All Lycoming X1Y and X3Y hollow crank?

[Saville]

I'm trying to look for documentation that will tell me whether or not a particular engine - say for example O-320 A3A - has a hollow crank and therefore is amenable to switching back and forth from F/P to C/S.

I saw references to Lycoming SSP-108 but cannot find it on the web. Past posts gave a Lycoming URL for that but it's no longer functioning.

Anyway, is it correct to say that any X1Y and X3Y designated engine has a hollow crank and therefore could be modified to run Constant Speed props?

Is there a document handy that will describe which Lycomings come with hollow cranks?

thanks!

[ccsmith51]

This should help you:

http://en.wikipedia.org/wiki/Lycoming_O-320#Variants

[Saville]

Originally Posted by ccsmith51

This should help you:

http://en.wikipedia.org/wiki/Lycoming_O-320#Variants

Hi Chris,

It helps but I already have that and it still confuses me (which isn't hard).

For example we have:

O-320-A1A
150 hp (112 kW) at 2700 rpm, Minimum fuel grade 80/87 avgas, compression ratio 7.00:1. Provisions for a controllable pitch propeller and 25-degree spark advance.

ok and then we have:

O-320-A2A
150 hp (112 kW) at 2700 rpm, Minimum fuel grade 80/87 avgas, compression ratio 7.00:1. Same as A1A but with fixed pitch propeller.


But that doesn't tell me whether or not the crank is hollow. In what way is the A2A fixed pitch?

no plumbing?
solid crank?
Both?

Or take this example:


O-320-B2A
160 hp (119 kW) at 2700 rpm, Minimum fuel grade 100/130 or 91/96 avgas, compression ratio 8.50:1. Same as B1A but with fixed pitch propeller provisions.

What are those "provisions"? Is that word an indicator that the engine is easily converted?

thanks

[jrs14855]

SSP-108 does a very poor job on crankshaft and engine mount configuration.
There are really only two issues with the popular engines regarding constant speed/fixed pitch. The solid crankshaft, which I believe is quite rare on 0 320, and some of the E series engines with the 0 235 front main bearing.
The 0 360 is a different situation. Lots of solid shaft 0 360 engines, starting with the A4A around 1965, many Cherokees and later derivatives had solid shaft engines.
I posted a week or so ago a list of the E series engines that have the 2 piece front main that can accommodate constant speed.

[ccsmith51]

Check out the last post in this thread.

http://www.vansairforce.com/communit...p?t-59148.html

I used to think that if it was fixed pitch it had a solid crank. But that appears to not be the case with O-320's.

Mahlon posted here recently so perhaps he can help you better.

[jrs14855]

0 320E2D, E2G, E2H. E3D and E3H originally had 0 235 front main bearings and cannot be converted to constant speed unless you split the case and have it modified.
E2H and E3H were not used in any production aircraft.