What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

rv-6a o320 150 or 160 hp

pylotttt

Active Member
When I bought my rv6-a I was told the engine was 160 hp. The logs have conflicting data, one page says It's an o-320-e2a and another says it's an o320-e2d. I don't remember what the plate on the engine says for model, but it does say it is a 150hp. The seller said when the engine was purchased it had the 160hp upgrade.
Is there a way to determine if it has the 150hp or the 160hp pistons without taking a jug off?
 
If you are using the FP metal Sensenich prop the prop pitch might indicate which version of engine you have. When I upgraded my E2D to 160hp I added 3" of pitch per Vans published recommendations.
 
The data plate on the engine might not mean anything since it’s an EAB. I think the upgrade from 150 to 160 hp has to do with the higher compression pistons. I might not be right about this, but if you have the logs and parts list and sign off for the upgrade, you might be able to figure it out.
 
150 to 160

My O-320 E2A has been upgraded from 150 hp to 160 hp and there is an entry in the log book for 75089 pistons to increase compression for the higher hp. Maybe a compression test could detect if your engine is higher compression, in case the log book lacks an entry for the upgrade?
 
The 160 version has higher compression ratio. It achieves this by increasing the distance between the piston top and the piston pin hole. The resulting smaller compressed area creates the increase in CR. I don't know the difference in height, but expect it is more than a 1/4" If you have a buddy with either a 150 or 160 version of the 320, You could take measurements through the sparkplug hole at TDC and compare. Don't know how you would do this with compression testing, as you would need the dynamic version used with auto engines and no one in the aviation business uses them, so difficult to find comparative data. Can't compute it without knowing the cam details (intake closing angle), which aren't published.

Larry
 
Last edited:
Carry out a compression test using a direct reading gauge, rather than differential?
E model regular C/R is 7:1, so should be in the region of 85 psi ( 6 atmospheres increase)
D model C/R is 8.5:1 so should be in the region of 109 psi.
All assuming no losses, real world numbers might be around 80psi or around 100psi? I would also measure the height of the piston.

From the propeller perspective I had the same experience as Sam and had to have my Sensenich repitched to 80" pitch when upgrading to 160hp.
 
Carry out a compression test using a direct reading gauge, rather than differential?
E model regular C/R is 7:1, so should be in the region of 85 psi ( 6 atmospheres increase)
D model C/R is 8.5:1 so should be in the region of 109 psi.
All assuming no losses, real world numbers might be around 80psi or around 100psi? I would also measure the height of the piston.

From the propeller perspective I had the same experience as Sam and had to have my Sensenich repitched to 80" pitch when upgrading to 160hp.

Seems way off to me. My porsche boxer engine (air cooled) has about 9:1 CR and registers 160-170 PSI and that is with tired rings.

Larry
 
Back
Top