Jump to content

Ignition module failure rates up


Safety Officer

Recommended Posts

FYI,

 

Ignition module failure rates seem to be on the increase either because reporting and communications are better or because installation issues are causing this. These seem to be failing between 400-800 hours TTSN from the ones I have been hearing about. These won't be covered under warranty after warranty is past.

 

Here is the tip of the day.

 

Ignition modules can only take so much heat and with the huge increase in LSA Mfgs. and nice tight cowls the heat inside can get trapped with no where to go. The issue isn't usually when you are flying as there is usually good air and heat exchange. The problems start when you stop flying and park and the under the cowl temps climb and they can climb quite high. It would be nice if aircraft Mfg's had known this and given the heat some where to go. Some are lucky and have an oil door on top to open, but many don't.

 

It would be a very sound practice to buy some heat sensitive tape strips. The target heat to stay away from is anything over 175F. So a strip that reads anywhere from 150F-220F may be a good place to be. Place this heat strip on the ignition module. If the heat strip keeps popping above 175F you might think of a way to get rid of some of the heat after your done flying. If you need to replace your modules the newer soft start modules are going for around $750 for the pair, but may not be this way forever..

Link to comment
Share on other sites

John,

 

Thanks for the post. I've never given this any thought and usually install cowl plugs after shut down.

I won't do this in the summer months anymore and will pop open my oil filler door.

 

Do these temp strips mark the highest temp reached so you can observe at a later date or do you need to look under the cowl on the hot days to look at the strip before it begins to cool?

 

Where are these strips available?

 

Rich

Link to comment
Share on other sites

Eddie's example shows it perfectly. Thanks Eddie.

 

 

You can find them on line by just typing in temp test strips or something similar. They also come in many different temp ranges. I would think something along the line that the Safety Officer recommended for temp range. These strips many times have little dots and when it breaks out of that temp it darkens.

Link to comment
Share on other sites

You're welcome!

 

If anyone's curious, this is the recommended Bullyhawk SoftStart module installation:

 

9753689696_515bb514d6.jpg

 

The tywraps are kinda funky but get the job done.

 

It goes inline with the regular ignition module wiring, and a separate red wire runs to the starter solenoid (you can just see it on the lower left).

Link to comment
Share on other sites

Good news,

 

I did some testing with some heat indicating strips that work with temps from 160F-230F. I placed them on a CTSW ignition modules and flew for an hour. I came back and landed and let the engine sit for an hour with the oil door closed so as not to throw off any results. The heat strip did not break the 160F indication. That's good news because that mean the CT's are not over heat and heat soaking our ignition modules. :D

The number not to go over is 175F so the CT group is in good shape.

 

Note*

This was only one test and I'll try to fly some more, but if it didn't break the 160F barrier then things should stay the same.

Link to comment
Share on other sites

Yea... but that was in Iceland ;) with a high today of about 100. Surprising, but good, news. I'll have to cancel plans for cooking "pheasant under cowl".

tim

Ah, the memories. 40 years ago on a cold fall day my girl friend and I were visiting the home farm from where I lived 100 miles away. We were in her VW bug. I went pheasant hunting and was happy to bag a couple of birds because times were lean. I field dressed them and put them in plastic bags on the floor in back. (You old timers are already ahead of me.) Wouldn't you know it, I happened to lay them right beside the heater outlet. Now, the heater system on the air-cooled boxer VW motor is notorious but one of the tricks to getting it to work right is to keep the engine up to speed. You can guess that with 100 miles of interstate we were in top gear and high revs all the way home.

Yep, when I retrieved the birds they were half cooked in the sack. I decided to forgo pheasant ala VW. It's still worth a chuckle to this day.

Link to comment
Share on other sites

I got two sets of the strips Eddie linked to...my modules like Eddies are "stacked" one on top of the other. Should I just put a strip on the top of the top module, or one on the side of each module, or just one on the side of the lower one? It seems the lower module is most vulnerable to heat, since it is more exposed to engine heat, the heat from the other module above it, and gets very little air around it to cool it.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...