source for inexpensive EGT probs

[n502pd]

Thanks much for the info. That is what I need to determine that I would be better off getting commercial made ones. I do want to fly this craft some day soon!! :D

[Bryan Cotton]

I am thinking of trying some cheap probes.
http://www.ebay.com/itm/173777289773
I need to buy something so I can wrap my exhaust. Looks like the GRT probes are $43 each. Has any cheap homebuilder actually tried these?

[n502pd]

ha! hello again! i got 10 probe off of either amazon , or ebay, from china. took a couple of weeks, i bought 6 to have spares. be sure to get the adjustible insertion length ones with the hose clamps. i also wrapped my pipes. The adjustable ones need to be matched depth wise. i set mine to be about 1/8 in off the opposite side of the pipe
from the mounting hole. i am sure u realize there j type and k type, grounded and un grounded. ur instrument will tell you which. but, i tell you stuff i am sure you already know!

Joe

[Bryan Cotton]

So Joe, you are flying with these? Working ok I assume?
Thanks!

[NWade]

Hello All,

While I don't want to dissuade people from experimenting or building their own solutions, I did want to put the cost of an EGT probe (and the possible savings of getting a "cheap" one) in perspective:

A Sonex is going to cost you somewhere between $30,000 and $45,000 (USD).
You can get good-quality EGT probes from Dynon or MGL Avionics for $36 to $45 apiece.
So a complete set of EGT probes will cost you about $160 to $300, depending on the number of cylinders your engine has.
That means a set of quality EGT probes from a reputable source only makes up 00.7% of the cost of your airplane.

If your goal is to complete your airplane, ask yourself whether its really worth extra time it takes to source 3rd-party probes (or build your own)!
The simpler and more-straightforward your build, the sooner you'll be done and enjoying your airplane. :-)

--Noel
Sonex #1339, inching towards first flight...

[peter anson]

I'll put an alternative view. Price doesn't necessarily equate to quality. When I built my Sonex I wanted to do everything right so bought my sensors from the Australian MGL agent along with the Stratomaster panel. Price was about A$60 each so over A$700 for the 12 thermocouples or more than 2% of my total build cost. The CHT sensors have been consistently reliable but 2 of the EGT sensors failed within the first 2 years. When I updated the exhaust a few years ago I paid another A$350 for a new set of EGT sensors (the original exhaust had screw-in type). The newer set have been reliable but if I did it again I think I'd just buy the cheap ones plus a few spares. Thermocouples either work or they don't.

Peter

[kmacht]

[quote="NWade"]

If your goal is to complete your airplane, ask yourself whether its really worth extra time it takes to source 3rd-party probes (or build your own)!
The simpler and more-straightforward your build, the sooner you'll be done and enjoying your airplane. /quote]

Every penny adds up when building a sonex and there is quite alot to be said for the learning experience gained from small decisions like choosing egt probes. If your goal is just to get in the air as quickly and cheaply as possible then you are better of buying a used sonex.

Keith
#554

[DCASonex]

GRT's EGT probes are good, but be sure to get the long life versions, More economical in the long run. Only got a bit over two years on the cheap ones.

David A.

[n502pd]

So Joe, you are flying with these? Working ok I assume?
Thanks!

Yes, i am flying with these. only a couple of hours, but with the adjustable depth able to be set on all four, now the numbers are a bit closer. further, in an attempt to better ballance the fuel-air charge at each valve inlet in the heads, I have put on the other manufacturers intake manafolds in place of the aerovee style manafolds. all of my engine building buddies agree I should get more even charge distribution on all cylinders.I probably will have to adjust the mixture needle again. I have yet to run up, and fly, because of bad, rainy, low ceiling cold days....still !....here in N tx. for the price differences, even if I only get a couple years out of them, I still would use them again.

[Bryan Cotton]

Thanks for all the feedback. I am going to try out the eBay probes. I am also going to try the eBay CHT probes for a 14mm plug. I have some type K wire, which I could easily use to make CHT probes if those don't work.