b heads direction

[assasinator]

i am building a forged turbo mark viii. i like the b heads from the get-go. anyway...i like them.


i like the idea of one large port and one small one. obviously the idea is really a failure. so,

i am going to clean up the secondary(mirror), no egr.
i purchased 8 frpp stainless valves.(back cut, undercut stems.) i am going to spend my time doing a basic amateur port of the primary. contour and enlarge it a tiny bit and use the new valves in the primaries and leave the stockers in the secondaries.

thoughts?

[yellowsvo]

Got this from another site, it kinda made me rethink porting mine. But im not forced induction either:
B/Swirl Port: (93-97 Lincoln Mark VIII, pre 99 Lincoln Continental, 96-98 Cobra).
The first and only production Ford head with two (square primary, round secondary) intake ports per cylinder, these swirl port castings arrived first in the ’93 Lincoln Mark VIII. Aptly named, due to the way they promoted the incoming air to swirl into the combustion chambers, much like water running down the drain of a once full sink.
Through the years these heads have proven themselves to be excellent high rpm (8000rpm+) performers—mainly in power adder applications--since their tremendous combined intake port cross sectional area and volume (when combined, a full 55cc more than any other 4.6L head design) provide for exceptional power production in the upper regions of the tach. Ironically, it’s those same big, beautiful, twin ports that also prove to be the B head’s largest inherent design flaw. The extra intake port size has a tendency to kill low/mid rpm intake port velocity and power production—hence the use of Ford’s first IMRC (intake manifold runner control) intake on the 96-98 Cobra. By allowing air to reach only one of a B head’s twin intake valves, velocity, and therefore low/mid range torque production was restored in situations under 3250rpm. Later head designs are clearly superior in this regard, which happens to be the one of the most important considerations for those wanting a stout street motor.
There is also some controversy over the single fuel injector/dual intake port setup. Some claim insufficient air/fuel mixing because of the compromised design, however, others contest that the ability to make 1000+rwhp with only minor porting and some form of power adder is testament to the contrary. Whoever you believe, there is little doubt that even after as little as 8,000 miles, carbon and other deposits tend to form on the secondary ports, causing a major airflow impedance, as there is no fuel present to clean them. B heads feature a somewhat small stock exhaust port that really hinders flow in power adder applications. Major gains from porting come with a quality valve job, some pocket and lots of exhaust work. There really isn’t a lot of material to remove from the intake ports themselves.
The Bottom Line: B heads aren’t the best choice for a naturally aspirated street motor. In order to really shine, they need to be paired with a power adder and a short block that can sustain high horsepower and rpm levels. These, the oldest heads, may still be a great choice for full race applications.

Stock Intake Choices: ‘93-‘97 Lincoln Mark VIII, ‘96-‘98 Cobra.
Aftermarket/Modified Stock Intake Choices: HCI, SSR, PHP.
B head dimensions: Combustion Chamber: 52cc, Intake Port Vol.: 107cc primary (square), 115cc secondary (round). Intake Port Entrance: 1.500x1.300” primary (square), 1.660x1.400” secondary (round), Valves: 37mm Int., 30mm Exh.
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[assasinator]

the idea is to enhance the primary to balance flow a bit. how much? well heck its hard to quantify on a posting, but low lift enhancment by these valves should prove invaluable.

[assasinator]

and port work. i will probably get them on a local flow bench just for number; total, and primary ports.

i am interested in the low lift primary flow. i am keeping the imrc's for now. until i determine another way to operate the secondaries, the factory method is sufficient.

mind you i am after 35 mpg AND big power with a boost controller i have. that requires the imrc's, os a substitute.

so the tall gears stay.

i must mention i have spent the last 3 years cutting , heating and modding 5.4 3v intakes with methods too numerous to mention. it is detailed here and there under this username and billfisher on other sites. i mention it because i am going to make a manifold change i doubt anyone has tried. words mean nothing, but i will post details as i start the work. firstly it WILL work. it isnt some hairbrained idea. it could best be described as a mix between the sullivan untake and the mark viii. 2 seperate plenum volumes.

i have to get the stipid thing in the car and tuned before i even start that.

