Starter Motor Conversion

How to keep the Cessna 170 flying and airworthy.

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doakes
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Starter Motor Conversion

Post by doakes »

Has anyone done a starter motor conversion?
There is the Sky-Tec and the Niagara models.
Which is the better? It seems to me that they both install about the same way.
Any experience would be appreciated.
Thanks
Dave
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Curtis Brown
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Post by Curtis Brown »

A couple years ago I had my c145 overhauled. At that time a B&N (I think or B&C) push button start was used to replace the old pull starter. I love it! It turns the engine over much faster and therefore starting is much better, especially cold weather starts. It is lighter also.
Curtis
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GAHorn
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Post by GAHorn »

B&C makes this conversion, as does SkyTec of Grandury Texas.
Sky Tec has promised to donate a starter to our Association for this years convention in Tehachapi.

http://www.skytecair.com/about_us.htm

Mr. Chiappe (pronounced "Chappy") is our contact. Tell him you learned of them from the 170 Assoc. so he'll know their donation is appreciated.
George Horn, Parts/Mx

2006 Update: Unfortunately they dropped the ball after promising a starter and forgot to ship a starter to Tehachapi. I'll give 'em another call.
Last edited by GAHorn on Sat Jul 08, 2006 12:39 pm, edited 2 times in total.
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
zero.one.victor
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Post by zero.one.victor »

I don't know about the Skytec,but the B&C requires removal (read that as cutting off) of the shaft that the starter clutch rotates on inside the accesory case. Pretty simple if your engine is apart,but I'd be pretty nervous about doing it with the engine together. Awful easy to let the debris from cutting get into the works.
The B&C starters are big bucks--my old Spruce catalog lists them at around $800,plus another $70 for an installation kit. The you gotta wire it,do a 337,etc. Sounds like the best part of a thousand dolar bill to me.
Near as I can tell,the same catalog lists the Skytec at around $525,but it's not too clear if that starter is applicable to pull-start type engines. The same wiring,starter button,paperwork,etc would have to be done for the Skytec.
I don't know if these aftermarket starters use a starter clutch or a solenoid/bendix or what. I do know that the Continental key-start starter clutch is turning (and wearing out) any time the engine's running. I had one come apart on a key-start O-200 and very luckily avoided disastrous engine damage from the debris. I kinda like the pull-start arrangement for that reason--the only time that thing is turning (and wearing out) is when you have the starter pulled.
The same Spruce catalog lists the stock Delco-Remy p/n 1109656 pull-type starter at around $220 exchange. A new starter clutch costs about $175 exchange. Totals up to about $395,not counting any labor. This is an easy job,but I guiess requires an A&P sign-off.
A bit of advice--I had a local automotive-type electrical shop "refurbish" my starter & alternator after everybody told me it'd be way cheaper than a regular aircraft outfit. Not so--it ended up only saving me maybe $50 or so to do both the starter & alternator,and I had to take it back twice for little things. I wish I'd just gone ahead & exchanged my stuff for yellowtagged OH'd units. I just pulled the starter switch (on the side of the starter) & it looks kinda bad--the local guy probably never even looked at it.
Good luck with it,let us know how things turn out. Why are you thinking of converting,Dave,didn't you just tell me that your starter only had about 50 hours on it?

Eric
doakes
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Starter Conversion

Post by doakes »

I did say that the starter had no more than 50 hrs SOH, but the reason I am considering the change is torque, it just does not want to turn over when the engine is hot, and the oil leaks badly from the shaft that engages the gears.
I have taked to a salesman at Sky-Tech and he told me he converted his Champ or Stinson to the push button and followed the instructions that are in the Kit. He said it was not hard. With Sky-tech he said it was not necessary to pull the accessory case to cut off the starter/shaft in the engine housing. He used a Dremell tool and cut it into 2 times. I have seen the instructions on their Web page.

What I have done at this moment is purchase the oil shaft seals from NAPA airmotive and I will install them and make an attempt to stop the leak and live with the lack of torque for now. If the problem still continues I will probably convert it to the push button.
Thanks for all the input you 170 drivers have given me.
Dave
dacker
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Post by dacker »

