Angle Valve Cyl#1 Intake Pipe

[DanH]

Plenty of past debate about cold air intakes, but not much actual data.

I'd like to measure the intake air temperature just prior to arrival at the cylinder head. Doing so would require drilling a hole in the intake pipe, and possibly welding a bung or fitting. My 390 has a nice set of chromed pipes; I don't want to drill or weld on them.

So, anyone have a rusty old intake pipe gathering dust? Looking for cyl #1, angle valve with the tuned plenum sump, Lycoming # 78741, same as most IO360 angle valve models.



Temperature is also required for understanding intake pipe wave activity with this sump.

[hgerhardt]

Dan, why not use the primer port in the head? That's pretty close to the gasket interface where the intake tube mounts, and with the engine running should be plenty of gas flow to get reasonably close to the same temp as in the pipe.

You could use a Swagelok compression fitting in the port with a thermocouple inserted to whatever depth you want. You can find cheap TC readers on ebay.

Also, you could tap a hole (1/8 NPT) into the back of the plenum/sump and put a probe there. That's what I did years ago to tap off the manifold pressure for my panel gauge and electronic ignition. Could even do that while installed. Just remove the rear intake pipes so that you can clean out the chips from drilling/threading.

Heinrich

[868RM]

Dan I have either a number 1 or 2 intake pipe for a 390 will look later today

[larosta]

Dan,

If you can slip an extra gasket in place you might be able to position a thermocouple across the diameter and centered in the airflow. The extra gasket would electrically insulate and provide a seal around the thermoouple wires. We have used this technique to measure temperatures of in fluid flows where we did not want to make permanent modifications to a system in the past.

- larosta

[DanH]

Originally Posted by hgerhardt

Dan, why not use the primer port in the head?

Good idea, but already have a pressure tap screwed into the primer port.

Originally Posted by larosta

If you can slip an extra gasket in place you might be able to position a thermocouple across the diameter and centered in the airflow. The extra gasket would electrically insulate and provide a seal around the thermoouple wires.

Hey, there's a trick worth remembering!

[TShort]

I don?t have one, but am interested to see the data from this testing..

[rv6ejguy]

Dan, how are you determining crank or cam position?

[DanH]

Originally Posted by rv6ejguy

Dan, how are you determining crank or cam position?

Spark signal to a second channel...the 23 BTDC marker.

[Bdalporto]

I've always wondered if cold air intakes worked. It seems that the time the air spends in the hot part of the sump wouldn't be long enough for it to absorb much heat.

[airguy]

Originally Posted by Bdalporto

I've always wondered if cold air intakes worked. It seems that the time the air spends in the hot part of the sump wouldn't be long enough for it to absorb much heat.

Depends greatly on whether you are talking to someone from Engineering, or someone from Marketing.