Denso spark plugs

[Tweetr]

I need to replace the Denso spark plugs in my RV-4 with LSE Plasma II ignition. My local AutoZone doesn't have the Denso W24EMR-C or W27EMR-C plugs in stock. They also were unable to cross-reference these plugs with those of other manufacturers. Does anyone have cross-referenced part numbers for these plugs? NGK, Bosch, or whatever?

Thanks,
Tom Stearman
RV-4 with 1150 hours
(completed June 2000, still unpainted!)

[rv8guy]

just do a google search. I think they are really motorcycle plugs, and the lightspeed site has them for sale as well, you just need to buy 8 minimum.

[Tweetr]

Yeah, I know I can order them. I need equivalent part numbers so that I can buy them locally. My airplane is down and me need da spark plugs!

[Bryan Wood]

I don't know if you are willing to run plugs other than the Denso's, but the Auto Zone should have NGK 5422's or BR8ES. They are cheap and work very much good. I have been using these with my Lightspeed for around 250 hours now.

Best,

[dan]

Bryan already touched on it, but I want to expand a bit...

Denso W24EMR-C = NGK BR8ES
Denso W27EMR-C = NGK BR9ES

Different heat ranges.

Klaus sells the Denso plugs relatively inexpensively, but I switched to NGKs and never looked back.

Link to a cheap source for the NGKs ($1.70/ea):
http://www.rvproject.com/pricewatch.html

I've seen them on Amazon shops before for less $ in larger quantities.

If you happen to be ordering from Aircraft Spruce, they even sell them (for slightly more $):
http://www.aircraftspruce.com/catalo...s/ngkplugs.php

[Tweetr]

That's what I needed, thanks! My local O'Reilly's carries the NGK BR8ES and BR9ES.

Incidentally, Klaus Savier said he has less luck with the NGKs than the Densos. He thinks the Densos are better plugs. I'll pick up a set of NGKs, then order a set of Densos to keep on hand. He recommends changing plugs every couple of hundred hours. We're putting much more energy through them than automotive electronic ignitions do.

[dan]

Originally Posted by Tweetr

Incidentally, Klaus Savier said he has less luck with the NGKs than the Densos. He thinks the Densos are better plugs. I'll pick up a set of NGKs, then order a set of Densos to keep on hand. He recommends changing plugs every couple of hundred hours. We're putting much more energy through them than automotive electronic ignitions do.

How does 1100+ trouble-free hours on NGKs sound in terms of "luck"?

Haven't had any issues whatsoever with the el cheapo NGK plugs. But I still do change the plugs every 150-200 hours. For less than $7, I can rationalize doing that. I do see measurable electrode wear.

[martin333]

I have 1400+ hours on my RV8 now (IO-390-X) engine, fuel injected, Lightspeed Plasma 3 ignition. I have tried just about every brand of sparkplug in this engine and have always returned to the Denso sparkplugs from Klaus @ lightspeed ign. Since I do a lot of Air Racing with my RV8, I am always looking for the best performance that I can get. In order to rate my experience with sparkplugs on a number basis of 1 to 10 with 10 the best, I rate the Denso 27ESR-U the best @ 10. and the various NGK models @ 8 or 9.
I usually clean and regap them @.027 every 50 to 75 hrs. When the electrode begins to show excess wear usually after 150 hrs. I replace them. (they are cheap compared to Champion aircraft plugs) After comparing prices at local auto and speed shops, I find that Klaus's prices are very competitive, and his service is excellent.
Dick Martin
RV8 N233M
the fast one

[dan]

Dick,

I'm surprised you use such a small spark plug gap (you mentioned .027").

I use .034" and regap if they're over .036". I figure I'm getting more spark energy out of the bigger gap, but that's just an assumption.

Curious why you use a smaller gap?

[alcladrv]

Dan,

My engine came with a Lightspeed Plasma II in place of the right mag. Denso W27EMR-C plugs were installed, so I'll swith to the NGK BR9ES. I know the heat range is different than the BR8ES plugs. How do you decide which plug to use?

Mike