OK guys,
I might be ready to try & port my own intake. My friend BAJAXRIDER04 ported his own & loves the results plus he said it was fairly easy. I just hate to mess with something that really isn't broke. However the added power gets me curious. I've ran a search on the subject & have found some opinions & tips. Some say pay to have it done right, others say you can accomplish the same thing with a dremel & some elbow grease.
My friends says it helped the bottom end mostly. Others say it improved top end. Is there a way to port it that you "tune" it a certain way? Maybe the way you jet it even? It just seemed weird the opinions were so different on where the power ended up. I just wondered if maybe certain diameter porting tuned it low or high end hit. Maybe even the smoothness of the finish? What do other recommend for the texture? smooth? factory type texture? swirls?
Do most of you drill out the mounting holes larger to line up the intake better? It seems as if some may have been lines up at the factory better than others.... What do you torque the intake bolts to in ft lbs?
Do most of you port out the initial ridge on the edge? So it's even larger than the rubber boot?
Do you try & keep the vein in the middle like the factory? Should you only port from the carb side? What about the bump on top, how much can you take off that without going through?
Do you trim the inside of the rubber carb boot out?

Sorry for all the questions, just want to make sure I do this right!!!
Thanks for any advice.

 

anyone?

 

Look at my pics and make your intake look like that. You could even make the carb side of the intake a bit bigger if you want.

 

The picture of MisterHP's intake picture under the gallery page answers a lot of your questions. His intakes are consistently good. The photo doesn't show the backside of the porting. Not much done back there.

On port matching, I use the allen wrench to drag across the joint as I torque the intake. Amazing how much misalignment you can feel by doing this. If I can't feel the joint by pushing or pulling the wrench across it, its close enough. I've seen the misalignment off by as much as 3/32".

I think 80-120 grit is fine. There should be enough slop in the stock holes so you don't have to drill out, but I would if the alignment was off. I lightly snug up the bolts and then thump the intake into postion with a rubber hammer....and then final torque.

jbt

 

The 1st thing you need to do is make sure the intake and the port openings align 100% when the intake is fitted to the head. The same for the carb side. There is a rubber mounting between the intake and carb, make sure that it also matches the intake and the carb opening. Clamp the intake, carb and rubber down, the same as you would do when it is mounted to the motor, and check if the rubber shape distorts inside the opening between the carb and intake. If so, grind it down so that the carb, rubber and intake is 100% aligned.

I know some people grind the intake opening much bigger. I don’t understand why. You have to think of the carb, rubber and intake port to the head as a unit. Grinding one part bigger does not mean more flow, if the other part it connects to have a smaller opening. Air needs a smooth even path. Adding holes and passages into the flow path will cause all kinds of turbulence. Something you don’t want in the intake side as it slows down airflow.

Looking at the intake on its own, people might think that grinding the opening bigger will result in more flow. It’s true, if you only have the intake and there is not carb in front of it. On a working motor the intake, carb and other things join together, so the bigger intake opening is doing nothing for performance. The carb is still smaller than the intake and air flow is restricted by the smallest opening in the whole intake tract. It’s like a human breathing thru a straw. Your air passages is way larger than the straw opening, but it does not mean you can suck more air thru it than the straw will flow.

Then try and remove all the sharp edges and pumps from inside the intake. Feel it with you finger and make sure it is even and smooth. Do not polish the inside of the intake. It still needs to be a bit rough.

 

I ported my intake ports to match my manifold as well....

 

Andrew,
if you have access to a micromiter (SP) it would be a big help. mesure the opening on the carb then take out what you need in the intake opening. past the mouth of the intake this will need to be a gesstamet, take out the bubble on top becarfull no to go through. dont touch the opening on the motor side unless theirs some groves from the cnc machine when the manifold is manufacterd( mine did ) you will know when you see it. do what freeze said for the rubber boot. Try to leave the vein all the way to the end ( kinda tuff but manageable) its not that hard really it took me 3-4 hrs total I took my sweet time. I used the wond feture on my craftsman dremmel with the little die grinder disks, sanding barrels. then when I was done took 80-120 grit ran it through it by hand.

drill out the bolt holes 1 size larger so you can align it to the head perfictly. I bored mine out to 47mm but im running the TM45 too.

O allso you want to cut down the angle the air/fuel has to turn, on the outer side wall grind this out to. see my pics if needed.
do it in a plase with GOOD lighting and cleanable cuz you will make a mess[img]i/expressions/face-icon-small-smile.gif[/img]
Sam

You going back to silver lake this year??

 

Thanks for the help guys.
I think BAJARIDER & myself are going back on the 10th & perhaps 11th.