Doug T (10/12/2009)
If the competition rules stay the same for next year and the Aluminum heads do not materialize or (what I would like to see) the rules change to require OEM iron heads would you go for a smaller engine? If I remember past EMC results there were engines as small as 288 CID. I can't estimate how much extra would be gained in specific output but if going from 375 to 300 cid would result in a 10% increase, you could be looking at about 400hp on your dyno.
Besides the iron heads, the Y seemed to have the least exotic induction system of any others I saw pictured on the EMC web site. Are you thinking of any improvements on that side?
The rules this year allowed engines as small as 280 cubic inches. That got a 4.6 Ford Mod motor into the show.
Regardless if the heads are iron or aluminum, the smaller cubic inch Y engine would have been more favorable under this years rules format. I know that now but in hindsite would not have known before actually testing this combination. Better flowing aluminum heads will obviously support a larger engine though. There’s no doubt in my mind that last years 316 engine with this years iron heads would have produced a much better score this year while potentially still coming close to the 400HP barrier with a pump gas combination. At the EMC competition, it’s all about the score and not the peak values.
This years rules format specified a cast intake manifold without external modifications and the Mummert intake was definitely the best available. A big Thank You goes out to John Mummert in getting me some of the new intakes to work with for this competition. The next best intake design on the list was the Blue Thunder. Most of the 3X2 and 2X4 intakes as originally cast are not the big power producers for this kind of competition and especially if limited to the carb bolt patterns that came on them. If a good single plane design had been available, then that may have helped the overall score. Testing is really the only way to know for sure on any of this. This particular engine saw seven different intake manifolds on it during testing along with a variety of carb spacers and carburetors. But an injection intake with Webers would be worth looking at based on the performance of the early Hemi that was running that combination this year.
The 375 incher did surprise me in testing when I tried a 1050 Holley Dominator on the Mummert intake and it made even better numbers. Made three pulls with the Dominator and as I leaned the mixtures, the power levels just kept climbing. Started out with 88 jets square and was down to 81 jets square by the third pull with the indicators still pointing to the engine being on the rich side with 81 jets. And the Dominator idled just fine and cleanly with all the jet combinations. Unfortunately I was already in a time crunch situation at that point and didn’t have the aluminum stock available to whittle out a spacer/adapter that would fit the rules. For the test, I used a 2” adapter I had on hand just to try the Dominator carb and that particular adapter was just too tall as required by the rules.
Lorena, Texas (South of Waco)