Comparison of Mummert Heads to Original Ford Castings

Author	Message
Ted	Posted 14 Years Ago
Co-Administrator Group: Administrators Last Active: Yesterday Posts: 7.3K, Visits: 204.6K	Oldmics (8/18/2010) Can we get the air flow numbers on Johns new heads and also an air flow number on a set of stock "G" heads for comparison purposes? Oldmics Here’s what John said awhile back regarding flow numbers on ported iron heads John Mummert (3/19/2010) The upper port of almost any Y-Block head can be ported into the 210-215CFM range. The G, -113 and -471 heads can be ported to around 225CFM with 1.94" and 230's with 2.02" for both upper and lower. The problem with the less desirable heads is the lower. I've tried every trick I can think of and most won't reach 200CFM. The lower on the C head is one of the worst. High 190's is the best I've found. The C1AE can be made better with good porting and 1.88" valve,1.94" cut down to 1.88" to avoid spark plug interferrence. And here’s John talking about flow numbers on the unported and ported aluminum heads. John Mummert (7/21/2010) ….The first heads sent to Ted flow in the 235 range. Having ported more Y-Block heads than I can count we put most of the tricks in the new castings right out of the box. Granted, some material has to be left around pushrod holes and headbolt holes in case of core shift ect. The out of the box head also needs to work on a 300 cu in street engine. That was the goal. There are some things that can be done in a reasonable amount of time that will increase the flow into the 250-255 CFM range but 270CFM requires non stock port openings and pushing every corner to near the limit. This takes a great deal of time. At 270CFM the heads will run a 320 inch engine well into the 7000 RPM range. I wouldn't consider this with cast pistons, stock rods or main cap fasteners. That is why I felt that running the EMC heads on the mule engine was not a appropriate test since the redline would need to held well below the potential of the heads. A low compression 320 incher with an antique cam and low redline simply won't show the true potential of the EMC heads. Doing a search on this site can bring up some other discussions. Here’s a link to get you started. http://www.y-blocksforever.com/forums/Topic41409-3-1.aspx Lorena, Texas (South of Waco)
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PF Arcand	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 8 Months Ago Posts: 3.3K, Visits: 238.8K	Flow on stock & ported "G" heads is available in issue #96 of YBM. And flow numbers on the aluminum heads have been issued here recently, back a bit.. Paul
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Oldmics	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 4 Years Ago Posts: 710, Visits: 78.1K	Can we get the air flow numbers on Johns new heads and also an air flow number on a set of stock "G" heads for comparison purposes? Oldmics
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*Hoosier Hurricane*	Posted 14 Years Ago
Supercharged Group: Moderators Last Active: 1 hour ago Posts: 3.7K, Visits: 321.5K	Paul: The angled portion of the exhaust ports (all 4 have them) is one place where you can hit water when porting. The water jacket in that area is there because of the spark plug location. Compare the plug locations of John's and Ford's heads. John doesn't need that angled water jacket casting. By the way, '54 heads had squared ports, they used 14mm plugs instead of 18mm. John - "The Hoosier Hurricane"
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PF Arcand	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 8 Months Ago Posts: 3.3K, Visits: 238.8K	I note that the new heads have virtually square exhaust ports at the exit. Ford ports had an angle in the inside corner at exit (just on the end ports if I recall without looking at a head) & I recall reading that this was because flow dropped there if the port was opened up there to much. Comments? Paul
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John Mummert	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 3 Months Ago Posts: 911, Visits: 7.4K	The correct length pushrod for the aluminum heads is the same as the 1954-55 and 60-64 Y-Blocks so they are readily available. I have 300 on the shelf just in case. Valves were moved closer to the intake manifold. Rocker shafts also needed to be moved to retain the same distance from the valve stem to the rocker shaft so existing rockers could be used. Intake valves were moved toward the exhaust valves. Exhaust valves were moved away from the intake valves. Current valve spacing is 1.815". This limits total valve diameter of intake and exhaust valve to 3.52". Spark plug has been moved closer to the exhaust valve while Ford put the spark plug on the exact centerline of the cylinder. Spark plugs are now 14mm instead of 18mm. As you might guess the ports are not as large as they could be. We needed to make a streetable head for engines as small as 298 cu in ( .030 over 292). Intake valves are 1.94" as sold. We have already done some porting and testing with 1.98" intake for Ted's EMC engine. We have tested a lower intake port @ 274CFM and 255CFM with a ported intake installed. This pencils out to 500HP+ http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico
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aussiebill	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 4 Years Ago Posts: 1.8K, Visits: 11.4K	Oldmics (6/2/2010) Can you tell us what venders are offering the longer push rods to accomidate the al heads? I assume (you know what happens when you assume ) Mummert is selling the longer push rods? Oldmics Why not keep things in perspective! just ask john, i think you will find that after developing these heads, he, john has the accompanying parts to make it all work!!: AussieBill YYYY Forever Y Block YYYY Down Under, Australia
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Oldmics	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 4 Years Ago Posts: 710, Visits: 78.1K	Can you tell us what venders are offering the longer push rods to accomidate the al heads? I assume (you know what happens when you assume ) Mummert is selling the longer push rods? Oldmics
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PF Arcand	Posted 14 Years Ago
Supercharged Group: Forum Members Last Active: 8 Months Ago Posts: 3.3K, Visits: 238.8K	I could be mistaken, but I believe there's a correction needed on the inquiry about original valve sizes. 1957 head intakes were 1.925" in Dia. not 1.94". Replacement Stainless valves are 1.94". Correct? Paul
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Ted	Posted 14 Years Ago
Co-Administrator Group: Administrators Last Active: Yesterday Posts: 7.3K, Visits: 204.6K	marvh (6/1/2010) Ted: I noticed on the top picture with the old style rockers with jamb nuts it has different stands than stock. Does the new head require these different rocker stands? The pictured stands are supplied with the aluminum heads as the original stands will no longer bolt up. The relocated valves necessitated new stands with a wider bolt spacing but these new stands still work with factory shafts and rockers. The bolt sizes holding the pedestals to the heads have been increased from 5/16-18 to 3/8-16. marvh (6/1/2010) Does the new heads require a special length of push rod or will one of the three lengths of '55 and later y-block push rods Ford used fit. Going from the iron to the aluminum heads and keeping the 1.54:1 rockers in place required a longer pushrod. The iron headed engine had the 7.970” pushrods while 8.105” pushrods were used with the aluminum heads. When switching to the 1.6:1 rockers on the aluminum heads, a set of 7.935” long pushrods were installed. Lorena, Texas (South of Waco)
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Comparison of Mummert Heads to Original Ford Castings

Comparison of Mummert Heads to Original Ford Castings

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