460 Ford questions
460 Ford questions
I have done some searching but haven't determined what I should do. What I have is a 1989 460 F-250 with the factory port fuel injection. I would like to do a propane only fuel conversion and I have most of the components for a vapor system including an adapter that goes from the two hoses to the throttle body to where a mixer / carb would attach. (it was an e-bay part with no paperwork) My questions are, can I attach a CA-425 to that adapter component and disable the gasoline fuel supply and let the ecu handle the ignition without having to add more electronic components? I have another 460 that was born with a carb (1978) and I just brought the centrifugal advance in sooner(weaker springs) and limited the total advance and I'm very happy with it and if I could get similar results on the '89 I would be content. Any suggestions or links would be appreciated. Thanks!
Re: 460 Ford questions
The technical answer to your question is yes you can do it the way you described. The other issue is where are you located and what government regs do you have to adher to. If your in the US or BC in Canada you ahve to follow specific government requirements to enasure youe emissions are acceptable.
There are two cautions when conveting this truck. When you install the mixer you have to ensure the IAC is drawing fuel and air downstream of the mixer or the engine will not start and ide properly. Number two, be careful how you disable the injectors. You cannot just take the fuse out or cut the common power wire. The injector power also supplies power to the EGR, IAC and Purge canister. The ECU is fine for controlling the timing. Ford 460's have preprogrammed timing that will work with propane. There were timing enhancers made but they are hard to find now. The enhancers were good for optimizing the power and economy. Since you are going to go straight propane you can advance the timing a few degrees at idle. Do not get carried away as advancing a few degrees at idle can mean 8 to 10 degrees at higher RPM's. Get carried away and you could cause engine damage.
There are two cautions when conveting this truck. When you install the mixer you have to ensure the IAC is drawing fuel and air downstream of the mixer or the engine will not start and ide properly. Number two, be careful how you disable the injectors. You cannot just take the fuse out or cut the common power wire. The injector power also supplies power to the EGR, IAC and Purge canister. The ECU is fine for controlling the timing. Ford 460's have preprogrammed timing that will work with propane. There were timing enhancers made but they are hard to find now. The enhancers were good for optimizing the power and economy. Since you are going to go straight propane you can advance the timing a few degrees at idle. Do not get carried away as advancing a few degrees at idle can mean 8 to 10 degrees at higher RPM's. Get carried away and you could cause engine damage.
Re: 460 Ford questions
Thanks for the response C3H8. I will study up on the intake plumbing and on the electrical for disabling the fuel side of the factory setup. There isn't emissions testing where I live (although I will strive to have it as clean and green as is practical) so authority intervention shouldn't be an issue. My plan for the truck is towing and it won't be a daily driver so should I shoot for a maximum ignition advance (I'm assuming that I could bring the rpm's up until it appears to be at it's maximum and adjust it up or down from there?) I definitely don't want to flirt with meltdown, I'll settle for a safe total. If anyone has pictures or diagrams of a similar setup and specifications (such as recommended total advance) that they would care to share it would be appreciated. Thanks!
Re: 460 Ford questions
My experiance, be it what evver fuel, is get the curve in the ball park plus 5 or 6 degrees....then start retarding till the economy and power drop right off...it will do so withing a couple degrees.
overadvanvancing power drops off slow but the engine tone sounds more 'grunty', giving a very strong 'opical illusion'
overadvanvancing power drops off slow but the engine tone sounds more 'grunty', giving a very strong 'opical illusion'
My Spelling is Not Incorrect...It's 'Creative'
Re: 460 Ford questions
I'm in the market for a different mixer / carb mount for a CA425 than I have. I'd like to find one that the mixer mounts to like in this thread.
viewtopic.php?f=5&t=1207
I posted in the parts wanted forum also.
viewtopic.php?f=13&t=1249
thanks!
viewtopic.php?f=5&t=1207
I posted in the parts wanted forum also.
viewtopic.php?f=13&t=1249
thanks!