This topic is rather interesting to me. Before I got my 170 I had never seen the pull type starter we have. Seems to me the lack of a solenoid is a good thing. Does anyone know why modern light aircraft went to using solenoids? My experience with starters (automotive, at least) is that about half the time the solenoid wears out before the starter does. Also, from what I know, starters usually burn up from constant prolonged cranking without giving them time to cool off.
I know a lot of guys install the other starters to save weight, but they would be even lighter if designed w/out the solenoid switch. Are they really that much lighter that they make any significant differences?
As far as starting easier, I couldn't imagine my airplane starting any quicker hot or cold, (usually within 2-3 revolutions), the only time I ever had a hard time starting was when I had mag problems. I think as long as I can get mine overhauled I will stick with the old.
I think I would spend the bucks on another neat gadget or maybe a weight loss program :lol: .
David
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wa4jr
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Post by wa4jr »

Time to revive this thread :wink: Referencing my comments in the "C-145 Starter" thread, I've decided to go with a B&C unit. I had hoped to find a direct replacement lightweight starter from Lamar, but they did not have one for the O-300A and it took three people to determine that they did not have one as nobody could tell for sure without some research :roll: The B&C is made much better and avoids the cracked casting problems of the Skytec by using an endbell machined out of solid aluminium vs. the cast assembly of the Skytec. The only big problem is the removal of the pinion shaft. The owner of B&C starter said that the accessory case MUST come off and that a hacksaw be used instead of an abrasive wheel. He did not think there was any way possible to remove the pinion shaft in place as per the Skytec instruction. Especially when using an abrasive wheel with all the fine particle dust in addition to the metal dust, he said there was no way to avoid engine contamination. Sooooo....the accessory case must come off...and the gen and the mags and the oil filter housing. I'd like to hear from someone who has done the B&C conversion with the engine in place. Did you indeed remove the accessory case or did you remove the pinion shaft through the starter mounting hole. This has turned from a quick DIY with A&P signoff to a real experiment. If I take the gen off but leave the mags in place on the case cover, will the bazzillion gears stay in place to preserve timing or will they all fall out onto the floor into the puddle of oil 8O I KNOW the stove is HOT, but I feel compelled to touch it anyway in order to get this job done so I can fly to Oshkosh.
John, 2734C in Summit Point, WV
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cessna170bdriver
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Post by cessna170bdriver »

John,

I installed my B&C during overhaul, so this wasn't an issue for me, but here's my take on it. All of the gears are attached to their respective accessories' shafts with nuts and cotter pins, other than the pull-starter drive gear, which is captive behind the starter plate. You COULD remove the accessory case without removing the mags, but you'd have to lock both of them in place with Bendix mag tools or their equivalent, and risk damaging the internal nylon gear if one or both should inadvertently turn. Many years ago I had to replace a camshaft gear between overhauls, which required removal of the accessory case. I chose to remove all the accessories just to make handling the case that much easier, and I'd do it that way again. With the proper tools available in any A&P's shop, re-timing the mags is not a huge deal. Timing needs to be checked periodically anyway. The B&C instructions are very specific about how to go about preventing contamination using a plastic apron. Be on the safe side and follow the directions.

When you cut off the pinion, cut it as short as you possibly can. You'll open up a small hole (1/8 or less) through the large diameter part of the pinion when you cut off the shaft, but that is no big deal. I cut mine as close as I could get it and still just BARELY had the required 2.5 inches clearance from the starter mounting face on the accessory cover to what is left of the pinion. You might want to measure it before you remove the accessory cover, so you'll know how far you'll have to go.

While you're waiting on delivery of the starter, go ahead and order, scrounge, or steal a 5-amp circuit breaker or fuse and find a place on or near the panel to mount it and the push-button switch. I used the $4.35 W58XC4C12A5 circuit breaker from Aircraft Spruce. I mounted them in existing unused holes on ther far left of the instrument panel bulkhead as shown below. You could use the existing hole for the pull cable for one of them, but I decided to put my engine analyzer annunciator light there.

Also, find a good place on the firewall for the solenoid so that both your battery cable (from the master contactor) and bus wire will reach (both should currently be connected to the starter post). I put mine just to the right (from the cockpit point of view) of the pull cable bracket. See photo below.

You won't regret the B&C starter. It is well-built and will surprise you the first time you press the starter button. Like another poster said, you'll think you're about to taxi away when that starter turns the engine.

