Vacuum leak, Dizzy Recurve and Fuel Pressure Regulator.

From previous post, Job 3 was to replace the carb gasket as it had a bit of a leak. I have had the carb off a couple of times to check and adjust float levels and the gasket must have got torn and damaged where it was half stuck to the carb.

Combined with the fact that I had a fuel pressure regulator to fit, I figured this would be easier if I removed the distributor. Now I know how to avoid disaster when refitting, I was a lot more confident about this. Made a few pen marks and whipped it off.

Carb came straight off, checked floats again just for piece of mind. 7/16 and 1" as per carb manual.

One carb removal, coming right up!

Label everything. Label the labels.

Ta-da!

The eagle eyed will of course now be staring at the top picture screaming out "his throttle return spring is going the wrong way, increasing the wear on the throttle pivot shaft!" Fear not, for just out of shot dangling on a bit of wire waiting for the paint to dry is a bracket made from some spare steel strip I had lying around.

With all that guff out the way, I fitted my fuel pressure regulator, an Aeromotive 13255. I thought long and hard about -6AN quick release fittings and braided fuel hose but when I priced it all up it was about £300 which I couldn't justify so I decided to stick with hose barbs and jubilee clips. 

With great pleasure I ripped out the temporary plastic elbow from where I tried to fit the previous fuel pressure regulator (the Edelbrock one that was terrible and leaked all over the place) and fit the new one, with a Moroso 65370 pressure gauge. A nice SMALL blob of Permatex 59214 high temp thread sealer on the fittings and all was well. 

I'm not 100% convinced about the lie of the braided clutch hose but that's as good as I could get it without major rework so that will do for now. Something to think about for the future.

Fitted and set to 5.5psi as per carb manual. With no regulator my Carter fuel pump gives about 7psi. According to the internet some people say the carb will take this and others say it will cause no end of problems. The manual says 5.5 and a fuel pressure regulator in the engine bay looks cool so there we go.

Now, carb back on with new gasket. Forward throttle return spring bracket. Not a patch on some of the fancy machined ones you can buy but hey it does the job and cost about 5 pence in paint.

Before I put the distributor back on I whipped to top off to see how my Accel advance kit was doing. The answer was, not very well! The bushings that slip on the weight pivot pins had fouled on the inside of the rotor arm and the weights were binding, the rotor wasn't snapping back on the springs. This means that my timing was probably completely messed up.

I ripped all that out and swapped the Accel kit for a much better made Moroso 72300. The bushings supplied didn't foul on the rotor (I don't know how I missed that when I assembled it with the Accel kit!) and the rotor moved very smoothly on the springs. I went for a combo of the lightest spring and the medium spring which should give total timing all in at somewhere around 2700-2800rpm. I don't yet know what the total mech advance is with this kit. The centre plate is the same shape as the stock one but the weights are a different shape.

With the Accel kit you may remember I had the Accel weights and the stock centreplate. The limit bushings in the kit are for the older points type distributor. The mechanical advance limit in the HEI dizzy is controlled by combinations of different shaped centre plates and weights. Or if your a ham fisted hick you can weld the slots up. The accel weights and stock centreplate limited the mechanical advance to around 15° which meant with 18° initial I was only getting about 32-33° total advance which is a bit short of optimum for a small block chevy. It should be said that I couldn't feel the difference when driving between 32° and 36° max advance but it would be throwing away a little bit on peak power.

The instructions that come with the Moroso kit say the centre plate and weights give a total of 23° mech advance but playing around with pen marks and manually rotating the rotor on the springs I'm not sure of this. I know the stock setup was 22°, my hyrbrid stock/Accel setup gave about 15° and the Moroso kit seems somewhere in the middle, probably 18 or 19°. We won't know until we get the car running again but hopefully it might just be perfect, allowing me to run 18° initial and hit the magic 35-36° total.