Hangar Flying => Hangar Flying => Topic started by: walter on October 02, 2006, 10:12:11 PM
Title: Bolt Pattern?
Post by: walter on October 02, 2006, 10:12:11 PM
How do you determine SAE bolt pattern?
Title: bolt pattern
Post by: xbirdone on October 03, 2006, 11:57:34 AM
Is this a trick question? -1 is the smaller one, -2 is the norm these days. early early Lycs were dash-1 as was 65, 85, 90, and O-200 Continentals
Title: more specific
Post by: walter on October 03, 2006, 05:18:46 PM
Okay maybe I need to be more specific! By looking at a crankshaft how does one determine which SAE bolt pattern it is?
Title: bolt pattern
Post by: spy on October 03, 2006, 06:33:37 PM
:( just by looking at the crankshaft? you cant?...the sae1 and sae2 are almost ,, almost identical.....your gonna have to consult the engine manufacturer.
Title: Bolt Pattern?
Post by: Gilbert DRIEUX on October 03, 2006, 09:26:58 PM
Sure, you can determine the SAE bolt pattern by just "looking" at crankshaft. Just to misure Bolt Circle diameter (and lug diameter):
SAE 1 is 4-3/8" (lug 5/8") => external diameter (out of lug's holes) = 4-3/8" + 5/8" = 5". SAE 2 is 4-3/4" (lug 5/8") => external diameter (out of lug's holes) = 4-3/4" + 5/8" = 5-3/8".
==> SAE2 is 3/8" larger than SAE 1, with same lugs. Cont. engines are SAE 1, Lyc. engines are SAE 2, BUT O-235 can be SAE 1 or SAE 2. My own O-235 has both patterns available on its flangue.
Regards. PS : Have a look at Aircraft Spruce catalogue for more details.
Title: Bolt Pattern?
Post by: walter on October 03, 2006, 09:30:55 PM
Thanks Gilbert! I knew the difference was a matter of measurements. Just not sure what the measurements were!
Title: Bolt Pattern?
Post by: Waiter on October 04, 2006, 05:47:50 AM
ALSO - be aware that the SAE2 flange can also have different size bolt lugs;
7/16 or 1/2 (AN7 or AN8)
Waiter
Title: Bolt Pattern?
Post by: Gilbert DRIEUX on October 04, 2006, 02:33:03 PM
Exact, :oops: I didn't want to enter too much data upon big engines.
Lyc O-235 SAE 1 or 2 lud dia 5/8". O-290 SAE 2 Lug dia 5/8". O-320 SAE 2 Lug dia 5/8" or 3/4". O-360 SAE 2 Lug dia 3/4".