Re: 460 Ford questions
Steps:
Retarding timing will increase the exhaust temp before the power or economy becomes noticeable to the average driver. All original engine spark mapping consists of advancing timing for "Mean Best Torque" before the onset of detonation. In all cases, the torque will begin to drop off before detonation is detected. Setting ignition timing by the way an engine feels is obsolete and not very accurate. While we are on the topic, the higher the compression ratio is, the more critical the timing curve is. 4 to 7 degrees on a 8:1 engine will not make much difference while that same change on a 10:1 engine will be noticeable, and on a 12:1 engine can spell damage. On a high compression engine, there will be practically no drop in torque when the engine begins to detonate, and there will be some level of inaudible detonation, thats where the piston begins to develop craters.
Franz
Retarding timing will increase the exhaust temp before the power or economy becomes noticeable to the average driver. All original engine spark mapping consists of advancing timing for "Mean Best Torque" before the onset of detonation. In all cases, the torque will begin to drop off before detonation is detected. Setting ignition timing by the way an engine feels is obsolete and not very accurate. While we are on the topic, the higher the compression ratio is, the more critical the timing curve is. 4 to 7 degrees on a 8:1 engine will not make much difference while that same change on a 10:1 engine will be noticeable, and on a 12:1 engine can spell damage. On a high compression engine, there will be practically no drop in torque when the engine begins to detonate, and there will be some level of inaudible detonation, thats where the piston begins to develop craters.
Franz
Re: 460 Ford questions
I assume that ppl are not silly enough to advance up into detonation, and back work from there.
Yep the higher the CR...or more accurate the DCR makes the advance quite a bit more sensitive...which is why engines with high compreassion and a hi performace cam are quite tolerent down the bottom end,the DCR can get very low...down into 8s but up in the power range 6000 rpms very sensitive....
Bur a 10:1 CR with a stump puller cam down low is dam sensitive down low...within a couple degrees
Agree but not many ppl have a dyno in the back yard... or data logger O2. MAP, and even a detonation sensor...it is far safer and noticable to find the point where power drops off ..retarding, than advancing up, think that nice engine note is more power..like an opitical illussion...and have it running with inaudable detonation.Setting ignition timing by the way an engine feels is obsolete and not very accurate.
Yep the higher the CR...or more accurate the DCR makes the advance quite a bit more sensitive...which is why engines with high compreassion and a hi performace cam are quite tolerent down the bottom end,the DCR can get very low...down into 8s but up in the power range 6000 rpms very sensitive....
Bur a 10:1 CR with a stump puller cam down low is dam sensitive down low...within a couple degrees
My Spelling is Not Incorrect...It's 'Creative'
Re: 460 Ford questions
Getting older, hard to remember all the part numbers. The adaptor in the link is a Gann adaptor. Part number is AA9-36 I thinkor AA9-36-2. Not 100 % sure. I can check tomorrow to make sure I have the right part number.
Re: 460 Ford questions
Thanks for the responses gentlemen. Regarding my ignition timing, the engine is a stock 140 some thousand mile one so it is probably in the 8.5 to 1 ratio range. With that in mind, what would be a reasonable (safe) total advance? My thinking is to bring the rpms up until it quits advancing and set the total and let the electronics take care of what I can't do anything about anyway. (meaning advance rate) Am I thinking funny? I did find an Impco number (A1-80) for the mixer mount that hooks to the two snorkels and the offshore piece I have fits the top of the mixer and allows me to use the stock air filter assembly. It is a copy of the Impco A1-81 I believe. I may get back with Gann Products with numbers when I get them and see if I can obtain one of theirs. If something don't materialize I may just fab one out of light gauge steel. Thanks again
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Re: 460 Ford questions
I have the same conversion that Ive ran for over 5 years now on straight LP. To kill the injectors I found the 2 ground wires that trigger the injectors and cut them and put a switch in line. I also shut down the fuel pumps. My one tank leaked so I removed it and used the power for that pump to turn on my LP solenoid. I did set my initial advance to I think about 20*, factory is 10* btw.