Porting the LIM (w/ pics) - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Performance, Brainstorming & Tuning Talk about modifications, or anything else associated with performance enhancements. Have a new idea for performance/reliability? Post it here. No idea is stupid! (please use Detailing and Appearance for cosmetic ideas)

Reply
 
 
 
Thread Tools Search this Thread
Old 12-10-2007, 04:29 PM   #1
Senior Member
Posts like a Camaro
Thread Starter
 
Join Date: Jun 2007
Location: Chambersburg, Pennsylvania
Posts: 882
Thanks: 0
Thanked 0 Times in 0 Posts
putertopia is on a distinguished road
Default Porting the LIM (w/ pics)

I've decided to start a new thread, one of the many LIM porting threads, incase I run into any trouble.

Agrazela hooked me up with an LIM, and here it is:

Name:  IMG_0280.jpg
Views: 4
Size:  118.5 KB

Name:  IMG_0281.jpg
Views: 4
Size:  120.6 KB

Pretty good shape, but I'm going to clean it after I do the porting. I figured this way, there can't be any stray metal shavings in there anywhere when I go to install.

So, I've outlined the ports with sharpie, and I'm going to scratch off the area that needs cut out. Problem is, how to you find the center of the port, and accurately measure how much needs cut off each side? How do I know the port isn't off center from the port on the head already?

Name:  IMG_0292.jpg
Views: 4
Size:  59.8 KB

Also, some of the dimensions already exceed the measurements willwren got from the heads. But I'm assuming that'* typical for that area of the port?

Name:  IMG_0298.jpg
Views: 3
Size:  98.8 KB

Name:  IMG_0299.jpg
Views: 4
Size:  73.2 KB

I want to do this perfect so I don't have to waste my time/money working on this AGAIN, and I can devote it to the list of parts I have sitting in my room that need installed.
putertopia is offline   Reply With Quote
Old 12-10-2007, 05:12 PM   #2
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

At it'* widest and tallest, it'* the correct dimensions. Clean out the corners and edges to those points. Smooth out the roughness all the way up after that, including the injector boss, but don't enlarge that.
willwren is offline   Reply With Quote
Old 12-10-2007, 05:21 PM   #3
Senior Member
Posts like a Camaro
Thread Starter
 
Join Date: Jun 2007
Location: Chambersburg, Pennsylvania
Posts: 882
Thanks: 0
Thanked 0 Times in 0 Posts
putertopia is on a distinguished road
Default

So then I really don't want to touch the top and bottom lines, other than to smooth them, right? From the looks of it, a lot of material can come off of the top left side.
putertopia is offline   Reply With Quote
Old 12-10-2007, 05:22 PM   #4
Senior Member
Certified GM nut
 
Join Date: Oct 2006
Location: burb of detroit. 2 miles north of 8 mile Rd.
Posts: 2,028
Thanks: 0
Thanked 0 Times in 0 Posts
samueljackson is on a distinguished road
Default

i thought the end result for a head match was 1.900 by .900?

is that LIM 45 and 23 thousansths over before you started?
samueljackson is offline   Reply With Quote
Old 12-10-2007, 05:22 PM   #5
Senior Member
Posts like a Camaro
Thread Starter
 
Join Date: Jun 2007
Location: Chambersburg, Pennsylvania
Posts: 882
Thanks: 0
Thanked 0 Times in 0 Posts
putertopia is on a distinguished road
Default

That'* what I thought. I haven't touched it yet other than with sharpie.
putertopia is offline   Reply With Quote
Old 12-10-2007, 05:53 PM   #6
Senior Member
Certified GM nut
 
Join Date: Oct 2006
Location: burb of detroit. 2 miles north of 8 mile Rd.
Posts: 2,028
Thanks: 0
Thanked 0 Times in 0 Posts
samueljackson is on a distinguished road
Default

