|
|
|
Dec 28, 2011 22:36:02 GMT
|
|
I asked this over on the LPG Forums so interesting to compare and contrast the answers...
Dez and I were shooting this one out the other night.
Lets say you have a car with a V8 and a carb. You install a sequential LPG kit by tapping the manifold like as if you were installing a nitrous fogger. You install the ECU from the LPG kit and to make this run you need to give it TPS and O2 readings which mean installing a couple of senders.
Other than this...
Are we smoking crack or is this going to be a day full of WIN?
|
| |
1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta
|
|
|
|
`state
Yorkshire and The Humber
Posts: 1,215
|
|
Dec 28, 2011 22:41:43 GMT
|
|
As long as you tapped into each runner for the manifold,so each injector was only feeding one cylinder each and you`ve got the needed sensors i cant see why not.
Now pass the crack pipe...
|
| |
Look at all the plastic people who live without a care.Try to sit with me around my table,but never bring a chair.
|
|
RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
|
|
Dec 28, 2011 22:53:15 GMT
|
Interesting. I was under the impression that sequential LPG kits intercepted the signal for the stock petrol injectors and modified it to work with the new target AFR and the LPG injectors fuel flow-rates. I say 'under the impression', because I have no idea why I thought that. Having thought about it, this would actually limit you to cars with sequential petrol injection from the factory, so I guess I'm probably completely wrong, and therefore this post is somewhat pointless.  . In my defence I'm 90% sure I have food poisoning, and I have spent all day being battered around the inside of a rally car that's not been run in 20 years, being driven by a rather enthusiastic mate. I've confirmed my respect for co-drivers, and spent most of the day grinning, but I feel like my head's been repeatedly kicked in all day  . Pictures will appear sometime. Time for me to shut up now I think  . |
| |
|
|
`state
Yorkshire and The Humber
Posts: 1,215
|
|
Dec 28, 2011 22:58:41 GMT
|
|
Thinking again wouldnt you need a crank sensor maybe for the timing side of things?
|
| |
Look at all the plastic people who live without a care.Try to sit with me around my table,but never bring a chair.
|
|
|
|
|
Dec 28, 2011 23:01:28 GMT
|
|
I have literally no idea.
Do Megasquirts and the like need crank position sensors?
Or can you run it off the stock distributor?
|
| |
1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta
|
|
`state
Yorkshire and The Humber
Posts: 1,215
|
|
Dec 28, 2011 23:11:23 GMT
|
|
Yeah some will run off the standard crank sensor or you use a trigger wheel bolted/welded to the bottom crank pulley.The trigger wheel would be your easiest option i think.
You`d not be able to use the dizzy either,think you`d have to go coilpack.
You`d really need to see what each individual lpg ecu needed to run and replicate it on your engine.
Oh notice theres alot of `i think` ect? I`ve never even thought about this before or in any way know alot about lpg conversions.Just thinking that it would be the same as converting a carbed engine to injection.
|
| |
Look at all the plastic people who live without a care.Try to sit with me around my table,but never bring a chair.
|
|
RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
|
|
Dec 28, 2011 23:11:24 GMT
|
I have literally no idea. Do Megasquirts and the like need crank position sensors? Or can you run it off the stock distributor? Megasquirt can indeed run the crank position off the signal from a distributor, although to run fully sequential injection you need a cam position sensor as well so the ECU knows which revolution of the 4 stroke cycle the engine's in. |
| |
|
|
|
|
|
Dec 28, 2011 23:18:43 GMT
|
|
Hmmm LPG Forums initial response is that the ECU on a sequential kit is only a controller for the LPG and all the ECU functions are retained by the "Host" - ie the car's ECU.
However a Megasquirt based solution may work...
|
| |
1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta
|
|
Onne
Part of things
Posts: 822
|
|
Dec 28, 2011 23:22:01 GMT
|
|
It definitely doesn't work on my merc.
I think the trick is in the electronic injection bit. No signal = no sequence to inject. Hence me running a vaporiser on my mechanically injected merc (K-Jetronic)
That's how I understood it anyway...
|
| |
Last Edit: Dec 28, 2011 23:22:34 GMT by Onne
1990 Mercedes W126 300SE
1997 Mercedes W140 S320L
|
|
froggy
Posted a lot
Posts: 1,099
|
|
Dec 28, 2011 23:51:57 GMT
|
|
The only sequential system I've worked on mimics the pulse duration of the cars injector then a fairly simple set of adjustments to get the LPG flow at steady state running to go roughly into the closed loop lambda . Even if you could supply a signal based on Tps It wouldn't be load based so transient fuelling would be hard to get any control over ,
|
| |
|
|
|
|
|
|
|
Dec 28, 2011 23:58:10 GMT
|
|
Megasquirt would work, and would also work fine with a standard dizzy sending the rpm signal.
You have to remember that "sequential" injection isn't anywhere near as timed as the spark is. Remember, the inlet valve is shut through 240 degrees of crank rotation but the injector is open up to 360 (100% load) so it actually doesn't matter much WHEN you inject, more that you need to inject the right amount. It will pool around the valve, and get drawn in when the engine wants it. You don't need a cam sensor, you just need the engine rpm and some way of measuring load (MAF or MAP, throttle position, lambda - one or more of these needed) and a suitable fuelling map in the ECU. Air and coolant temp sensors modify the map based on temperature to improve flexibility and economy.
|
| |
To get a standard A40 this low, you'd have to dig a hole to put it in |
|
ChasR
RR Helper
motivation
Posts: 10,309
Club RR Member Number: 170
|
|
|
|
|
AFAIK pretty much all of the sequential kits work off the car's existing petrol injector values.
