classics on the HOT common

[Kev]

Well what a turn out, an excellent evening show with a good smattering of P5's and a record number of the public turning out in support.
Four p5b's from the Heathrow area trundled up to Harpenden and had an excellent journey right up to the road leading to the common where we sat and sat and sat getting hotter and hotter and the cars suffering slightly in the gorgeous sunshine,now as we know the cars don't really like to sit for to long in heat and the car behind me konked out due to vapor lock so a toe rope was attached and i towed the car in to the show and before we could park up i too konked out due to vapor lock.I mention this because i have fitted a new 3 core rad and a facet pump and still it was getting into the red at the rad and the pump was pumping but it was just too hot.A few minutes later my car started and the other got going after about half an hour,some other p5's also experienced the dreaded "lock"along with others makes probably.So just because a modern set up is fitted don't bank on it being any better than the original (well not in this extreme heat) once again a big well done to Pete Madden and the crew for an excellent show.
Big Kev.

[Phil Nottingham]

Did you descale the cylinder block as I have had no trouble with the conversion. The scale and oxides are good insulators so the water does not remove the heat as fast.

Water wetters help a lot too in borderline cases

[Smallfry]

Very curious actually. Any carburettor system with a return line should not suffer vapour lock at all. The whole idea is to keep the fuel moving and to maintain a certain volume.

The only time you may suffer vapour lock is after the engine has been stopped for a while. i.e. a hot start. However, your electric pump should cure this. Another thing is, the carbs only need about 2.5 to 3 psi max, more than this and they tend to flood. Be aware a round Facet pump puts out more than this.

As Phil has pointed out, I would be inclined to look at the cooling system or even the ignition system first.

I would check to see if you have good water flow from the "peak" of the inlet manifold. They are notorious for furring up.

[Deleted]

I hope I am not tempting fate but my P5B has NEVER conked out due to vapour lock in the summer heat.
My car has 16" electric cooling fan (without the engine driven fan), Facet electric fuel pump and heavy duty radiator core.
I have never insulated the fuel lines in the engine bay, so why does my car not suffer? Not that I want it to!!!

Adrian

[Kev]

Smallfry,
the facets got a regulator on it and ive set it at 3 bar and up until that rally i had experienced no problems at all.
What i did do when it stopped was open the regulator to its max at 5 bar just to get fuel up to the carbs then re set it.
The 3 core rad is brand new and again seemed so good that i even removed the kenlowe and when we all went to Poole the other month at the start of heatwave it performed just as it should with other p5's struggling a bit it a terrible traffic jam.
Water movement is excellent from what i can see but i didn't descale the block and don't think that it's needed.
Speaking on behalf of the other members who attended the rally were putting it down to the fuel line being so close to heat sources and the exceptional weather, i think Geoff made comment that in 20 yrs this is the 2nd time its happened and for me too it's the second time in 8 yrs.
Not a big deal really but i am going to shield the fuel pipes ready for global warming. Big Kev.
PS. HAPPY BIRTHDAY GLENNR

[lagain]

Did you have your heater on ?

This may seem a daft thing to do on a hot day but I find it helps to drop the temperature as it increases the cooling area