Author Topic: SBC V8 carbureted engine Vapor lock issue  (Read 4853 times)

CCIE

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #17 on: June 30, 2016, 11:40:40 PM »
Backing up a tad, you could install a fan in the front of your trunk to pull the hot air out of the engine compartment.  Put two vent holes in the rear of your trunk.  The down side is you will not be able to haul any icecream back there. :'( :'(

Ya but man it would make a heck of a coffee carrier or a pizza carrier......
If I cant find the solution to remove the entire trunk that was my next move to put 4 inch hose with ducted fan right through the trunk
Two of them


01Lambiero

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #16 on: June 30, 2016, 08:37:02 PM »
Backing up a tad, you could install a fan in the front of your trunk to pull the hot air out of the engine compartment.  Put two vent holes in the rear of your trunk.  The down side is you will not be able to haul any icecream back there. :'( :'(
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jrule78

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #15 on: June 29, 2016, 05:05:50 PM »
I think it needs a longer air filter stud.
I second the placement of that filter.

msaby

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #14 on: June 29, 2016, 02:02:14 PM »
If that is your fuel filter mounted on the firewall that might be causing an issue.  The fuel filter is right above the  exhaust header I'm sure it get hot.  It might be boiling the fuel as it enters the carb.  You may want to try and re-route your fuel line away from the exhaust.....Just a thought.
Mike


CCIE

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #13 on: June 29, 2016, 11:17:26 AM »
01 Thank You!!!

I have the laser Temp and will take temp later today (Local Harbor freight under $30 and well worth it)
Attached is the pic of my F40. As you can see the rear glass is not cut out for venting and the trunk is in place so yes it gets hot (working on it). Thermostat installed is 180 and there is a 4 core high performance aluminum radiator in the front. It has a Edelbrock 750cfm carb on it.
Generally it runs fine but I had it in the shop and they warned me about vapor lock issue (before this I never heard of it) It has stalled before but nothing major.... 2 days after the discussion with the mechanic local temp reached 97 and yep it stalled after driving if for couple of hours. The engine bay was hot. I let it sit for an hour or so and it started right up. I have already ordered the spacer for the carb and looking into removing either the rear trunk or cutting out the vents in the glass. I have it for sale so I am thinking I will let the new owner do it.
http://www.ebay.com/itm/262499474441?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1558.l2649

For my Diablo I have the same issue, I haven't driven the car too much this year but I am sure as it gets hot I will run into the same issue. Air movement in the engine bay is critical and unfortunately it was a after thought since the Diablo is fully built, Again the fiero trunk is there which blocks the heat from escaping from the rear.
More to follow on the Diablo:
« Last Edit: June 29, 2016, 11:19:37 AM by CCIE »

01Lambiero

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #12 on: June 29, 2016, 10:31:43 AM »
But without pictures of the problem child we are really guessing from experience as to the cause of the vapor lock.  Once again, a laser temp gun would narrow the problem or at least give us temps along the fuel supply circuit and the carb.  Under $10 on Ebay.
« Last Edit: June 29, 2016, 10:35:17 AM by 01Lambiero »
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Robert

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #11 on: June 28, 2016, 08:23:19 PM »
Robert hit the nail on the head, that will go a long way toward fixing the issue
Thank You Adrian!
Robert, Journeyman experimental mechanic, Journeyman experimental painter.

AdrianBurton

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #10 on: June 28, 2016, 05:08:21 PM »
Robert hit the nail on the head, that will go a long way toward fixing the issue

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #9 on: June 28, 2016, 01:33:22 PM »
I believe a fuel pressure regulator with a return line to the fuel tank, will solve your problem. When your fuel is constantly being circulated, it does not have the chance of getting hot.
Aeromotive Universal Bypass Regulators 1330, looks like a good prospect. It is for carburetor, and fuel injected. Adding a heat shield under the intake manifold would help also. Heatshield Products.
« Last Edit: June 28, 2016, 01:46:06 PM by Robert »
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Thumper

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #8 on: June 28, 2016, 09:01:42 AM »
Probably the easiest is to re-route the lines away from any heat source, or even add a cool can.  Timing can be an issue too like SchulzeA said.  I see you mentioned about cutting out the trunk.  That will open it up and help a lot of heat escape.  Unfortunately, you won't have a trunk though.  haha

SchulzeA

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #7 on: June 28, 2016, 01:44:18 AM »
Have you checked the timing? I've had this same issue in the past until I discovered the the timing was way off. I set it correct and never had an issue again.


CCIE

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #6 on: June 27, 2016, 11:46:12 PM »
I would recommend putting on of these on, just put one on a soldid roller BBC, runs great! My  friend just ordered on for his '32 Ford. http://www.fitechefi.com/products.html

If your funds dont allow you at this time just get one of these, it will help but not cure your problem- http://www.ebay.com/itm/Edelbrock-8720-Carb-Spacer-1-Open-Wood-Fiber-Laminate-FAST-FREE-SHIPPING-/281608591869?hash=item41912e19fd:g:C7QAAOSwQupXWsxF&vxp=mtr






Tonypaul..... Ouch If I have to go that route for the Diablo I will but before that I would like to try the cheaper option

CCIE

CCIE

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #5 on: June 27, 2016, 11:44:42 PM »
O1.... Funny you mention the phenolic spacer.... I just ordered a 2 in spacer for my Ferrari F40 off of ebay.
For my Diablo though I really have no space , specially with the engine cover on top of it. I am not sure if the 1/2 in will help.
I suppose I will give it a try. Still need to pump more air in the engine bay and cut out the rear trunk to provide better air flow exit from the engine bay.

Thank You
CCIE

tonypaul

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #4 on: June 27, 2016, 11:31:58 PM »
I would recommend putting on of these on, just put one on a soldid roller BBC, runs great! My  friend just ordered on for his '32 Ford. http://www.fitechefi.com/products.html

If your funds dont allow you at this time just get one of these, it will help but not cure your problem- http://www.ebay.com/itm/Edelbrock-8720-Carb-Spacer-1-Open-Wood-Fiber-Laminate-FAST-FREE-SHIPPING-/281608591869?hash=item41912e19fd:g:C7QAAOSwQupXWsxF&vxp=mtr




01Lambiero

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Re: SBC V8 carbureted engine Vapor lock issue
« Reply #3 on: June 27, 2016, 10:55:15 PM »
If you are sure that the carb is getting too hot, how about trying a phenolic spacer under it.
01
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