Inverted Fuel and Oil

[jja66uk]

I've just bought G-ARFV which is fitted with a VW1834 engine with no inverted fuel or oil system. Can anybody advise me how I might modify the engine to allow it to run for a short time inverted, just long enough to get me out of trouble and avoid damaging the engine should I inadvertently pull negative 'G'? I know Barry Smith produced the ACRO engine but I've no plans to replace the existing installation (even if I could get my hands on such a rare beast).

[Neil Spooner]

Hi and welcome to the forum and the fun world of Nippering.

So I can keep my database up to date to inform owners of issues/events would you mind pm ing me with your contact details please?

I don't know of any "easy" way of creating a "short term" oil supply, your main worry if you go inverted for long enough to suffer oil starvation is engine stoppage.....not for the faint hearted!!

For your inverted system you are going to need:
1- christen oil changeover valve.
2- modified rocker covers
3- modified lower sump.

Those are the main bits, then obviously all plumbed together. here are a couple of pic's.
It would be much easier to talk you through it, where are you based?

Neil

Engine (80).JPG (663.69 KiB) Viewed 7259 times

[jja66uk]

Hello Neil

Thanks for getting in touch and for the pics, I live in County Durham and the Nipper's based at Bagby. I've been away for a few weeks and haven't had chance to fly G-ARFV yet and it looks as if the weather's closing in now. I tried to start it yesterday and couldn't get it going so I took a spark plug out to see if there was fuel on it. Unfortunately the plug was damaged (not by me, looks like it's been forced in, though it could be 'galling', hard to tell) and there's swarf on the plug threads of the cylinder head so I'm going to have to take the head off and hope there's no serious damage. I've pm'd you my email address, if you'd like to drop me a line I'll give you the rest of my contact details.
I saw your YouTube video and read your report regarding the flat spin, very scary, is your Nipper flying again?

Cheers

John

[Neil Spooner]

Hi John,

The pic's are of the development of my 1834cc engine, it all looks very different now.

Sorry to hear your woe's with the spark plugs.....threads "picking up" (galling) is a common problem unfortunately, make sure you NEVER use "Copperslip" or any other copper based lub' for the 'plugs, it will encourage galling and seizing of the threads, a graphite lub' is best, such as Graphogen. http://cgi.ebay.co.uk/Graphogen-Colloid ... 1244wt_911

Sounds like you could probably get away without removing the head, use a helicoil kit, coat the thread of the tap with grease to collect the alloy cuttings, and you could also apply compressed air at low pressure to the cyl' via the bottom plug to ensure nothing goes into the cyl'. HOWEVER, check the colour of the plug after running it, a thread insert (of any type) reduces the heat soak from the plug and can lead to overheating of the plug. A grade cooler may prevent pre-ignition/detonation.

My Nipper is going very well now thanks, I have just posted some photos in the photo section of the 'site. The spin was a wake up call for me, and I felt that the video footage such a valuable training tool I felt unable to sit on it.

I have dreams of doing a "circuit" of the Uk in my Nipper, visiting other Nippers on the way round, sounds like a lot of fun! Something I will do when I have "less" time! (I don't think I will ever have more time!)

Good luck with yours, I am happy to chat and pass on my limited knowledge should you wish it. 07971966286

Thanks for your email address, I will do a list of 2011 events and try to get some enthusiasm for Nipper meetings soon.

All the best,

Neil