I'm asking the experts: engineering a solution
 

Given the amount of technical knowledge, backyard engineering, and as my friend calls it "Booty Fab" here, I'm hoping to for a bit of creative advice here.

In the current stable I have a 1999 Isuzu Vehicross that has the factory 3.5L engine and an aftermarket supercharger. That's where the problem begins. The shop that installed the supercharger (prior to my purchasing it) did a bad job and stripped several holes in the aluminum parts.

The area of concern right now is the EGR valve. The stock EGR valve is a solenoid that's mounted at the back of the intake on the passenger side near the firewall. The supercharger intake doesn't have any material in that area, so the company that created the kit (A non-us company, so parts can be hard to obtain) built a small (2"x3"x2") aluminum block. There are 3 mating surfaces on this block. The bottom has an approx 1" female threaded fitting that the egr pipe threads into. The top has the mount for the EGR valve, and the right side has a 2-bolt flanged fitting for the output, which connects to the vacuum side of the supercharger.

The EGR fitting on the bottom was threaded in at an angle, cross-threading the large female fitting in the aluminum. I'm having a hard time finding a place that has helicoils in any metric size larger than about 14mm (the popular spark plug size).

So, here is where the creative part comes in. I'm trying to figure out how to connect an approx 5/8" steel EGR pipe to the aluminum block. Using the threaded fitting is out for now. I'm thinking of purchasing a new EGR pipe, cutting it off short and using some kind of flexible tubing to connect to the aluminum block. If I can do that, I can relocate the EGR valve to somewhere other than it's current position at the firewall.

FAQ:
Q. Do I need the EGR.
A. Yes. I still have to pass emissions, I have an OBDII vehicle that can tell if the EGR flow is incorrect.

Q. Do you have a photo.
A. Yes. http://tad2.grosvenor.org/albums/NewVX/Engine2.sized.jpg The EGR valve is the black upright "canister" at the back, behind the passenger's side fuel rail.

There is some Mercedes content here. While the Vehicross is parked, I'm driving my wife's Mercedes. It makes me want a 300Dt engine in my truck, just for the smooth "500k mile" lifespan :)

-Tad

Here is your
 

source for any helicoil made. :)
http://www.emhart.com/products/helicoil.html

i second the beauty of a helicoil. I used one on my fuel injector mount on my VW TDI. Been working great for 10,000 plus miles now.

Tougher than heli-coils
 

Stronger, tougher, and make a better looking job than heli-coils.

http://www.timesert.com/

I vote for the Timeserts also... these look like an updated version of Threadserts.... the standard fix on the head/jug stud hole in millions of aircooled aluminum VW bug blocks.

Note that these (Timeserts) might require a counter bore if you need them flush with the surface you are dealing with.....

So part of the question is whether you will have this item out of the vehicle so that you can use a drill press.

Why not take the whole piece out of the car, take it to a machine shop, and have them duplicate it? Minus the buggered threads, of course.

It would cost you a bit, but I kinda agree with Rick on this one, as far as I'm able to follow your conundrum here. Find a small machine shop that could make a whole new adapter block for you. They'll probably charge you something in the area of $50/hr, and shouldn't take any longer than a couple hours to make it, if they have decent equipment and hunks of aluminum laying around.
Next best would be helicoils, or any of the above mentioned inserts. But it kinda sounds like they did a hack job in making the block in the first place. Got any pictures of the block by itself?

I'll take a few more of the block itself. I just have pics of two of the three interesting sides.

http://tad.grosvenor.org/gallery/VXMods/CIMG2005

http://tad.grosvenor.org/gallery/VXMods/CIMG2007

I'll take a pic of the EGR pipe (large threaded ) hole tonight.

I've struck out at one machine shop. $25/hole for helicoils and they couldn't do the large hole as they didn't have anything that size.

I have a decent tap & die set but nothing as large as the EGR fitting. It's somewhere around 18 or 19mm. The 18x1.5mm helicoil kits are around $150 and the Time-Sert kits are around $190.

I'm still trying to contact the company to get a replacement, and still trying to find a machine shop that can either reproduce it or install a helicoil that large.

-Tad

Your OBDII needs and EGR something huh ?

Over at neons.org (look in their 1st gen forums...) there is a "fix" where you solder a resistor in and connect it to the factory EGR connection- this resistance "fools" that computer into thinking the egr is really connected and functional-

**for off-road use only of course***

=)

I'm not sure if the isuzu resistance is the same, but the method is described somewhere in the neons.org forums. but I bet even a clymer manual would tell you all you'd need to know (where to connect, ohm value of stock egr...)


Mercedes diesel content: My wife had a neon up until last weekend (we bought a subaru), while she had that neon- she was married to a guy who has a 240D.

Oh, I could just leave the EGR valve hooked up if that was all that was needed. The computer is "smart" enough to know when the flow through it isn't right though. If the line becomes plugged with carbon, it will throw the check engine light.

So, who can tell me the dimensions of a 300D turbo engine. I'm looking for firewall to front of fan. It pains me that my wife has the only Mercedes in our household. I'd love to do a diesel swap.

-Tad

The swap would be very difficult...and very expensive, unless you are an experienced welder/fabricator/"inventor" etc. and can do it yourself !
Also, what would happen when you went to get your first emissions test after the swap ???? Would it be something like "Hi, I just replaced my clean burning OBD2 engine with a mid 80's "oil burner"...

Other than these two things, it seems like a great idea to me !

You could use a 1 1/4" pipe thread tap to enlarge and retap the aluminum block, they're easy to find and cheap. Then, depending on what the EGR 5/8 piece you mentioned is, you could 1) get lucky and find a pipe adapter, 2) fab a new piece from steel pipe with the right size male end, or 3) be able to relocate after some plumbing. Problem solved.