Air injection removal . . .

[Ronnie's.930]

I'm in the process of rebuilding the engine from my 1987 930 - I would like to remove the air injectors and plug the holes (mainly to do away with all the components associated with the air injection system) but a reputable Porsche engine builder in the Dallas area thinks that the injection system actually helps to cool the exhaust valves on the 930 engines . . . any opinions on this (seems far fetched to me)? Thanks!

Ronnie

[BMAN]

You know the funny thing is when I was ripping mine out I was thinking the same thing. It pushes air though the system and it might not be a bad idea to leave it installed.

[beepbeep]

It introduces O2 which helps burn residual HC which helps the emissions but actually raises temperature as it's exotermic reaction. Remove it.

[930gt-40r]

I think this engine builder you speak of may have mistaken assembly lube for doughnut jelly...
Air injection is evil unless your a part of green peace. As beepbeep says, it is there to burn residual hydro-carbon (gas) and help the catalist in this function. I would get rid of all emissions junk including the cat and you should see a nice diffrence. + the loss of weight, its probley close to half a passenger.
There is no way that it cools the valves enough to make a diffrence If you think about volume of air vs. volume of exhaust gas...
I have a set of injector port plugs if you need.

[NathanUK]

I thought that thing was a supercharger

[930gt-40r]

Originally Posted by NathanUK

I thought that thing was a supercharger

I thought it was a flux capacitor judging by its complexity...

[Ronnie's.930]

Thank you for the input, guys . . . I will be removing the system as advised.

I'll be happy to take the port plugs off your hands - I'll PM you . . .

Ronnie

[jwmarc]

I would just say that the euro spec cars doesnt have the associate emissions stuff ...so why not get the extra HP of a euro car...my two cents.. also maryland Metric sells the plugs for 50 cents a piece... I did my 87 930 in March when the car turned 20.

[beepbeep]

Originally Posted by jwmarc

I would just say that the euro spec cars doesnt have the associate emissions stuff ...so why not get the extra HP of a euro car...my two cents.. also maryland Metric sells the plugs for 50 cents a piece... I did my 87 930 in March when the car turned 20.

I believe all 930's had air-injection fitted. My German-sold 81' 930 had. Some (ROW) cars did not have catalystic converter and O2-sensor installed though.

[WERK I]

Originally Posted by beepbeep

I believe all 930's had air-injection fitted. My German-sold 81' 930 had. Some (ROW) cars did not have catalystic converter and O2-sensor installed though.

Me too. My 930 Slant, circa 1985, came from the factory with air injection.

[equality72521]

Anyone have pics of the air injection system installed and uninstalled?

[Robbbyg]

An old threasd but i revived it because im wondering about the air plugs..

As im removing the injection things they are all snapping off leaving the bit inside,

Do i need to remove this also?
ive removed three on the right and put the proper bungs in but the ones ont he left are pain and i dont have room to move.

Can i just jbweld the holes up leaving the remnants of the plugs inside??

Right side removed air and installed Bung -ok

left side (under pistons 1,2,3)
cant even get to them properly and i dont want to remove exhaust
can i JB weld hole??

[Ronnie's.930]

WOW, Robby, you just pulled up the very first post I ever made on Pelican (first thread I started, too). It is bizarre to look back on this thread and to think how I was just starting to learn about these cars in earnest back then.

The problem with leaving the broken off bits in the heads is that they will likely break apart further and then travel into your turbo and destroy it. Also JB weld will burn off very quickly - I think that JB claims that it can withstand 600 degrees for very short intervals, and that area of the head sees sustained temps of more than double that.

Also note that there are no references to Paul or any bird flippage gifs in this thread - well, that's because I was not acquainted with either of those "things" back then!

[oilonly]

I hate to say it but i think you have to remove the exhaust manifolds to get at those injector bolts. That's what i did when i removed mine. Of course then you run the risk of breaking one of the manifold bolts. Slippery slope.

