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Brazing in lambda bung
se7ensport - 13/6/08 at 01:24 PM

basically will this work or is it likely to melt the braze out once running?


Cheers

Alex

Werner Van Loock - 13/6/08 at 01:39 PM

moving to the next step with the vems?

will121 - 13/6/08 at 01:40 PM

how far are you placing it down the manifold? if after the collector or 750mm would expect it be ok, but would think it be better welded.

02GF74 - 13/6/08 at 01:49 PM

manifold distance from engine will make that decision for you as well as melting point of solder.

I was playing with IR termometer just a coupld days ago.

crossflow with 4-2-1 exhasut.

temp at head 300 C
temp at pipe where it exits through body 50 C
temp at tail pipe 30 C

these temperature will be higher if engine is driven hard but then there is air cooling.

se7ensport - 13/6/08 at 01:52 PM

quote:
Originally posted by Werner Van Loock
moving to the next step with the vems?


Indeed Werner, I'm planning on going to injection over the next few weeks, just a few odds and sods to sort first.

iank - 13/6/08 at 01:53 PM

Melting point of the filler metal is going to be the decider. 450 degrees C is about the lowest going up to over 1000oC IIRC

twybrow - 13/6/08 at 01:54 PM

Were you measuring stainless with an IR thermometer? If so, the readings will be tosh, due to the emissivity (shinyness!) of the tube. Put some masking tape on, coloured black with a pen. If not - ignore me!

se7ensport - 13/6/08 at 01:55 PM

quote:
Originally posted by will121
how far are you placing it down the manifold? if after the collector or 750mm would expect it be ok, but would think it be better welded.


Planned to put it approx 100 cm from head, after the 4-1 collector to ensure I'm getting an accurate reading from all cylinders.

i'm thinking that I should just do it properly and weld it, its just that I have brazing gear readily to hand....

02GF74 - 13/6/08 at 02:03 PM

quote:
Originally posted by twybrow
Were you measuring stainless with an IR thermometer? If so, the readings will be tosh, due to the emissivity (shinyness!) of the tube. Put some masking tape on, coloured black with a pen. If not - ignore me!


indeed - so ignore the last 2 readings although when I grabbed the tail piece, it was not that hot so 30 was reaonable I thought.

Bluemoon - 13/6/08 at 02:21 PM

From what I recall, Stainless steel is actually quite black in the infrared, I expect the readings at not to bad.. Shiny surfaces in the visible are not always shiny in the infrared...

Dan

stevebubs - 13/6/08 at 02:53 PM

quote:
Originally posted by se7ensport
quote:
Originally posted by will121
how far are you placing it down the manifold? if after the collector or 750mm would expect it be ok, but would think it be better welded.


Planned to put it approx 100 cm from head, after the 4-1 collector to ensure I'm getting an accurate reading from all cylinders.

i'm thinking that I should just do it properly and weld it, its just that I have brazing gear readily to hand....


Just pop round to your local welder...will be cheaper than having the sensor damaged by brazing filler....

bikenuts - 20/6/08 at 12:27 PM

Just after the collector can be a bit of a hot spot - so I'd weld. To be honest anywhere that's hot enough to keep a lamda sensor nice and clean is likly to be a bit hot for braze.