Vapour lock cures?

[slumbers]

I fitted a heat shield to mine when i restored the car with a 1/2" thick spacer

https://www.summitracing.com/parts/hly- ... MxwIu38cIG

Never had a problem with it in 8 years

[Stu Twin]

Thanks again chaps. Yes a heat shield would probably help but we'd like to keep it a bit less 'visible'. Could paint it orange i suppose

Derek - i expect it's a bit tight for space if you have a separator and a filter between the pump and carb? Can you get some pics to show how you've arranged things? Does your return line point up or down? (or is it level?)

[Derek]

Hey Stu. Best I can do for now, more than enough room but my alternator is probably in a slightly different place to yours being an air con car, return comes out the bottom of separator which bolts on to manual pump. All the pics are sideways for some reason.

[MattH]

Electric pusher pump near the tank. That solved my M43 ambulance flat head six issues which were horrendous for vapour lock. Alot of Willys Jeeps do the same. Older tech I know but it solved my issue completely, and i ran the leccy pump through the mechanical to act as a regulator.

[Stu Twin]

So I’m moving the Wix 33041 filter with return line to after the mechanical pump. And before I figure out the best way to mount it I thought it would be best to make sure I fit it the right way round. Photo below.
As it’s been on the car a while, whatever printed arrow has disappeared so I can’t be sure. I’ve done plenty of Googling but as this specific part seems to be discontinued there’s very little info on it.
When it was fitted, pre pump, next to the chassis rail, it had the return line pointing back towards the tank. So inlet was at the same end as the return. But everything I’ve found since contradicts that. Which is strange as I presume it still had an arrow when fitted.
I’ve found an image of a Wix 33040 (same except for smaller inlet) which clearly shows a direction arrow, and a also an Uncle Tony video on YT showing a similar filter installed. He has it with the return on the outfeed end.
And I read that the return should be uppermost.

Anyone used one of these? Or know a way to test which is the inlet? Airflow seems similar which ever end I blow into.

More confusing is that the factory style ‘evaporator’ fitted after the mech pump clearly has the return line pointing down and back to the tank.

https://m.youtube.com/watch?v=-t6geNGbE ... Y3VyZXM%3D

[mygasser]

yes to the phenolic spacer and also the heat shield under the carb.
as far as the return line to the tank goes there's a simple solution that was used by ford uk in the 80's. between the pump and carb they fitted a 't' piece, the inline fittings obviously were pump to carb with the other having a tiny (just under 1mm from memory) hole allowing return to tank. you could say this might restrict fuel flow to the carb at wot but as long as your pump will feed more than the engine can use you'll have no issues. you're ahead of the game with 3/8" fuel lines fitted as the pump doesn't need to work as hard. of course ford's 't' would be too small but it would be easy enough to make one 3/8" bore. just solder the return outlet solid then drill through with a tiny drill bit, maybe start at 0.5mm and see how it goes.
neil.

[Blue]

Just been on thinking about this, are you sure it’s vapour lock and not flooding?

[Stu Twin]

Thanks Neil, Blue.
I’m not sure really what it was, it just cut out when idling on a hot day after a long journey. And no fuel came out the feed to the carb when I cranked it.
I also thought about a tee off the carb feed with a small hole. I think the Wix one has around 60 thou orifice.
I’ll see how we get on with in it’s new cosy location.

[Blue]

Had you taken the fuel line off the pump on the carb side and got no fuel then you have another issue. Fuel should leak out at that point by gravity no matter what but if it didn’t it’s nothing to do with vapour lock IMO.

[Stu Twin]

I can't remember to be honest Blue.
I think it was certainly at the inlet end of the dual feed, just before the primary inlet. I went for that as it was easiest on a hot engine. Nothing came out of the hose from the pump when cranked.
And i also disconnected one of the hoses off the sender hoping to vent things, but i can't be sure which one that was. It was last June

[Blue]

I think the way you had the return style filter on the suction side of the pump was a big part of that particular incident. I can imagine the pump drawing air down the return line rather than fuel down the main line.