Sunday 27 June 2021

Exhaust (again)

There's never a dull moment in the world of kit cars 😁

Took her out today and 200 yds down the road there was an almighty roar and the engine started misbehaving.   Instantly realised that the exhaust had separated somewhere.   As it turned out it was just behind the lambda sensor.

It wasn't much of a surprise as it has happened before.   To be fair it is definitely a self-inflicted problem.  I sometimes wish I had left the exhaust system how it was given it to me, i.e. single pipe from the 4:1 manifold to the catalytic converter and a fixed mounting at the back.  But this was at the peak of my 'tinkering' phase and I thought it would be a good idea to put a rubber mount at the back (Which Richard Stewart had recommended to me when he saw the car), a flexible joint in the middle (to dampen the vibration) and make it modular so I could adjust the angle of the lambda sender.   

Ever since then I have found it difficult to assemble without leaks.  Luckily the heat shield caught it and stopped it dropping on the road.   And when I took off the heat shield there was a sooty mark level with that join showing it has been leaking.

So did a 180 and brought her back home.  I had assumed the engine would still work without an exhaust pipe but in reality she was an absolute pig.  Revs all over the place, no power and bucking and weaving.   Lucky it was only 200 yds.  In hindsight I guess she had just gone into closed loop and with the gap being right next to the lambda sensor it was probably sending all sort of odd values to the ECU, which tried to compensate by playing with the fuel ratio.

Only took 15 minutes to rebuild and re-seal  (Had to use a hammer on the back of the silencer to get the pipes connected with a decent overlap).   But what I did notice while I was tightening up the clip was that all the other clips needed tightening.  They weren't exactly loose but each managed at least 2 x  360 deg rotations of the nuts.   I hadn't considered it, but obviously after going through a few heat cycles they settle in and you need to give them an extra tighten. 

So back on the road for a 20-miler and I purposefully left my hearing aids working so I could check.   She was back to her usual roar and popping on the overrun and all the other usual rattles and bangs were there, along with a new 'tinkling' noise I hadn't heard before.  I'll again follow my Dad's advice and ignore it, on the basis it will either go away or get worse and bad enough so you see what's happening 😁

Just got to replace the heat shield when she has cooled off.

Friday 25 June 2021

Cooling System (again)

 Just completed a 100 mile day trip and when I got back found I had lost about 1/2 litre of water.   Not a major problem but I would still like to fix it.

So I used a hi-tech solution to find the leak.  And after running the engine in the garage for 15 mins it is obvious the leak is in the are of the bottom hose on the radiator. 

I tightened up the hose again but I will probably put a slug of Radweld in to see what happens.