Hot start
Turbo Mini Forums

I read loads of TM stuff on this issue before I did a couple of things which have worked on the van now for nearly 7 months out of its build.

First off I made up a fan cowl and used a Honda VFR750 motorbike fan which I recessed into the drivers side inner wing. Cold air is piped from under the wheelarch over the top of the flywheel housing to the turbo and base of the carb.

I set this up to operate on a timer to operate for 5 mins after ignition switch off. The air whips out of this duct and as long as its moving over the turbo and float bowl up out of the rear bonnet vents, I've so far not needed to use a heat shield. I originally lagged the turbo and manifold with heat wrap but only have the manifold wrapped now due to overheating the turbo and blowing the seals - a costly mistake which I should have heeded advice on. You win some you lose some, its all a learning curve really. Needless to say, I would advise against wrapping a turbo to prevent carb heat soak. The best bet is to get cold air to the carb when the engine's just been shut down.

I also use a float bowl extension bought from Ian Hargreaves at Avonbar for a few quid. The extra fuel capacity (I guess about 30-35 cc extra) in the base of the float bowl takes alot longer to boil off than the standard setup where the extension is omitted.

Before I did both tricks, I could phyisically hear the petrol boiling in the base of the carb when shut down for more than a minute !

I guess a couple of mini Desktop PC 12v fans could be used instead of a m/cycle jobbie - its just that I had purchased one at an autojumble with this use specifically in mind when I was designing the layout of all the various engine bay kit.

I've been having upload problems but I hope that a couple of early shots are attached showing the mounting point in the wing and the DIY duct, made from the base of a saucepan and an old fuel tank inlet pipe !

Usually takes me no longer than 2-3 seconds tops to start the engine. I'm also using a 625 Amp crank H/D battery which helps spin her up. Works a treat !

Richard.

Attachments:

1.79mb

430.21kb

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

I have often wondered weather the bi-metallic strip holding the jet is also a factor.. when the carb (fuel) gets hot it is probably leaning out the mixture... cant help can it?

Anyone with a solid jet holder notice am improvement in warm starting?

Terry

Edited by Turbo Tel on 27th Jan, 2009.

website:- http://www.terryhunt.co.uk

Yeah Terry.

Modded my carb from the start as well. Made from st steel. Probably contributory along with the cooling fan and float extension.

Shot attached.

Richard.

Attachments:

140.14kb

Minivanless, but reluctantly happy living with the decision. There'll be another one day.
http://www.youtube.com/profile?user=minimadmotorman#p/u

I have suffered from this problem but due to the way my fuel pump is wired in to run it has cured itself.

I run the earth -ve return for my fuel pump through a relay the relay is controled by the oil pressure switch. The relay coil is in series with the oil pressure switch and is normaly open when the relay is activated. This means when you switch the ignition on the pump will not run because the contacts are open.

Once I start to crank after about 3 seconds the oil light goes out the relay de-energises the contacts close and the pump runs and she fires up takes about 5 seconds whether cold or hot.

Rob.

Own the day