EMC 2016 is in the history books. It was a good time had by all. Ted held up the Y block 2-0 Vintage class victory. We all can hold our heads high for another year, this time with a cylinder head,manifold package that is more agreeable to the Y-Blocker.
The Mummert build came about this year with many different reasons in mind and EMC wasn't the first on the list, but was a consideration being pondered. As stated earlier in this post the new manifold was supposed to be done earlier in the year and get tested on the new 355 cu/in motor being raced in the falcon. The 343in had been running in John Hildebrands 31' coupe and weren't wanting to yank it out of the car to replace that manifold dyno test it, just to take the manifold back off and get prepped to put it back in the car, because the coupe has so much engine set back that the tunnel ram won't fit without cutting up the car.
Having many of the parts for the 331cu/in motor on the shelf the decision was made to get it running again. A running engine was worth more than a shelf full of parts and it would give us more latitude to do manifold testing or EMC and not have to pull one of the race cars apart.
Once we had decided to enter the competition we knew the work load in the shop was going to get harder, it now had to more than a good dyno mule it was going to have to be a competitive EMC entry. We had to call on John Hildebrand and Todd Ferguson to help us out. This engine would not have been possible without everyone rolling up their sleeves.
Having competed in the EMC in 2002 we had some good knowledge of what we wanted to do, but much of this information was 14 years old so we knew we would have some catching up to do as this competition has gotten more competitive every year.
The bottom end of the engine is comprised of a B9AE block, bored to 3.84". The block was tapped for screw in freeze plugs and 1/2 filled with Embeco. The crank is a C1TE steel truck crank. ( seeing the part number on the crank did give some inspiration) It was offset ground to 3.57" 1.889" honda journal, nitrided and undercut outer counterweights 53lb ready to run. ARP main studs with factory main caps deburred and shot peened. Molnar 6.125" rods with Race-tec pistons. The original pistons were set up with 10cc domes. Looking at technology through the year we decided to reshape the dome to a 4cc finished size and reduce the combustion chamber down to 49cc.
After pondering right up until we made the phone call the camshaft ordered was 248@.050" .345" lobe lift ball nose grind on the intake and 247@.050" .337" lobe lift, on a 104 lobe center. With the start rpm raised to 3500rpm the cam was installed straight up at 104. (In 2002 we ran a 106 installed on a 100, but we were starting at 2500 rpm.) I think I would advance it some or reduce the intake duration a tick, doing it over again, hind sight is always 20-20. Trend tool steel lifters, and Smith Bros pushrods
Oiling duties were left to an OEM ford gerotor pump. The idea was to use this engine to try a direct AB test on the two styles of oil pumps available to see if there was any measurable power difference between them. After researching it more we decided to build a better gerotor. Dual inlet feeds and adjustable external bypass was the surest method to reduce aeration, raising the quality of the oil entering the engine. It would also raise the efficiency providing a more linear flow allowing good low speed oil pressure without having to run to much pressure at high speed. (We may have over thought this, but it did work well and looked good doing it.) The marine oil pan made perfect sense for us. It has large capacity, built in windage tray, fits our short timing cover, and fits just about nothing but a boat or a dyno. Still never got to AB the two styles of oil pump.
The top end of the engine was really the easiest part. The head gaskets are OEM steel shim units. Mainly to reduce the dead area around the bore an raise the combustion quality. Deck height was set to .015" . The cylinder heads are our angle mill CNC race heads milled to 49cc. The rocker arms are 1.7 Mummert roller rocker assemblies. New Tunnel ram intake topped off by C&J modded 650 double pumpers. and R2C velocity stacks.
Headers are 15/8 to 13/4 built to fit the F-100.
We were very pleased with the performance of the engine generating 100hp/litre @6400rpm while still making good low and mid power. However the score is what matters in EMC competition, and we have to pick up some grunt in the first 1000 rpm. We may take it to the dyno and see if a few tweaks get it headed in the right direction.
I really enjoyed meeting everybody. We may do it again if John is up for it, but for now its time to go back to work.
Geoff Mummert
http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico