Most physical difference.

[circlepilot]

I've done a lot of research and owned a 273 Commando engine, way back when...in a "nut shell" what is the physical difference between the 180 HP and the 235 HP engine; over and above cams, carburetion and valve covers? I want to convert a 180 HP to a Commando.
Norm

 

[RustyRatRod]

Paging @toolmanmike

 

[perfacar]

I've done a lot of research and owned a 273 Commando engine, way back when...in a "nut shell" what is the physical difference between the 180 HP and the 235 HP engine; over and above cams, carburetion and valve covers? I want to convert a 180 HP to a Commando.
Norm

View attachment 1714953885

pistons are biggest difference, 180 had 8.8 cr. 235 had 10.5 cr. same heads, also, 235 had dual point dist. cast iron,

 

[circlepilot]

pistons are biggest difference, 180 had 8.8 cr. 235 had 10.5 cr. same heads, also, 235 had dual point dist. cast iron,

Thanks, forgot about the dual points, cast iron?? The crank right?

 

[RustyRatRod]

Thanks, forgot about the dual points, cast iron?? The crank right?

I believe he was talking about the distributor. The early ones have a cast iron housing.

 

[Charrlie_S]

4 BBl manifold and AFB carb, also.

 

[RedFish]

I feel certain that any 273 build today would include more fuel/air movement through it. A better dual plane intake, carb, cam, and exhaust from heads on. Electronic ignition would replace the points too. And any must be turned to run on todays fuel regardless.
10.5 to 1 pistons was the main "Commando" ingredient and the least compatible with todays/tomorrows fuel.
Bottom line, pay out the nose for the OEM Commando external "eye candy" if you wish. That stuff will bolt onto a smarter LA build.

 

[circlepilot]

Good post RedFish...Sounds like the way to go, based on today's available fuel. (I do have access to 100LL AVGAS. ) Thanks for the reply.

 

[RustyRatRod]

"Today's fuel" will work better with the higher compression. The ethanol content helps with that. This is why you can run 12:1 compression on E85. Alcohol supports more compression than gasoline. There are of course other drawbacks.

 

[perfacar]

I've done a lot of research and owned a 273 Commando engine, way back when...in a "nut shell" what is the physical difference between the 180 HP and the 235 HP engine; over and above cams, carburetion and valve covers? I want to convert a 180 HP to a Commando.
Norm

View attachment 1714953885

ok, the 180/273, the piston sits down at .011 down. cut head to min cc of 57.3, use .024 gasket, CR will be 9.86. just food for thought.