Ball milling reamer??

[Paul Workman]

OK, you machinists out there...Where would be a good starting place to start looking for a ball shaped milling reamer that is either chased or pulled thru a curved (i.e. intake plenum and IH) (aluminum) runner? Aside from a drill press and assorted air-driven tools, I don't have anything in the way of machining tooling. And, wanting to open up the plenum runners, I'm looking for a tool that a lay person could push or pull thru the runners that would open up the 33mm runners to a 36mm ID, perhaps in stages, if necessary. Sound crazy?

I've done more than a "little" time on a die grinder in my dayz, but looking at the LT5 runners makes me think there must be a better way than a TC ball bit and air-driven die grinder...NO?

I'm thinking of a TC ball cutter that can be attached to a flexible joint so the tool will (more or less) faithfully follow the existing centerline of the runner while opening it up.

Am I making sense, or am I doomed to hours with a grinder?

Also, where would one find a 36mm ball gauge?

TIA,

P.

[lbszr]

Did it the old die grinder way here but salemball.com I think was were I got chrome ones for not much.

[IowaZR-1]

You might want to look into extrude honing.
http://www.gethoned.com/process.html

[flyin ryan]

Originally Posted by IowaZR-1

You might want to look into extrude honing.
http://www.gethoned.com/process.html

No, you wouldn't

Originally Posted by flyin ryan

No, you wouldn't

It's garbage, doesn't remove enough material.

[XfireZ51]

Sorry Paul! I used a die grinder from Powerhouse
http://www.compperformancegroupstore...ory_Code=Burrs

I used the double fluted bits that don't gouge as much. More control.
Lgaff is still using one of my bits for doing the plenums he's porting.
Well worth the money, IMO.
Go ahead. Pull out the credit card. Resistance is futile

[IowaZR-1]

Originally Posted by IowaZR-1

You might want to look into extrude honing.
http://www.gethoned.com/process.html

I was wrong after seeing several of the threads posted.....die grinding/polishing by an experienced grinder is the only way to go.

[Polo-1]

I think it needs to be ground out by hand, then if you have the money to spend.... ex honing would be icing on the cake.

[flyin ryan]

Originally Posted by IowaZR-1

die grinding/polishing by an experienced grinder is the only way to go.

you said it, 100%. it's funny, the people i deal with & talk to daily in the higher end porting world is in fact rather small, the upper echelon of porters in North America ALL have the same opinion of the Extrude Hone process...it's a joke. i will say, on the outside, to people who are not semi experianced it does seem like it's a GREAT idea...it's like saying a bigger port will flow more air, while it MAY, that doesn't mean it will accelerate hard or quick, more often than not it will be the opposite...slow moving lazy air speed. i tell people all the time...you want the smallest port that moves the most/fastest mixture...not JUST air, MIXTURE!, Fuel & Air. i wish i could lay out some quick & easy mathematical equations or some simple guidlines to help, but there simply aren't any. it's a complex issue, which is why so many people have trouble. i'll lay out what i consider the five most important variables used to tune the induction system:
1. Average velocity;
2. Individual instantaneous velocities;
3. Shape/design (maximize a homogenous velocity profile over the ENTIRE port & at the same time promote efficient flow);
4. Rate of velocity change; & last
5. Airflow;
If a person follows these five variables you'll soon find out the most important rules of designing an induction system are: Velocity, Velocity, Shape, Velocity &, finally, Airflow.
I try to keep my engine building arm out of this forum, for the most part, but i hate seeing people going down the wrong road, so i apologize for partially stealing this thread. it wasn't intended. i could have jumped in many times in the past but i just let it go...can't educate everybody. i still don't know why some people think they can port out of the blue just by picking up a die-grinder? i call them carbide cowboys. you know what they say...a little bit of knowledge is dangerous...so true. one last thing...i PORT, not polish! i make the intake tract as rough as possible, the ONLY time i will lightly polish is on the exhaust port side & the only reason for that is so the carbon will have a harder time sticking to the port walls & building up over time on a street driven engine. absolutly nothing to do with so called flow. i've said enough

[tpepmeie]

Originally Posted by flyin ryan

1. Average velocity;
2. Individual instantaneous velocities;
3. Shape/design (maximize a homogenous velocity profile over the ENTIRE port & at the same time promote efficient flow);
4. Rate of velocity change; & last
5. Airflow;

Haven't I read that exact same quote/order of things from Darin Morgan over on SpeedTalk? I won't say who's doing my induction system, but I can assure you that he is following this very good advice.

According to this expert, The worst spots on the LT5 induction tract are the head-to-housing interface, and the too large bowl areas beneath the valves. The head-to-housing area is troublesome in that to make the air follow the awkward turn, the cross-section area of the port has to be slightly larger than optimal. I will say, overall, these heads will still be smaller & faster than current thinking in LT5 port work. Cant wait to get them back!

Todd