Forgot to put stroke in heading I remember seeing welded up yblock cranks , not sure if they were over 3.75 stroke or not . With modern race engines , I have seen some crazy crankshafts . 

Po ol Davie

Sparta , Tn.

This was asked on Facebook a couple of days ago.  There are several folks with 4.000" stroke 292s, 4.290", and one 4.300" stroke.  You can do the math, but 390-403 cubic inches have been built.  My 2018 EMC engine had 3.862" x 4.000" 292 is 374.86 cubic inches, or 375 Y.  Ted has done several at this size or larger.  Rod clearance with camshaft lobes comes into play after 4.000" stroke.  Joe-JDC  

JDC

Took care of that.



Lawrenceville, GA

The small bore limits the valve sizes that can be used. How do you compensate for that on an engine of 390-403 cubic inches? Are you seeking torque or horsepower? 

Superchargers solve that. Long cams and extensive port work help.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

You can make 500 or more horsepower with iron heads on a Y with porting heads and intake manifold.  My 303Y with only 10.4 compression, iron heads, aluminum 4V intake, that I ported makes 463 hp.  I have ported Mummert heads for several folks that have made 560-585 hp, and my own Mummert heads, Mummert single plane intake made 613hp at 375 cubic inches.  I have the 303Y ready for another round of dyno testing, hoping to improve the horsepower closer to 500 with iron heads.  If I were to take the Mummert heads off my 375, I am sure I could make close to 540hp with the iron heads from my 303Y.  There is a lot that can be done with the Y block if folks want to spend the time and money for the right parts.  That was proven with the Engine Masters Challenge dyno sessions.  As far as valve size for iron heads, folks have put 2.020/1.600 valves in the iron heads, and Mummert has 1.97 intake valves in their race heads.  Those heads are capable of over 600 hp with lots of compression and cubic inches.    Joe-JDC

JDC

I have used strokes up to 4.300” in the Ford Y. Being a 1.000” stroker just has a nice ring to it and makes for a very torquey street engine.  Have not experimented with anything smaller than the Honda rod journal though but the smaller VW journal has always been an option. Crankshaft strokes over 4.000” have required a custom connecting rod with an angled parting line to provide adequate rod to camshaft clearance.  Here are pictures of the 6.500” long Cunningham rod I have used when going with strokes in excess of 4.000”.
  

  

Lorena, Texas (South of Waco)

I think everyone answered my question . I kind of know interference problems . Next time I talk to Bryant 3.850 range with honda journals  1.850  ,  Thanks to everyone !

Po ol Davie

Sparta , Tn.