34V pretty much done

[GAHorn]

the C-145/0-300-D requires a dash 45 prop bolt, the 0-300-D 6 bolt hub/ crank requires a -42, but with out the 2 prop spinner bulkheads in place, the -42 is too long. You must either build a spacer or use a dash 40 bolt. AN8-40A.

Trying to follow this.

First the C-145/0-300-D requires a dash 45 prop bolt. Is the D a typo. Did you mean A.

I see the -42 was with the first spinner which had 2 bulkheads.

AND.... using WHICH SPECIFIC self-locking nuts? (Different nuts have different depths.)

[T. C. Downey]

AND.... using WHICH SPECIFIC self-locking nuts? (Different nuts have different depths.)

What does the nut have to do with the grip length of a bolt?

Or did miss your point?

[GAHorn]

AND.... using WHICH SPECIFIC self-locking nuts? (Different nuts have different depths.)

What does the nut have to do with the grip length of a bolt?

Or did miss your point?

The bolt should protrude thru the nut to display at least some thread.
The choice of nut will affect that bolt length. (I hope it's obvious that shear
nuts are not to be used in this application, but remember we have non-certificated
owners who participate in their maintenance and who sometimes take on the responsibility
of ordering parts.)

[Bruce Fenstermacher]

George is right and I think Tom would agree IF we were not talking about bolts being used to hold a prop when the crank has integrated nuts or bushings in the hub such as is found on the C/145 through 0-300-E.

Item 4- Bushing, propellor nut # 24769

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You don't get to change nuts in this case to something else.

[GAHorn]

Not all crankshafts use those bushing/prop-nuts. (The TCM crankshaft has been superceded since publication of that document.) Alternative fasteners are allowed.

[T. C. Downey]

The 0-300-D has no bushings in the prop flange, they require a specific length (dash number) which will have the correct number of threads for the nut. (AN365-820A) the AN standard bolts are not ordered by the amount of threads it has, they are ordered by the diameter and the grip length. the correct ones for the 0-300-D using no spinner bulkheads would be a dash 40.
When my customers are ordering parts they get a list by part number to order, they do not get a choice of what I'll sign off.
OBTW, I am the customer in this case.

[johneeb]

Oh Oh!

[Bruce Fenstermacher]

Ok sorry your right I did reference an old IPC. Here is a new fresh just downloaded version from Continental.

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Tom the part is called a propellor nut bushing.

This is the nut that goes in the crank flange that the bolts, which Tom listed, go through, that holds on the prop on a C-145 through 0-300-E. What other nut is approved for this purpose on these specific cranks George? Yes my taper shaft A-65 was different but that is not the installation we are talking about.

[T. C. Downey]

Tom the part is called a propellor nut bushing.

First of all, I do not have a C-145-A,thru E, I have 0-300-D with a 6 bolt flange that has no "Propeller nut bushings". To reference the proper bolt you must use the C-172 manual, and that will show a dash AN8-42 because the propeller uses two spinner bulkheads. which the prop bolts must pass thru plus the prop prior to protruding thru the crank flange and elastic stop nut.
When you use the little domed spinner with out any bulkheads, you must compensate by using a AN8-40 or the grip length will be 1/8th" too long. I elected to use a spacer under the head of the bolt, which serves two purposes, 1 to take up the space for the two bulkheads that are not used, and 2 it serves to center the little domed spinner.
As far as which nut to use, it is called out in the C-1964-67 172 IPC, they are readily available why would you use anything else?

[GAHorn]

[...As far as which nut to use, it is called out in the C-1964-67 172 IPC, they are readily available why would you use anything else?

Tom, I'm not trying to play "stump the chump" or trying to be overly critical or anything like that.... but I don't recall in your previous posts as to which exact prop you installed. The 172 IPC you mentioned is only one such that may apply. The 56-62 IPC may also apply since some of those serials also used the 6-bolt O-300-C and -D engines. Those IPCs offer various methods of attaching the prop, including about 5 more bolt possibilities...and several nuts which match up... depending upon which exact prop and/or spinner is mounted.... And THAT is why I asked which nut you used with your -42 bolt.

