Skytec starter question - NL vs. XLT

I'm looking for a new starter for my Lycoming O-320 engine overhaul, and I see that there appear to be 2 types of Skytec units available.

One is a 149-NL, which by the pictures looks to be similar to the OEM Electrosystems Inc. starter that was on my core engine, i.e. longer length.

Then there is the 149-12 XLT that is sold by Van's, that looks to be shorter than the OEM or 149-NL units. It's touted as being a lighweight PMA unit.

Which one of these starters are builders using and why?

I'm very surprised that the Skytec website, has little discussion on comparison of these two units that they sell. What does it mean, that the XLT is a replacement for the LS starters? They seem to be underutilizing their website,,,

Thank you,

AC

I'm not a builder but I do remember one of the first things that they builder who I purchased my plane from told me was that he had gone through a couple of the "standard" size Starters before deciding to put the "heavier duty" on this plane. One of the reasons on my plane may be because I have a wood prop that there is less inertia so the starter has to do a bit more work. So make sure you consider that too. . . or just get the heavier duty one regardless.

149-12XLT on my -4

I used the small 149-12XLT on my 0-320 160 hp., -4 . The larger OEM type is heavier and that was the main reason. Be sure you have a 149 tooth ring gear (most common) and I'm sure your 12V.. I have had no issues with this starter in 8 years of service, and it cranks my engine better than most any OEM starter I have seen in the past.

My o360 had a sky tech 149-lsx on it when I bought it. When the temps got down below 50f, it would not turn motor over. This was using the odyssey 690 battery. I replaced with 149-nl and it now starts at any temp. The nl has more torque.

800+ hours with the XLT and composite prop with zero issues. My engine is a stock O-360 with 8.5:1 compression.

NL

After 20-years of flying my RV with SkyTec starters, I switched to the NL starter after going through 3 solenoids in less than 18-months on the PM starter after an overhaul replacement.

RV6_flyer said:

After 20-years of flying my RV with SkyTec starters, I switched to the NL starter after going through 3 solenoids in less than 18-months on the PM starter after an overhaul replacement.

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I always value Gary's comments and now have an NL as well.

tracy said:

My o360 had a sky tech 149-lsx on it when I bought it. When the temps got down below 50f, it would not turn motor over. This was using the odyssey 690 battery. I replaced with 149-nl and it now starts at any temp. The nl has more torque.

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Just another datapoint for you for the 149NL on an IO360 with a 7 year old PC625 battery.

Winter temps here are closer to what you have (-22C -6F) today. Started last week at -5F and the NL can swing the Hartzel prop and the thick oil... I preheat with a sump heater, plus on days below -10C I will use additional blown hot air up through the cowl exit for 15-20 mins.

That being said, I think its right at the limit on those days... the prop swings pretty slowly and I have to get prime right because I'm only going to get a few tries. (The 7 year old battery probably explains that behavior)

The NL uses a series-wound motor.
Other Skytec starters, and the B&C, use a permanent magnet motor.

The series-wound motor is FAR superior. Less inrush and steady-state current draw and more torque. I've actually measured the current draw and compared them.

rocketbob said:

The NL uses a series-wound motor.
Other Skytec starters, and the B&C, use a permanent magnet motor.

The series-wound motor is FAR superior. Less inrush and steady-state current draw and more torque. I've actually measured the current draw and compared them.

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The B&C is a wirewound unit and my favorite, the NL is much better than the PM/lightweight Skytec.
(My original 14yr old B&C starter and alternator are still working perfect.)

FWIW, the B&C starter employs a ?series field" - as does the Skytec 'NL' 'inline ' starter.

I'm in the midst of an investigation/study to characterize the current requirements of various starter models.

Based upon some measurements of the Skytec 149LS series on an O360-A1A, the first compression stroke typically requires 400 amps or more to get past TDC. I've measured two different starters on the same model engine with different batteries and wiring feeding the starters. Both starters had quite similar cranking current profiles.

Would be interested in making similar measurements on other starters - if anyone reading this in the Sacramento has a different model Skytec (different than the 149LS) and is interested in helping, please let me know. I'm also seeking someone in the area with a B & C for the same type of measurement.

Measurement of the current profile consists of putting a "clamp on" (really better described as a "clamp around") current meter around a conductor carrying current to the starter. The engine is then cranked through 2-3 revolutions with the mags off, during which time the current profile is recorded.

Skytec starter question - NL vs XLT

Years back my friend and I (both Rockets) were having trouble starting as well as several RVs on the field. We were all using the Skytec LS starters (in my opinion is junk). I was using an aftermarket Concord 25 size RG battery. On my Rocket I ran the battery down cranking till it wouldn't turn with the LS starter (didn't take long). I then put a B&C starter on, it cranked 2 or 3 blades and it was done. I then put on a Skytec NL starter. It cranked like a fresh battery. Several pilots were watching and all put on NL starters. There is a reason. The LS is a permanent magnet motor (which takes more amperage to start) with a 3.7 to 1 reduction gear. The NL has a series wound motor and a 6.5 to 1 reduction. If you want more details, give me a call at 317-718-3415.