[JFairman]

If you can't get at them you have to remove the heat exchangers. JB weld is kinda like plastic and will burn off real quick.

The nuts (usually 12mm but maybe 13mm) holding on the heat exchanges are probably rusted on to the 8mm x 1.25mm thread pitch studs so spray some stuff on them and let it soak in for a while. They're fun to get at too. Offset box end wrenches and 1/4" drive sockets usually work there.

If the nuts resist you don't want to force it and break off the studs because you'll be in for another painful adventure drilling out the old stud. If that happens there is a jig to do that without destroying the threads in the heads. You can also time cert them if the threads do get messed up. That's actually an upgrade.

If the nuts are rusted on carefully heat them up a dark red hot with an acetylene/oxygen torch while moving it around continuosly so you don't melt any metal, let them cool off the amount of time it takes to turn off the gas to the torch, put it down, pick up a wrench, put it on the nut, and by then it won't be glowing dark red anymore and they usually screw right off easily with a little squeak as they break loose at that point.

With a torch it's all pretty easy but I never had those heat exchangers, my car had B&B headers on it with the air injection system functioning when I got it. There is no emission testing/checking in Florida so I sold the Nippondenso air pump Porsche put on there after removing all that stuff. The rest of it was junk and I tossed it.
I bought the stainless steel plugs with copper washers that screw in with an allen head wrench that Pelican sells and put them in with red loctite. FWIW, I think I read somewhere that the stainless plugs were originally made for a Mercedes.

When you put it all back together use ultra high temp nickel anti seize on the studs and nuts that's good for up to 2400 degrees. Permatex makes little tubes of it. I bought some off ebay for around $6 and had it in a few days.

[Robbbyg]

Dammmmmmmmmmm what a pooftie!

not only the exhaust bolts but i gunked in a lot of jbweld i will have to remove the turbo and somehow blow it out!

Another painful and unnessary job i created on my car.

what do i do scrape it out before it sets or let it harden ?

[Robbbyg]

And happy anniversary Ronnie on this old post lol

[JFairman]

Use a machinest scribe do dig it out. They have them at hardware stores for a few bucks.
One of the most useful tools you'll ever have.

[Ronnie's.930]

Robby (aka: the air injection pooftie supreme!) - sound advice from Jim.

One thing I wanted to mention is can you get AeroKroil down thar in ASStralia? I ask, because it is an excellent penetrant to use on rusty/stuck fasteners.

Here's what I'm talking about -

Amazon.com: Kano Aerokroil Penetrating Oil, 10 oz. aerosol (AEROKROIL): Automotive

[Robbbyg]

Originally Posted by Ronnie's.930

Robby (aka: the air injection pooftie supreme!) - sound advice from Jim.

One thing I wanted to mention is can you get AeroKroil down thar in ASStralia? I ask, because it is an excellent penetrant to use on rusty/stuck fasteners.

Here's what I'm talking about -

Amazon.com: Kano Aerokroil Penetrating Oil, 10 oz. aerosol (AEROKROIL): Automotive

I have a mix of Engine Oil and acetone in a spray bottle, it does most nuts prettywell ill see how that goes, i also have a small oxy to heat them up, and i actually do have a set of scribes funningly enough so i should be able to get off the exhaust studs and pick out the crap i put in there, without too much trouble, about 4 months ago i bought the tools and the barrel nuts to remove exhAUSt STUDS so im prepared in that area,
I took it for a drive to the pub tonight and one of the air holes are def leaking i was expecting worse, on the plus side i nust have reduced vacuum leaks by doing what i did so far, ill drop it all out tomorrow and do it properly,
I hate jobs when you have to lay under the car all day i dont have any sort of hoist so its laying with the bottom of engine pressed against my face very uncomfortable.

While the exhaust is off ill also prob take off the turbo and muffler while im in there is there anything i can do while its all off?

Any checks or upgrades ?