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I'll wait to see if he chimes in with some Commentary.

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Why do guys do this??????? The old bait & switch. SHOW US SOME NUMBERS ALREADY!!


Pretty please?

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What size bench does Chapman Flow on, and what is Dwayne using these days? I do recall Dwayne telling me ages ago, but I can't remember everything, lol. I do recall Dwayne's bench being conservative regardless.
AL...

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O.K. I'm probably the only person who doesn't know this, but WTF is a Chapman head? How much do they cost?

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CNC ported MP stage 6 head , cost switching to B1's would be cheaper

i have a set also ...

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O.K. I'm probably the only person who doesn't know this, but WTF is a Chapman head? How much do they cost?

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well Ken after talking to you at the Grove i'd hafta say the only way a set would ever be found on your car is if someone gave em to ya.

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What size bench does Chapman Flow on, and what is Dwayne using these days? I do recall Dwayne telling me ages ago, but I can't remember everything, lol. I do recall Dwayne's bench being conservative regardless.
AL...

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actually the better question would be..
what size bore fixture was used?
what was the elevation, pressure?
airflow temps?
;these would be the biggest factors in seing different #s from one to another.
you have to understand conservative is relative.
now this is directed at no-one, just in general.
people have to understand.
proper bore fixture diameter, if not the same will show different results,too small for the heads application "can cause the stall" or lower peak #s
elevation in reguards to sea level is one of the biggest factors for the difference.
id say thats the biggest source of the confusion.
next would be the correction factors.to try to compensate..
just my 2 cents.

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everyone is an expert

i think you need to do a little more homework on flow bench design before you start casting a shadow of doubt about whether or not flow data is directly comparable or not.
not all flow bench designs require corrections for weather variables.

from the Superflow website;
"the flowbench measures the ratio of the pressure difference across the orifice, to the pressure across the valve. Both the orifice and the head see air at the same temperature, density, and humidity. A flowbench of this design provides results, which are independent of the atmospheric conditions. In fact, if you put a cylinder head on the flowbench, and run it at a barometric pressure of 24" of mercury, and run it later at 29" mercury, with the same cylinder head, you will get exactly the same flow numbers. You don't have to correct for temperature or correct for pressure. "

my own personal opinion is that you cant directly compare results from any two flowbenches as being 100% equal.

i dont really have anything else to add at this point about these heads.
i was hoping to get some measurements off them today, but as it turned out, i was on the dyno all day.

the bowls "appear" to be pretty generous on both the intake and exhaust side, and there is much more height on the intake short turn than on the original VI's like what were used for the EM470 motor.
i'll paw through my notes and see what the best port on the EM470 heads was for comparison.

as for the port stalling at high lifts....thats more of a "welcome to my world" kinda thing.
the short turn doesnt "feel" like one that would make it to .800 lift on my bench without stalling...and it didnt.
on a bigger bench...who knows.
regardless....these things are pretty impressive in the mid-lifts.
they really put the hurt on the SR's, 440-1's, BD's, in those lower mid-lift ranges....and are impressive up top too.

the only concern i would have with these on a larger CI motor like what Wize is going to build is the port cross section of the exhaust port.
it appears to be a fair amount smaller than a good flowing SR or 440-1....and sometimes when there is a lot of volume to deal with(like on a large displacement motor)....they just need to be bigger.
from the looks of the flow numbers for all 3 versions of the Chapman VI's on the Chapman site, the exhaust ports are done the same for all of them. im sure its overkill for the small version, really good on the middle version....but i feel is a tad small for this version.

i'll have to test it with a 2" tube on it to see how it responds.

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Another one....

I call this the 'Welcome to Hooters!!' shot!!

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the key is not all. some do , i wasnt refering to your bench as incorrect/
just that to compare his flow numbers to someone elses #s done elsewhere shouldnt be taken so literally.
and that some bench's do require correction factors/math
they should focus/measure the change

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but IMO flow #s that get posted should be accompanied by the other data.
like what i mentioned in 1st post..you do agree that it makes a difference yes?
bore fixture size's are important due to valve shrouding.
and temp,baro make a diff. and should be considerd
since none of this ever gets posted along with the #s then the differences would be relative

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The only downside is they would probably cost more than a set of B1's, or come close anyway.
AL...

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no the bare heads alone cost more than the B1 sale at the end of the year

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i dont know Ryan.....i still think that $4400 for a set of bare castings that arent vastly superior to some of the other stuff out there that costs a lot less $$$, is a big chunk of change.

where is the special niche that these heads are going to fill that will justify the cost?

these heads arent going to make the "big" power numbers on a large cube motor....not like a set of B1's or 572-13's will....they just arent big enough.
so, why tie up $6500 in some heads that arent big enough to support the big cubes, and build a 500"+/- motor, when for the same kind of total cash outlay you could build a 540 or 572 with different heads, and make more power.

i think in a 450-500ci package they are going to be great heads....with more difference than some of the other offerings showing up on the lower end if that CI scale.
at 500", i think the std B1's are going to make more power....at a much lower cost.
and, they dont need a $2200 CNC program porting job done to them to get 380+cfm from them(i have a set here that had a quick home port job done to them that flow over 380cfm).

so, regardless of how much R&D went into them, and the fact that they flow very good numbers for their runner size....the fact is that on a dollar per HP scale, they dont really stack up all that well.

