M112 - 300 Build for the '56

Wesman07 said:
I have been getting very similar results. I am more confident in the quality of my gas than my abilities so I’m looking for other possibilities.
What cup size are you using? How long is your post flow set at?
Click to expand...
Using an 8...which is small (largest in ny arsenal). But Im confident it wasnt the issue. I couldnt even weld a spot without it graying.

Welds like crap on mild steel too, and Im confident with it.

Post flow at 5 seconds...which is probably a waste of gas...

Another hint is the tungsten is immediately blueing, only at 35 amps. So there is something not right with the mix.
 
They probably gave you a mig mix instead of the 100% argon for tig...The mig mix will not work with tig...Make sure that you have no hole,leaks in your lines..
I may have some new 60lbs per hr matched injectors if you think they are big enough.
 
O2 sensors all in...that was one of those jobs that should have taken a few hours, and took all day...

Burnt up my step drill, drill the 18 ga stainless...will have a hole saw for any stainless in the future.

20210322_165551_HDR.jpg

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Any recommendations on where to mount the MAP sensor?

Id like to keep it on the motor but I don't know it that is a good idea or not?

Maybe on the mount I will be mounting the coil packs to? On the side of the valve cover?
 
You don't want the MAP sensor near any ignition coils.
Nor do you want to run the wires from the Map near any of the wires going to the coils.
 
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pmuller9 said:
You don't want the MAP sensor near any ignition coils.
Nor do you want to run the wires from the Map near any of the wires going to the coils.
Click to expand...
Any issues with mounting it on the motor somewhere? Or should I be looking at mounting it on the cab, firewall, inner fender, or possibly close to the ECM?

I could mount it on the opposite side of the valve cover from the coils, above the fuel injector rails. Any issues with it being ran with the FI wires?
 
I would try to keep both the map sensor and the vacuum line going to it away from any heat source that will fluctuate. I have never heard of it being an issue, but I imagine it could screw with it?
 
The shorter the cable between the MAP sensor and ECM the better.
I would keep the MAP sensor off the engine from a heat and vibration perspective.
It is best to keep any sensor cable away from any other cable that has a strong switching current like ignition coils or fuel injectors.
 
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That's a long way for all the sensor and driver cables.
Can you mount anything under the dash?

If behind the passenger seat is still the best spot I would run all output or driver cables in one metal conduit and all input and sensor cables in a separate metal conduit from the ECM to the engine compartment up the firewall near the back of the valve cover.
The metal conduits need to be well grounded at the ECM end.

You will have to use a Hall Effect sensor for the crank trigger wheel.
The cam sync signal from the distributor should already be Hall Efffect

To answer the vacuum line question.
A longer vacuum line increases the delay between intake manifold pressure/vacuum changes to when the MAP sensor see those changes.
You may want to put that on the firewall.
 
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Holley, Megasquirt and other high end standalones that use internal MAP sensors seem to work okay being remote mounted in the cabin, but it seems best practice to keep the distance from the source short. Even then though, you can have to damp the signal if it's too sensitive in some cases. I vote for firewall mount, it has worked well for many OE applications.
 
Most everthing looks to be fitting nicely! Is there room to duck the air intake behind the grill, under the front part of the drivers fender, or next to the radator support with a hole to bring in air?
 
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