Has anyone tried Autolite sparkplugs? Particularly the AR 3933?

I need a thick threaded section with a 5/8” hex so I can install a pressure sensor.

The equivalents below are from Chuck Westbrook’s tuning notes.

AUTOLITE PLUGS, normal electrode, 14mm, 3/4" reach, 5/8" hex. Non-resistor,
AR3935 = NGK 7 heat range,
AR3934 = NGK 8 heat range
AR3933 = NGK 9 heat range
AR3932 = NGK 10 heat range
AR3931 = NGK 11 heat range

Thanks,
Barry

 

Geez, the 3932 are only $2.99 each. Never heard of anyone running autolites.

 

They are used in the 454 BB and the Hemi as their racing plug.
Barry

 

Right, I just never heard of anyone using them in rotaries.

 

I run the AR3933...work great.

 

Thanks Jack.
What is the highest boost your have run with them.
Barry

 

What I am trying to do is to install a 3000 psi sensor into the spark plug rim so I can do Brake Mean Effective Pressure (BMEP) testing.

I think the plug will work in vacuum OK but I am worried about boost. Has anyone used it to say 16 psi?

Barry

 

i have used the 9 and 10 heat range. they work fine around one bar and i have not tested them at higher boost levels. i only run the NGK 6725s for higher boost. good luck on your very important project.

howard

 

Whats the output of that 3k sensor? 0-5v?

 

Thanks Howard, that is a good pressure to start with.

The output is 0-5 volts but our datalogit can only handle 68 samples/sec (if that is what you are thinking).

We need 360 degrees X 8000 rpm = 48,000 samples per second.

Does anyone have any suggestions on a reasonably priced 60K sample/sec data acquisition unit in that range?

Barry

 

Yeah, i was thinking about logging, but knew even if it was 0-5v that my innovate hardware would be far far to slow

48k samples a second, thats alot of information....

 

14 psi

 

Thanks again Jack. I feel better about using the AR 3933 now that you and Howard have used them to 14-15 PSI.

The AR 3933 plug with its thick threaded area and 5/8" small hex allow it to be drilled for the sensor... but what good would that do if it introduced other issues during testing?

Still looking for an inexpensive 60K/sec data acquisition device!

Barry

 

innovative has a couple datalog boxes, dunnno if its 60k/sec though

 

If you have a laptop, you can get a PCMCIA data acquistion card:

http://sine.ni.com/nifn/cds/view/mai...id/1036/ap/daq

or a USB card:

http://sine.ni.com/nifn/cds/view/mai...id/1036/ap/daq

There are a lot of cheaper options than Natiaonl Instruments if you check around.

So, do the Autolite plugs require a turned down socket to fit inside the rotor housing?

Glenn

 

Nothing special just a regular 5/8" deep socket.

Barry

 

In my experience they don't foul as easily as NGK. They work well for the initial stages of tuning.

 

Glenn do you think this would work?

http://www.starting-point-systems.com/specs.html

Barry

 

Hello guys,

I know you are considering these plugs more so you can perform pressure tests with them but I have a question.

Do they work lengthwise on the 13B without modifications in the trailing and leading positions?

I am trying to tune my car at around 14-15psi right now and my plugs are fouled which is making it impossible. Not to mention that the stock spark plugs cost an arm and a leg(about $150) and are not the right temperature rating for a boosted car(7L and 9T). I have been looking for some 9 leading and 10 trailing so I could replace the ones in my car at least until I get it tuned properly Will these work?

Thanks in advance.

Chris

 

Sounds like you just have to lean it out some. I could send you my Excel program for tuning if you were using a PFC.
Barry

 

Thanks for the info Barry.

I am actually talking about an RX-8 engine so no PFC. I have a Microtech LT-10X and I am running LS2 Coils.

I am using a 70mm turbo and running about 14psi at the moment. I will be going with meth injection once I get the car dialed at 14psi so I can push it to around 20psi.

Any other suggestions?

Thanks.

Chris

p.s. Do those plugs you suggest have the "gap-able" tab on them or do they just have the center electrode and the cross?

 

It looks to me like there is no supplied software to control the daq. If you are a programer, maybe this is not a big deal. At 149 Eur ($231), I would lean towards:

http://sine.ni.com/nips/cds/view/p/lang/en/nid/14605

instead. Comes with software for $40 more.

Glenn

 

The BURs are nonadjustable but the BR10EIX adjust.

Here are the AFR targets that I shoot for.

Barry

 

LabView is supported. It's an awesome program, but if you don't know what your doing it's not very user friendly. If you could get a intro/free package that would be the best way to start. It would provide step by step work instructions. Since your only recording one channel and maybe do a single conditioned output it shouldn't be to hard to do. Being able to sample at a rate of 60K/sec would be the only ??

 

Thanks Glenn,
I went to see a avionics friend for advice. I am trying to learn as much as possible before making additional purchases. He wants study the output of the sensor with an oscilloscope. Unfortunately it is out for calibration. We will on it as soon as it comes back.
Barry