Chips are a flyin'!

[Paul Workman]

Boy...My hat is off to all of you that have done the P&P on you uppers! The first hole on the plenum took perhaps 3-1/2 hours of try this and try that with a combination of burs and rotary files. And, true to what Marc H and Pete have said, "If you don't perforate the plenum at least a few times, you not tying hard enough." I managed to "burn thru" in a couple runners (so far) but hopefully the cause for that is behind me. Oh, well...I planned to repaint the engine anyway. Now I have the motivation to do it (after the holes are welded and ground down).

I bought the speed control for my electric die grinder fm Harbor Freight, but I also have a fairly good pneumatic, right-angle die grinder. As anyone that has done this knows, there is a art to getting a 3/4" open flute bur to cut w/o chattering - it is the chattering that is a real killer, because it can be rather violent! As it turns out, the pneumatic approach is working 10X better than the electric grinder (for me). The degree of control and power is far superior to the 'lectric die grinder, IMO. (For one thing, max torque on the electric is available only at "wide open", and there are times I want to go slow and still have sufficient torque to cut w/o the load dragging the rpm down. Then there is the ability to start and stop and start again by just pressing the air control lever and no inertial issues: instant on and instant off = much more to my liking! I'll relegate the electric to sanding chores later.)

Aside from my back killing me from being bent over for hours yesterday, I was pleased to be able to rough out (yet to be sanded) my last hole (so far) in 35 minutes w/o perforating the plenum, and w/o the bur chattering at all. (I figure the plenum is a good piece to start with. I want to be "comfy" with the tools and burs before I wade into the IH work (next).

I'm using the (carbide) burs with the rather large open flutes recommended by the tool maker for aluminum, and I think I'm good with that as far as the plenum work goes. However, if there is a different bur U experts would recommend especially for the IH - to say nothing of the heads (which will be done in place) this rookie is all ears!

Pix later. I hope I'm on the right track. I'm getting excited about the end product that I hope to realize at the track come spring! And, I want to thank Pete for the use of his balls! (No, I'm not going to spit on 'em, Pete. But! I promise to keep 'em warm!)

P.

[LGAFF]

I am on my third plenum, this one is for Karterdon......CCmano has another one I did last year, and of course my own. I take mine to 36mm(meaning I can pass a 35mm ball through), I did go through one plenum on my first time through, but none after that. You really should not burn through, if you are you might be taking too much out of the short turn. My guess is you went through on the short turn in an area where there is a crease.

[Paul Workman]

Nope. Actually it was on the outside turn; the large radius opposite to where you are pointing. I was taken by surprise at how fast the bur was cutting and I wasn't aware that I was in danger of not following the existing radius. (Lesson learned) It is pretty thin at best, and I've learned to be aware of the radius when I get there. So far I haven't bitten thur the short radius side.

You mentioned using a 35 ball gauge to end up with 36mm. Hmmmm.... I'm using the 35 followed by the 36. I suspect I'll be closer to 36.5 after dressing it up a bit with the sander. 36 would have been fine, I think...Less work if nothing else! (If 36 = the magic number, and 36.5 = excessive, it can be to top end of a proper taper into the IH where I can (in effect) build in an (air column) acceleration cone effect which will ultimately extend a couple inches into the head...(But don't tell anybody...That's a "Helmholtz" secret)

Yours is nice looking work, BTW. My first couple of holes were not so perfectly round - result of initial issues keeping the bur from chattering. Now that the trick to eliminating that is found, ("it's all in the wrist") the last 3 holes are "poifect" (at least to the naked eye!). My next one (if ever there is one) will be sans those neophyte kinds of "tracks".

But, I AM having fun!

P.

PS. Thanks Lee for the help! (Lee and all the gang of the "Brotherhood" have made my transition to the ZR-1 a breeze!...But, spit shine Pete's balls? Forgeddaboudit Pete!!)

[Pete]

Paul, buy yourself a steel cutting carbide,with small cutting flutes no chattering and more control.

I have one it's old,i need to get a new one,if you wanna try it.

Get 3/4" oval.

I know it sounds crazy but works great.

Pete

[Jagdpanzer]

Originally Posted by Pete

Paul, buy yourself a steel cutting carbide,with small cutting flutes no chattering and more control.

I have one it's old,i need to get a new one,if you wanna try it.

Get 3/4" oval.

I know it sounds crazy but works great.

Pete

Pete,
You mean like this type?


http://www.ruffstuff.com/pages/carbide.html#cut

Can you tell us what shaft length you find works best?

[LGAFF]

Originally Posted by Jagdpanzer

Pete,


Can you tell us what shaft length you find works best?

The wife says 12" shaft


I use the 4" shaft....6" ideal to reach, but with my Die grinder it lead to alot of whipping.

[A26B]

What method are you using to keep the port centerline & spacing to spec?

[XfireZ51]

Originally Posted by LGAFF

The wife says 12" shaft


I use the 4" shaft....6" ideal to reach, but with my Die grinder it lead to alot of whipping.

Lee,

Are you using Enzyte or ExtenZe?

[flyin ryan]

Originally Posted by Jagdpanzer

Pete,
You mean like this type?

similar to that but single cut, not double cut. will be an SE-6. i get mine from Quality Carbide Tool in Elk Grove, IL. tool # 170171.

[GOLDCYLON]

PW my hats off to you for taking this job on by yourself. Locobob did mine before Jeffvette Pced the rest. Dominic also did this and I think the both of you have come to the quick conclusion just how damn hard and painstaking this work is that most here take for granted. Keep up the good work and keep in the back of the mind how much $$ you saved and how much pride you get from doing something yourself !