PI fuel system, again, and coolant clamps

Bit more progress over the week, which I have been able to finish off this weekend, the fuel swirl pot is now fitted.

At the same time, a bracket has been found for the large fuel filter, it turned out that a wiper motor bracket is just about the right size for my filter. So what we have is the low pressure Facet pump supplying fuel to the bottom of the swirl pot, fuel exiting the bottom of the pot to go to the filter and high pressure pump, a return from the pressure release valve (PRV) going to the top of the pot and a outlet from the very top of the pot to the fuel tank, through which air and excess fuel is bled out.

I've been out for a run since fitting all this up and it works fine, but the only issue I have had is the lack of pressure for the Facet pump to work against. The problem is that these solid state pumps get very noisy when they do not have a sufficient pressure to work against, so I have clamped in a piece brake pipe in the return to the fuel tank to restrict the flow. This has quietened it down a bit, but I don't want to restrict it so much that it won't be able to clear the air fast enough when it really needs to.

With this recent talk of cooling systems and leaks it reminded me that I had some misgivings about one or two or the hose connections and it had been my plan to change the hose clamps. So today a set of eight Mikalor clamps turned up in the post, should get them fitted tonight.

They should hopefully provide a better seal than the thinner jubilee clips and actually work out cheaper than stainless jubilee clips from Car Builder solutions, these were £1.17 each

I've been using Mikalor clamps on exhaust systems for a few years now, but they do seem to have got a lot cheaper and easier to find now, no need to spend over £5 each now.

I did think about the potential for warmer fuel from the PRV getting back to the pump before going to the tank, but seeing as it enters towards the top of the swirl pot, is warmer (so more likely to rise than sink to the bottom of the tank) and that the low pressure pump is at the same time pushing an excess of fuel up though the swirl pot outlet, it should push that warmer fuel back into the main tank. I guess I will have to wait until we get one of those hot days to see how it copes.

Smaller jobs and settling down

So I got a few more jobs done in the week, rear brakes re-assembled and hopefully setup right this time and a bit more sound deadening has gone down on the gearbox tunnel before the carpet, which of course has to be modified. I've been trying to go round and finish off some of those jobs I started a while ago or have bought parts for, but never got round to fitting  to this end, the car now has a Spitfire front spoiler.

At the same time I have been working on the fuel system, again , and have been looking at fitting a fuel swirl pot I bought some months ago. To give me some extra freedom of where to position it, the outlet and bleed-off tails were cut off before being re-tapped to take a 90 degree fuel union and sealed with JB weld for good measure. This means I can run the swirl pot much higher, giving a greater head of fuel to the high pressure Lucas pump.

I then had a chance to take the car out for a run and I am pleased to say that the majority of the speed related vibrations have gone. There is still some vibrations coming through the steering column, but at the same time the whole of the dash is vibrating, so this could be related. At the moment the 'H' bracket is not in place between the dash and the floor/gearbox tunnel, so I might have a go at modifying a bracket to fit. It's been good just to get some miles in on the car and try to get the feel for it, after driving Spitfires and the 2000 driving the GT6 is so different with the increased power and the ability to corner, though I have not found the limits yet, probably more down to the driver.

The car seems to have bags of torque, just driving around choosing the quieter road, I was sat behind a car doing 50mph till he jumped on the brakes for an even slower car in front, a MG BGT complete with wire wheels and spinners, once the road was clear it accelerated beautifully in forth from 40mph all the way up to legal. I know I am never going to have it setup as well as some of the faster Spitfires, but it is still a hoot to drive and so much easier to do so with many of the vibrations done away with. Feel a lot happier about going out for a blast without tools now and would be happy to drive all over Europe in it, not something I would have wanted to do twelve months ago.

Propshaft changing

As I'm still not happy about the vibrations in my car, I had a new propshaft delivered from Dave Mac. The company where I had bought the first one from wanted another £75 to re-balance it, plus three days to do the job, whereas Dave Mac delivered a new one for £95, which meant the car would not have to be left disabled for long. Oh, it's 29" long just in case anyone is interested.

In-between working on the Lightweight Land Rover I managed to find time to do a few jobs on the GT6. First off was the propshaft, but to do that I had to remove the centre section of exhaust, not that hard to do really and it gave me a chance to have a proper look at it.
Below are the two propshafts, the newer one being at the bottom, having a smaller tube diameter and having far fewer balance weights stuck on.

In the week I also received a pair of brake drum centring rings for the CV converted cars, which are fortunately a nice and tight fit, so they should hold in place nicely with a bit of bearing lock. Part of the idea of fitting these rings is to try to reduce the problem I had with peculiar brake shoe ware, where the bottom part of one of the shoes was heavily worn. Though I am starting to wonder if that was more down the brake shoe not moving up as it should after to was tightened up on the brake adjuster.

I've still to reassemble the drum brake on one side before I can go out for a trial run, but I am hoping I have managed to do away with the vibrations I was getting at speed.

Ramblings and engine mounts

Got a couple of tyres fitted this weekend, I've been wanted to fit something half decent this time, so I went for Continental Pro Contact 3's, as I had fitted on the 2000. Was going to get them mail order, but it worked out cheaper to order them online, supplied and fitted through Kwik-Fit.

The vibrations, coming through at over 70mph, are still present. This is despite new front vertical links, trunnions and bearings, so I'm pretty sure it is not coming from the front. So what else could it be? the propshaft has only done 3.5k miles, the CV joints and driveshafts are second hand though, perhaps one of these is the root of the problem?

While the car is in the barn I've decided to reduce the camber up front by taking out one of the thin shims. It was about 2.5deg negative each side, a bit too much I thought for normal driving.

While I wait for my new propshaft I thought I'd have another crack at sorting out my engine mounts as the original type repro ones are not looking too good. The plan is to use the original GT6 block mounting point, but extend the bracket to sit on the back part of the suspension tower and use Jaguar engine mounts.

 It's only tacked in at the moment, so it'll need welding fully before cleaning up and fitting

Anti roll bar drop links

I need to go about setting up the chassis on my GT6, so I've been looking at the few remaining dodgy looking suspension parts on my car. The anti roll bar drop links from Wolfitt Racing look pretty good, but are out of stock, so I thought about sourcing the parts myself.

 I went through McGill Motorsports to order the parts, slightly more expensive per piece than eBay, but no delivery costs.

So ordered:
3/8" UNF Male-Female Studded Rose Joint Track Rod End
3/8" x 3/8" UNF Right Hand Male Economy Rose Joint
3/8" UNF Rose Joint Misalignment Spacers PACK OF 4
3/8" UNF Half Nuts Right Hand Thread

The parts were delivered from McGill Motorsports the next day (Saturday) all the way down from Fife, so I've sourced some fasteners and have welded in a spacer on top of the lower wishbone arm for the bolt to pass through. Started off with just having an extra plate on the back of the spacer to support it, but then decided to box it all the way in as it looks a bit neater.
While I was there, the brace bar on the arm was welded around to stiffen it up, which it has done a surprising amount.

Here are before and after shots:

Before

After

Not surprisingly the anti-roll bar was not flat as it should have been, so this has now been corrected for using the rod ended drop links. One thing I had forgotten about previously was that the anti-roll bar is not as free to move as it should be due to the bushes being too far along the bar and restricting it. With this in mind, I have bought some solid anti-roll bar blocks from Merlin Motorsport, unfortunately they don't sell them with 11/16" ID, so I shall have to bore them to suit.