Quote:
Originally Posted by putertopia
That'* what I thought. I haven't touched it yet other than with sharpie.
ive only had time to finish a whole 2 ports on the LIM i am porting, so im far from an expert. but all 6 had about 80 thou to get to "the magic #*" of .9x1.9

so going from those specs ur at, i would just smoothe em out as bill said.
samueljackson is offline   Reply With Quote
Old 12-10-2007, 06:25 PM   #7
Senior Member
Posts like a Camaro
Thread Starter
 
Join Date: Jun 2007
Location: Chambersburg, Pennsylvania
Posts: 882
Thanks: 0
Thanked 0 Times in 0 Posts
putertopia is on a distinguished road
Default

I do have to widen the upper part of the port, as it only measures .823 ish.
putertopia is offline   Reply With Quote
Old 12-10-2007, 06:55 PM   #8
Senior Member
Posts like a Corvette
 
Join Date: Jan 2007
Location: San Diego, CA
Posts: 1,451
Thanks: 0
Thanked 0 Times in 0 Posts
agrazela is on a distinguished road
Default

That LIM actually went from Boosty to TJ, and it was coming to me, but I sold it to putertopia instead without ever having seen it myself...glad it looks good!

In my experience, there are certain "spots" in the up-down and side-side of the LIM ports that are already larger than the head port dimension. They seems to be right at seams in the casting. There'* nothing you can do about those...just make sure you don't go over 0.9" by 1.9" anywhere else.

As for locating the porting...in my case, I had a set of heads on my bench to mate the LIM to; sans that, I guess you have to take your current LIM off and do ALOT of careful measuring...

(Note, if you want to do this before removing your current LIM, you can usually buy a set of cylinder heads--especially L36 heads--for around $100 shipped on various forums...use them as a guide then resell them, or port and polish those, too and install them )
agrazela is offline   Reply With Quote
Old 12-10-2007, 07:10 PM   #9
Senior Member
Posts like a Camaro
Thread Starter
 
Join Date: Jun 2007
Location: Chambersburg, Pennsylvania
Posts: 882
Thanks: 0
Thanked 0 Times in 0 Posts
putertopia is on a distinguished road
Default

Yeah, I could buy a set of heads for it... but I think this LIM will be good enough for me. If I ever figure out a way to buy an SSE/SSEi (or a dead se for cheap and drop in l67), I'll consider that. But until then... I'll stick with the areas I'm familiar with, or whenever I get a chance to go to a meet where people are ten years familiar with this motor lol.
putertopia is offline   Reply With Quote
Old 12-10-2007, 09:46 PM   #10
Senior Member
Posts like a Camaro
Thread Starter
 
Join Date: Jun 2007
Location: Chambersburg, Pennsylvania
Posts: 882
Thanks: 0
Thanked 0 Times in 0 Posts
putertopia is on a distinguished road
Default

Well the porting is done... now I just need to find a bit to smooth it out on the inside. The wire wheel didn't last long...

Here are the pictures:

Name:  IMG_0306.jpg
Views: 3
Size:  140.8 KB

Name:  IMG_0307.jpg
Views: 3
Size:  138.3 KB

And... are you sure this is tolerable? This is even before I touched the thing with the bit to smooth it out a little.

Name:  IMG_0304.jpg
Views: 3
Size:  135.2 KB
putertopia is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
General Cylinder Head Porting/ Intake Manifold Porting 101 Speedster400 Performance, Brainstorming & Tuning 6 11-07-2007 10:51 AM
My L36 LIM Porting (with pics)...NOW WITH DATA! agrazela Performance, Brainstorming & Tuning 66 04-06-2007 01:48 PM
KDG LIM Porting karldergrosse Performance, Brainstorming & Tuning 39 03-29-2007 07:07 PM
Porting LIM; do any good for a Series II n/a? agrazela Performance, Brainstorming & Tuning 20 02-02-2007 02:04 PM
Black94SSEi's LIM gaskets and porting (new pics) BillBoost37 General GM Chat 27 09-18-2006 09:06 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:37 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.