Solex 32 PHN-1 setup

Dragcurve · Post by **Dragcurve** » Tue Jun 29, 2010 8:53 pm

Can anyone help with the setup of my solex.

The autochoke has been removed presumably the two feeder holes need blanking?

Does the accelerater pump on top still need connecting?

many thanks.

JohnLindsay · Post by **JohnLindsay** » Fri Jul 02, 2010 10:33 am

Hi Bob,

I don't profess to be an expert because I am still refurbishing my VP-1 and have yet to fly it, but it is fitted with a 32 PHN-1 and has 700+ hours in its logbook.

I'll PM you some photos in the hope that they might be of help.

Regards,

John.

JohnLindsay · Post by **JohnLindsay** » Fri Jul 02, 2010 11:25 am

Bob,

I don't think the PM worked (seems to have vanished from my system altogether) so I'll try and post the images here.

John

P.S. Do check the carb lid for warping, they are very prone to it but can be machined/filed flat again (with some difficulty!)

Dragcurve · Post by **Dragcurve** » Wed Jul 07, 2010 12:02 pm

Thanks John your pictures have answered all my questions - brilliant!

cardiffrob · Post by **cardiffrob** » Wed Jul 07, 2010 4:29 pm

Appols for a bit of 'thread hijack" but I've got a Stromberg CD150 on a VW 1835 and have been calibrating the needle. I bought a Wideband Lambda sensor kit for a couple of hundred quid and have used it on the carb.
Very good results. It showed a rhythmic cycling of fuel/air mix but I've realised that it was sensing the difference in mix from the changing float height! Fairly accurate readings. I get a lean mix below 600rpm (15.5-ish to one ratio) and it then runs at about 14.5 until about 2500 when it starts to get a bit richer. At that point it starts to run out of revs due to the prop size.
This kit only works with a full exhaust system where a boss can be welded onto the exhaust collector (below) but might be useful for tuning if anyone gets stuck.

So far I haven't been able to discover any other way of calibrating a carb for a Leburg engined aircraft. Anyone got any other ideas?

JohnLindsay · Post by **JohnLindsay** » Thu Jul 08, 2010 7:42 am

Bob - glad to have been of some help.

Foggy - what an elegant exhaust system you have; something I might aspire to after I have got my VP-1 flying! Unfortunately, with the current stub exhausts I can't realistically fit a lambda sensor or I would ask to hire your kit. I tried a Gunson CO analyser but got some highly inconsistent readings at the same time as the aluminium sampling tube shoved up the exhaust was quietly melting! So, I'm currently looking at CHTs, the colour of the exhaust and doing plug cuts in the hope of satisfying myself that the mixture is ok. Do you happen to know if a change from Avgas to Mogas makes any difference to the mixture or to plug colours?

cardiffrob · Post by **cardiffrob** » Thu Jul 08, 2010 2:14 pm

John. Just a thought, but couldn't you get a few VW "J Tubes" and weld them together roughly so that you could have a temporary 4-into-1 system with a Lambda boss welded on? Might even be possible to have a complete kit of parts to loan out for wideband tuning?
I don't know if Avgas makes a difference but a 4-into-1 certainly does. At low rpm it will still run smoothly. I can get it down to a smooth 475 rpm without it stumbling and it still responds to a slammed throttle. 4-into1 might actually be worth the weight penalty. I believe this system is sold for the KR2 by GPASC.

http://www.innovatemotorsports.com XD16 and LC1

cardiffrob · Post by **cardiffrob** » Thu Jul 08, 2010 2:20 pm

Quantum Performance engines hire Lambda kits at £50 per week from Leamington Spa.

Mike Mold · Post by **Mike Mold** » Thu Jul 08, 2010 11:11 pm

Mark Langford's got some useful notes & photos about his mixture meter set up at http://home.hiwaay.net/~langford/corvair/o2meter

Mike

JohnLindsay · Post by **JohnLindsay** » Fri Jul 09, 2010 7:16 am

Foggy/Mike, many thanks to you both for these suggestions and leads which I shall store away and come back to, probably in the winter. My main aim now is to fast-track the refurbishment and get the VP-1 flying this summer (before I find that I am suddenly too old and have lost my medical!). After that, I shall enjoy looking for ways to improve things, like the exhaust system.

John.

cardiffrob · Post by **cardiffrob** » Sat Jul 10, 2010 9:38 am

The one Mark Langford uses is a narrowband sensor which tells you either rich or lean, not how much. Narrowband sensors have a voltage output of from zero to 5 volts but the range 'of most interest' is a tiny voltage near the mid range. Wideband has a linear output of voltage against air-fuel ratio and hence are much better at being read by a gauge.
The Narrowband works in older EFI systems by constantly switching back and forth between enrichening and leaning in the hope of 'straddling' the correct mixture.
Innovate kits are about £250, including the fancy self-programmable gauge that lets you change the scale and the colours of each segment of the display. It also records max and min data that can be dowloaded to a laptop for reading later on.