| [GMCnet] Bad news from the corn belt [message #90112] |
Sun, 27 June 2010 07:19  |
Gerald Work
Messages: 102
Registered: June 2010
Karma:
|
Senior Member |
|
|
The local news as we have passed through Iowa and now Illinois has been all about new studies sponsored by the govt and the ethanol/corn lobby concluding that increasing ethanol in gas would be a good thing. According to these news broadcasts we can expect an increase from 10% ethanol to 12% soon as the "base standard" for most of the country. So, whatever we are doing now to try to mitigate fuel boiling in our old GMCs we will need to redouble. We are going to have to learn how to deal with this issue - it is not likely to go away. Time to light some candles instead of railing at the dark.
Since redoing our fuel system last summer we have had only minimal issues with vapor lock at altitudes from sea level to 12,000 feet. While the tanks were out I cleaned the outside and coated the bottoms with industrial elastomeric roof coating. This is a bright white material that is filled with microspheres designed to reflect heat away from flat roof industrial buildings. I used material left over from coating the commercial torch down roof on our 1907 former Masonic Temple building (studio and gallery on the first floor and living quarters on the second). I purchased it from a compay in Florida called something like National Chemical Co. You have to apply a bonding coat (primer) first and then over coat that with two or more coats of the elastomeric material. I have no idea how long it will stay on. It is designed to over coat metal and to reject very high surface temperatures but not to hang upside down splattered with all kinds of road junk.
We also removed the socks and installed one of Jim K's electric fuel pump kits with a large fuel filter. Both are mounted outside the frame rails after the selector switch. These kits include everything you need to draw fuel around this electric pump when the mechanical fuel pump is functioning properly and to also use the electric fuel pump to push fuel to the mechanical one. Some take the mechanical fuel pump off all together since it is possible to pump fuel into the engine oil if the mechanical pump diaphragm split. I find the electric fuel pump noisy and mechanical fuel pumps have been fine for millions of miles on countless cars in the past so have elected to keep the mechanical one. I have the electric one controlled by a large bat handled switch mounted on the wall where it is out of the way but easily accessible by touch via my left hand. I turn it on before starting the coach in the morning then turn it off. It stays off until we get a stutter from a vapor lo
ck then I quickly switch it on for a few moments. I also switch it on when under very heavy load like climbing a steep mountain pass where I know the secondaries will be open some or all of the time. But, most of the time I run only on the mechanical fuel pump and that seems to be fine in both hot and cold weather.
We also installed two of the exhaust shields also from Jim K. and I think they made a big difference as we had more sputter occasions before installing them than since. They are a bit of a chore to get in place with 3" exhaust, but well worth the effort.
Based on several days in the corn belt now I have to revise my estimates on how much effect removing the high AC and pod may have on fuel consumption. I simply cannot tell for sure as our mileage is bouncing all over the place. I think this is likely a function of the ethanol content bouncing all over the place from fill up to fill up. Most pumps are not marked except for the E85 (85% ethanol) and the "plus" grades which often say 10% or more ethanol. Those are marked as having higher octane ratings than the "regular" grades which are unmarked and area also cheaper than the unmarked regular grade. We have been purchasing whatever is marked 87 octane at the pump. Over the 2500 miles of this trip so far over all mileage is 8.2. It was significantly higher before this multiple day steady diet of mid-west fuel.
High single tank so far has been over 10 and low under 7, way too much variation to blame on any single factor like pump shut off alone. We try to set the pump to a flow rate of less than 0.1 gal per second. We let the tank settle for 20 to 30 seconds after it first shuts off, then refill by hand to a second shut off. We seldom get spit back unless filling up late on a really hot day and then it is only a little.
I space cadeted the total amp hours on our four battery set up as someone mentioned the other day. I just finished a 8 battery installation for another application before we left on this trip and I guess I still had those number stuck in my head. Sorry for the confusion. Anyway, the percentage usage specified in that post are correct so you can still use the numbers as a rough guild for your applications. You can also download the presentation I made at GMCWD/GMCMI rally at Pueblo, CO last summer if you want details and lots of pics. It is available from my web site http://jerrywork.com. Go to the Presentations tab and scroll down.
Jerry
Sent from my iPad
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
|
|
|
|
GMCforum
Search
Help
Register
Login
Home
