Monday, 1 October 2018

Dressing The Engine (Part 2) - Fitting the CRC and Weber Carburettor

These two major components are best fitted at the same time as they are linked via the rotating ‘flector’ wheel.
The CRC and Carburettor Are Joined By The Flector
The flector joins the butterfly spindle on the carburettor to the cam shaft on the CRC so that they rotate in unison
A Flector
It is important that there are no tight or knotty spots when the flector is rotated. Two alignments needed to be checked – the horizontal alignment of the lugs that slot into the flector and similarly the lug alignment when rotated to the vertical plane. The process is covered in operation DX.314-1 (paragraph 47) of manual 518.

The following checks were carried out with:

·       - The CRC setting pin correctly engaged
·       - The control rod (the black ‘finger’ part) and it’s bolt only loosely put on the CRC shaft.
·       - The fibre spacer (and any intended gaskets) under the carb
·       - Both units loosely bolted into place.

I set the horizontal alignment first. In the idle position, the two lugs on the carb spindle should be in the horizontal plane and needed to be level with the lugs of the CRC control lever.
Checking horizontal alignment.........
If they are not, then the technique is to either put thin packing pieces between the CRC unit and it's seat on the manifold to raise it, and/ or raise the carb by adding a paper gasket under it. To raise my CRC unit slightly I made several shims from thin pieces cut from the lid of a tin of mackerel, and with suitably sized holes drilled through them! I rechecked alignment to make sure the two  pairs of lugs were level.
..........and re-checking horizontal alignment
I next set the vertical alignment. I turned the carb accelerator spindle such that the lugs rotated through 90 degrees. I similarly rotated the control lever of the CRC. Both sets of lugs should be parallel and in the same plane. If not, the technique is to slide the CRC unit slightly forward or backwards to align the lugs. 

Once I’d found this point, I tightened up the CRC bolt under the inlet manifold. With the CRC unit now fixed in place, I removed the carb and got ready to bolt it in place. I allowed the carb spindle to return to the idle position – meaning the lugs were in the horizontal position again. I slotted the flector wheel over the carb lugs and, with the CRC setting pin still in place, married the lugs on the black CRC control lever to the other pair of vertical slots on the flector
The CRC control lever was slotted vertically into the flector
The alignment is done with the pairs of lugs touching, but when the lugs re engaged in the flector they will overlap. Before bolting up in this position, I therefore slid the black CRC control lever a fraction further along the shaft towards the flector. You don’t want the flector to be loose, but neither do you want it pinched tight. When I found the position I was happy with, I tightened the pinch bolt of the CRC control lever to the CRC shaft....... 
Lugs Engaged - But Don't Pinch The Flector Too Tight
........and bolted on the carburettor. The bolts should not be over-tightened. My carburettor base, and the fibre spacer, were both slightly curved on their mating faces. Possibly because of a combination of over-tightened bolts and heat expansion.Fitting a carburettor like this can cause problems as the engine vacuum will suck in additional air - meaning you will have trouble setting up the cars running. This becomes more of a problem where the car is  a bvh, with several engine rev-determined settings.
Warped base. Can you see it?
Rather than remove carburettor base material to level this (this risks making the base thinner and so weaker and more prone to warping), and since both base and spacer still marry well to one another, I have opted for leaving the warp but used a very small amount of RTV sealant between carb. and spacer, and spacer and manifold. I'll try this. If I find I have problems setting idle and with running, I've always got the option of going back and dressing the carburettor base.
I used a small amount of RTV sealant to bed-down the carburettor and spacer
With both the carburettor and CRC bolted down, I was then able to remove the CRC setting pin and fit the rubber plug in the hole. I blipped the throttle shaft a couple of times to make sure that everything moved smoothly as it should.
Rubber plug in the setting pin hole
Last step was to bolt the hydraulic pipe plate to the CRC – using new ‘O’ rings on the ‘sandwich plate’.
Preparing to bolt on the hydraulic pipe union
One of the two ends of the hydraulic pipe was routed between the camshaft pulley and distributor tower and connected to the clutch cylinder. The other end (with a female connector) was plugged and will be connected up later in the rebuild.

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