Looking for a reference for 2-piece cam parts

I moved this from my accessory case thread...

I am preparing to build an O-320-E2A. It is an older engine I bought as parts. It came with a 2 piece camshaft, which I will probably use unless someone gives me a reason not to.

The cam has been ground/resurfaced by Aircraft Specialties Services (yellow tagged). The gear has been yellow tagged also by Central Cylinder Services.




My parts catalogs (both the current one, and a 1984 version that I have) only show the 1 piece cam. I found this picture in the Overhaul Manual:


I have the gear, slinger, and 2 lockplates. I will need to source the other parts.

Does anyone have an old (pre 1982, I think) Parts Catalog for the O-320 that would list the part numbers for all of these parts?

An old O-360 parts manual -



Here is my camshaft assy. before it went to the assembler. You can see the two bolt retainer plates and the formed sheet metal "SLINGER, Breather" under the bolt heads.

Gil, thanks SO much!

Is the rod in the center the "Tachometer shaft"? I think it would be OK to omit those parts (tachometer shaft, tach shaft spacer), what do you think?

My lockplates are probably OK but I'd like to get new ones. I"m not sure if they should be reused.

Want to come to NM and build an engine

Cam

I'm pretty sure you need to install the tach drive shaft. The covers for the tach drive(Spruce etc.) are just dust covers and would not create an adequate oil seal.
The locking plates should not be reused.
The cam gear bolts have probably been superceded. Dart Aircraft in Waco TX might help with superceded parts. They have Lycoming ECI and Superior.

jrs14855 said:

I'm pretty sure you need to install the tach drive shaft. The covers for the tach drive(Spruce etc.) are just dust covers and would not create an adequate oil seal.
The locking plates should not be reused.
The cam gear bolts have probably been superceded. Dart Aircraft in Waco TX might help with superceded parts. They have Lycoming ECI and Superior.

Click to expand...

I think the bolts are still around, however a good description of them is here -

http://www.aircraft-specialties.com/bolt-3125-24-x-66-long-sl-std-1791/

The lockplates are also easy to get -

http://www.aircraft-specialties.com/lockplate-3125-bolt-x-1-33-sp-sl72078/

az_gila said:

An old O-360 parts manual -

Click to expand...

Hi Gil - can you post the picture that goes along with these parts? It looks like I need Item 23 (STD-1199, "Pin - 3/16 x 1-1/8") as well. The figure would sure help.

OK

IowaRV9Dreamer said:

Hi Gil - can you post the picture that goes along with these parts? It looks like I need Item 23 (STD-1199, "Pin - 3/16 x 1-1/8") as well. The figure would sure help.

Click to expand...

Not one of Lycoming finest - the viewpoint is poor -

Because part #23 goes cross-wise to the camshaft, I think it is the early equivalent of the pin that retains the tach drive in the later one piece camshafts. Same diameter, but now 2 21/64 inches long.

A stolen picture -

Thanks Gil - both pictures help a lot.

You are right, the Lyc drawing doesn't show this clearly... but I find those old hand drawn pictures strangely beautiful. Much nicer than modern CAD stuff.

You stolen photo is really good to show the tach shaft on a modern camshaft. It shows that the tach shaft (and its crosswise pin) is installed on the outside of the camshaft gear. Looks like it is held in with a snap ring.

Your stolen picture inspired me, so I stole this one: I think it is similar to what I will have:


This shows a 2 piece cam - the shaft/pin is installed between the cam and gear. I think it still floats around a bit but can't be removed without taking the gear off.

I'll find a servicable tach shaft - the pins are still available. This is a bit annoying because the tach function will never be used.

Thanks again for the pictures,

dave

Good news - I found what appears to be the tach shaft and centering spacer:


It needs a cleaning and inspection but initially appears serviceable.

I still need the cross pin but that is available. Thanks Gil!

Cams

Dave: Any possibility of just not installing the tach shaft? I left mine out on my integral gear cam. I can't imagine ever needing to drive a mechanical tach.
Aircraft Specialties Services in Tulsa should have any steel engine part that you might need, Bob over there knows almost all there is to know on this subject.

Don Broussard

RV 9 rebuild in progress

cajunwings said:

Dave: Any possibility of just not installing the tach shaft? I left mine out on my integral gear cam. I can't imagine ever needing to drive a mechanical tach.
Aircraft Specialties Services in Tulsa should have any steel engine part that you might need, Bob over there knows almost all there is to know on this subject.

Don Broussard

RV 9 rebuild in progress

Click to expand...

If you omit the shaft then you need a way of properly plugging the hole where the shaft goes through this seal on the accessory case -



I think most folks just leave the tach drive shaft in place and cap off the threaded end where the cable fits. It's easier that way.

I'm with Gil - I'm going to install the shaft. ACS sells a tach cap for $19 (which is better than the $68 Lycoming version).

dave

Tach shaft

Not to muddy the water but our very own and highly esteemed guru, Mahlon Has seen problems caused by running with the tach shaft installed when there is no tach connected. Apparently when not loaded the tach shaft drive pin can chatter in the drive slot and make some metal. That being said we can acknowledge that many are flying around with tach drive shaft installed and not causing problems. I left the tach drive shaft out of mine and another 320. For a gasket I cut out a disc of the red silicone baffle seal material to fit inside the metal tach drive cap. ymmv.

Don Broussard

RV 9 rebuild in progress