Jim Blair wrote: > Yesterday I was chatting with an LPG agent and he told me that as of > 2001 the US has started blending Butane in with the LPG and his truck > which ran excellent for years on the old stuff, now pings. The octane > equivalent of LPG has dropped to 104 from 130 so if you go past > 10.25:1, your motor will ping. It's always been a propane/butane blend, but I imagine that the ratio went to crap in 2001. My 9.5 to 1 or 10:1 or so propane motor (232ci) did ping. It never COULDN'T ping, I mean depending on timing etc. Sad to say (or not) modern EFI gets you everything that LPG carburetors will do. And LPG is still petroleum, the price tracks the rest of the stuff. In practice it's not much cheaper than gasoline, for two reasons: * fewer BTUs per unit mass -- you use more fuel (about 15%) * it's not always cheap Price can be very good if you buy at big tank farms, but they are open 8am - 5pm Mon - Fri and are often out for lunch, "driver's out making deliveries, come back at 3", you name it I heard it. So more than half the time I bought from smaller retailers, and the price was not much less than gasoline, because of THEIR cost. (From the mom'n'pop stores you get the rest of the LPG fuel-up woes: * pop doesn't know how to pump it, come back when mom is here * we can't sell you road fuel (this is true, it's not legal unless the retailer has a road tax certificate, true most states) * we don't have that adapter (1-3/4" ACME) I drove my Classic on 100% LPG (no gasoline tank at all) for 19.75 years, and I did more than one cross-country road trip, the longest being 11,000 miles in 1996. Believe me, I did every trick and heard every excuse! It can be done but you gotta be dedicated... If you drove only in town, had a BIG tank (25+ gallon capacity, not tank rating), and you lived such that M-F 8-5 fillups were OK, and you were near a tank farm, it'd be not very inconvenient. That's what most fleet use is like (laundry trucks, etc). Else fanatical dedication. My engine sure ran clean though! Here's a photo of some cylinder taken this July. What appears to be scores are just wipe-off crap. Built in fall of 1987. Valves were toast though. http://wps.com/AMC/1963-Rambler-Classic-550-Cross-Country/Howell-TBI/images/piston4.JPG _______________________________________________ Amc-list mailing list Amc-list@xxxxxxxxxxxx http://splatter.wps.com/cgi-bin/mailman/listinfo/amc-list