KDG LIM Porting
#21
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Modifying the outlet of the LIM and the inlet to the head to try to negate any 'pocket turbulence' will actually disrupt the airflow and hurt performance.
This isn't from my own personal experience, but rather from research I did on the subject before I ever ported my first LIM.
This isn't from my own personal experience, but rather from research I did on the subject before I ever ported my first LIM.
#22
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The intake ports in the LIM reduce in cross-sectional area by over 30% from UIM to head.
If you open the port up to the size of the LIM gasket, the cross-sectional area at the outlet is still smaller than what you started with. And if you continue to gasket match the heads and taper the port back to the valve, you are still effectively decreasing port size..
In other words, if you gasket match the LIM and heads correctly, you will still be ramping up velocity but with less turbulence and more flow potential.
I can't see that hurting performance.
If you open the port up to the size of the LIM gasket, the cross-sectional area at the outlet is still smaller than what you started with. And if you continue to gasket match the heads and taper the port back to the valve, you are still effectively decreasing port size..
In other words, if you gasket match the LIM and heads correctly, you will still be ramping up velocity but with less turbulence and more flow potential.
I can't see that hurting performance.
#23
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Ag,
My g jnumber is the same as yours. Bolt holes measure .465. Am using your tear down guide from your post. It works well. Good guide. Decided to skip the knock sensor. After playing with it for a half hour I said screw it. I think I may have a major problem though. Some pics to follow.
My g jnumber is the same as yours. Bolt holes measure .465. Am using your tear down guide from your post. It works well. Good guide. Decided to skip the knock sensor. After playing with it for a half hour I said screw it. I think I may have a major problem though. Some pics to follow.
#24
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Some pics:
![](https://i173.photobucket.com/albums/w53/karldergrosse/DSC01113.jpg)
There was almost NO clearance between the stovepipe and the hole in UIM
Only have 89000 miles but it was starting to weld thru. Glad I'm doing this now.
![](https://i173.photobucket.com/albums/w53/karldergrosse/DSC01117.jpg)
UIM off. whew... no coolant.
Now here'* my problem...........
![](https://i173.photobucket.com/albums/w53/karldergrosse/DSC01116.jpg)
After taking the fuel lines out of the hold down I thought I saw a hole in the line. I think it is just a nick or crease. Don't know if it was from me removing it or if it was there already. I think I'm screwed. After reading the factory service manual, it said to replace fuel line if it'* nicked or dented. I thought no big deal until I see it runs all the way back to the fuel filter. Looks like a huge PITA to replace. Is it possible to repair a fuel line even though they reccomend against it? Help!!!
![](https://i173.photobucket.com/albums/w53/karldergrosse/DSC01113.jpg)
There was almost NO clearance between the stovepipe and the hole in UIM
![Shocked](https://www.gmforum.com/gm/images/smilies/icon_eek.gif)
Only have 89000 miles but it was starting to weld thru. Glad I'm doing this now.
![](https://i173.photobucket.com/albums/w53/karldergrosse/DSC01117.jpg)
UIM off. whew... no coolant.
Now here'* my problem...........
![Crying or Very sad](https://www.gmforum.com/gm/images/smilies/icon_cry.gif)
![](https://i173.photobucket.com/albums/w53/karldergrosse/DSC01116.jpg)
After taking the fuel lines out of the hold down I thought I saw a hole in the line. I think it is just a nick or crease. Don't know if it was from me removing it or if it was there already. I think I'm screwed. After reading the factory service manual, it said to replace fuel line if it'* nicked or dented. I thought no big deal until I see it runs all the way back to the fuel filter. Looks like a huge PITA to replace. Is it possible to repair a fuel line even though they reccomend against it? Help!!!
#25
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Originally Posted by karldergrosse
Ag,
My g jnumber is the same as yours. Bolt holes measure .465. Am using your tear down guide from your post. It works well. Good guide. Decided to skip the knock sensor. After playing with it for a half hour I said screw it. I think I may have a major problem though. Some pics to follow.
My g jnumber is the same as yours. Bolt holes measure .465. Am using your tear down guide from your post. It works well. Good guide. Decided to skip the knock sensor. After playing with it for a half hour I said screw it. I think I may have a major problem though. Some pics to follow.
Thanks for the shout out on the guide...I'm using it again myself starting in about 2 hours on my wife'* 2004 LeSabre (I discovered that the newer car'* alternator is physically smaller and does not block that one LIM bolt, and that will shave some serious time and trouble!). Just remember to save the oil change for last.
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If that'* not a hole, maybe you could ignore it... :?
Maybe you could slip some 3/8 ID fuel line over it, lightly hose-clamp it to either side of the crease, keep your nostrils open, and visually check it weekly...
Or maybe there'* a way to cut and hose-barb in a replacment segment...
You'll probably want other opinions than mine on this.
Maybe you could slip some 3/8 ID fuel line over it, lightly hose-clamp it to either side of the crease, keep your nostrils open, and visually check it weekly...
Or maybe there'* a way to cut and hose-barb in a replacment segment...
You'll probably want other opinions than mine on this.
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#27
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2.018 x .983 are the port size on my gaskets. Sorry bout that.
Edit 1: How did you measure with the calipers? Did you keep one point steady and rock the other side (keeping light pressure on the thumb dial)? There is a lot of room for error.
Edit 1: How did you measure with the calipers? Did you keep one point steady and rock the other side (keeping light pressure on the thumb dial)? There is a lot of room for error.