Generally speaking LPG kits come with their 'slave' ECU, vapouriser, MAP sensor (for the LPG side of things, injectors, wiring loom as far the injection side goes.
Whether you could make the car mimic these values when it is a carbed car is another area altogether.
|
| |
|
|
|
|
|
|
|
|
^ That is why it would work with a megasquirt. You wouldn't need the "slave" ECU but you would need to map the megasquirt to the car's LPG fuelling requirements. The fact that the petrol fuelling system would be a carburettor is neither here nor there - once you cut the fuel to it the carb becomes a throttle body instead and the megasquirt can deal with injecting the LPG.
|
| |
To get a standard A40 this low, you'd have to dig a hole to put it in |
|
Dez
Club Retro Rides Member
And I won't sit down. And I won't shut up. And most of all I will not grow up.
Posts: 11,790
Club RR Member Number: 34
|
|
|
|
|
exactly my thinking SOC, and what i was trying to expain to AK. i think its doable, expecially on a big old rather unrefined yank v8. there would be loads of room/metal to attach the necessary sensors too as well.
granted most off the shelf sequential stuff uses a piggyback ecu, and taps into the current lamda and CPS sensors, but welding in a lambda boss and fitting a trigger wheel to the crank pulley really isnt hard. youd need to fit a TPS to the carb, but again its nothing really complicated to make up. but theres really no reason they cant be standalone, as its no different to converting a carbed car to run on 'normal' EFI system. all youre doing is skipping a step and going for even more economy by going straight to sequential LPG. as i understand it, the megasquirt wouldnt know the difference between petrol and LPG, all it does is send an electronic pulse to the injector to tell it to 'squirt'.
shame i don't know enough about megasquirt to give it a go really!
|
| |
|
|
|
|
|
|
|
|
Have you tried the megasquirt site, and a read of the FAQ section? It isn't hard!
|
| |
To get a standard A40 this low, you'd have to dig a hole to put it in |
|
|
|
|
|
|
sounds like a good plan. i guess this kind of lpg setup gives much better economy then the basic setups. wonder why it's not been marketed before? you'd obviously need to build the kit yourself and map it all. thou could well be the best way to run a big old yank (or any old pertol lump) on modern fuel prices. do it. then sell kits one thing i don't get with carb converted lpg kits thou. when switching off the petrol to run on gas, how do you stop the fuel thats left in the float bowl from entering the manifold? thou i guess. if you get it all working nice on gas, you'd only need to use petrol if you got stuck. |
| |
|
|
|
|
|
Dec 29, 2011 10:02:51 GMT
|
|
you have a 3 position swtich - petrol/LPG/run-dry.
In "run dry" the car pumps no further petrol but still runs on the petrol in the float chamber. Once this is used up you switch to LPG. Basically you run it out of petrol. This seems, well, curse word to me.
This is why I'd want to be able to cold start on gas.
This whole megasquirt and all that stuff - this is going to be a fun one to explain to the insurance company LOL.
In fact I'm wondering if the best course of action would be to convert the car fully to EFI using a megasquirt and adapting whatever system a suitable yank big block pickup uses.
Suddenly its not a weekend's work LOL.
|
| |
1941 Wolseley Not Rod - 1956 Humber Hawk - 1957 Daimler Conquest - 1966 Buick LeSabre - 1968 Plymouth Sport Fury - 1968 Ford Galaxie - 1969 Ford Country Squire - 1969 Mercury Marquis - 1970 Morris Minor - 1970 Buick Skylark - 1970 Ford Galaxie - 1971 Ford Galaxie - 1976 Continental Mark IV - 1976 Ford Capri - 1994 Ford Fiesta
|
|
|
|
|
Dec 29, 2011 10:24:17 GMT
|
|
my mate's just fitted an Audi 5 pot in his T25 syncro
and that's now running on a home built LPG, i'll have
a word today about it, its a beast.
|
| |
|
|
|
|
|
Dec 29, 2011 11:58:29 GMT
|
|
Megasquirt has a dual map feature - (well my MS2 v3 does). So you can switch between the 2 maps for petrol/lpg.
However, I find MS generally to be too complicated for its own good. Next time i'm going with VEMS I reckon - especially as it has inbuilt wide band lambda.
|
| |
'83 GTM Coupe. 4A-GE Powered
'00 GTM Libra Auto. Ick.
'71 Detomaso Pantera. Current Resto
'89 GMC Safari Tow/Kip bus
'05 SAAB 9-3 Daily
'71 Siva Moonbug. Not even contemplating resto yet.
|
|
froggy
Posted a lot
Posts: 1,099
|
|
Dec 29, 2011 13:07:39 GMT
|
|
maf based would make more sense on a n/a engine to me as it would give a much more accurate load based signal when in vaccum compared to a map sensor especailly on a big capacity engine .
if it was run on a manual gearbox you could use a fuel cut on overrun to save wasting gas too
|
| |
|
|
|
|
.
. Pictures will appear sometime. Time for me to shut up now I think 
.
