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dougknight

Well Known Member
I have seen some reference to Autolite UREM37BY spark plugs but cannot find a price nor source for them. Is Autolite the same Manufacture as Unison/Tempest?:confused:

thanks
doug
 
Thanks guys. I have 450 hrs on the original champions and think they are due for a change @ 500 hrs. Not sure of their resistance values (starting annual inspection today, will check them) but re gapped them last year (50 hrs) and noticed the center electrode was quite worn to a football shape.

UREM37BY vs UREM38e question. Other than the temperature range I notice UREM37BY has a longer nose and electrode profile than the 38e's.
Any advantages/disadvantage of one vs. the other?

thanks
doug
 
Doug,
Just ordered (8) UREM37BY's from Aircraft Spruce. $23.50 each and got them in 2 days USPS. Best price I found.
Tempest also guarantees the resistance values for the life of the plug.
Some good reading on the Tempest website.

Ross
 
dougknight said:
Other than the temperature range I notice UREM37BY has a longer nose and electrode profile than the 38e's.
Any advantages/disadvantage of one vs. the other?
Click to expand...
From what I understand (from a Mike Busch webinar on spark plugs IIRC) the BY's are especially resistant to plug fouling, so for engines that tend to foul plugs, they are good. FWIW, they came as factory originals with my 0-320 from Aerosport.
 
I thought I would offer some info on the BY plug. Although my current company is Tempest, I spent almost 10 years with Champion where the BY plug was originally designed. The BY plug was developed primarily for the smaller Lycomings such as the O-235 and O-320 models, although today it is approved for many other engine models as well. Since most of these engines were originally certified with 80 octane fuel and since 80 octane is no long available and we are left with 100LL, which contains 4X the tetraethyl lead that 80 octane contained, the industry was experiencing some pretty severe lead fouling. The BY was designed with an "extended core nose" which allowed for a larger area for lead to scavenge, delaying, but not eliminating, the effects of lead fouling. Over time, it has been accepted as a plug that helps significantly with fouling conditions and if it is certified for your particular engine, may be a very low cost alternative to fine wire plugs. Although the service life will be comparable to other massive plugs, not the fine wire plugs.

I hope this has helped to answer the questions posted here about the BY plug. If there are other specific questions please feel free to email me directly at [email protected].
 
wow!

John:
Thank you so much. That was the perfect answer and better information than I ever could have dug up on my own.:)

doug
 
sparkplugs

I just found 26 of the Unison 37BY plugs I would sell for 20.00 each if your interested. I have a few other numbers as well but the 37BY is the better plug.

Jesse
 
....only found 26????!!! :)

659JR said:
I just found 26 of the Unison 37BY plugs I would sell for 20.00 each if your interested. I have a few other numbers as well but the 37BY is the better plug.

Jesse
Click to expand...

...gee Jesse, you gotta clean them bottom drawers more often!:rolleyes:

......by the way, there's this guy they are still looking for, perhaps you should check under your bench etc.


(James R. Hoffa!) :D
 
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