I was wondering if there was a difference in the cylinder head on the ISBe and the cylinder head on the ISB. Which head has the potential to flow more air? Are there any differences in stock valve size and which head can have the largest valves installed. Are the injectors in the same location on both heads? Also if both heads are modified for maximum airflow can they outperform a similiarly modified 12 vavle head?<br><br><br>Thanks, Clayton

 

There was a story a year ago that Banks was working on a head modifacation to mount a 12v pump and injectors on the ISB. Never heard any more about it. I was interested too, if it was financially possible I would do it on a rebuild. I don't like the computers that much.

 

MM,<br><br>While I have never flow bench tested the ISB cylinder head against the 12 valve I can tell you that from the port design of both engines the 12 valve should be able to outflow the 24 either ported or not. Once the 12 valve head is ported correctly it should be able to walk away from the 24 that is ported. It has to do mostly with the port design of the 24 having some runner dimensions that are not as easily tweaked as the 12 is.<br><br>Larger valves are fine, but in most cases the valve is not the biggest restriction...the runner is. The 12 valve head has good valves for its runner size. <br><br>The Echo and the ISB use the same injector location and the same basic design...it may even be the same head.<br><br>Airflow is very important and most guys overlook it and just wanna pound in more fuel becuase it is generally a less expensive modification.<br><br>Don~