Another gutted NB intake manifold
09-03-2009, 07:33 PM
#1
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Another gutted NB intake manifold
As promised in another thread, here are pictures of my recently ported intake manifold. This is from my '99 engine. I'll be adding the water injection nozzles next.
For the pictures go here:
Picasa Web Albums - John - manifold porting
This is about 10-12 hours of work to get this far. Most of the material removal was performed with a die grinder and various attachments. The upper manifold is not too bad to port out. The lower manifold on the other hand needs much more material removed. Note that the upper is completely open now. The lower has the two round ports joined together so that the runner is now one large oval plenum for each cylinder, transitioning into the section that connects to the head. I think that this will effectively shorten the runners though it is difficult to say by exactly how much.
For the pictures go here:
Picasa Web Albums - John - manifold porting
This is about 10-12 hours of work to get this far. Most of the material removal was performed with a die grinder and various attachments. The upper manifold is not too bad to port out. The lower manifold on the other hand needs much more material removed. Note that the upper is completely open now. The lower has the two round ports joined together so that the runner is now one large oval plenum for each cylinder, transitioning into the section that connects to the head. I think that this will effectively shorten the runners though it is difficult to say by exactly how much.
Last edited by ZX-Tex; 09-03-2009 at 08:20 PM.
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09-03-2009, 08:54 PM
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It should improve top end torque a bit, though probably not as much as a full-up custom manifold with a larger throttle. We will see when I get it to the dyno.
The main reason has to do with the water injection system. I am installing port nozzles and the open plenum space will allow for better mixing. It will also provide some fail-safe redundancy by sharing some of the water/meth mix between cylinders should one of the four nozzles become clogged.
The main reason has to do with the water injection system. I am installing port nozzles and the open plenum space will allow for better mixing. It will also provide some fail-safe redundancy by sharing some of the water/meth mix between cylinders should one of the four nozzles become clogged.
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09-03-2009, 09:05 PM
#5
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Hmm... we're looking at a long weekend. All my women folk have the flu. I need something to occupy my time and keep them away from me.
Maybe some "quality time" with the dremel is just what the doctor ordered...
- L
(Looking good...)
Maybe some "quality time" with the dremel is just what the doctor ordered...
- L
(Looking good...)
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09-03-2009, 10:13 PM
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Die grinders also consume a lot of compressor air. My compressor was running continuously for an hour or two at a time trying to keep up.
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09-04-2009, 03:04 PM
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I would get the die grinder from Northern by the way. The one I got is the Northern brand one with the red rubberized grip. It is holding up well with a dryer and some occasional lubing. The last die grinder I got from Harbor Freight went back; it was broken right out of the box. The Harbor Freight compressor is holding up well though.
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09-04-2009, 05:51 PM
#13
Throwing this out there. I had a $200 Sioux Tools die grinder. It was nice, but died after extensive use over a couple of years. I replaced it with an AmPro from Advance Auto. This thing was under $40 and has more power andhas so far lasted longer than the $200 Sioux. Highly recommended for The $.
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09-04-2009, 05:59 PM
#14
The cheap die grinder I have is just brutal on my compressor (5hp, 60 gal). I assume that it is very inefficient and that something that cost more than $30 would have less requirements for CFM. The China unit uses way more air than my 1/2" impact. Better have a good compressor.
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09-04-2009, 07:09 PM
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The cheap die grinder I have is just brutal on my compressor (5hp, 60 gal). I assume that it is very inefficient and that something that cost more than $30 would have less requirements for CFM. The China unit uses way more air than my 1/2" impact. Better have a good compressor.
You can reduce consumption a bit if you use a regulator set at say 40 psi, but then you do not have as much available power. It works OK if you are doing light grinding or polishing.
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