Manifold depression

I did some more tinkering on the Alvis today.

It did not begin auspiciously.

I decided to trial fit the inlet and exhaust manifold.

Easy-peasy lemon squeezy.........

Yeah, you'd think.......

Except that virtually the first thing I did was to drop one of the manifold nuts down the exhaust downpipe.........

Some swearing occured.

Followed by an attempt to disconnect the down pipe from the steel flexible pipe that leads on to the exhaust proper..........

Now, this hasn't moved since at least 1975, so I shouldn't really feel too dejected by the dismal failure of said attempt.

In the end, and after a quite lengthy period of entirely fruitless sodding about, I sacrificed a nice magnet on a stick (actually a 'magnet on a telescopic radio aerial' - £1.00 from Tesco style job)......   bent to fit the radius of the downpipe.

Suffice to say I managed to retrieve the errant nut just before the magnetic device 'failed in service'.......or, less euphemistically, I clumsily snapped it in half.......

DOH!

So, by no means a great start........

I did stretch a disposable latex glove over the down pipe flange to prevent this from happening again, however.

I may not be the fastest learner, but I do learn........

Anyway, I removed the inlet manifold to take some pictures of the modifications.

Showing the thin alloy plate (top centre) that fills in the hole machined into the inlet manifold. This then faces the hot shoe on the exhaust manifold (centre below).

 

To ensure a reduction in fuel vapourisation, we also wanted to create an air gap between the new plate on the inlet and the hot shoe on the exhaust.

To achieve this, we made two spacers:

We used the old gasket (centre) as a pattern

They are about 8mm thick

You can almost see how the inlet manifold will 'float' over the exhaust hot spot without touching it in this photo.

Apologies for the quality of the photo's composition: I ran out of hands.......

Spacers and inlet manifold gaskets in place.

 

(Note the missing oil feed pipe which should run from the brass tee-piece below the left alloy cover to the vertical brass union between the L/H inlet port and the centre exhaust port - thereby hangs a tale................. :-)

Trial fitting of the inlet and exhaust manifolds: it's all gone together rather nicely!

This is very definitely a trial fitting: the pushrods are all over the shop! 

 

But that's a job for another day...........after the day I'm going to have to spend tightening up all the head stud nuts to a correct and even degree.......

Here's some close ups of the modified manifold assembly in place.

 

(Just in case you were interested.......)

Remember, it's all coming off again so it's only finger tight.....

The closed-off bit of vacuum pipe is part of the redundant vacuum-driven screenwasher.

Re-instating this is means finding a Trico glass washer bottle with a sound metal lid.

To find one of these, look in the parts book under "Manure: (Rocking Horse)"............

Inlet manifold spacer sandwiched between two gaskets.

As the inlet and exhaust manifolds are now no longer attached to each other, it won't be necessary to fit two gaskets to each of the exhaust ports.

 

 And here it is looking really quite tidy and deceptively complete.......

And so, for my next trick:

That'll be the oil feed pipe to the rocker gear, then......

An oil feed pipe with a substantially knackered union...........

The extensive swerve around this particular problem may very well get a blog post all to itself.

It may even stretch to two.

You lucky people..............

:-)