The International Cessna^® 170 Association

Hi all,

My 20amp Delco-Remy generator just died again on my 170b.

Last year, it died so I replaced it with a new unit. Now, it started leaking and when my mechanic went to replace some seals, he saw the drive shaft was completely stripped. A new Delco generator costs about $700

Would there be a lot of additional wiring/electrical associated with upgrading to an alternator, or any panel modifications? I don't have circuit breakers, only fuses and a 20amp voltage regulator.

What's a realistic solution pricing for installing an alternator replacement? The additional amps would be nice, because with my all my lights on at night on final/takeoff, I'm at a negative discharge of about 30amps total (10amp more than I can produce).

How drive shaft threads should look vs stripped on mine

That sucks, and should not have happened.

I have a ford alternator (at least I think I still do) that you can have, and I may have a regulator. Its really big and heavy. wiring is required to switch to an alternator.

An alternator will not charge from a totally flat battery, a generator will.

I think B&C do one, and there is a really cool little 30 amp alternator which is STCd for a swift, but I don't think it is for the 170.

Reece are both the generator pictured in your possession? Are the armatures interchangeable?

I HAVE A GENERATOR REMOVED FROM MY 170. I WILL CHECK THE ARMATURE WEDNESDAY WHEN I GET HOME FROM WORK AND IF IT IS GOOD I WILL SEND IT TO YOU FREE FREE FREE!!! I AM USING A ALTERNATOR NOW.
JUST NEED A ADDRESS AND HOW TO SEND IT TO CANADA.

JOHN PERRY

eskflyer wrote:I HAVE A GENERATOR REMOVED FROM MY 170. I WILL CHECK THE ARMATURE WEDNESDAY WHEN I GET HOME FROM WORK AND IF IT IS GOOD I WILL SEND IT TO YOU FREE FREE FREE!!! I AM USING A ALTERNATOR NOW.
JUST NEED A ADDRESS AND HOW TO SEND IT TO CANADA.

JOHN PERRY

That would be amazing! Please keep me posted or feel free to shoot me a personal message.

Are you able to get me a part # so I can confirm it will fit?

I cannot get a part # until I get home from the frigid far north off the edge of the continent. I will get you one Wednesday. The generator was is off a o300D had 700 hrs on it when she died. ummmmmmm actually I forgot i have a working generator on a engine I just bought, you can have it. it is also off a o300D that was on a 172 that got flipped over in bristol bay AK in a wind storm.

Send me your address and how you need it sent and I will get it in the mail on Wednesday to you. I have never sent anything to Canada so need some instruction on how to label so can get thru customs.

John Perry
eskflyer@yahoo.com
1-907-394-3579

reecewallace wrote:Hi all,

My 20amp Delco-Remy generator just died again on my 170b.

Last year, it died so I replaced it with a new unit. Now, it started leaking and when my mechanic went to replace some seals, he saw the drive shaft was completely stripped. A new Delco generator costs about $700

Would there be a lot of additional wiring/electrical associated with upgrading to an alternator, or any panel modifications? I don't have circuit breakers, only fuses and a 20amp voltage regulator.

What's a realistic solution pricing for installing an alternator replacement? The additional amps would be nice, because with my all my lights on at night on final/takeoff, I'm at a negative discharge of about 30amps total (10amp more than I can produce).

How drive shaft threads should look vs stripped on mine

There are no “new” generators. You previously installed a replacement “rebuilt” generator which was “new” to you. Usually, when you purchase a replacement or exchange generator … it does not come with the hub and gear (items 13 thru 17 in this pic.) This means that whomever installed those items on your “new” exchange generator likely stripped that shaft when they over-tightened the nut. That person is whom you should discuss this problem and how to repair it, IMO>

The least expensive repair for you is likely to acquire another generator on an exchange basis (even if you do not receive full core-value for your unit.)

This is the time for you to consider two additional options: 1- Upgrade to a higher output generator such as a 35A unit….. OR…..2-modify your system to an alternator system.

