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View Full Version : Vapour Lock...AAARRRGGGHHH



bcarter
07-13-2003, 12:26 AM
We were running in the heat today,in the nineties, and after both pit stops, my car pulled out of the pits, ran about half a mile, and STOPPED. (Streetported 12a)

Vapour lock.

I sat by trackside for two laps the first time, and for about a lap the second time before I got it started again.

Then it ran perfectly.

How do I stop this #@%$*&# problem??? http://Forums.ImprovedTouring.com/it/mad.gif

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G. Brooke Carter
Wheat Buckley Racing
# 10 Challenge Car
2002 Class Champion
Calgary, Alberta

Speed Raycer
07-13-2003, 05:00 AM
My first two suggestions would be a return line if you're pump is deadheaded at the carb, and then a good old fashioned heat sheild above the header.

What kind of regulator are you running and have you checked your fuel filter lately???

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Scott
It's not what you build...
it's how you build it

<A HREF="http://www.pfmracing.com" TARGET=_blank> http://home.swbell.net/srhea66/PFMSigPic.jpg
www.pfmracing.com </A>

bcarter
07-13-2003, 07:47 PM
Happened again today during qualifying...got it going again, and qualified not so bad, but it wasn't that hot out.

Figured out that if we pushed the car to pre-grid, and didn't start the motor until the first car went out onto the track, we were OK.

I will replace fuel filter, as well as fuel pump. We have to run stock pumps, and no regulator. Return line will also be checked out.

What sort of heat shield? I don't want to wrap header pipes.

[This message has been edited by bcarter (edited July 13, 2003).]

Speed Raycer
07-14-2003, 08:52 AM
Just build something out of aluminum that shields the intake manifold from from the header. Even the stock heat shield that everyone tosses would probably help.

rx7chris
07-14-2003, 10:29 AM
If you build a heat shield, attach it to the body not the motor. Otherwiswe you'll end up heating up the shield, and that would intern heat oup the carb, and then you're back to square one.

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Chris
PowerTrip Racing
http://www.geocities.com/ptripracing/

Allen Brown
07-14-2003, 11:50 AM
Brooke, I think the comments about the heat shield attached to the body, and mounted between the header and fuel lines would help. As you know, I suffered the same after stopping for fuel. When I pulled my fuel line off the regulator, the fuel was very hot..

Once I turned down the reg, and the fuel was able to bypass and circulate, my fuel pressure came back....Unfortunatley, that one lap was timed at 29:43.xx minutes. I wish it did not take so long for me to come up with that thought. Maybe the heat shield will help out for next time....

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Allen Brown
#36 IT-1
GT-3 in 2004 or 2005
[email protected]

Allen Brown
07-14-2003, 11:54 AM
Just had another one of my delayed thoughts.... Has anyone thought about or put a duct so air blows along the header to take the heat away from the underhood area..

Just another comment from the peanut gallery...

bcarter
07-14-2003, 10:57 PM
OK, well, the fuel lines aren't really near the header, as they come in on the other side of the car, and the closest they get is when they actually enter and leave the carb.

I imagine the heat shield to be a process to stop the direct heat from the header getting to the carb, which is where I think the problem arises...??? The carb rather than the lines.

Also, the gas tank is close to the muffler, so maybe the fuel is getting heated up in the tank...???

note: I just replaced the header, as the old one cracked. never had the problem with vapour lock before...is Racing Beat doing something with their new headers that may cause more heat???

Could also be the fuel pump, which is now 2 years old, I'll replace it anyway.

Also thought about a duct, not to take hot air from the header, but to blow cool air onto the carb area...

This is only going to be a problem in races long enough to require pit stops, and the next one is an hour and a half, right on the limit of fuel...

AAARRRGGGHHH http://Forums.ImprovedTouring.com/it/confused.gif

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G. Brooke Carter
Wheat Buckley Racing
# 10 Challenge Car
2002 Class Champion
Calgary, Alberta

bcarter
07-16-2003, 01:02 PM
I was under the car last night, and see that the way the muffler is mounted, it is REALLY close to the gas tank. I think I am heating up the fuel in the tank...

I am going to re-insulate that area.

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G. Brooke Carter
Wheat Buckley Racing
# 10 Challenge Car
2002 Class Champion
Calgary, Alberta

joeg
07-16-2003, 01:25 PM
Don't worry about the gas tank. That is not your problem.

Your problem is the location of the carb and the exhaust. Make a shield.

Cheers.