O-320 Engine Installation

[Wayne G. O'Shea]

Richard and All,

I have done numerous engine installations on the Rebel and would highly suggest that you bolt the engine mount to the firewall first. Then put the engine in place and while still on the hoist/chain fall, mark and locate all the components that need to go on the firewall. Throttle/Mixture cable attach platform, tach line (if mechanical), cabin heat damper, etc, then pull the engine out of place and do the necessary drilling and riveting. (note I also still have my Gill25 battery on the firewall with an O-320-C2A, but would suggest you put yours in the tail cone!) Also, I highly suggest you mount the oil cooler on an angle (as you can see in my Firewall Reinforcing pics on our web site). This allows a much cleaner (straighter) scat hose routing as opposed to the position MAM shows it to be installed. The immediate benefit is that it is easier to hook up the 3" scat hose. The most important benefit is that on my installation the oil temperature runs at 195-205F as opposed to Howard's that ran at 230-240F, with the same engines, props & cowlings. (I did both installations, so I know they are identical) This is largely due to the increase air flow with the less restrictive SCAT hose and the fact that the oil cooler air outlet is now pointed directly at the cowl exit opening and not the closed area of the cowling bottom. I am now looking at putting a control damper in the SCAT line as on cooler days I can not get the oil temperature up high enough to get the moisture out, were as Howards was always above 225F.

The Factory engine mount itself, should have a 1 degree offset in it according to the factory thrust line drawings. And yes if you feel a need for a thrust line adjustment, you put a penny washer under the 2 mount fittings on the side opposite to the direction you want to point the engine in. Keep in mind however that this .063 of an inch at the firewall moves your prop flange a substantial amount and your cowling may not fit right anymore!!!!

Blue Skies'

Wayne G. O'Shea
www.irishfield.on.ca