Rick Engman's Exhaust Port Shape - Thoughts
02-23-2005, 12:16 PM
#31
Senior Member
Join Date: Feb 2003
Posts: 240
Originally Posted by C. Ludwig' date='Feb 23 2005, 08:34 AM
How To Modify Your Mazda RX-7 by Dave Emanuel and Jim Downing. Out of print. I picked up a used copy for $85. Lot's of good info but most of it is dated (1987) and common knowledge on the boards now.
and as I showed before, a lot of the tools/methods/examples that were shown in the book in pictures and descriptions are still at Rick's shop
02-23-2005, 01:00 PM
#32
Senior Member
Join Date: Oct 2003
Posts: 352
Originally Posted by 93BlackFD' date='Feb 23 2005, 10:15 AM
and as I showed before, a lot of the tools/methods/examples that were shown in the book in pictures and descriptions are still at Rick's shop 
it's like a museum of rotary history
Before your thread I knew who Jim Downing was and knew the accomplishments that had come from his shops. I didn't realize Rick was the man behind the the engines. And let's face it, the engines are what we really are interested in. After reading the thread and making the connection I had to have the book.
02-24-2005, 10:09 PM
#33
Senior Member
Thread Starter
Join Date: Oct 2004
Posts: 110
This turned out to be a pretty good threat. Still, my courosity hasn't been satisfied. To bring it back to my initial question, is there a significant pulse and if so is it desirable. My turbo builder buddy was replying to my question " what pulse??? Have you ever heard a drag RX of the line. It sounds like a never ending explosion...that is the beauty of the rotary, continous exhaust flow"
CW
CW
02-25-2005, 10:01 PM
#38
Member
Join Date: Sep 2004
Location: Alaska
Posts: 35
My 2 Cents,
What if the rounded port opening was made to assist on exhaust evacuation/scavenging?The first pulse comes out and while the closing seal is passing the port,the next exhaust pulse is starting to come out of the port pushing the first exhaust pulse gradually until the port is fully open.This could (in theory) help draw out spent exhaust gases from the first exhaust pulse.Similar to an h pipe on v-8 engines(equalizes flow while aiding in scavenging).Just figured I'd throw this out there.
Nick
What if the rounded port opening was made to assist on exhaust evacuation/scavenging?The first pulse comes out and while the closing seal is passing the port,the next exhaust pulse is starting to come out of the port pushing the first exhaust pulse gradually until the port is fully open.This could (in theory) help draw out spent exhaust gases from the first exhaust pulse.Similar to an h pipe on v-8 engines(equalizes flow while aiding in scavenging).Just figured I'd throw this out there.
Nick
02-26-2005, 06:09 PM
#39
Senior Member
Thread Starter
Join Date: Oct 2004
Posts: 110
So,
I filled up the original ports and now have a 1.5 inch round hole going through the housing ready to be ported and shaped to my desire. Still not sure what I want. My timing is (looking at the pics) obviousely set-up for a lot of overlap, late exhaust port closing.
I filled up the original ports and now have a 1.5 inch round hole going through the housing ready to be ported and shaped to my desire. Still not sure what I want. My timing is (looking at the pics) obviousely set-up for a lot of overlap, late exhaust port closing.
02-27-2005, 11:33 PM
#40
Member
Join Date: Aug 2004
Location: Houston
Posts: 76
Originally Posted by z8cw' date='Feb 26 2005, 07:09 PM
So,
I filled up the original ports and now have a 1.5 inch round hole going through the housing ready to be ported and shaped to my desire. Still not sure what I want. My timing is (looking at the pics) obviousely set-up for a lot of overlap, late exhaust port closing.
I filled up the original ports and now have a 1.5 inch round hole going through the housing ready to be ported and shaped to my desire. Still not sure what I want. My timing is (looking at the pics) obviousely set-up for a lot of overlap, late exhaust port closing.