| Slant Six Forum https://slantsix.org/forum/ |
|
| Vapor Lock Conundrum https://slantsix.org/forum/viewtopic.php?t=68733 |
Page 1 of 1 |
| Author: | Daddiojoe [ Fri Aug 21, 2026 8:22 am ] |
| Post subject: | Vapor Lock Conundrum |
So I have been suffering from vapor lock--big heat saturation after shutting off the engine. Wrapped fuel line, relocated fuel filter, checked fuel pump. Everything is warm, not hot, to the touch. What IS hot is the base of my 500 CFM Edelbrock, which is mounted on a Clifton 4BBL aluminum intake. I am not running coolant through the bottom of the intake. Also added a 1/2" aluminum spacer, and still getting vapor lock. Intake sits on closed off rear exhaust manifold in Dutra Dual modification. So Here's The Question: If I am getting vapor lock without running coolant through the intake, why is the intake heating an option, and if people do use the intake heating, why don't they get vapor lock? Insights appreciated, Joe |
|
| Author: | mcnoople [ Fri Aug 21, 2026 12:39 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
Are you running real 100% gasoline or the almost gasoline stuff that is currently at most pumps in the midwest? I think the pumps in my locale are currently all 15% alcohol except for a few premium pumps that are either 10% or the single station that has 100% gasoline at 93 octane. I remember reading vapor lock is worse with higher alcohol contents but I don't know that to be a fact. |
|
| Author: | SlantSixDan [ Fri Aug 21, 2026 1:38 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
A lot of people use "vapour lock" to mean a lot of different hot-fuel-related things. In fact it means only one thing. So let's figure out what's actually happening here. Please describe the symptoms in detail. |
|
| Author: | SlantSixDan [ Fri Aug 21, 2026 1:39 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
Quote:
Are you running real 100% gasoline This is no longer an option for most people in the US and Canada.
|
|
| Author: | Daddiojoe [ Fri Aug 21, 2026 3:54 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
Dan-- Good point. So my symptoms are: Car runs great shut down engine for 10-30 minutes car starts up again fine, but after approx. 5 minutes of driving, loses power. Engine eventually stops. Rest for 10 minutes, car starts up again, but power loss is quicker. Last two times I have been able to nurse it home by driving below 35 MPH Engine temp. gauge reads approx 185--not overheating there. What I have done to fix the problem: Changed coil (old coil--Pertronix--felt hot to touch) re-routed fuel line per article by Dan here on Slantsix.org used DEI sheathing on fuel line from filter to carb line is 3/8" injection fuel line installed 1/2" aluminum spacer under carb changed to metal fuel filter per article by Dan here on Slantsix.org checked air filter ran gas tank down to half full and filled with hopefully higher quality gas Remaining symptoms: Fuel line cool Fuel filter cool base of 500 CFM Edelbrock carburetor hot. Next fix: 1/2" phenolic spacer ordered. I think that's everything. Still curious about coolant heating Clifford manifold. I had used the heating in the past, but it made the engine run too hot. Thanks, Joe |
|
| Author: | EC_CO [ Sat Aug 22, 2026 5:32 am ] |
| Post subject: | Re: Vapor Lock Conundrum |
Quote: Quote:
Are you running real 100% gasoline This is no longer an option for most people in the US and Canada.
https://www.pure-gas.org/ |
|
| Author: | SlantSixDan [ Sat Aug 22, 2026 1:09 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
Aluminum transmits heat very effectively. Ditch the aluminum spacer and replace it by a phenolic one. Add a heat shield, sandwiched with thin gaskets; something like this. Double-check your float level and your bowl vent adjustments. |
|
| Author: | Daddiojoe [ Sat Aug 22, 2026 1:30 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
Thanks, Dan. Your advice is always appreciated. Joe |
|
| Author: | SlantSixDan [ Sat Aug 22, 2026 4:57 pm ] |
| Post subject: | Re: Vapor Lock Conundrum |
Gladly. Also pay some attention to what's heating up the engine bay: the exhaust. Things under the hood will cool way down if you'll wrap at least the headpipes and perhaps also the manifolds with this. |
|
| Page 1 of 1 | All times are UTC-07:00 |
| Powered by phpBB® Forum Software © phpBB Limited https://www.phpbb.com/ |
|