The 56-62 C-172 IPC indicates that with a McCauley prop one could use AN8-43A, -46A, or -46AS bolts. Those bolts are shown matched up to MS20365-820C nuts.... or a special McCauley nut, PN A-1639-2.

Meanwhile, my own B-model, using a McCauley EM series prop and original style bullet spinner (as shown in the TCDS) is mounted using AN8-45 bolts, and using the MS20365 nuts, and only 1 complete thread is showing past the nut. Any bolt shorter than this will not be properly engaged in that lock-nut and any longer bolt will come very close to striking the crankcase nose. This leads me to believe there are other possibilities, and indicates that each installation will have to be examined closely before ordering parts, no matter who orders them, and the person specifying the exact parts might wish to look at his specific installation before relying upon a single discussion thread here in the forums.

I don't think it's entirely "safe" to simply order a -40 or a -42 bolt expecting that will work in every case.

Hope that helps.

[Bruce Fenstermacher]

My last post had a picture showing the crank in the IPC which covers the C-125, C-145 and ALL models of 0-300 A through E. All of these cranks in these engines use "Propeller nut bushings"according to the IPC.

So looking at the 172 IPC I do see in the listing, though they are not on the illustration, that MS20365-820C fiberlock hex nuts are called for the prop bolts.

So I'm trying to figure out how you would use a crank flange with a hole sized to fit a bushing nut, without the bushing nut, but just a washer and a MS20365-820C fiberlock hex nut. The answer is the engine and our 170 IPCs call for AN6 bolts (3/8" diameter) and the 172 IPC (and presumably the called for props) call for AN8 bolts (1/2" diameter). Obviously the larger diameter bolts fit the crank flange holes correctly. Learned something new today.

[GAHorn]

Bruce, you will notice that despite the part number listing in the TCM IPC... the figure depicts an 8-bolt prop flange. While the figure is not a specification, only an illustration of how the bushing/nut fits into the early crank... Clearly that figure cannot apply to the 6-bolt flange.

I think you already knew all this, but simply forgot. (I am recalling how, as aircraft judge, you inspected aircraft for the "original" propellers by looking behind the prop flange and inspecting/counting the nuts.) Yep. YOU KNEW.

[T. C. Downey]

My last post had a picture showing the crank in the IPC which covers the C-125, C-145 and ALL models of 0-300 A through E. All of these cranks in these engines use "Propeller nut bushings"according to the IPC.

So looking at the 172 IPC I do see in the listing, though they are not on the illustration, that MS20365-820C fiberlock hex nuts are called for the prop bolts.

So I'm trying to figure out how you would use a crank flange with a hole sized to fit a bushing nut, without the bushing nut, but just a washer and a MS20365-820C fiberlock hex nut. The answer is the engine and our 170 IPCs call for AN6 bolts (3/8" diameter) and the 172 IPC (and presumably the called for props) call for AN8 bolts (1/2" diameter). Obviously the larger diameter bolts fit the crank flange holes correctly. Learned something new today.

The -Ds have a different crank. it requires 6 bolts (AN8-42) the 0-300 A- has a large crank flange and requires 8 AN6-42 bolts that use the bushing attachment method. You are not allowed to remove the bushings and use a nut in their place because the hole which they are pressed is not a size that will allow a standard AN bolt to be used.

I would post pictures but as always the pictures my camera takes is too large of a file to fit here. (I wish that could be cured)

[T. C. Downey]

For those who are not lost, read the differences between a -A and a -C in the overhaul manual. you will see the prop flange change to the ARP 502 type 1 flange, then see the description of the -D it is the same as a -C except the angle starter and addition of a vac pump pad.

[hilltop170]

I would post pictures but as always the pictures my camera takes is too large of a file to fit here. (I wish that could be cured)

Tom-
I have that same problem with the iPad. It's a PITA but you can email the pictures to yourself and they will be reduced in size enough for the website to accept them. Sometimes the email will ask what size do you want to use and I always pick medium. I then save them to my photo file and then upload to my posts the usual way. It works great but you just have to take a couple extra steps. If there was no size limit, the website would not be able to store all the data and we don't need that high resolution 99% of the time anyway.