B1 Ken has an 875hp motor using std B1's that he has about $9000 into, for the whole motor.
if you start out with the Chapman VI's and end up having $6500 in the top end....that only leaves $2500 to build the rest of the motor.


IMO, MP missed the mark on these heads by making them so expensive.
the object is to make parts that people will buy. if you price things too high, they dont sell.

there just isnt any justifiable reason why a std stage VI head should cost any more than a B1 head or an Indy head....it certainly isnt made any better.

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LOL Again, I'm not arguing that they are a good value per $ (IMO they are'nt), all I wanted to point out was that it is more or less Chapman setting the price on them not MP. And if it was MP's bright idea to come out with this head, full knowing what it would cost in the end, then you are right, they missed the boat once AGAIN at what customers are really going to go buy and want. Then again they miss the boat every day though, so should'nt be surprising.

But my guess is with a grand total of 35 CNC heads currently on the shelf, they will in time sell them all. They've had NUMEROUS NUMEROUS Chapman CNC W7/8 heads with special part #'s over the years with outrageous prices, and stuff always ends up selling out eventually. The set of 8's I'm trying to snag right now were a low production Chapman CNC head that has a MP CNC part #, list price was $3250 on them each.

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i'll repeat it again , chapman is not a source for the head , i am going to go out on a limb here and guess that MP is marking up what chapman is charging for the CNC work .

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No, the heads are coming out of the Zeus Foundry, under MP contract, designed in the Chrysler Technology center, using a MP casting core box....The heads are MP DESIGNED castings, I don't know who is doing the initial Machining, it used to be Arrow or Galaxy that was doing stuff like the plug holes, bolt holes etc, but Chapman is installing the guides and seats and doing the CNC work......I'll stand by my statement that MP is not marking up these heads much at all, when all is said and done between modifying the cores, doing a new casting run at Zeus etc etc.... These are such a limited run head, there is no way they will pocket dime one on these heads, they will be a net loss for Diamler IMO when all is said and done.

I can't say for 100% sure what if any markup tehre is on those particular heads but MP made the mistake of inadvertently allowing a Chapman Machining Invoice attached to the side of a box of CNC W9's I had here and based on the MP pricing of those heads, they were not marking them up much at all... It's just one of those deals where, if I knew EXACTLY how much they had in the bare castings, between engineering, R&D, Paying the foundry, and paying for initial maching of head bolt holes etc, I could tell you exact markup, but as of now I'm just GUESSING as to the costs they have in the bare castings, but even if I guess low, the markup ain't much.... They definitely rip people off on the markup of some stuff (like the MP .001" oversize main bearings for SB ) But the Chapman heads are'nt one of those things IMO.

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by the way MP does also list a part number for that zues casting in a rawish state so someone can do their own CNC work and or hogging by hand ...

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Cost is kind of irrelevant to the customer, they only care about the price. Spending so much in R&D that you can't sell the product at a profit is a classic mistake.

We'll just have to see if people are willing to pay double for the Chapmans what the B1's would cost them.

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Are the heads ready to assemble and bolt on then? Has this been determined? Or is it still possible that some things are "off."

The partially machined heads are only $625 from at least one vendor. The completed heads are $2100.

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John what is the part # for the Unported 6's with raised spring pockets? I just want to go look up the price....

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John,

Did you wind up trading for the 260's ??

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one so far ... i owe the person/company i traded a few bucks for some parts i purchased and i think he's holding it hostage till i pay up ...

i'll be sending my 452's back up to dwayne next week sometimme so i'll send up the head i have ( my dad goes to Burlington,Vt. 3 times a week , free shipping ) , of course i don't have any valves ... maybe i can get one of each from MP , i think i'm going to get a custom set and use lashcaps ...

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Looks like the ports liked the tube, huh?

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I use AutoCad and I work at a machine shop with a water jet, I might be able to talk the boss into letting me cut out a 'Paper Doll' manifold Prototype, might need some expert input to calc total runner volumes and lengths, anybody have the latest version of Engine Analyzer Pro I could borrow for a week?

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Martin, you don't know what the titles of the books that David Vizard had written in regard to this???
AL...

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Putting these on a low deck, what would be the best Intake to run? I know an indy or possibly a B1 would be an obvious choice

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Putting these on a low deck, what would be the best Intake to run? I know an indy or possibly a B1 would be an obvious choice

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My experience with my 471 and several intakes was the Indy (400-2) 4150 intake was the fastest down the race track. However, driving on the return road and in the pits was notably worse than the others I tried. So "bad" in fact, I would not recommend one for street use. A 508 CID might work a little beter, or a turtle/cone in the plenum might help the part throttle performance.

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