocity. I think he doesn't remember to tell the fact that the Indy heads have longer valves, bigger short side radius and overall wider head, and therefore much longer ports. The Indys have raised ports too, but you don't have to use any intake spacers with them. So to compare the velocity thing you should add the spacer to the intake port displacement of the Stage VI. I just measured it and it was 38cc, this takes the port to 248 vs 260. When you consider the effect of the 1/2" longer valve of the Indy and the higher bowl, you can just guess the velocity differences. And by the way, I also have measured the ineake poerts in my Stage VI's, and they were 210cc after porting. And a lot of material was removed, I think they were about 200 cc out of the box.

[PRO]

Dartgt66,I'm just quoting MP on their spec,s,inaccurracies in cc measurement though is a given in my book,all burrettes are not made with the same precision as are not all chamber plates,to read 84-86cc when MP says 78 might on paper seem like a big difference but 6-8ccs is in reality about 4 drops of water,the most accurate burrete I've found has the smallest diameter of 1" and has the graduations molded in the glass.When I compare it to one that is 2 1/2" dia. and has painted graduations ,theres a 5cc difference at 100cc's.MP states 40hp gain and 2 fellow racers gained more than that when changing from stock 452s to stage VIs,both did slightly clean up the bowls as recommended by MP,1 car took .4 off his et and one .6(he also went to 2" headers vs 1 3/4")so I believe 40hp is actual.The exhaust port is substanstially raised as you said,MP claims a 70% flow increase!!! The P4876311 does not require an intake spacer when used on a RB,all other Stage VI heads do(there are 8 different Stage VI heads),I'm sure they had the average street/strip low dollar guy in mind here and as far as intake runner length again cc measurement isnt always an exact science especially on "cast" items.Its always a good idea to check and double check anything stated by piston/head/ etc manufacturers.What gains did you see with your heads? and what do you think of the int gasket end rail spacers?are they leak prone?....PRO...

[This message has been edited by PRO (edited January 08, 2000).]

[DartGT66]

I'm not using a burette when measuring the combustion chambers, I'm using an other medical instrument, I think more accurate thing, but I don't know what it is in English. I also doeble check the result using a weight scale accurate to 0.5 gram; I use water with a drop of soap to remove the tension, and since the water weighs 1 gram / cc I can weigh how much water I have put to the chamber, both systems give the same results so I think it's pretty accurate. I have not dealt with the end spacers, in my 440 stage VI I used self made spacers and a modified bath tube gasket to seal the lifter galley. I think that RTV seals almost anything and I use it enough. I can't straight compare the results with the Stage VI's since there were some other changes too. With the pocket ported iron heads the cam was a MP 280 hydraulic, with the Stage VI's a custom mechanical with 262 advertised degrees, but more lift than the 280 cam had. There was also more CR because I milled the block, about 9:1 with the iron heads and little over 10:1 with the Stage VI's. The iron heads were with M1 single plane and 900 cfm Pro-Jection EFI, and the Stage VI's with the same intake and a modified 3310 Holley. Also with the iron heads I had a 2500 stall converter and a 3500 with the Stage VI's. The gear ratio was 3.23 in both cases and the tires the same, 205/75/14 BF Goodrich whitewalls. So traction was pretty limited. With iron heads the car run 12.94/109 mph and with the stage VI's 12.16/116 mph. By the way, I just put together the 'no buck 318' It's a stock 318 short block with the pistons the usual .085" in the hole. I use '70 wintage 318 heads that had huge 71 cc combustion chambers before milling. After .080" cut the chambers were 59cc. Except the one with a new seat ring, 3CC less. The exhaust valves are pretty deep and I had to port the chambers a lot to get them up again, that's why the cc's are pretty big. I have another virgin '83 set that measured 68cc. Anyway the CR is now 8.7:1 with the Victor composite gaskets, and with that amount of milling! My part supplier didn't have the 260/268 cam in stock that I would have liked to use, so I took the one step bigger 268/272 cam and installed it 4 degrees advanced to 104 degrees. I first thought about shimming the rocker shafts for pre load, but since the valve stem heights varied a little, I shortened the stock pushrods in a lathe. Those things are pretty hard stuff. Although I intended to use the 1.5$ quadrajet with the engine, the plan may change. I just got a Holley 6210-3 spread bore free, and will propably use that istead. No idea where has it come from, but it seems to be a replacement carb and even the choke systems etc. seems like a bolt on. But we'll see, more on that later...

[Rue]

Advice please ... I have a pair of Stage VI Heads (P4876311). I ordered a set of Stage VI Porting Templates (P5249506) from out of the MoPar Performance Catalog. I have recieved the templates and upon reading the Instruction Sheet it states that "These templates can only be used on Stage VI aluminum heads, P4529335; they will not work on any other cylinder head, cast iron or aluminum"

What?!!

I surmise that because the Stage VI P4876311 is one of MP's latest offerings, and that the template kit P5249506 was offered before the advent of these particular heads that ... they will be Ok for using on my heads.

Comments?