Miles

Image Modified Starter Pinion

ImageStarter Button and Circuit Breaker

Image Solenoid Installation
Miles

“I envy no man that knows more than myself, but pity them that know less.”
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wa4jr
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Post by wa4jr »

Thanks for the detail Miles :D Makes me feel a bit better about diving in and taking the case off. The TCM overhaul manual is really skimpy about a lot of details on the engine or maybe I'm just used to good Haynes manuals with really detailed step instructions along with many nice detailed photos. One thing I do worry about when using a hacksaw to cut the pinion shaft off as close as possible is inadvertantly raking the hacksaw teeth along the rear machined sealing surface of the engine. Perhaps I can wrap the area of the blade that passes the sealing surface with electrical tape and just go real slow. That hole you mention in the shaft created by a pilot bit on the other side is a major reason B&C said not to use an abrasive wheel....would blow abrasive dust into the little hole as you went by and there is no way to recover the dust with a magnet. What is the 5 amp CB for? Bill did not mention the 5 amp breaker, but he did say he was including information on installing a yellow "starter engaged" light. Had I had a "starter engaged" light earlier this week, I would have known that my old Delco Remy starter switch had failed closed and that the starter was running continuously! Nice little precaution to have as it is not alway easy to hear the starter running above all the other noise in the cockpit. So the fun starts today :roll: Since the DR starter failed here at the house, I'll take everything off, do the hacksaw boogie while my Guiness sits on ice, put everything back on with the exception of the mags, and then see if I can lure an A&P friend over with pizza and beer to install and time my mags....and of course fork over the required signoff. Darn....forgot I'll need a gasket for the accessory cover :? What is the best place for engine gaskets? I've used Spruce before, but do you have any better source?
John, 2734C in Summit Point, WV
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GAHorn
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Post by GAHorn »

Tell the B&C folks to send you the gaskets you'll need!
RE: the engaged starter..., ...heh-heh... if you have a generator...and not an alternator...and if you'll include the ammeter in your instrument scan... you'll see the big DISCHARGE after starting, which is the clue that the starter is still engaged! :wink:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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cessna170bdriver
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Post by cessna170bdriver »

gahorn wrote:Tell the B&C folks to send you the gaskets you'll need!
RE: the engaged starter..., ...heh-heh... if you have a generator...and not an alternator...and if you'll include the ammeter in your instrument scan... you'll see the big DISCHARGE after starting, which is the clue that the starter is still engaged! :wink:
George, how does having a generator cause you to be able to read starter current on the ammeter? :?: :? I like the idea of a "starter engaged" light, maybe even a lighted pushbutton starter switch to obviate the need for another hole somehwere. I presume it would be connected to the starter power terminal. That wouldn't have been easy to do with the old pull-cable starter, as the power terminal was upstream of the manual contactor and had system voltage on it any time the master switch was on.

The 5 amp circuit breaker (or fuse) is for the starter solenoid. It goes in series with the starter switch. The wiring is covered in the B&C instructions, but the breaker itself isn't included in the kit. You can also get gaskets from Superior.

Miles
Miles

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GAHorn
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Post by GAHorn »

cessna170bdriver wrote:...George, how does having a generator cause you to be able to read starter current on the ammeter? . ..
Miles
Immediately after starting many "cabin class" and larger airplanes, one of the "after start" checks is that the starter disengaged. On some airplanes, one way to do that check is to look at the generator output. If a large output (greater than normal battery re-charge rates), ...or in the case of our 170s, ... a larger than the normal 1-3 amp or so discharge rate of the ammeter... would indicate a large (huge actually) electrical draw. If there's not yet any avionics/lights turned on,...a large discharge in the vicinity of 10-20 amps or greater would indicate a huge electrical demand somewhere. Guess where. There's only one thing on these airplanes that draw more than taxi/lnding lites. ... :wink:

(An idling alternator might partially mask this large discharge.)
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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Kyle
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Post by Kyle »

wa4jr ,

you mentioned "maybe I'm just used to good Haynes manuals with really detailed step instructions along with many nice detailed photos".

What are the Haynes manuals?

Thanks,


Kyle
Kyle Takakjian
Truro, MA
52 C-170B, N8087A
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wa4jr
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Post by wa4jr »

The Haynes Manuals I referred to are for the automotive field. Just as the automotive field is light years ahead of GA as far as engines go, so their manuals are much more detailed so as to make sure even the first timer is in a good position to do the work. For one thing, I see no fastener torque specs in the TCM overhaul manual 8O Perhaps you go on the "feel" technique to stop just before the threads come out, or there is some other manual somewhere just for torque values :? Does anyone know? I"ll ask Bill tomorrow for the accessory case gasket. The starter gasket is included. Yes, my amp meter was showing a big draw while the starter motor was running and when I checked the 35A GCU fuse it was so hot that the solder had run out from the metal end caps! I'm goint to a CB here instead of a fuse :wink:
John, 2734C in Summit Point, WV
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Bruce Fenstermacher
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Post by Bruce Fenstermacher »

John the torque specs are indeed in the overhaul manual. Look in the back under "Table of Specifications" (or something like that)
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