Extended tip spark plug NGK BPR9ES

[SHIPCHIEF]

I have been looking at extended tip spark plugs after becoming a convert to Tempest (Autolite) UREM37BY.
When I switched to one P-mag, I naturally installed the 18mm to 14mm adapters and NGK BR8ES plugs. BR9ES plugs are also on the 'preferred list'. Lately I have noticed an extended tip version, BPR9ES (stock # 7788) with a 2.5mm extended tip, and solid terminal.
https://www.ngk.com/product.aspx?zpid=9504 I notice the resistor is 10K ohms whereas the BR9ES is 5K ohms. They are the standard plug for a Polaris Liberty snowmobile.
Has anyone tried these?
Any comments from the 'Engine Guys'?

 

[Rick_A]

Don't know about the extended tip, but I use NGK BR9EIX (3089) with my P-Mags. This is the solid tip Iridium plug. You've got to get to 3089 for the solid tip.

I just replaced a set of my plugs. Two years old with 140 hours on them. I'm sure I could have run them longer if I wanted.

They are a bit pricey, about $9 per plug, but cheap compared to "real" aviation plugs.

 

[RetiredRacer]

Bpr8es

With my P-Mags I first fitted BPR9ES's but my low comp engine fowled them up if I wasn't on top of the leaning so I changed to BPR8ES's and solved the problem.

Bob

 

[SHIPCHIEF]

I looked up the BPR8ES for a solid terminal version:
https://www.ngk.com/SearchResults.aspx?kw=93427
it has a 5K ohm resistor that we commonly use.
It is gapped to .028", but we re-gap to the mag, Pmag or whatever...
Bob; for the record, is you engine a 7.0:1 Lycoming O-320...or?
I am exposed to a variety of Lycomings from a 7.0:1 O-290G, 8.5:1 O-320 & O-360, an 11.0:1 O-360 and a 10.0:1 IO-540 (no I don't own them all) I expect the heat range for the 7.0:1 O-290 would accept a hotter plug than the 11.0:1 O-360.
I have a set of BPR9ES plugs coming for my RV-8 with the 8.5:1 O-360. They will be fired by a Pmag, the same as you. I am using the conservative A curve
If they run too cool, I'll follow your lead and try BPR8ES.

 

[RetiredRacer]

I was out at the hangar today and looked up the engine log. Actually, I started off with the 8's and went hotter with 7's. Mine is a 6.7 comp 0-235 with 2 P-Mags and a Rotec TBI. In a 9a weighing in at 893 lb empty.

Bob

 

[SHIPCHIEF]

Bob;
That's a awesome combination of light weight & efficiency!
Thanks for the feedback. I just hope these extended tip plugs do live up to their reputation for better ignition and clean running.
I feel safe starting with a colder plug and working up to the desired heat range.

 

[NROBB]

Hi Scott,

How did the BPR8ES perform?

I see the BPR9ES uses 10k res, but the Iridium edition spec shows 5K for it (BPR9EIX). yes, I know, removable nut.

Thinking of testing that. Currently using BR8EIX 8.7:1 IO-360 200HP

Thanks for your update on the matter.

Nar.

I looked up the BPR8ES for a solid terminal version:
https://www.ngk.com/SearchResults.aspx?kw=93427
it has a 5K ohm resistor that we commonly use.
It is gapped to .028", but we re-gap to the mag, Pmag or whatever...
Bob; for the record, is you engine a 7.0:1 Lycoming O-320...or?
I am exposed to a variety of Lycomings from a 7.0:1 O-290G, 8.5:1 O-320 & O-360, an 11.0:1 O-360 and a 10.0:1 IO-540 (no I don't own them all) I expect the heat range for the 7.0:1 O-290 would accept a hotter plug than the 11.0:1 O-360.
I have a set of BPR9ES plugs coming for my RV-8 with the 8.5:1 O-360. They will be fired by a Pmag, the same as you. I am using the conservative A curve
If they run too cool, I'll follow your lead and try BPR8ES.