The other day I was working on porting my 13bt end plates to large strret port and seen a hole a little larger than a pin hole, oh ****,I stopped right there, so I read some forums about pros and cons of using epoxy or JB weld to fill overported ports, so I went ahead and did just that, I filled the hole from both sides with JB Weld and smoothed it out with the grinding stone and I looks great, I just need some info on cast iron expansion rates like if it will crack the epoxy or if it should be fine, cause if judge ito uses this stuff on his engines than thats good enough for me, and another thing, I am using NA intermediate iron on my turbo rebuild with NA rotor housings, so should I do the same to plug the EGR holes in the primary ports, my EGR is all blocked off so I need to make the airflow as smooth as possible in the primary ports, Thanks

 

For the temp ranges we are concerned with, JB Weld works fine.



Just make sure that the area you try to stick it to is "three dimensional" so that it has better bite.

 

Also use a long wood screw. Once you fill in the hole with JB weld put the screw into the stuff before it sets. That way if the stuff cracks it has something to grab. If it comes loose it will stay together. To keep it from falling in enlarge the hole on the EGR side to give it better grip.