SonexBuilders.net

Hi all
Have a question. I ended up replacing all my valves from single spring to dual spring. With all new parts as you know from a Gen 1 engine Jabiru changed the head bolts from hex heads to torque heads which are much better. However, the torque heads are much deeper then the hex heads which makes it impossible to install cylinder head temp leads on each intake plug. My plan was to cut a little of the fin on the head to give some room. Or another suggestion was to drill a hole onto one of the fins and add a screw to connect the wire.for the cylinder lead. So I was wondering if anyone has done done exactly that instead of the system that they have now. Any thoughts on this? Any suggestions would be appreciated. Thank you


Mark

Anyone?

Hi Mark, I'm not sure if this is of any help, but Sonex sells type j and k thermocouples that you can attach to the heads
with a screw.
www.sonexaircraft.com/eshop/cart.php?ta ... ory_id=330

I have a Jab 3300 (gen 2) and have cht sensors mounted between the plugs in an 8-32 threaded hole. They work very well in that location.

Rick
C-GRIX
Yorkton, Sk

Rick524 wrote:Hi Mark, I'm not sure if this is of any help, but Sonex sells type j and k thermocouples that you can attach to the heads
with a screw.
http://www.sonexaircraft.com/eshop/cart ... ory_id=330

I have a Jab 3300 (gen 2) and have cht sensors mounted between the plugs in an 8-32 threaded hole. They work very well in that location.

Rick
C-GRIX
Yorkton, Sk

Hi Rick. Thank you for the reply. That’s great to know that these are available as the old one need to be replaced shortly. Would you be able to post a pick on the location your talking about.

Thanks again for the reply

Mark

I suggest posting your question on the Jabiru / CAMit forum. There are some knowledgeable folks familiar with the old Gen 1 heads on that. If all else fails, Jabiru will be happy to sell you the type that install under the plugs, also easy to make your own just purchase type J or K wire as needed. the thermocouple is nothing more than the junction of two dissimilar metals in the thermocouple wire. Might also consider slipping a bit of thermal insulation over the wires at the junction end so that cooling airflow does not draw heat away from the junctions.

David A.

Mark, I sent you a pm.

Rick

Thanks Rick.
Appreciate it.

Mark

Hi Mark, well I dont think my pm to you got sent, its lost in the ozone....I have a picture of a jab head with the cht
sensor mounted on it. It would be easier to send it to your email address if you can give it to me.

Rick
C-GRIX

Thanks for the help gentlemen. I ended up purchasing all new leads as posted from by Rick. Thought I would replace as I wanted to change to the new cooling baffles so I ordered them as well.

Thanks you again for the advise.

Mark

For one I am a little confused here! As far as I seem to recall from my Jab gen 1 and -2 days, the Jab installation manual indicates the cht sensor ring is supposed to go under the sparkplug closest to the exhaust valve (not the inlet valve).

Discussions have run high for the best position for the pickup. Under the plug is fine, but there is a lot of cooling air circulating there actually causing erroneous readings. The hottest position of the head is on the underside of it, close to the lower cyl head bolt. There have been suggested numerous solutions to pick up the cht at this position.

Thx