337's for 65 case alteration to 85 jugs

[3Dreaming]

Re: 337's for 65 case alteration to 85 jugs

Does the added displacement require more fuel than the stock carb metering is designed for?

Gary

I wouldn't think so.

[PA1195]

Re: 337's for 65 case alteration to 85 jugs

Didn't notice any differences from the 65 at 2300RPM.
EO

I wouldn't think so.

That seems to also be the case when the C-85 is stroked and O-200 pistons and cylinders are installed...188 to 201 cubes. No carb change specified in the STCs.

Gary

[astjp2]

Re: 337's for 65 case alteration to 85 jugs

I would like to know if you have or know of a 337 approving milennium cylinders on a 75 case?

Not necessary, the Millennium cylinder is a PMA'd replacement for the 85 so just note it in the 337

[astjp2]

Re: 337's for 65 case alteration to 85 jugs

Has anyone tried to contact Robert Franklin to see if his data is available for sale? If not we cannot use it in a certified airplane.....Tim

[Ragwing nut]

Re: 337's for 65 case alteration to 85 jugs

Has anyone tried to contact Robert Franklin to see if his data is available for sale? If not we cannot use it in a certified airplane.....Tim

I doubt its for sale, its posted online. I found it and copied it from somewhere

[Ragwing nut]

Re: 337's for 65 case alteration to 85 jugs

I wouldn't think so.

I would think a minor change in jetting maybe required to something similar to C75 setup, although it does not specify it requires it.

[Ragwing nut]

Re: 337's for 65 case alteration to 85 jugs

The only thing that bothers me about this mod, it does not address piston cooling. Except for the A65, all other A and C series engines has a oil squirter pathway drilled in the rod cap to squirt oil onto the cylinder wall and bottom of piston. I think it should be a requirement as a part of the change.

[PA1195]

Re: 337's for 65 case alteration to 85 jugs

On most any other engine increased airflow flow through the cylinders or improved volumetric efficiency calls for more fuel. At some point the existing fuel metering system meets its capacity to maintain the designed air-fuel ratio at full throttle or rated rpm/power. How adding the displacement discussed here or in other STC's escapes that would be worth knowing.

Gary

[astjp2]

Re: 337's for 65 case alteration to 85 jugs

Most 65's have that included now....

The only thing that bothers me about this mod, it does not address piston cooling. Except for the A65, all other A and C series engines has a oil squirter pathway drilled in the rod cap to squirt oil onto the cylinder wall and bottom of piston. I think it should be a requirement as a part of the change.