/ 0
- Details
- Created on Sunday, 10 October 2010 17:06
(7) Peking - Paris - Report 7
or: the mechanical backup teams: a World of experience...
For several days we suffered from a strange problem in the Magnette engine:
It starts fine in the morning, then sometime along the day it starts to misfire on two cylinders, puffing and spurring along, making it very difficult to attain any decent average speed on the flat and crawling almost to a halt and the frequent use of first gear when climbing. A pain...
We measured compression on all four cylinders and it was fine, Next we checked that the sparks were being produced and delivered to the plug leads, and again everything was as expected. We changed the distributor cap and rotor. Plugs were fine so we kept them. Everything remained as before. Remove plug one or four and the engine would keep idling as before, so they were not functioning properly...
This was puzzling everybody. With compression, fuel and spark why would it not fire?
But this is when fifty years of experience of some of the rally backup teams came to our rescue... After sleeping over the problem, Peter Banham said: "I remember a MGB with Webers having the same problem nine years ago on the the Classic Marathon. At the time we could not solve it during the rally, but once finished we realized what was happening. I bet you are having the same problem..."
What was going on? With vibration, one of the Venturis (they are locked in place by a bolt through the carburettor body) came loose, changed position and was blocking the air supply to the cylinders...
Compression, fuel and spark are not enough... You need air.
Bingo. Rob Kitchen removed the air filter and immediately realized one of the venturis had twisted indeed... Easy to solve.
Well not quite. It became loose again quite early the next day... That evening Andy and Simon put it back in place, and this time used copper wire through the bolt to prevent it from becoming loose again.
What I just mentioned about the Weber Venturi is only a very small example of the miriad number of problems these guys solve every single day. On the road side, or on the hotel car park, at 4 am or at midnight, under rain or snow, they are always ready and willing to help competitors get their cars roadworthy again. Pp
I thought the least I could do is to leave here a small note on who's who, as a small token of appreciation for your wonderful spirit and competence. Many thanks to all of you:
Peter and Betty Banham
Simon Ayris and Bill Hitchcock
Andy Inskip and Bob Manchorov
Rob Kitchen and Alan Page
