Carb boilover solved

we have had the pleasure of being served solely 10% ethanol here in S Florida for past 2+ years

I have a noticeable drop in fuel economy that I attribute to it.

My mechanic insists that I use Ethanol Medic with every tank



http://shop.fuelmedics.com/product.sc?productId=1

and I try

all 3 of my cars run relatively well but they do like their gas

oh and BTW I stopped using super a couple of years ago - they run better and get better mileage on regular

 

The term I was looking for is Reid Vapor Pressure (RVP). Adding ethanol or methanol to gasoline changes the RVP and will cause MORE evaporative emissions as gasoline will evaporate at a much higher rate. The gasoline will boil at lower temperatures adding to the problem. This is the theory of why my car will continue to experience these problems per the experts and confirmed by several of my freinds who have now experienced the problem on their carbed cars that did not have the problem prior to the addition of oxygenates to the fuel.

http://www-erd.llnl.gov/ethanol/proceed/autoupd.pdf

 

That's one informative article, TBird! Excellent to have the facts.

 

Here's a guy with a Cobra with the same issue - high altitude.

http://www.chuckbrandt.com/living.htm

This Vette thread is good, but not related other than using a Holley carb.
http://forums.corvetteforum.com/c1-and-c2-corvettes/1548837-fuel-percolation.html

I guess the Rockies could be a challenge for my six, but it's only a 5 hour drive through to sea-level. Valley dwelling is good.

 

You have to remember that Denver is in a valley above 5,000 ft.

 

I meant my Red River Valley. I'm at 792 feet above sea level. No boil-over so far.

 

TBird, I found this on Boiling, Altitude and Jetting. Might be useful.
http://www.thumperfaq.com/jetting.htm

 

Explained perhaps, not solved.
Coolant temps will actually rise on engine shut down as heat transfers from the metal but isn't circulated through the radiator.

By eliminating the engine's heat soak cycle with an auxillary water pump you just might cure this.
A small electric pump plumbed into a heater hose will keep water circulating until the engine cools evenly.
M-Benz for one has these small pumps on some models. It could be wired along with a low temp limit switch to shut it off at a predetermined temp.
I'm reasonably confident this would cure your carb boilover.
Found you a nice price on one;
http://www.autohausaz.com/search/product.aspx?partnumber=0392020026&gclid=CNfv35enwKECFRUhDQod0x6UhQ



EDIT; The OP is fighting an issue with the boiling point of his fuel. I don't believe any tuning in the form of carb or timing adjustments will do any good. Only lowering the actual temp in the carb after engine shut down will effect this. Popping the hood open may also be enough but rather impractical.

 

I would never have though about that. I do know that on a mid to late 80s Ford trucks with the 300 cid engine there was a fan that would blow on the carb for that same reason. Factory installed.

I don't see how circulating water would cool the intake manifold. There is no water in it.

 

The idea is just to remove heat from the engine, not specifically the intake.
Fuel could also be boiling in the fuel line overwhelming the float pressure on the needle.
His problem is obviously related to heat soak.

 

I have discovered that if I let the engine idle for about 30 seconds before shutting it off seems to help.

 

Here's an aftermarket solution:
http://www.daviescraig.com.au/Electric_Water_Pumps-list.aspx
Pretty neat bunch of controller options with these pumps.

 

Sold in the US too! Neat find Andy!
http://www.hrpworld.com/

Under Engine Accessories (also Electric Fan controllers):
http://www.hrpworld.com/index.cfm?t...ucts&form_cat_id=747,1066,363&action=category

 

The old flat head Fords were terrible for vapor lock. I used to keep a gallon of water in my first car (49 Lincoln) and pored it on the fuel lines when I needed to cool the fuel to start it. Some would clip aluminum foil on the fuel lines with clothes pins to help pull the heat off of the lines.
Another more permanent fix was to drill holes in the water pump fins. That would slow down the water and allow it to be in the radiator longer.
Drag racers used to put a cooling canister similar to a beer keg chiller (smaller) with ice in it to cool the fuel. It was built into the fuel line going to the carb.

 

Norm, I looked at the pics you posted of the Capri "cannister". Mine doesn't have that. Although I have the "big" four bolt manifold my car doesn't have that cannister on it. No wonder everyone is saying there's a pre-catalyst in there. There must be 1,000 different configurations on these Fox platforms. I knew I wasn't crazy. Also my A.I.R tube is coiled three times no just one coil. Very wierd.:confused: