Inliners International
Posted By: Phantom Shafter cam for propane motor - 01/11/04 04:15 PM
I have had a stone stock 230 in my '50 Chevy for 30 years, on propane. Now I'm building a warmed up 292 for it. Does anyone out there have knowledge about cam selection for LPG fueled sixes?
The plan is for a strictly street motor. About 10-12:1 CR (LPG is 100+ octane), Offy single 4 intake, headers. I want good low to mid range performance, but I also want it to sound meaner than stock.
Is picking a cam for LPG the same as for gas?
Posted By: bigchevy66 Re: cam for propane motor - 01/11/04 11:05 PM
I don't have any answers for you, but I do have a few questions. Can you post any links to websites with propane info., or suggest any books. I'm curious about running propane on my truck, but I have no experience/knowledge with it. Any info at all would be great. Thanks. John
Posted By: Phantom Shafter Re: cam for propane motor - 01/12/04 04:14 AM
Most of what I know came to me long before there was such a thing as a website. A good start for info will be your local propane company. Another source is Ak Miller, (310)949-2548; he has built a 700hp ChevSB with twin turbos.
The basics are that propane is 110 octane, creates no carbon when it burns so the oil never gets dirty, and the exhaust has zero HC, zero CO, and 1/3 the NOx you get with gas. It has fewer btu's per gallon, so around 10% less power. I was getting 18 mpg with an underpowered 230. Not as available as gas, and your car will have a slight aroma of cooked cabbage. The fuel delivery system is different, but actually very simple, & since LPG is a gas in its natural state, no need for a choke, no rich/lean issues. It starts when the first plug fires, every time. The cost per gallon is usually close to gas - sometimes a bit lower, sometimes a bit higher, but I'm not sure you can buy 110 octane gas at any price.
Posted By: Phantom Shafter Re: cam for propane motor - 01/17/04 03:27 PM
Big Chevy: My last post was shooting from the hip, and may have had some bad info in it. EG., when I tried the Ak Miller number myself, I think I got some sort of talk dirty service. And my suggestion of compression ratios as high as 12:1 may have been a bit extreme (LPG runs hot, and may burn holes in pistons at super high compression ratios).
But I did locate a website that will provide most of what you want to know:"www.wps.com/LPG/index.html"
Happy surfing!
Posted By: bigchevy66 Re: cam for propane motor - 01/17/04 07:48 PM
Phantom Shafter-- LMAO That's pretty funny. I didn't try that number, but thatnks for the heads up. Thanks for the further info. I keep meaning to look into propane further, but I'm always short on time. Thanks. John.
Posted By: buickroadster Re: cam for propane motor - 01/22/04 03:32 AM
picking a cam for a propane motor is the same as a gas motor(but let your cam grinder know it's propane, as he might have a "trick" propane grind)i run 12:1 comp on my street ,propane, fuelled motor(tripple mixers and duel converters)no problems at all(make sure the timing has no more than 30'total advance)you can see my rod(aussie 265 hemi inline six-277 cu in)on http://members.optusnet.com.au/~c_s_rod_and_custom/gallery.html
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