Soooo, I've been a little concerned as to how much crud actually get's into the exhaust when you drill and tap for the pyro.

So I did a little experiment, just to ease the nerves and here is what I found.

I used several pieces of angle iron, in various thicknesses, to simulate different spots on the manifold.

Drilling the pilot hole with 1/8" bit

Low Speed Drilling:

1 - Using a new, VERY sharp bit at low speed produced larger pieces and also some spiral fragments. These spiral fragments came up and out with the bit.

High Speed Drilling:

1 - Again, a new, sharp bit, but at high speed and VERY LOW pressure produced nearly NO bits or spirals. Basically just dust

Drilling the main hole with a 21/64" bit

1 - Drilling at low speed produced larger fragments and a more jagged cut.

2 - Drilling at high speed, low pressure produced tiny, tiny fragments and no noticeable spiraling. Almost all fragments were to the outside of the hole. What was inside was dust like.

Tapping the hole - I did this 3 different ways

1 - Tapping with no grease, no vaccum, no magnets produced the largest pieces and these went into the hole. What was produced was larger than I felt comfortable with, but still HIGHLY unlikely to cause any damage at all.

2 - Tapping with a magnet placed near the hole produced similar results as the previous attempt, but all pieces ended up stuck to the inside of the iron where the magnet was placed. Nothing actually fell down to the surface.

3 -Tappingwith vacuum and a magnet prodcued no fragments in the hole, everything was either captured by the magnet or sucked up in the vaccum. Very little was even on the magnet.

Results / Recommendations

1 - Drill a pilot hole at high speed, low pressurewith the engine off.
1a. Do not drill this with the engine running. If this small drill bit does break, it WILL cause damage.

2 - Drill the main hole at high speed, low pressure with the engine off.
2a. Do not us grease here. This will clog the bit flutesand if it does drop into the manifold, this makes for a sticky abrasive goo.

3 - Tap the hole with either vacuum or the engine running to expell any particles.
3a. Tap to the recommendations of the manufacturer.

4 - If you are not comfortable with the engine running or vacuum, loosen (do not remove) the bolts on the turbo mounting flange and slide a piece of tape (sticky side up) between the turbo and the manifold to catch anything that does fall. Obviously remove this and re-torque the mounting bolts to 24 lb/ft before starting.


Just some observations I made while doing a few test fits.

 

That is some real good info, I have been putting off gauge installation because I did not want to run a risk of turbo damage,

I might still pull the manifold because Murphy is always just around the corner at my house.


paul

 

What I did with the vacuum was I took one of the brush attachments for the shop-vac, pulled the brush off and drilled a 3/4 inch hole through the top of it.

What this let me do was run the drill with 360* of vacuum at the drill point and still see what I was doing.

I did the same thing on the tap and had almost no pieces on the magnet at all.

Instead of removing the manifold, just loosen the 4 bolts on the turbo mounting flange and place a few pieces of duct tape (sticky side facing the manifold) and anything that does fall will stick to that. Then jsut re-torque the mounting flange bolts back to 24 ft/lb.

 

Awsome write up....I will definitly have to look this one up again when I get my gauges...

 

I'll get actual pics as soon as the wife gets back with my truck on Weds / Thurs.

She's got the camera too, so I couldn't get pics of the tests.

 

good job

 

great tip's 'I have preformed this procedure and had no problems 'I used a magnet that came from a old dodge trans pan there round with a hole in the center .

 

Have you got any pics of this modified vac attachment ?

EXCELLENT write up !! Thanks !!!

 

As soon as the wife gets home with my truck and camera, I'll get you some pics.

I'll do the step by step so you see the whole thing.

 

Did the wife forget to come home ???