Naturally Aspirated Performance Forum Discussion of naturally-aspirated rotary performance. No Power Adders, only pure rotary power! From the "12A" to the "RENESIS" and beyond.

Porting mistake and porting question

Thread Tools
 
Search this Thread
 
Old 05-11-09, 10:17 AM
  #1  
Full Member

Thread Starter
 
D7ig's Avatar
 
Join Date: Oct 2005
Location: Kempen, Germany
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Porting mistake and porting question

Hi,

yesterday I started porting my housings and i jumped with the grinder out of the port
Look at the picture:

(inside the red marking you can see my work)
You can feel the marks a little bit with the fingernail.

Is that housing now very good for looking at it on rainy days? Or can i use it if i (maybe) polish the spots?


Another question:
Here is the primary port - i started with the porting:


I'm using the pineapple "large street port" templates. Maybe you can see the marking on the picture at the top left of the port. I should go further, but i am unsure how far and "deep" i can go (i don't want a hole to the coolant).

Thanks for advice,
Daniel
Old 05-11-09, 10:31 AM
  #2  
now
Rotary Freak

iTrader: (1)
 
now's Avatar
 
Join Date: Apr 2001
Location: alberta, canada
Posts: 1,825
Likes: 0
Received 1 Like on 1 Post
is that porous spots around the port?
if so they are worse than what you did,
I would say make sure you smooth down what you did and you should be fine.
my 2 cents
matt
Old 05-11-09, 10:41 AM
  #3  
Full Member

Thread Starter
 
D7ig's Avatar
 
Join Date: Oct 2005
Location: Kempen, Germany
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Hi matt,

the black spots around the port is paint for the porting template markings.

Thanks for advice!

Daniel
Old 05-11-09, 01:42 PM
  #4  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,835
Received 2,603 Likes on 1,847 Posts
Originally Posted by now
is that porous spots around the port?
if so they are worse than what you did,
I would say make sure you smooth down what you did and you should be fine.
my 2 cents
matt
yeah, intake stroke outside of the oil seal
Old 05-11-09, 02:44 PM
  #5  
Full Member

 
allbee's Avatar
 
Join Date: Nov 2003
Location: ohio
Posts: 69
Likes: 0
Received 0 Likes on 0 Posts
I just did the same thing porting out one of the end plates. Probly a little worse than yours. I sent it to be lapped so I'll see what the lapping did for my screw up.I'll let you know.
Old 05-11-09, 04:36 PM
  #6  
Junior Member

 
Mazdanowski's Avatar
 
Join Date: Jan 2008
Location: Chicago
Posts: 34
Likes: 0
Received 0 Likes on 0 Posts
I think most of us that rebuild motors port the housings first before we take housing in to get lapped. That helps with that problem. Remember it is not the low spot that the grinder dug out. You won't even lose 1 hp. It is the high spot that will catch a seal and nick it up. For a friend who nicked his housing, that did not need lapping, I cleaned it up with a palm sander and progressively finer grit. Just don't scratch it all up. It takes some time. If you have an old junk housing or piece of metal practice on that first.

Regarding the closing edge I don't own one of pineapples templates so I don't know how far they took it. But personally I like to make it a very gradual taper. That way the incoming air doesn't have to make that sharp bend. Plus it you are just adding a radius to that closing lip you don't have to worry to much about the water jacket.

On some of my housing, can't remember if they were the 12A or 13B, I can stick my little finger in the water jacket and reach the backside of the intake port. Then I know how much material is left and how close that template maker makes it. I think on the S4 I could stick a wire down the EGR passage and get a little idea how thick the casting was in that one spot. Again that is only from memory.

FYI I now run some pretty long grinding bits that I never walk all the way out. I also hold the grinder with two hands and rest them on my work. Even so I often tape off the unported area or lay a piece of scrap sheet metal over it so I can't knick one (any more).

My two cents.
Old 05-14-09, 04:24 AM
  #7  
Moderator

iTrader: (3)
 
diabolical1's Avatar
 
Join Date: Feb 2002
Location: FL
Posts: 10,819
Received 307 Likes on 268 Posts
i used to do that all the time when i first started. none of my ported engines have shown bad compression or smoking. i think you'be fine. i've learned to use duct tape for surface protection, so for future reference, try that. good luck with your build.
Old 05-14-09, 11:39 AM
  #8  
Old [Sch|F]ool

 
peejay's Avatar
 
Join Date: May 2001
Location: Cleveland, Ohio, USA
Posts: 12,507
Received 416 Likes on 296 Posts
The front housing on my current engine had a bunch of dents/dimples in it, near the top about an inch below the coolant seal area. Smack dab in the middle of the side seal track, in other words. (It looked like it was transported with something else next to it and dinged it several times) Every ding had a raised area around it.

I first gently used a *swank* miniature, curved file to clean off most of the high spots, then the leading edge of a small regular file to shave off most of the rest. Then I kept running my finger over it and used a sharp gasket scraper to shave them down to the level around the housings.

About 9k on the engine, so far still has great compression.
Old 05-14-09, 01:38 PM
  #9  
Lapping = Fapping

iTrader: (13)
 
Jeff20B's Avatar
 
Join Date: Aug 2001
Location: Near Seattle
Posts: 15,725
Received 70 Likes on 64 Posts
The dents are tiny and the seals move past quickly.
Old 05-15-09, 08:30 AM
  #10  
Full Member

Thread Starter
 
D7ig's Avatar
 
Join Date: Oct 2005
Location: Kempen, Germany
Posts: 51
Likes: 0
Received 0 Likes on 0 Posts
Hi,

that is nice to know, thank you guys! :-)

Daniel
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
The1Sun
New Member RX-7 Technical
9
03-18-18 11:08 PM
hotshot2014
New Member RX-7 Technical
8
07-18-17 02:30 PM
Skeese
Adaptronic Engine Mgmt - AUS
65
03-28-17 03:30 PM



Quick Reply: Porting mistake and porting question



All times are GMT -5. The time now is 10:45 AM.