2G ported intake manifold- completed and installed(PICS)**
Oct 31, 2014 18:38:44 GMT -6
Randy T. and jamezruiz like this
Post by scottyaurorav8 on Oct 31, 2014 18:38:44 GMT -6
So I had the cracked/leaked intake plenum boot issue the Northstars seem to get, months and months ago. When I fixed it. The entire job took me 4 1/2 hours. I was very thorough and never did it before. (Having the torque wrench and extra injectors o-rings on hand made it a lot easier).
Well when the manifold was off. I checked out the runners etc... And always thought to myself, they could be ported. Nothing major, but I do see imperfections that could be smoothed out. If the corvette ls2 guys can do it, so can I.
So I measured the heads. The inlets (I was only concerned with the width, not the height b.c the way the injectors fit into the manifold from the outside, no shaving down on the inside top ridge could be done. Well from side to side the heads inlets each measured 2 1/4 inches, on the dot! (All 8). Well the intake manifold runners measured 2 1/8th inches. So basically the manifold when its seated to the head, the runners are narrower than the heads. So the manifold runners arent allowing the most optimal amount of air flow to enter the head.
I purchased a used intake manifold from eBay for $40. Degreased it, scrubbed it, let it dry and it was perfect. I took my dremel and used the cylindrical sander bit, set on speed #10 and started shaving down the lip on the inside of the runner (the bump on the inside b.c of how the injector set into it from the outside). B.c of that, there's a lip on the inside. I also widened the sides to 2 1/4 and smoothed everything out with a triangular stone bit that the sander couldn't do b.c of certain angles. After doing each runner, I hand smoothed it all with fine sand paper. It came out great.
So here's the deal, stock- you can fit a 17mm socket inside the runner directly in the center where the edge of the base is where the injector gets set. On both sides of this center ridge you can fit a 19mm socket in there. Well after i finished my sanding, I was able to fit a 19mm socket nicely in place of the 17mm socket, and a 22mm socket in place of where the 19mm socket was placed. The structural integrity of the runner was not compromised, but anything more I wouldn't do.
Looking on the inside of the main large intake opening, there were lined ridges deep in the inlet, I could have smoothed all that out as well, but since this was a test piece, I didn't want to go to crazy yet. Esp. if this doesn't work. The porting job took me about 4 hours total. 2 hours each side.
So today I swapped the intake manifolds. It took me a little over 3 hours this time. I got a lot better doing this now haha. I have to be honest I was expecting it not to work at all so I was going to be my own harsh critic when driving.
After everything was attached, she fired right up. (Now I did not dyno her guys, this is based on feel and the fact I drive her every day) I don't want to spend $100 dynoing her.
I noticed the car idled smoother. First driving impressions. The throttle response was a little quicker. Nothing mind blowing, just noticed a little bit more pep. And much smoother acceleration without a doubt.
I noticed the most from my 40-50, and 60mph launches. It pulls noticeably better. Again nothing seat of the pants crazy, but I can confidently say I feel a good difference more so from already moving, rather than from 0-20mph. And it makes sense b.c when you are already going, the air is filling up the plenum and stacking the air, so now more volume can exit and funnel the runner faster.
So now I know it works, I want to take my original intake manifold and do the other things I planned on doing. Maybe it will work even better. Hope you guys like this.
I will attempt to post pics. I always have issues posting.
Well when the manifold was off. I checked out the runners etc... And always thought to myself, they could be ported. Nothing major, but I do see imperfections that could be smoothed out. If the corvette ls2 guys can do it, so can I.
So I measured the heads. The inlets (I was only concerned with the width, not the height b.c the way the injectors fit into the manifold from the outside, no shaving down on the inside top ridge could be done. Well from side to side the heads inlets each measured 2 1/4 inches, on the dot! (All 8). Well the intake manifold runners measured 2 1/8th inches. So basically the manifold when its seated to the head, the runners are narrower than the heads. So the manifold runners arent allowing the most optimal amount of air flow to enter the head.
I purchased a used intake manifold from eBay for $40. Degreased it, scrubbed it, let it dry and it was perfect. I took my dremel and used the cylindrical sander bit, set on speed #10 and started shaving down the lip on the inside of the runner (the bump on the inside b.c of how the injector set into it from the outside). B.c of that, there's a lip on the inside. I also widened the sides to 2 1/4 and smoothed everything out with a triangular stone bit that the sander couldn't do b.c of certain angles. After doing each runner, I hand smoothed it all with fine sand paper. It came out great.
So here's the deal, stock- you can fit a 17mm socket inside the runner directly in the center where the edge of the base is where the injector gets set. On both sides of this center ridge you can fit a 19mm socket in there. Well after i finished my sanding, I was able to fit a 19mm socket nicely in place of the 17mm socket, and a 22mm socket in place of where the 19mm socket was placed. The structural integrity of the runner was not compromised, but anything more I wouldn't do.
Looking on the inside of the main large intake opening, there were lined ridges deep in the inlet, I could have smoothed all that out as well, but since this was a test piece, I didn't want to go to crazy yet. Esp. if this doesn't work. The porting job took me about 4 hours total. 2 hours each side.
So today I swapped the intake manifolds. It took me a little over 3 hours this time. I got a lot better doing this now haha. I have to be honest I was expecting it not to work at all so I was going to be my own harsh critic when driving.
After everything was attached, she fired right up. (Now I did not dyno her guys, this is based on feel and the fact I drive her every day) I don't want to spend $100 dynoing her.
I noticed the car idled smoother. First driving impressions. The throttle response was a little quicker. Nothing mind blowing, just noticed a little bit more pep. And much smoother acceleration without a doubt.
I noticed the most from my 40-50, and 60mph launches. It pulls noticeably better. Again nothing seat of the pants crazy, but I can confidently say I feel a good difference more so from already moving, rather than from 0-20mph. And it makes sense b.c when you are already going, the air is filling up the plenum and stacking the air, so now more volume can exit and funnel the runner faster.
So now I know it works, I want to take my original intake manifold and do the other things I planned on doing. Maybe it will work even better. Hope you guys like this.
I will attempt to post pics. I always have issues posting.
