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I'm working on the Sonex-A (Revmaster R2300) condition inspection. Decided to install Iridium plugs as I just feel they are a better plug with some advantages (price is not one of them). Figured I'd post a pic or two and ask the crowd "Do you use Iridium plugs, if so why and what do you like of them. BTW - plugs in the picture are gapped at .016" per Revmaster.

I use Autolite 4163 as per the Aerovee manual. I'm happy with them.

BRS wrote:I'm working on the Sonex-A (Revmaster R2300) condition inspection. Decided to install Iridium plugs as I just feel they are a better plug with some advantages (price is not one of them). Figured I'd post a pic or two and ask the crowd "Do you use Iridium plugs, if so why and what do you like of them. BTW - plugs in the picture are gapped at .016" per Revmaster.

I have a 3.0 Corvair conversion. In the beginning we always ran the factory recommended AC plugs (R44F) but many moons ago William Wynne, after much research, gave a recommendation for the use of Denso Iridium plugs (5378/IWF20) for various reasons. Now almost every Corvair flight engine uses them (or should).

The Corvair conversion employs Bosch Blue ignition coils (45K volts) so we gap plugs at .032-.035 and that helps to prevent any shorting from lead build up between the electrode & the ground strap. Secondly, they do not rust like the old AC plugs would do and this helps to prevent (along with anti-sieze) galling or stripping of the heads when removing the plugs. They tend to last much longer also.

As for the price ... I buy mine from Rock Auto and current price is $5.70 so a set of six (I have dual ignition/single plugs) costs me less than $35.00. To me that is a very reasonable cost for what I get and I generally change them at annual.

FWIW, I have never fouled a plug in my engine and that includes when I was using AC plugs.

Dunno if this helps ...

Dale
3.0 Corvair/Tailwheel

For an Aerovee, it looks like Denso 5376 IX24B Iridium Power Spark Plug or Autolite XS4163DP Xtreme Sport Spark Plug or NGK 6681 DR8EIX Iridium IX Spark Plug might work. As much as a PITA as it is to get the back top plugs, I'm tempted to go that way. Back in the day, as I recall (DANGER!) when you got a bug with AC, you got ONE Iridium plug because the compressor(?) was in the way, and you couldn't change it without pulling the engine.

karmarepair wrote:For an Aerovee, ... As much as a PITA as it is to get the back top plugs, I'm tempted to go that way. ....

Is the intake manifold in the way of the back plugs on the Aerovee? Does it have to come off to get to them? On the Revmaster there is room to just get at the back plugs but the side baffling has to be removed (or have a hole cut in it).

BRS wrote:

karmarepair wrote:For an Aerovee, ... As much as a PITA as it is to get the back top plugs, I'm tempted to go that way. ....

Is the intake manifold in the way of the back plugs on the Aerovee? Does it have to come off to get to them? On the Revmaster there is room to just get at the back plugs but the side baffling has to be removed (or have a hole cut in it).

You have to do one or the other. I removed my manifolds last time.

Hi Guys,

I'm interested in all things fuel and spark. It was difficult to find a book that was specific to ignition. I did find one book that was published back in the mid '80s. That was apparently before iridium plugs were invented. Here is a page scanned from that book. Check the pic in the upper left and the associated text that follows. Made me smile.

I'm now leaning toward iridium plugs and 5 Ohm coils for my plane.

Question: Has anyone researched exactly which iridium plugs are the proper heat rating and reach for VWs?



Thanks,

Wes

Hi Guys,

For those interested in iridium plugs, there is a published cross-reference for NGK plugs.

Ref: https://www.ngkpartfinder.co.uk/assets/Uploads/NGK_Upgrades.pdf

For me CR7HSA cross references to CR7HIX.

Wes