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O320-A1A Issues to look out for?

mizer2167

Member
Are there any issues or problems to watch out for in earlier narrow deck Lycomings vs. newer engines like the E and D series?
 
The Mighty ND...

Are there any issues or problems to watch out for in earlier narrow deck Lycomings vs. newer engines like the E and D series?

Dave,
I bolted a Narrow Deck 0-320 (Dash Nada) in both my RV4 and RV6"X" Hybrid. They are great, smooth and economical options to traditional newer or larger displacement engines. I paid $5K total for 2 run-outs removed from an Apache.

Here are some things I discovered over the years (and 2K hours)

1. Depending on RV model, The finish kit for the ND is different as the lower cowl scoop, engine mount, baffling and hardware are unique. The Vetterman exhaust is also unique as 2 of the pipes aren't interchangeable with the E series.

2. The ND has smaller cylinder (hold down) flanges than the wide deck 0-320B and E series as well as smaller case through bolts. You can't use the 8.0 or 9.0:1 pistons (160/170HP) in the ND for that reason. (you can with the wide deck). You can however balance the internal parts, polish and flow the ports and get a very smooth engine that will run on MoGas or the new proposed Non Lead 89 Octane AV gas.
On the good side it's 12 lbs lighter (I hung it from a fish scale alongside an E2D) than an E series 0-320 and 15lbs lighter than an 0-360J2A. (Same test)

3. If you keep the RV empty weight down and use a wood prop you'll have a very nice flying RV. With the Hartzell 2 or MT 3 blade CS (yes they have a CS crank as they were on early Apaches) they will really perform on takeoff and climb.

Great engine and a good budget option if you so choose.
V/R
Smokey
 
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Dave,
I bolted a Narrow Deck 0-320 (Dash Nada) in both my RV4 and RV6"X" Hybrid. They are great, smooth and economical options to traditional newer or larger displacement engines. I paid $5K total for 2 run-outs removed from an Apache.

Here are some things I discovered over the years (and 2K hours)

1. Depending on RV model, The finish kit for the ND is different as the lower cowl scoop, engine mount, baffling and hardware are unique. The Vetterman exhaust is also unique as 2 of the pipes aren't interchangeable with the E series.

2. The ND has smaller cylinder (hold down) flanges than the wide deck 0-320B and E series as well as smaller case through bolts. You can't use the 8.0 or 9.0:1 pistons (160/170HP) in the ND for that reason. (you can with the wide deck). You can however balance the internal parts, polish and flow the ports and get a very smooth engine that will run on MoGas or the new proposed Non Lead 89 Octane AV gas.
On the good side it's 12 lbs lighter (I hung it from a fish scale alongside an E2D) than an E series 0-320 and 15lbs lighter than an 0-360J2A. (Same test)

3. If you keep the RV empty weight down and use a wood prop you'll have a very nice flying RV. With the Hartzell 2 or MT 3 blade CS (yes they have a CS crank as they were on early Apaches) they will really perform on takeoff and climb.

Great engine and a good budget option if you so choose.
V/R
Smokey

Narrow deck O-320 models came in higher compression 160 HP versions (B and D versions), they just needed the banana shaped reinforcing plates on the cylinder mounting bolts, and longer mounting studs.

s-l225.jpg
 
Narrow deck O-320 models came in higher compression 160 HP versions (B and D versions), they just needed the banana shaped reinforcing plates on the cylinder mounting bolts, and longer mounting studs.

s-l225.jpg

With the hold down plates, you can bump the compression up just like on the Wide Deck engine.
 
Dave,
I bolted a Narrow Deck 0-320 (Dash Nada) in both my RV4 and RV6"X" Hybrid. They are great, smooth and economical options to traditional newer or larger displacement engines. I paid $5K total for 2 run-outs removed from an Apache.

Here are some things I discovered over the years (and 2K hours)

1. Depending on RV model, The finish kit for the ND is different as the lower cowl scoop, engine mount, baffling and hardware are unique. The Vetterman exhaust is also unique as 2 of the pipes aren't interchangeable with the E series.

2. The ND has smaller cylinder (hold down) flanges than the wide deck 0-320B and E series as well as smaller case through bolts. You can't use the 8.0 or 9.0:1 pistons (160/170HP) in the ND for that reason. (you can with the wide deck). You can however balance the internal parts, polish and flow the ports and get a very smooth engine that will run on MoGas or the new proposed Non Lead 89 Octane AV gas.
On the good side it's 12 lbs lighter (I hung it from a fish scale alongside an E2D) than an E series 0-320 and 15lbs lighter than an 0-360J2A. (Same test)

3. If you keep the RV empty weight down and use a wood prop you'll have a very nice flying RV. With the Hartzell 2 or MT 3 blade CS (yes they have a CS crank as they were on early Apaches) they will really perform on takeoff and climb.

Great engine and a good budget option if you so choose.
V/R
Smokey

Thank you for the response. This engine came from an Apache. I don't know much of the history as I haven't seen the logs, but it's reportedly 5000 TT and 550 SMOH with cold compression from 76 (highest) to 70 (lowest).
 
Narrow deck

No problems with my 160hp Narrow Deck 0320D2B after about 500 hours on my 6A. I bolted an aluminum Sensenich FP on it and would really like to have a CP prop, or at least, a ground adjustable prop to improve take-off performance. My static RPM is only about 2100 with the Sensenich. John
 
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n/d has conical engine mounts while the wide decks have dynafocal mounting systems. On the n/d engines you can't run the wider diameter intake pipes that the wide deck engine uses.. which may be a consideration if really pumping the HP.
Good Luck,
Mahlon
 
n/d has conical engine mounts while the wide decks have dynafocal mounting systems. On the n/d engines you can't run the wider diameter intake pipes that the wide deck engine uses.. which may be a consideration if really pumping the HP.
Good Luck,
Mahlon

Mahlon, is the intake pipe size restricted by the sump used, or is there some other obstruction?
 
restricted by the sump outlet tubes and also the position of the rear outlet tubes in the sump makes it necessary for them to be smaller.
Good Luck,
Mahlon
 
n/d has conical engine mounts while the wide decks have dynafocal mounting systems. On the n/d engines you can't run the wider diameter intake pipes that the wide deck engine uses.. which may be a consideration if really pumping the HP.
Good Luck,
Mahlon

I bought a "Maintenance shop" O-320-A2B n/d. Had to have to whole thing checked out so I had the crankcase shop rework the engine mounts from Conical to Dynafocal 1.
 
So a later model sump could get you the bigger intake pipes?
Yes, but then you will have to rework the accessory housing, as plumbing for the oil pick up is drastically different between the two. Also, with the later configuration there may be issues with engine mount interference due to them being conical with a later style sump.
Good Luck,
Mahlon
 
o-320 dash nada mounts

So I have an early o-320 (no dash) that was shipped from Lycoming on March 15th, 1957. My question is the mounting points just look flat to me. They are slightly recessed on the front side and completely flat on the back side. There is no conical shape to them. What do I really have here?

Thanks,
Andy

UPDATE- I now know that it is an 0-320 G4. 1961 non-certified engine. Conical mounts on the bottom mounts but flat on the top mounts. Not sure why yet.
 
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