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ARRRGH vapour lock!!!!!
BiX - November 14th, 2004 at 09:09 PM

Well I got a bad case of vapour lock today. Was out racing and doing very very very well. and went to launch, dialed up 3k dumped the clutch (0n dirt) and grabbed second to have the engine die on me :( I had been sitting in the line up for 5 mins in the heat of ipswich.

the steel line in the engine bay was hot to the touch and once cooled the car ran fine. Options to fix this?


options i know of
1- insulate steel fuel line
2- go to rubber line
3- go to a elec fuel pump

any other ideas? which option above is the best?

this cost me 15 places :( so need it fixed before sunday for the next event


silver - November 14th, 2004 at 09:16 PM

Make sure the tank is vented. I once blamed vapor lock for a break down and couldnt fix it, then I thought to check the fuel and found the tank under extreme pressure when I released it the car started with no problems. I regularly release it on hot day's now just in case..


speedster356 - November 14th, 2004 at 10:05 PM

Fitting an electric pump may not be the answer, I had a problem recently in the Speedster replica with a 1916/44 webers/ Holley fuel pump etc. http://www.aussieveedubbers.com/forum/viewthread.php?tid=30015#pid245918
It was a very hot day, and got stuck at the traffic lights for about 5-10 mins, just at idle. When I took off the thing just died the same as you explained. I had to put a wet rag around the fuel pump base to cool the fuel down enough to get pressure again. The pump was running just about dead headed against the regulator/carbs and putting lots of heat into the fuel in the pump.
This could be the same problem you are having even with a mechanical pump?
I think if you just rev the engine whilst you are staging and keep the fuel flow up (cool fuel being delivered from the tank) this will reduce the heat being put in and may solve your problem.
cheers



[Edited on 14-11-2004 by speedster356]


BiX - November 15th, 2004 at 09:17 AM

Yeah i ended up making it water cooled and pouring water over the hard line. The hard line that comes into the engine bay and around the fan shroud was getting almost to hot to touch. I now just sit there and give it a rev. just trying to sort out if there is a way aorund it. is there an easy way to rig it up so it returns to the tank, when at idle?


speedster356 - November 15th, 2004 at 09:55 AM

Was it the line going into the pump? or out of the pump to the carbs?


BiX - November 15th, 2004 at 10:26 AM

is pretty mush still all standard, the fuel line is a hard line that enters the engine bay, runs aroudnt eh fans shroud then uses rubber line to the pump and then rubber line from the pump to the carbs. It was the ahrd line before the pump, it does sit pretty close to the intake manifolds.