RV-3: Trying the Engine On for Size

After getting Junior on his gear last weekend, we did a little cleanup work on empennage fiberglass, then had to do some hangar cleanup to host the Houston RV builders on Saturday. That meant that this morning, we got to the workshop with no ?in progress? projects to work on ? everything had been put away. What to do, what to do?.i guess we have this engine, a hoist, and a clear path between the fuselage and the back door ? might as well see just how tight this installation is going to be!

Louise had done her homework and read up on engine installation, but I warned her that we weren?t going to be putting it on the mount today ? for one thing, we hadn?t gathered the necessary tail weights, and for another, we didn?t have any oil cooler fittings for the accessory case. Knowing just how tight the firewall/engine interface is going to be, (I used to own a Yankee, and former Grumman owners will know what tight means!) I am planning that EVERYTHING that goes on the back of the engine needs to be there before we hang it for good.

Sure enough, we learned stuff right from the start. Like we were reminded that this is an RV-3?there ARE no firewall forward kits, instructions, or drawings. I had to dig out the RV-8 firewall forward drawings and start making a list of fittings we?ll need for the fuel and oil plumbing. That was the easy part ? next came the fitting (like a slow, stabilized approach). We learned right away that the oil filter had to come off:


The good news was the Randy Lervold?s pictures were right ? the recess was in the correct spot for the prop governor. He was also right that the standard cable mounting bracket doesn?t work. Add that to the modification list?
Next, the oil filter adapter ? going to need that 1.4? spacer that Randy mentioned!


We used to ask ?how did people build these things before the Internet came along?!? Now I ask, ?How did we build these things before the digital camera?!? Invaluable for capturing data from a fitting session, here, we see an image that will help me fabricate the necessary cable bracket for the prop governor:


Louise was not idle by any means during the fitting session ? she took this picture after saying ?I think we?re going to need a shorter dipstick (and tube):


At the end of the day, Junior was back in his building spot, and the Mattituck was cradled back on its pallet. Junior is sporting a bunch of blue tape labels telling us what is going to go where on the firewall ? one of the most important outputs of the session:


So it was back to the computer this evening to place a fittings order and do a little photogrammetry on that prop governor bracket. Looks like it will be fun! I expect it will be a few weeks before junior gets his new engine ? lots of little things to get done before we hang it for good.

Paul

Grumman Tight!

Paul,
I feel your pain. Owning a Grumman AA1-A for twenty three years, and doing all my own maintenance, I lost plenty of skin off my hands trying to fit them between the firewall and the mags! The generous space offered behind the engine on the Doll, has been wonderful.

Paul,

I wonder is some of the things that nominally go through the firewall could go out through the cheeks instead. Then if the cheeks were held on with piano hinges they could be opened rather easily, and even some of the equipment might be located in them.

They'd be behind the firewall and outside the cockpit but could be brought in to the cabin in front of the panel.

It wouldn't simplify controls but there might be some of the electrical details which would be more accessible this way.

Dave

Don't forget the plate nuts for the oil breather lines and oil and fuel pressure lines.

Not to mention holes next to your contactors to feed the wires through the firewall.

Paul and Louise-

are you still planning on an inverted oil system? Looks like things are going to be tight!!!
Tom

David Paule said:

Paul,

I wonder is some of the things that nominally go through the firewall could go out through the cheeks instead. Then if the cheeks were held on with piano hinges they could be opened rather easily, and even some of the equipment might be located in them.

They'd be behind the firewall and outside the cockpit but could be brought in to the cabin in front of the panel.

It wouldn't simplify controls but there might be some of the electrical details which would be more accessible this way.

Dave

Click to expand...

Maybe not exactly what you are talking about Dave, but I was impressed with the use of space in this RV-3. Great access behind the panel.








Paul and Louise are aware of this airplane and expressed to me something to the effect that they were going to keep things simpler on their first 3.

David Paule said:

Paul,

I wonder is some of the things that nominally go through the firewall could go out through the cheeks instead. Then if the cheeks were held on with piano hinges they could be opened rather easily, and even some of the equipment might be located in them.

They'd be behind the firewall and outside the cockpit but could be brought in to the cabin in front of the panel.

It wouldn't simplify controls but there might be some of the electrical details which would be more accessible this way.

Dave

Click to expand...

That's not a bad idea, and I know of at least two airplanes that are using the cheeks for heating/ventilation (one of them is the one that Larry just pictured). We actually have other plans for the cheeks - taking a tip from a very nice RV-4 here in Texas, we are planning on putting access hatches in the cheeks (behind the firewall), and using them for small storage (oil for instance) as well as access to the cowl side pins. Probably run the external power jack in one of them as well.

We are still planning on the inverted oil "if" we can make it fit. Fortunately, it is pretty easy to try installing it and then back out (so long as we haven't drilled anything to the firewall), so we'll give it the old college try.

Paul

Mmm

We are still planning on the inverted oil "if" we can make it fit. Fortunately, it is pretty easy to try installing it and then back out (so long as we haven't drilled anything to the firewall), so we'll give it the old college try.

Click to expand...

Not sure that was the deal Was rather hoping you were going to make it fit, so we can copy you

Andy