LM-1 exhaust Boss fitment

[twoforty]

I have just bought myself the LM-1 wideband unit, I was wondering if anyone had welded the boss onto the manifold and the best way to go about it.
Should I weld the boss in place and then drill out the manifold or drill the manifold and then weld the boss in place?
Thanks

 

[Mr.G]

I think a 19mm hole must firstly be made into the manifold, then the bung is tack welded and then properly welded on.

By welding the bung on first, and then making your hole you risk damaging the threads of the bung.

I will probably take my manifold to a precision engineering place and have them drill it and weld it, since I don't have a welder nor a way of making a 19mm hole.

 

[twoforty]

I found this on the net,

The sensor boss should be located between 24" and 36” from the cylinder head if possible. On vehicles with tubular headers the boss should be installed in the collector. Weld the boss to the exhaust then drill through with a 15 or 16mm drill ( 5/8 ). Install the sensor. Use antisieze compound to ease subsequent removal of the sensor.


the part of the sensor that sticks into the manifold is actually smaller than 19mm, I have all the kit here so I think I will drill a hole with my cone cutter until the sensor will fit and then weld the boss on top. Hopefully my manifold isn't too rusty

Mr.G I will let you know how I get on, that LM-1 looks like a trick bit of kit

 

[Mr.G]

Good luck! And please do let us know.

Before you drill, don't forget to check out the tips on locating the bung, in the full manual. There was some warning info. about how not to place it, which I cannot recall now.

 

[twoforty]

Yeah you need to mount it so its between 10 o'clock and 2 o'clock so as not to get condensation on the sensor. You also need to start the car before turning the sensor on.

 

[twoforty]

Hey Mr G,

I fitted my lambda probe today, it wasn't too hard to do. My mig welder developed a fault whcih didn't help but once I had borrowed another it was done in an hour.
I marked the boss on the pipe with a marker pen, drilled the hole out to 18mm and then welded the boss in place.
I fitted mine to the ehaust rather than the manifold as it was easier to remove than the manifold. I had just fitted the manifold back on after a bad head gasket, If I had known I was going to buy this I could have done it then.
here are some photos...my welding isn't great !

 

[twoforty]

and a few more,

 

[Mr.G]

Hey Well Done! And thanks for sharing the photos.

You're welding is fine! I wish I could weld.

Job well done there, how very satisfying for you. There is definately pleasure in saying I did it then I got someone to do it.. Top marks that man

The great thing about your LM1 is that it's portable so you might find yourself ordering the bung kit for other cars, especially as you know you can make a hole and weld a bung easily.

 

[twoforty]

Thanks!

Yeah I'dlike to weld a bung in each branch of the manifold to map each cylinder...maybe a little over the top though .

I will wire it up tomorrow and let you know what kind of readings I get.

The manual says the sensor life is betwen 50 and 500 hours, seems a bit strange as most sensors on permanently in the exhaust. I had a car with one that was 10 yrs old and still worked. It was only a 3 wire sensor so maybe the fact its a 5 wire has something to do with it.

 

[twoforty]

Hey Mr G.
I got it all working, after adjusting the idle mixture I took the car for a quick blast and recorded the run.
I've not hooked up the rpm module yet so the log is pretty hard to understand
here is a link, you can download the log and playback the file on your Logworks program.
Its running at 10.6:1 at WOT which is rich so I'm going to drop the main jet size and try again, the idle circuit seems pretty good.

http://www.innovatemotorsports.com/forums/showthread.php?t=5086

 

[Mr.G]

hey well done!

You are very far ahead to where I am, I have just looked at it and put it back in the box.. lol

I did download your file and have the Logworks program installed so i did view it, it's deciphering it that Im having trouble wiv.. I am going to have to get me manual out and have a read.

I know that the boys at HybridZ.org are very well versed with the LM1 and it will also be worth posting this question on that forum also.

Top work though.

 

[twoforty]

True,I'm going to make a throttle position sensor tomorrow and also connect the rpm module, will make reading the results a lot easier.

Will check out hybridz, thanks!

 

[twoforty]

Arghhhh my manifold has a crack in it now which is giving lean spikes on my LM-1. So today I spent all day removing my exhaust and manifold, Man that manifold is a PIA to get off. I also removed my Carbs just to make sure the throttle plates were adjusted correctly. will get there eventually

 

[Mr.G]

What a PITA! At least you know that your LM1 wasnt at fault.

If you don't want to source a new manifold, may be best if you did though, there is a sealer made by Por15 called Fire Seal 2000, which is supposed to be good at repairing cracks in manifolds.

Here is the link, its available from Frost Automotive CLICK ME

 

[twoforty]

Thanks Mr G
It only cracked because the system is one piece not my doing. When I removed the rear clamp the whole system was hanging on the manifold

I could have done with that stuff when I had my Esprit, that manifold was cast iron and had cracks all over it, it caught on fire in the end!

 

[twoforty]

How not to change an Exhaust!

what a nightmare this has turned into. After welding up the manifold and spending a day fitting it I find out its still blowing!!! arghhhhh
Ok so I buy a new manifold and remove the exhaust system again but this time the rear silencer snaps off when I pull the system from the manifold, in anger I throw the old silencer at my house, it bounces off and breaks the back light on my VW golf
I go to my van do get my drill, open the side door and can't reach it, slam the door and break the catch! go to the rear door which won't open as the lock is sticking so I kick it and smash the rear number plate light

At this point I was ready to kill someone so I packed up all my tools and went out to cool down.

I bought all new 2 1/2 inch pipe and rear silencer, fitted the new manifold and made a new system.

Just started the car and the new manifold is leaking....anybody want a 240 for £1
who ever designed that ehaust manifold/intake manifold bolt pattern wants shooting, It's so hard to get to all the nuts.
Oh well another 2 days wasted.

 

[Arkwright]

have you had a bad day then?

I've get the £1, do you take paypal? (or I could pay C.O.D)

 

[twoforty]

Bad day? bad 4 days more like

 

[Mr.G]

Hey mate, I totally know what you mean about those days!

I want to scream for you or at least scream with you. Best thing to do is to take a break go and chill have a good malt whiskey or a pint or both or whatever is your poison . Leave the Z be till the weekend!

 

[Mr Ex]

[who ever designed that ehaust manifold/intake manifold bolt pattern wants shooting, It's so hard to get to all the nuts.
Oh well another 2 days wasted.[/quote]
IT HELPS IF YOU HAVE LITTLE FINGERS!