Resolving Heat Soak
We would like to take some time to share with you some of the answers to the common questions we receive on our Technical Support hotline.
After driving my vehicle for a period of time, and after shutting off the engine I sometimes encounter a hard to start situation (engine cranks over several times before starting) and it usually occurs within a window of 15 minutes to one hour. What can I do to resolve this situation?
Chances are you are experiencing heat soak, compounded by today’s blended fuels. Following are some things to keep in mind in an attempt to alleviate this situation.
- Ensure that your fuel line is routed away from your exhaust and or block. This will help alleviate excessive fuel temperature in the supply line that can directly relate to pressure building in the line resulting in the needle and seat being overridden by the pressure causing a flooding condition.
- Remember, heat rises and when the vehicle’s engine is turned off, the rising heat can easily penetrate the carburetor and cause the fuel in the float bowls to expand and eventually boil or percolate.
If hood clearance permits (air-cleaner top to the underside of the hood) then consider installing a heat insulator gasket between the carburetor and the intake manifold. This will create an effective barrier between the hot intake and the carburetor. Here are a few tips when selecting a heat insulator spacer.
- Aluminum spacers offer little if any protection against heat soak.
- Wood fiber laminate, black phenolic plastic and heat insulator gaskets provide great insulation.
- If hood clearance is limited, the following three part numbers are recommended.
- #9265 open design best suited for single plane intakes (.320” thick)
- #9266 best suited for dual plane intakes (.320” thick)
- #9267 best suited for dual quad intakes with 4-hole style carb pad quantity of two (.125” thick)
For additional heat insulators in sizes from 1/2” – 2.00” please visit this link on our website. http://www.edelbrock.com/automotive_new/mc/install_items/adapters_spacers.shtml.
Got a technical question? If so, you can rely on our Technical Support Department for the right answer. The Edelbrock Tech staff is here Monday through Friday, 7 am – 5 pm PST to answer all your questions. You can reach them by phone at 1-800-416-8628 or you can visit our Tech Center for a complete listing of installation instructions, videos and FAQ’s .