[rackum]

My engine is Goodwrench 350. It is a replacement engine for models 1970 thur 1980 Chev. It has 260 HP. The engine starts very well when cold and even hot if it is started back within 2 to 3 minutes. If the car sits longer the engine will turn over 8 to 10 times before it will start. It always starts. I have been told this problem is called heat soak but I don't know. I have a 650 cfm Edelbrock carburator on it. I am using a 3/8 spacer under the carb. The manifold is a Holley Street Dominator, low rise dual plane. It has the EGR valve on it which I have blocked off. Would a thickner spacer under the carb. help? I don't know just guessing. The car has been like this for about 2 years and the engine has about 20,000 miles on it. I have had this problem every since day one. I have also moved the timing around but this does not seem to help. To begin with I am less than a shade tree mechanic. Any help on this problem would be greatly appreciated. Thanks

[Jmark]

Heat soak is common and can be a real pain to overcome. My first suggestion is to lower the float level in the carb by about 1/16 inch. One of the causes is when the fuel in the carb gets hot, it expands a little and dribbles over into the nozzles and into the engine. Lowering the fuel level will give you a little more room for expansion before it spills over.

Other considerations are way too much heat causing the fuel to actually boil and spill over into the nozzles and into the engine. With your setup, I don't think this will be the main issue.

Fuel lines that are close to a real hot source will cause hot soak problems too. The fuel in the pump/line will expand and push more fuel into the carb, again, spilling over into the nozzles.

Try the float lowering first and see how it does. If it does not help, let us know and we'll suggest some other things.


Mark

[ernkazern]

Have you tried varying your starting routine? Maybe with your particular combo you have to hold the gas pedal to the floor to start it. Maybe you have to pump the gas once or maybe twice for it to start. I'm basically pretty cheap and lazy, so if all it took for my car to start would be for me to hold the pedal to the floor that's what I'd do. On my personal toy if I touch the gas with a hot engine it starts hard. If I leave the pedal alone it's starts up hot on the first or second crank.That's less expensive and easier than making adjustments and replacing parts. Not that there's anything wrong with that if you have the time and money.

[F&J]

I'd do the float lower like Jmark said. I've seen that there are many complaints on the Edelbrocks being set too high right out of the box.

I bought a near new looking one and it was too high; I assume whomever bought it new had replaced it due to it "not being a good carb". It's been too long to remember, but I think I used an old Motors manual from the 1960s to find a car that had the old AFB (which is what an Edelbrock is cloned from) and used the float specs on the one that had the "lowest" setting....and I think I should have gone a little lower. Mine originally would flood-out & stall if I parked it on a steep sidehill. (like a ditch on the side of the road)

[rackum]

Thanks Mark, I will try lowering the float this weekend. I moved the gas line away from the engine last week and this did not seem to help. I have also try every combination there is trying to start the engine but nothing seems to work. The float might be the problem. It seems to me that it is harder to start when I park it on a hill. I will post the results after I lower the float. Thanks again.

[rackum]

I lowered the floats almost 1/4 inch this weekend. I could not see any inprovement in the starting. The car still runs and performs well with the lower floats. Would an inch spacer under the carb. help? Also would a different intake help? Thanks

[F-BIRD'88]

Because the fuel is held within the carb body AFB carbs tend to be sensative to heat soak.

Some things that will reduce the carb body temp and help a lot.
Install a wooden carb spacer (Edelbrock). Wood is a very good heat isolator.
Install a heat isolator gasket kit on the mechanical fuel pump (Seals-it)
move the fuel lines and or wrap them to isolate from heat.
Remove the intake manifold and block off one or both of the exhaust heat riser passages with a metal shim on the intake gasket. I usually block one side and restrict the other side. These passages were designed for a cast iron manifold. A aluminum manifold heats up a lot faster only needing a little or no exhaust flow thru the under plenum heat passage.

Use a fuel pressure regulator to limit the fuel pressure to 5- 6PSI max. Any more is too much. Readjust the float height.
If the car is hot, open the throttle while cranking to clear the over rich fuel vapours in the manifold. Do not pump the throttle.

Seals-It
Edelbrock wood carb spacers

If you lower the float height setting too much you get fuel starvation at WOT at high rpm. regulating the fuel pressure to 5-6PSi is key.

[rackum]

Thanks for the information. I will try these. Thanks again.