[assasinator]

let me say that i went from 9.1 in the 1/8th with a stock manifold to 8.5's with only a manifold internal mod and no tune. i am 100% positive with my current tuning and 4.30's it would run 8.0's on motor in the 1/8th.
stock auto tranny.

[yellowsvo]

Subscribing

[assasinator]

IMO ford goofed a great opportunity for the only head they needed.

by using imrc like these instead of short runner control like a mach1/aviator it ruined the idea.


if there was a manifold with individual runners like these heads, but seperate runner control with enhanced primary ports, these heads would be a better all around choice. i feel like the imrc's, placed where they, are can only hurt closed secondary port operation.

after working with xytel for the last 3 years these metal intakes will be a breeze to alter. think of a combo between a mark viii primary, and a secondary setup that looks like a 3.4l taurus SHO plenum.

if the primary runners actually MATCH the primary port design rpm they will flow their max. and if the secondary runners MATCH the design of the larger port, they will flow their max potential. so in short i will be eliminating the imrc's the way they look now but they will be there.

[assasinator]

ok the heads are torn down and what do i see to my suprise? a little secret in the primaries.

it is inexcusable not to pull the heads and enhance them a bit. no wonder guys get such good numbers with these ported.


they will do just fine. all of those comments about 'crappy' b heads are bullcrap. they need fixing is all. those guys who have seen the primary short side know what i mean.

[assasinator]

oh and btw 3 of the secondary ports were at least 60-70 percent clogged. 90k miles on these heads.

[assasinator]

when the intake i bought gets here i am cutting the plenum bottom off, removing all of the secondary port-runners, closing the plenum holes, and welding a second plenum with appropirate runners that will sit over the valve covers. the two secondary plenums will have 50mm throttle bodies acting as IMRC's tubed to a common plenum/extension i will add at the back of the lincoln part.



stock imrc's eliminated.



i will extend where the stock throttle body sits high enough for the throttle body to be positioned more normal and horizontal. that extension will be where the side plenums will attach with the throttle bodies between them. total plenum volumes will be appropriate for their usage.





a pneumatic cylinder will activate the secondaries with set bleed rates. with a solenoid spool and an rpm/WOT set of switches. the cylinder will have a check valve arrangment similar to stock early mark viii.





i am also going to weld on injector bungs for the secondaries in case i switch the mode. ie, the secondary ports become primaries. or i add an injector driver to run them in concert with the primaries.





all of that work is not reinventing the intake. it is seperating volumes for their best usage. a much smaller volume strictly for max torque, and the second plus the first for max HP.



imagine if you could get all of the torque that a single 1.4567" valve can produce in a 281 inch motor. forget high rpms. what if it could produce superior low end response. by low end i mean a few thousand off-idle to say 4000. if it had the plenum volume, velocity AND airflow to support 300+rwtq. you have the kind of throttle response and torque 96-98's lack.



stock primary runners. 6500rpm secondary runners.



do i think i will create the perfect intake. no. but it cannot be worse than stock. and i may have to buy a bunch of them to get it right. just like the dozen or so plastic intakes cut to pieces for the 5.4.





to reiterate.



stock primaries with plenum volume adjusted for low end.

new secondary runners/plenums tuned for 6500rpm.



pretty aggressive eh? well i have been planning this for years. oh since 1987ish. long before i knew ford had a 4v coming.

[assasinator]

and BTW i am finally dealing with metal. and round metal(tubing) at that. this will be easy compared to thermoplastics. which do not glue.

[4sdvenom]

Good luck!
Gonna keep up on your progress and results!

Ken

[PGreenSVT]

post some pics.

[bitemark46]

What intake you going with? I noticed you said remove the secondary runners. If you're using a cobra intake they don't have separate runners. Its a "Y" design. 1 runner that splits into 2 ports. I think I might try and fabricate some IMRC's to house 2 injectors (1 per port) and see what power I pick up with nothing else done.

-Mark

[assasinator]

i will post pics when i get started on it.


right now i am doing the heads. they are cleaned and i started some basic sand flapper work to fix the short side, or at least give it some short turn. and raise the roof. and give the primaries an actual turn.

it wont be more than a few days work on the start-up on the intakes.


i am not removing ANY material on the port floors. after i finish the shaping with 80 grit 300 grit finish. only polishing the secondaries. desgrouding the primaries,then the real work begins.

the exhaust. flushing the guides, merging and changing the shape to a 'B'. minor material removal. floors untouched.


pictures when finished.

