Classic cars forum & vehicle restoration.

[old iron]

My new stead, Austin cotswold campervan, has the original BMC ‘B’ engine
1622cc all standard except head worked for use of unleaded petrol.
The engine starts very easily from cold and runs just beautifully. The previous owner did advise me that restarting from hot was troublesome. I have yet to find out for myself as I have only just purchased the vehicle. But I will assume that what he advised me of is truefull.
I note the vehicle has an additional electric fuel pump, new copper fuel line from the tank to engine. It has a wide gasket from the carb (SU)to manifold, I assume heat gasket. Clearly to me this says some effort to cure hot start issues to no avail.
Comments and advise appreciated.

[alastairq]

'Hot Start' issues face many of us, entirely due to modern day petrol, and something called 'cyclic variability'....something which plagues all engines, but mostly overcome these days by the use of electronics,etc.
Mind, the engine bay on your camper will be a good source of excess heat too..

Is there a heat shield between carb and exhaust manifold?
One can be made up if such a thing is absent.
Also, to reduce the effect of the above phenomenon, try using 98 octane 'super' petrol?
[Note, this is nowt to do with the current ethanol crisis being promoted in popular media]
The super petrol will help the exhaust run cooler.

The electric pump will help offset any fuel boiling going on at the carb.
A better system [taking a leaf out of Datsun's book] is to have a 'supply' and 'return' fuel line, with the carb literally tee'd off it..the return line being smaller bore than the supply line. This keeps the fuel flowing constantly through the fuel lines, preventing it from sitting static near excessive heat.
However, that may well prove a step too far if trying to keep things 'original?'

Make sure the ignition timing isn't too retarded...a tad advanced is best I feel...also ensure the distributor's mechanical advance is appropriate for the vehicle the engine is used in.....running an advance curve suitable for an MGA will be no good in a couple of tonnes of van!

https://classicenginesmodernfuel.org.uk/Clubs/ModernFuel/BulletinBoard/Default.aspx?dyn_menu_useclub=1000001&dyn_menu_mainmenu=5

https://classicenginesmodernfuel.org.uk/Clubs/ModernFuel/Book.aspx

Above are links to the website of Paul Ireland, an ancient MG enthusiast who conducted tests at Manchester University, concerning this exact issue.....How it happens, and how to adjust to modern fuels...

Anyway, it's all worth a good read, especially the book, which covers & explains stuff the website cannot....

But, didn't these old vans have a hot restart issue from birth??
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Dellow Mk2, 1951 built, reg 1952.
Fiat 126 BIS
Cannon special [1996 registered. Built in 1950's]
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Ford Pop chassis, Ashley 1172 bodyshell, in pieces.

[old iron]

[mikeC]

I suspect it's a fundamental problem with forward-control vans; both my Standard Atlas vans suffered this problem, and this was years ago before modern fuels came on the scene. I would suggest fitting an electric fan in place of (or as well as) the mechanical fan might be the best way to go.
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in the garage: 1938 Talbot Ten Airline
Recently departed: 1953 Lancia Appia, 1931 Austin Seven, 1967 Singer Chamois, 1914 Saxon, 1930 Morris Cowley, 1936 BSA Scout, 1958 Lancia Appia coupe, 1922 Star 11.9 ... the list goes on!

[old iron]

[alastairq]

[old iron]

Thank you again, when I looked at the fuel pipe position I thought that may be a big part of the issue. I have ordered yesterday some fuel line sleeping which is apparently excellent at keeping heat away from the fuel line. I will give that a go as a start point and move onto your suggestions if needs be.
Petrol must be boiling away in the copper tube above the manifold.

Just to add, I have ordered the heat proof hosing from Funk Motorsport
It’s not inexpensive but if it goes some way to curing the issue it’s worth it.