American Clipper Vertical Limitation, Etc.

[RYBKA]

Well I just completed a 6,000 mile adventure from Washington to Michigan with my 79 Clipper, towing a 3,000 pound car.

All went pretty well, and the 440 purred like a kitten....I even made it up the mountain in second gear to see Mt Rushmore!  

However I did discover the Clipper's limitations, like absolutely conking out in the middle of the road at the 5,799 foot level, while trying to get up the 7% grade in 98 degree weather to see Yellowstone.  

The poor thing just gave up, but I was proud of her to have towed the car up that far.  Of course no steering, no brakes, and no movement on a mountain side road was a bit hairy.  After 30 minutes of cooling down, and bearing numerous irate motorists flipping me off,  she restarted and we made it back down the hill!

Also on route US-2, I saw at least seven other Clippers traveling about, no CB yet so I did not get to compare info.  

I did discover one thing about a hot Clipper in Sandy Point, Idaho.  They do not start.  So I pop the lid and immediately smell gas fumes.  Fumes, not gas liquid, fumes.  I had the wife hit the gas pedal and I could see the gas instantly vaporize..WOW!  

Result no gas hits the plugs to fire the thing up.  The solution was to pump the gas pedal to the floor REPEATEDLY and FAST while cranking the engine.  The 440 fired up everytime.

vty, RYBKA #3279

[handyman]

If you don't have a elec fuel pump get one asap that should stop all your problems unless it's really over heating bad

[Horst]

An electric fuel pump MAY solve your problem. If your gas is evaporating (the old vapor lock syndrome) then you have other issues to address, such as insulating or re-routing your gas line, getting a different gas cap, determining if you're too hot, etc.

[JeanneRon]

Horst, can you elaborate a little on the "Old Vapor Lock Syndrome".  We took a trip to Vancouver Island a couple weeks ago, the Clipper performed pretty well except when we were idling for a period of time (stuck in traffic, 45 min slow roll through Customs line, etc).  When trying to accelerate after these long idle times, he would cough, sputter, choke, etc until we got back up to speed.  Then run just fine again.  Even though the weather was in the 90's, the temp gauge never read over about 185 (just had a radiator flush, new T-stat, hoses, etc) so the engine isn't overheating.  Is this symptomatic of vapor lock?
Jeanne Gage

[Horst]

There's tons of information out there on vapor lock on the Internet.
Go to Google.com and type in "vapor lock" and you'll get more information than you can handle (be sure to search the "Groups")

Here's a pretty good explanation of it (borrowed from someone else)
==========
Vapor lock happens when the gasoline boils and forms vapor under conditions of high temperature and/or low pressure at some point in
the fuel supply system.  The lower the pressure, the lower the temperature at which the gasoline will boil.

In the case where the vapor lock happens between the gas tank and the fuel pump, it's because the pump generally has to use suction to lift
the fuel up from the tank.  If there's a hot spot in this line, the fuel can vaporize, and the fuel pump pulls only vapor - the carb or injector gets no fuel.

In the case where the fuel boils between the pump and the carb/injector, there are several cases to discuss:

-> Weak fuel pump: A weak fuel pump causes the pressure in the carb/injector supply line to be lower than normal.  Then either normal engine compartment temperatures or higher-than-normal ones on a hot day can cause the vapor lock.

-> Standard float-bowl carburetor: This problem is unlikely in this case, because any vaporized fuel should just be released out the float bowl vents. If the float bowl is not vented freely, as may be the case with pollution controls, then the vapor pressure in the float bowl might build up and cause vapor lock.

=============
Hope this helps

[DennisMalone]

While reading this topic I was remembering my recent (and probably not final) bout with "Vapor Lock." I bought my '79 Clipper, with: 440 Dodge, new Edelbrock 4 bbl, newer engine block, std engine fuel pump, 160 degree thermostat, Bunkbed model from a family on the New Mexico flatlands. Driving home to Denver, everything was fine. But as soon as I tried to go over an 11,000 ft pass in the mountains, the Clipper coughed and sputtered to a stop. I suspected vapor lock. So back down the way I came. While learning about this machine I noticed that there were dual exhausts, no crossover. But when looking at the underneath frame, there was only one side that had a heat shield above the exhaust pipe. That was the drivers side. The passenger side had no heat shield, and of course, that's where the gas lines were. This didn't strike me as a factory stock setup. I suspect there was only one exhaust pipe from the factory. On the drivers side. So my first step in attacking vapor lock was to put a high volume 4-7 psi electric fuel pump in the gas line, as close to the fuel tank as possible. This solved the problem. But I'm not happy with the fuel lines exposure to infrared and convective heat. Now I'm building a ventilated heat shield for the fuel lines and pump. By the way, the vapor lock situation out here in the Rockies is tough. First, at 11000 ft gas boils at a lower temp, Second, the steep hills, The Eisenhower tunnel is at the end of a 10 mile 6% steady grade, Third, whenever the sun is shining there is an uphill wind of 15-25 mph, (read as- tailwind), Fourth, in Denver they use 10% ethanol in the 87 and 89 octane fuels. Wow this brings out the weak spots in your rig pronto!!
Well, sorry for the long wind. Any questions?
Dennis Malone

[Horst]

Dennis,
What are you going to use for your ventilated hat shield, and how are you going to mount it?

I can't imagine taking my 360 to 11,000 feet in the heat with my mechanical fuel pump! I notice performance degradation at 7,000 feet - another 4,000 would probably shut me down.

[egibbons]

JC Whitney sells a flexible braided fiberglass insulating tube for helping to avoid vapor lock. Install it from frame to fuel pump, and from fuel pump to carb. I used it sucessfully on my Clipper and would recommend it highly.
Eric

[DennisMalone]

Horst and Eric,
Thanks for your ideas.
My thought was to duplicate the original heat shield that's on the drivers side of the frame. Which on my rig is an 18 ga steel, half circle by 3 ft long, mounted with u-bolts on the exhaust pipe. Of course I'd make it longer to protect the full length of the gas lines and elec. pump.
Eric's suggestion for fiberglass insulating tubing also sounds good. I'm using these heat shield covers on my spark plug wires. They do work.
I guess I like the metal heat shield better. As this would also keep the radiant heat off my floorboards on the passenger side. But the fiberglass insulating sleevs are only $10 bucks for 25', and easy to install. OK I'll do the Insulating sleeves first, while I'm building the heat shields.
Thanks Guys,
Dennis M.

[robert spence]

dear rybka  call me for location of super great supply place for  clipper things . spence ferndale  wa its in wa small drive from us has bins of things electric furniture  lights plumbing you name it they have it. the problem you had can be solved by installing a electric fuel pump , napa has them  regards neighor spencephone 383 0961

[Conrad]

Hi all, question:  Is an electric fuel pump installed as well as the mechanical cam powered fuel pump?  In other words, two pumps going at the same time?

[handyman]

Yes and yes your carb has a shut off valve that stops the gas so it can't keep coming in the elec pump just helps the mech plus it helps after the rig sets for awhile  

[Conrad]

thanks

[EKS]

NAPA sells an electric fuel pump designed for RVs
It includes a check valve and fittings so you plumb around the electric pump with the check valve. That way when using just the mechanical fuel pump on the engine it pulls through the check valve which has minimum restriction. Pulling through an electric fuel pump will have more restriction. check it out