[assasinator]

the intake will be a modded mark viii. with my own added runners. but heck thats a long way off starting. i have to finish this motor and turbo before march 28.

[assasinator]

bitemark i think you'll pick up considerable power doing that.

[assasinator]

especially if the two ports are somewhat bablanced in flow.

[tirefryr]

Subscribing.

[mark88]

It sounds incredible.

[na svt]

The Mach 1 intakes are not the same as the Aviators.

[assasinator]

i know it was a generalization about short/long in one manifold.

[na svt]

Originally Posted by assasinator

i know it was a generalization about short/long in one manifold.

That would include the F500 and the Avaitor intake. The 99/01 Cobra and 03/04 Mach intakes have 12" runners (or close to it).

[assasinator]

Originally Posted by mark88

It sounds incredible.

how bad would it suck to end up reverse engineering torque/hp.

i seriously doubt that will happen. i am not really planning to kill top end on the primary.


first things first. i have to complete the porting and get the motor going.

[assasinator]

i could have sworn the mach was nearly identical to the aviator with runner dimensions and throttle body type being the differences.

[na svt]

Originally Posted by assasinator

i could have sworn the mach was nearly identical to the aviator with runner dimensions and throttle body type being the differences.

nope, cobra and mach intakes are the same.

[trb'd331]

subscribing

[na svt]

Originally Posted by assasinator

i am not really planning to kill top end on the primary.

The secondary is larger than the primary by about 8cc so that means the primary is better suited for torque, not hp. Also, the best thing you could do to these heads is raise the floor about a 1/4". This will reduce the port volume, increase the velocity and if done right, make the short turns a lot better.

[assasinator]

what i was referring to is, that i am not going to runner it for low and and essentially ruin the primary ports ability to help at higher rpms.

[assasinator]

i am about 70 percent done with 1 head. I finished the chamber work on it. remember this isnt 'ruin the heads' day. its get what i can and leave well enough alone.


1. give the primary's as much short as it has. which aint much.
2. clean up the primary's and raise the roof/bowl transition a tiny bit. (try to get it more straight onto the valve. )
3. buy good race valves for the primary's.(undercut,backcut,swirled)

4. polish the secondary's. blend the seat/bowl/transition

5. raise the roof on the exhaust a little and blend the seats. ('B' the ports. )leave the floors alone.
6. remove most of the exhaust dividers.
7. deshroud the primary valves.

remove as little as possible to do those things.

[assasinator]

i am only out to get some flow on the backside of the primary ports that is factory limited.

[assasinator]

ok, heads are done and refinished. even though i removed the heads correctly one head warped .005 and the other .003. waved is more like what they did, and in the same spot. maybe i was too agressive untorquing them. anyway,

ill take some pics of the basic pocket porting i did. no flow benc :-(
craggs flowbench got auctioned when he sold and rebought his business. 20k flowbnch auctioned for 1500.00 and he didnt know it. so no numbers sorry. Cragg clack build mountain motors, pro-stcok, modifieds, atc. he thought the simple stuff looked good. the list of the small things i did is extremely long.

[assasinator]

1. back cut the exhaust seats to match ports.
2. removed flash in the exhaust ports
3. raised the exhaust port roof a tiny bit.
4. altered the inner short side.
5. removed a lot of the divider and knife edged it

more later.

[KennethWW]

I'm subscribing to see where this goes.

[assasinator]

6. more or less gave each exhaust valve its own gas path.

7. removed the shroud over the primary port in the chamber and laid it back to match the other port.

8. altered the primary bowl to change the gas angle more perpindicular. mainly after the guide.

the primary runner is really badly designed for power.

9. removed the short side bowl 'dam' and reshaped it resembling a short side.

10. where the primary port goes from square to round i lenthened that trasition from a 'step' to a ramp on the floor.

11. on the roof i eliminated the transition and raised the roof to the bowl.

12. removed the guide protuding into the secondary port.

13. blended ther runner to bowl

14. sanded it.

15. blended bowl to seat.

16. left the rest of it the hell alone.

all of that without removing a lot of meterial. gentle little alterations.