Thanks Joe. I’d like to know if the upper and lower ports flow an equal amount or is one better than the other?

How do these numbers compare to a contemporary SBF or SBC aluminum head with standard valve configuration?

Not to confuse the issue, but for the Y block, the Mummert head is the only thing being cast that has the potential to make 600 hp normally aspirated.  The old tried and true formulas for airflow needed in making x amount of horsepower would show us that to make 600 hp, the intake and heads need to flow at least 292cfm.  To make 640 hp, the heads and intake need to flow 312cfm by the formula.  Not trying to be cute with those cfm numbers, but if you plug in cfm x .257 x 8(number of cylinders), you will see what I mean.  292 x .257 x 8 = 600.352 possible hp, and 312 x .257 x 8 = 641.472 possible hp.  Many factors need to come together to make this happen.   It is all in the details, and removing parasitic loss every place possible, compression ratio, exhaust tuning, intake manifold efficiency, carb tuning, etc..  A Mummert head as cast flows in the 240 cfm range without porting.  With their CNC porting program, the street CNC heads flow ~270/280 cfm, and the race heads with their angle mill, 10mm spark plugs, 1.970/1.510" valves flow slightly better, but not much.  There is just so much aluminum you can remove before making holes in the heads.  I have seen just over 300 cfm on a couple of sets of heads that were hand massaged above and beyond the CNC programs.  To reach 312 cfm, a larger valve is needed, and that would require moving the guides and seats, and changing the ports to the new valve sizes, or a completely new head casting.  Lots of work, for not much return.  Smaller stemmed valves only increase the flow at most 2-3 cfm.  Joe-JDC   

JDC

Ted not to get caught up in flow numbers but are they where you need them to be at least roughly relative to the horsepower you need to see?

If so is there any way around it like a “faster” intake profile? Etc.

Nice work

The pistons showed up so I was able to get this years’ EMC engine together.  The engine assembled without any problems and there's plenty of room around the offending items with the new connecting rods in place.  Torque numbers are good but horsepower numbers are lacking or at least below what was anticipated.  Looks like the heads may be a bit small for 403 cubic inches.  Still have some different things to try but only see minor improvements.
 

Lorena, Texas (South of Waco)

Yes, I reworked them quite a bit, changed the valve job, changed the stem heights, milled them, added a 1/2" spacer to the exhaust ports, etc.  Should be a good pair of heads for the competition.  First dyno session was promising, just trying to get the carburetors figured out.  Not happy with the QF carbs right now, but that is a whole different story.  Just trying to not finish last!  LOL  Joe-JDC

JDC

Hi Joe, what heads are you using, are they Johns?

Got a couple of clarifications on rules today, and they do not require mufflers, can use air cleaner base, stub stack, or velocity stacks, but must run water pump with fan belt that is engine driven.  So, things are getting close to show time.  Ted is building a torque monster for sure.  Joe-JDC

JDC

Wow Ted! That 4.300” does have a very nice ring to it. Should be a torque monster.

I’ll bet your cylinder heads can feed all those inches as well.

Love the angled rod solution. I take it those are custom rods. Any reservations about their durability?

Love to see these full on efforts put into these old Ford engines. It’s neat to see what can be done with them.

Best of luck to you sir.

a picture is worth a thousand words.