Displacement is not so much of an advantage given the way they score the engines.  However, even if they did not have the bore and stroke limits, like previous years, an sbc can still be much bigger so allowing for that would not necessarily help, either.  The rules can't favor one engine, it's all or none.
Under previous years' nearly unlimited rules, a Y would not stand a chance against an sbc, which is why it's good that there are limits this year, to help level the playing field since more modernly developed engines are allowed.
An sbc has an advantage for intakes, headers and possibly heads - Joe might have a better idea about that - depending on what is accepted as "factory."  Like it or hate it, the reality is that a sbc or some other mainstream engine could dominate since they are now accepted.  That's just the advantage of decades (half a century) of continuous development.


Lawrenceville, GA

The largest sbc allowable under the rules would be a '67-68 350 which would be 3.480" + .348" offset stroke for 3.828" stroke, and 4.065" bore or 397.442 or 398 cubic inches.  A 292 with 3.330 + .330 =3.660" stroke, and 3.815" bore would give 334.696 or 335 cubic inches possible.  A 312 with 3.440 stroke + .344" would be 3,784" and bore of 3.865" would give 355.165 or 356 cubic inches.   With the heads available before 1968, There isn't a lot of advantage with the sbc head and .550" lift camshaft.  I don't think they will be able to flow huge numbers and fit the cylinder heads required for the competition.   Of course, each of these engines are hypothetical, and a builder would not push the limits on both the stroke and bore, because a simple measuring error could disqualify an entry, so I would probably be looking at 329-330 cubic inches for the Y if I were to build one for this year's competition.  Finding a good crankshaft that can be offset ground the maximum of 3.660" will be difficult at best.  The rest should be fairly straight forward with good machining work and blueprinting.  It will come down to intake manifold and camshaft selection to make the difference in horsepower/cubic inch and torque/cubic inch for the competition.  Since the intake can be 7" tall, spacers could be used to help with any deficiency in manifold selection for the Y.   There will be some heavy hitters in the Big Block category, and if the small blocks can get their friction and weight down, they should be more than competitive in my opinion.  Joe-JDC

JDC

Fuel quality was a big problem this last EMC. What is the situation coming up?..  Too bad that the SBC is allowed, cause it's had Billions of $$ spent on it by the factory & aftermarket & millions of hours of development also. To ask lesser developed or orphan engines to compete with that is just ridiculous!.  But, then it's Hot Rod you're dealing with, so it's not a big surprise.. 


Paul

The ‘Early Iron’ rules for this year are well written and very concise.  Someone in the back ground put a lot of thought into them.  Comments made last year on how to proceed forward with the class were heard and the ‘Early Iron’ class has been updated accordingly.  With the new rules, I expect to see an increased diversity of engines entered.
 
With how the current rules are written, I still think that the Y will outscore the SBC engines.  The Y had no problem besting the LS series of engines in the past when put head to head with them so I don’t see a problem with a iron headed Y up against any oem iron headed SBC.  Much of the unorthodox thinking that made its way into past vintage class engine builds has been eliminated but as rules go, I’m sure there are still some loop holes to be found.
 
For this year, oem iron heads and oem rocker arms are required and that by itself levels the playing field at least between these two families of engines (Y vs SBC).  The new players in this class would be the various Ford, GM, Mopar, and AMC big block engines with the BBC engines (IMO) having a clear advantage.  I’ll not discount some of the other small block entries but the big blocks may have an advantage this year simply due to some of the better flowing heads that were available from the factory for those engines.
 
The fuel being used is yet to be determined but with the compression ratio now limited to 10.5:1 for all entries in the ‘Early Iron’ class, that should not pose much of a problem even if ‘swamp gas’ is used again.

Lorena, Texas (South of Waco)

Well, it looks like some changes in the rules are in the works.  Only 7 months to go!  The 10% stroke increase should read .010" increase allowed.  That is ten thousandths, not ten percent.  Big difference.  All early iron competes in same class, no distinction between small blocks and big blocks.  Must use heads from factory for same factory block.  292 heads on 292 block, 312 heads on 312 block, etc.  Was contemplating another Y Block build, but looks doubtful now, the largest 292 would be 303ci, 312 would be 324ci.  The SBC can use a 350 from '67-'68.  Joe-JDC

JDC

Wouldn't the smaller engine make the heads look bigger? that's why I built my dragster motor so small.

Some folks tend to think this, but in reality, a head is capable of flowing x amount of air and fuel at maximum valve lift.  With a small cylinder pulling/giving a smaller atmosphere displacement volume, then you are not taking full advantage of the capability unless you can spin the air pump fast enough to reach maximum flow.  If you have a head that flows 230 cfm, theoretically it is capable of supporting at least 473 hp.  If you have a 292 cubic inch engine, it will need to make 1.62 hp/ci to reach that goal.  If you have a 338 cubic inch Y with those same heads, then it will only need to make 1.4 hp/ci which is a lot easier to do.  Some time ago Engine Masters did a segment on You Tube using a 410 cubic inch 351W stroker engine and installed three sets of heads to see if your theory is correct.  They did the tests back to back with 165 cc/190 cc/220 cc heads, and the results were fascinating.  You would think a 410 cubic inch engine would starve for air with 165 cc heads, but they equaled the 220 cc heads and had better torque.  The 190 cc heads were slightly better, but less than single digits difference.  "The more I learn, the more questions I have!"  I believe Ted finally came close to maximizing a set of Mummert heads with his EMC engine, but was handicapped with only ~.630" lift on his camshaft.  Would be very interesting to build that engine again with .700" lift camshaft.  I intend to rebuild my engine with a camshaft that will give me at least .690" lift at the valve and see if the heads are the limiting factor, or the manifold is the bottleneck.  Joe-JDC 

JDC

Updated rules posted on Hot Rod Engine Masters Challenge web site.   Called Early Iron now.   Joe-JDC  

JDC

Ted any thoughts after the new rpm rules have been posted?   Long stoke for low rpm torque looks less important when you can start a pull at 4200.  

There must be some thoughts that really small motors have an advantage as I see there is a 10% penalty for engines under 250 inches.. The 58 and older engines can use a manifold from another engine family which keeps the MEL and Lincoln Y legal, but not necessarily competitive

The main journal contradiction is not fixed.  The block must use oem main bore but the crank can have any journal diameter.


Lawrenceville, GA