IMAC Delro 2.5M Raven Build

[Wacobipe]

Back to making progress on the Raven...I installed the Graph Tech Tail wheel today... this is the first time I've used Graph Tech products and I am really impressed with the quality.

 

[Wacobipe]

Also Recieved the DA-85 for her...that is one big cylinder! Also came with as Mejzlik 24-12 3-blade carbon fiber prop.

 

[Wacobipe]

I need some advice from all the composite experts out there...

The firewall fits nicely within the fuse, but there is no reference and a fair degree of freedom for placement, and I am not sure how to mock the firewall/engine/fuse up to determine where it belongs.

The nose of the airplane where it meets the spinner has built in several degrees of right torque compensation...so I know exactly where I want the spinner to be....and I can mock everything else behind that off the nose surface where it meets the spinner...

I feel like I need to get the engine floating in space in the nose of the airplane located in the right position as dictated by the nose of the airplane, then clearance the firewall for the carb inlet, and finally mark the engine mount locations...but getting all that mocked up inside the airplane has me a bit stumped. I guess I can just start cutting spacers and supports out of wood and wedging the engine in place until it fits and is secured, then work the firewall into place...but I think there may be a better way.

How about it @Terryscustom, @Pistolera, @Jlc, @IMAC FANATIC ?

There's a clever method out there somewhere...I just need pointed in the right direction!

 

[Pistolera]

Put some padding on the floor and stand the fuse on its tail. Strap it against something, like a basement post, fridge, etc. Once secured you can carefully sit the engine on its mount and slide it around so you get you spinner centered on the cowl ring. Slide your spinner backplate on to check it. Then mark it, triple check and drill.

 

[Jlc]

My firewall is already drilled so I'm going to stand mine on its tail and put the spinner backplate on and get the gap even all the way around and epoxy it in. Would be easier with an extra set of hands. GLAD you back!!!

 

[IMAC FANATIC]

There ya go easy peazy,
measure out the difference and make a spacer if necessary to keep it tight. Dont forget to put down thrust spacers/washers in if you intend to use them to keep it purdy.

 

[Jlc]

I didn't even think about thrust adjustment washers. Glad you brought that up.

 

[Jetpainter]

Are you planning on bolting the engine straight to the firewall without spacers? I know the 85 doesn't like standoffs from what Ive been told.

I guess if you pull the carb off you can lay the engine right on the firewall and using Earl's suggestions get it aligned and marked.

You'll also need make some provisions for the needle valves. Their location makes their access when the engine is mounted to the firewall tricky at best, but I'm sure you ran into that on the 60 in your Pitts.

 

[Wacobipe]

My firewall is already drilled so I'm going to stand mine on its tail and put the spinner backplate on and get the gap even all the way around and epoxy it in. Would be easier with an extra set of hands. GLAD you back!!!

Mine has tiny holes drilled...but they don't come close to matching the DA85 bolt pattern anyway...

 

[Wacobipe]

Are you planning on bolting the engine straight to the firewall without spacers? I know the 85 doesn't like standoffs from what Ive been told.

I guess if you pull the carb off you can lay the engine right on the firewall and using Earl's suggestions get it aligned and marked.

You'll also need make some provisions for the needle valves. Their location makes their access when the engine is mounted to the firewall tricky at best, but I'm sure you ran into that on the 60 in your Pitts.

Direct to firewall would be ideal...and it could work in this case...but I am not sure I can get the engine in/out once I epoxy the firewall in if I do This (without removing the carb first)... And that seems like a pain in the a$$! I am going to mock things up first so I will try to see if I can make that work.

If I can't mount direct to firewall, then I will be using plywood spacers...not stand offs. The 85 is one big cylinder of pure torque so I think it needs all the support it can get!