Choice No. 1 will involve acquiring a serviceable 35A generator AND 35A regulator …AND….upgrading the ARMature wire from the gen to the regulator and to your panel electrical buss along with increasing the fuse or C.B. to accommodate that increased Amp rating.

Choice No. 2 will also require you to upgrade the associated wiring…. along with buying an approved conversion alternator system…. which would include either an STC’d “Kit” such as the Skytronics/Jasco system. ($2,000 plus installation labor of about 8 hours)….. OR…… using the early Cessna method by gathering together all the necessary parts (alternator, regulator) and modifying your wiring accordingly (only a “guess” but likely about$1500 plus about 8 hrs labor).

The simplest and cheapest solution will be to replace your generator with another generator and is what I would do if it were me….and if I were me I’d upgrade to a 35A generator/regulator system.
I see in his post above that John is offering you the best price possible on a replacment generator. EVEN IF YOU DO NOT INSTALL his particular unit…it will be a great “core” for you to use in an exchange for a rebuilt/overhauled unit. (My favorite rebuilt/overhauled generator would come from AeroTech of Louisville… who is a supporter of our Assoc’n….be certain to mention you are an Assoc’n Member…. the Owner came and made a presentation at our Bardstown, Kentucky convention.)

Remember this if you install a generator: WHATEVER GENERATOR YOU INSTALL MUST BE MATED WITH THE SAME SIZE (Amp rating) REGULATOR if you want the system to operate at full capacity without damage. Pay attention to the actual Part Number of any generator you install to determine it’s Amp rating.

I have a Jasco alternator in my 172 and frankly it is not my favorite alternator system because it is so proprietary. (You cannot obtain parts to repair it or it’s regulator… you must return it to Skytronics for any/all repairs.). If I were to convert my generator-equipped 170 to an alternator I would choose to use the Cessna system used on 150/172 by purchasing the alternator, regulator, and modifying my system in accordance with the Cessna instructions (which the Assoc’n can provide. This would be less expensive and those components can be repaired by aviation, automotive, and owners and parts are readily available. The price will be determined by how good you are at shopping (retailers, salvage yards, etc) and the labor is still about 8 hours.

Hope this helps.

I haven't installed it, but there is the B&C alternator with STC from Classic Aero .

viewtopic.php?f=39&t=15237

The generator I have is a 35amp delco removed p# 1101898, if this will work I’ll send it

eskflyer wrote:The generator I have is a 35amp delco removed p# 1101898, if this will work I’ll send it

That is indeed a 35A generator…and should be mated with the 35 A regulator if you want the full 35Amp capacity. If you install it using the existing 20A regulator..no damage should occur…but the 20A regulator will only “ask” for 20A maximum….the generator will output 20A.

(The problem only comes up if you (example) put a 35A regulaor onto a 20A generator. The higher-rated regulator will ASK for 35A…and the 20A gen will overheat trying to accomodate that. I.E. A small reg with a large gen is OK….but never the reverse.)

I would do the alternator conversion if you can.

When I first acquired my 170 (53 B model, O-300A), it had the generator / fuses. I flew it for awhile and then after a lot of random electrical gremlins that kept coming up, I decided to do the swap. We put in the Plane Power ER14-50 alternator (link below), specifically designed for replacing the generators on our small Continentals (i.e. it is gear-driven, not belt driven). It comes with the regulator and rated to 50 amps.

https://www.aircraftspruce.com/catalog/ ... -01321.php

You will need new wiring (and would recommend doing it anyway), and also highly recommend converting from the fuses to the CBs. I used the existing fuse panel and simply replaced them all with Klixon CBs.

I haven't had an electrical problem since - in over 120 hrs in the last 1.5 years. Power output is awesome and stable from about 850 rpm on. Very pleased with the product.

If you have or intend to add an oil filter adapter other than the Airwolf, some alternator conversions are too large to fit with the oil filter adapter.