Originally posted by haywyre
with the sedan cars nats comming up I have a question about something. I was told that the current batch of engines comming into the US has the exhaust ports to tall 
Has anyone else heard about this?? this will make them illegal under current ROAR rules. HAYWYRE
On O'Donnell race it was already allowed to use increased exhaust timing from 4.5 mm to 4.8 ( from 154.41 degrees to 159.73 degrees) I heard yesterday that on nationals it will be lifted too. But haven't seen yet written so far.