• Become a Subscribing Member today!

    PiperForum.com is a vibrant community of Piper owners and pilots with over 1,500+ active members.

    Access to PiperForum.com is subscription based. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched library of Piper knowledge.

    Why become a Subscribing Member?

    • Swap technical knowledge, plan meetups and sell planes/parts.
    • We host technical knowledge of general aviation topics and specific topics on J3-Cubs, Cherokees, Comanches, Pacers and more.
    • In addition to an instant community of pilots for you, PiperForum.com is a library of technical topics, airplane builds, images, technical manuals, technical documents and more.

    Become a Subscribing Member and access PiperForum.com in full!

    Subscribe Now

hot or finewire plugs

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Well-Known Member
Mar 16, 2011
Reaction score
Does anyone have any experience using hot plugs (eg. RHM-40E vs -38E) or finewire plugs (-38S) in their IO-540? I'm thinking of replacing my -38E's with something that is less susceptible to lead fouling. From what I've read online, both hotter plugs and finewires are supposed to help with lead scavenging.

The cost of f/w's is at least double that of the massives, but they are supposed to last 2-3x longer.

I run WOTLOPSOP most of the time, so my CHTs are down around 280-320F, which means the plug temps are pretty cool - maybe too cool for the scavenging agent to work. Hence the thought about running hotter plugs. The hot plugs cost the same as cold plugs, so that's a no-brainer for me.

But finewires are supposed to help with both fouling AND spark quality, and that is something that interests me running LOP. So I'm really tempted to bite the bullet and install f/w's, but before I do, I'd like to know if anyone else has been down this path before and has any words of wisdom. At $50-60/plug, it adds up pretty quickly.

Latest posts