Engine removal

Use this forum to discuss technical points relating to the Nipper and its ancilliaries.
MGR
Posts: 15

Engine removal

Postby MGR » Tue Jan 05, 2021 1:29 pm

Trying to release engine to move it forward enough to remove damaged Leburg controller. Can someone with knowhow give me a ring please 0750 541 0022
Working on it now.
Regards Malcolm

MGR
Posts: 15

Re: Engine removal

Postby MGR » Tue Jan 05, 2021 6:32 pm

I have a VW engine.
The top left engine mount (as viewed from prop end, in the bell housing doesn't appear to have a nut. The mounting point has a thick circular part which looks like a spacer but which is I think actually part of casting. See picture.
Image
I believe that the mounting point is threaded and in order to remove the engine you need to undo the bolt from the cockpit side of the firewall.
Can anyone confirm?
If so, how do you get access to the bolt? I have the bottom cowl off so can see up to rear of firewall in cockpit. I can see Nipper framework, however nut is high up somewhere and not visible from below.
Any thoughts on how to gain access?

Paul1954
Posts: 29
Location: Norfolk

Re: Engine removal

Postby Paul1954 » Wed Jan 06, 2021 7:42 pm

MGR. Hi, is it a mk 3, or is it a mk 2 with the attachment backplate?

The top attachment is usually by studs that screws into the engine backplate, or in the case of the original mk 2 was rod end assembly. Between the engine and firewall there are usually 4 light alloy spacers. These sit ‘loose’ on its respective stud.

To remove the engine, gain access to the slotted nuts on the cockpit side of the firewall by removing the fuel tank and lower cowling. You should then see nuts. Remove the split pins and then the nuts. If all other attachments to the engine have previously been disconnected (tachometer, fuel pipes, mag cables etc, etc, the engine should now be able to be slit forward and removed. Beware, make sure you support the rear fuselage with a trestle or the aircraft will sit on its tail!

There are a number of variables to the above. In the case of a mk 2 with unmodified airframe mounting attachments, you may find rather odd off-set bolts attaching the engine to the airframe. Same procedure as above, but there are no separate spacers. You may have a Nipper with an access points beneath the small heat protection panels on the airframe near the exhaust pipes. If you have this mod. then it is just possible to gain access to the top nuts without removing the fuel tank - but if you are not experienced in airframe work it may not be any easier for you.

Perhaps you need to find an owners handbook?

The upper image is of a mk 3 (built by Barry Smith) that may also help you. It has the modified access area to the rear of the front fuselage (and lots of other goodies). The lower image (mk 2 with engine backplate) may be of assistance.
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MGR
Posts: 15

Re: Engine removal

Postby MGR » Thu Jan 07, 2021 7:30 pm

Paul, thanks a lot for a most comprehensive reply. Mine is supposedly a Mk 3 but not sure what an"attachment backplate" or a "rod end assembly" is. I definitely have free moving spacers though.
The pictures are very useful. Moving the fuel tank is not so easy with mine as there are copper pipes attached and a device to take fuel from flop tube when doing aeros. But if we have to do it, so be it.
Anyhow I will need to study details a bit more before I do anything.
I have a paper Mk 2 manual. Doesn't say much about moving engine - just undo the 4 nuts (trestle tail) and move it forward. Similar instructions for fuel tank...drain, undo 6 nuts, slide & take it out.)
If you know where a build guide can be found that would be really useful.
Anyhow, thanks again.
Regards, Malcolm

Paul1954
Posts: 29
Location: Norfolk

Re: Engine removal

Postby Paul1954 » Thu Jan 07, 2021 8:05 pm

MGR. OK, a my 3 with a flop tube. Is the fuel tank modified as in the images below? If so, removal is easier than you might imagine.

Slingsby did publish a mk 3 owners handbook, but I no longer have a copy. There is also a parts manual produced and supplied with kits. I think my copy was also published by Slingsby. NK&C certainly used to sell both.
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MGR
Posts: 15

Re: Engine removal

Postby MGR » Sun Jan 10, 2021 1:46 pm

Paul, thanks a lot for pictures of tank. Haven't had a chance to go yet to check mine. But from memory, yes I think mine is like the ones shown.
Regards, Malcolm

Paul1954
Posts: 29
Location: Norfolk

Re: Engine removal

Postby Paul1954 » Sun Jan 10, 2021 4:34 pm

Malcolm. If that is the case, then not difficult to remove.

The ACRO engine installation requires that the standard Nipper fuel filler cap and fuel contents float are both removed, and that the redundant tube that guided the float level wire is blocked off. The various new plumbing items on the modified tank compensate for the changes. Referring to the fuel tank images previously posted:

Top image - left union is for fuel tank contents, right union small tube is for fuel tank venting. From memory the main part of that unit is blanked off or, in the case of Barry’s Nipper ‘YB, was used to transfer fuel up from the aux tank fitted.

Middle image - the union is the other end of the attachment for the fuel contents gauge. The clear (fuel proof) tube is wrapped around and secured to the spar, usually on the starboard side. The other hole is the standard one for the attachment of 3-way fuel cock (OFF/ON/AEROS). Although I do have a vague memory that this may have been a 4-way fuel cock with one outlet blanked.

Bottom image - flop tube fuel feed to fuel cock.

Assuming that you have taken precautions for fuel and vapours:

1/ Ensure fuel cock is in OFF position.
2/ Slip off the narrow vent tube at the tank or its other end.
3/ Disconnect the main fuel union at the fuel cock lower position. This is the one that runs to the lower starboard side of the firewall on the cockpit side. Disconnect the fuel contents tube from the tank (just behind spar) forward face.
4/ Place a fuel container under the outlet below the fuel cock, open the fuel tank filler, select fuel on. Fuel should now drain out into the container. You may have to repeat this draining of fuel as you can’t use too large container because of the narrow access to the under tank area.
5/ To drain as much fuel as possible, lift the fuselage at the tail to put in a level position. Once to have as much fuel out as you can manage...
6/ Slip out the split pin that attaches the fuel selector lever to the fuel cock. You should now be able to remove the fuel selector (not the fuel cock!) from the cockpit.
7/ Undo and remove the 3 screw/bolts from each side of the fuel tank that attach it to the fuselage (2BA).
8/ You should now be able to draw the whole tank aft about. 1/2” and lift out the tank complete with fuel cock and the tube attaching it to the flop tube union.

Make sure you cover all open unions using plastic bags and string. After you have cleaned and inspected all the screws, bolts and other fittings, bag the up too. Make sure you keep all appropriate bits together - don’t just throw them in one bag!

The fuel injected Acro engine also has a fuel primer plumbed in somewhere. Depends on who did the install as to where it fits into the fuel system.

If I’ve forgotten anything else ... sorry, its been a while since I took one apart.
Last edited by Paul1954 on Tue Jan 12, 2021 10:40 am, edited 1 time in total.

MGR
Posts: 15

Re: Engine removal

Postby MGR » Tue Jan 12, 2021 9:40 am

Paul, thanks very much again for extensive reply.
Regards, Malcolm


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