Adding an elec. fuelpump to an Impco vaporizer+425 setup

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BigBlockMopar
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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by BigBlockMopar » Sat Jan 12, 2019 4:39 am

I have a large, roughly 4", tube out of a clothes-dryes laying somewhere which I would like to use instead of the thin aluminium ducting.
Or if I stumble across something factory/readymade from a later car, I could use that, but I'm not actively looking at the moment.

With the tanks full, the engine still really pulls hard.
Also on the highway with transmission in overdrive, the car still accelerates nicely when pushing on the throttle. This is between 2500-3000rpm and above.

I will look into rotating the trunk-mounted donut-tank this weekend and maybe install an 8mm line and lockoffs at the same time.
https://www.bigblockmopar.com
'73 Dodge Dart - 360ci - 11.3:1cr
MegaSquirt + HEI 7-pin timing control - Edelbrock AirGap - Cold Air Intake
IMPCO E / 425 mixer - A518 OD-trans - 3.55 gears - 225/50/17" tires.

Frank
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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by Frank » Sun Jan 13, 2019 9:46 am

If it's not too inconvenient, could do one upgrade at a time? I would be interested to see what effect each has on its own.

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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by BigBlockMopar » Sun Jan 13, 2019 5:57 pm

I doubt I will be able to do all at once.
Winter has been very mild upto now overhere but it's bound to get colder next week, which means less garage time for me.
https://www.bigblockmopar.com
'73 Dodge Dart - 360ci - 11.3:1cr
MegaSquirt + HEI 7-pin timing control - Edelbrock AirGap - Cold Air Intake
IMPCO E / 425 mixer - A518 OD-trans - 3.55 gears - 225/50/17" tires.

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BigBlockMopar
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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by BigBlockMopar » Sun Mar 17, 2019 7:48 pm

Finally was able to rotate the 'lower' ringtank 180° in the car.
Didn't change anything else at the moment.
I will drive the tanks to empty during the week and report if the lack of power during accelerations is still present.

The tank(s) were just filled up when I started this morning, which let me having to use some levering provided by mother nature...


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https://www.bigblockmopar.com
'73 Dodge Dart - 360ci - 11.3:1cr
MegaSquirt + HEI 7-pin timing control - Edelbrock AirGap - Cold Air Intake
IMPCO E / 425 mixer - A518 OD-trans - 3.55 gears - 225/50/17" tires.

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BigBlockMopar
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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by BigBlockMopar » Sun Mar 24, 2019 6:15 am

Findings:
No more hesistations during firm/hard acceleration with the tank getting close to empty.

Other things I found recently:
The engine seems to go very rich during hard acceleration(9-10 AFR), and runs very lean during cruise (17-19).
I can't be sure if already was the case before, because the AFR-gauge in my car has been having issues for quite a while.
Just installed a new 02-sensor (which still only works for a short while after powering up) when I noticed these values.

At full throttle, the engine seems to hold back a little, compared to holding the pedal at 90% throttle for instance.
Need to do some troubleshooting to find out what's causing this.
https://www.bigblockmopar.com
'73 Dodge Dart - 360ci - 11.3:1cr
MegaSquirt + HEI 7-pin timing control - Edelbrock AirGap - Cold Air Intake
IMPCO E / 425 mixer - A518 OD-trans - 3.55 gears - 225/50/17" tires.

jono
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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by jono » Mon Apr 08, 2019 6:21 pm

at full throttle you may be upsetting the vacuum needs of the Impco gear for it to work nicely. It is a bit like my turbo boxer 1800 cc _ everything is better in power delivery if I sort of ride the wave of power with a lighter throttle rather than foot to the floor.

I do like that the suggestion of a 180 degree change to the tank orientation appears to have fixed your initial problem. No one suggested run a separate line from each of your tanks up to the front and if tank orientation was thought to be the problem, set one 90 degrees to the other.

One comment on the theorising of fitting a pump, no one suggested testing pressures at the front where it sort of matters to see if that was your problem. Testing has been an issue in a mates shop recently with a young guy just guessing the problems and throwing parts at it for a fix without a test. The result being car is fixed with more parts, time and labour than should be necessary and his boss explaining this to the customer. He put a permanent stop to this practice.


Mention of Bennett who tinkered with LPG...this most likely John Bennett in Melbourne? There seemed to be two people I know of that looked at water pump cavitation - him and All Head Services. As I understand it, the latter used to propose that heads were cracking or gaskets blowing due to hot spots caused by cavitation. They sold the idea of air bleeds mounted in the cylinder head culminating at a manifold and return to the coolant system. I only ever saw one of these fitted.

I have seen just one of Bennetts systems on a Leyland P76. It had a remote thermostat housing fitted to the lower radiator hose with a heater hose size bypass to the top hose? I am told Bennett liked to divert some coolant from the radiator path to recirculate back through the engine. He also customised each applications water pump to reduce tolerances and cavitation. Also hear he got more power from our propane or propane/butane mix by getting intake air temps up above 82 degrees C.
Each application needed his individual attention to detail for the best outcome so was not available in a box for expanded marketing.
The latest I have read of his work was an engineering or emissions excellence award for a Diesel generator in a building for their power back up if I recall correctly...in a Sydney building. By now he can't be no young spring chicken either

These people being Melbourne based or thereabouts, in Australias biggest LPG market area, so their work may have been more commonly seen in these southern regions. I have not even been in Victoria since July 1986 when I vowed to never return (got booked for speeding, twice in 55 minutes - first one my fault)these vehcles need to venture further north before I am gonna see them

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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by BigBlockMopar » Tue Apr 09, 2019 5:30 pm

I replaced the Innovate MTX-L AFR gauge & controller with an entirely different one (albeit based on same Innovate basics) and the problem dissapeared. The new (MSD) gauge/controller provides a more steady and stable (and expected) readings of the AFR-ranges during acceleration/cruise and deceleration.
https://www.bigblockmopar.com
'73 Dodge Dart - 360ci - 11.3:1cr
MegaSquirt + HEI 7-pin timing control - Edelbrock AirGap - Cold Air Intake
IMPCO E / 425 mixer - A518 OD-trans - 3.55 gears - 225/50/17" tires.

storm
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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by storm » Tue Apr 09, 2019 9:08 pm

jono wrote:
Mon Apr 08, 2019 6:21 pm
Mention of Bennett who tinkered with LPG...this most likely John Bennett in Melbourne?
Nope he was from Sydney. He didn't tinker with LPG he developed a liquid phase system that become the basis for systems like Orbital (now owned by SprintGas from memory). I called him when I was doing the engine conversion in my Troopcarrier in the early 2000s and offered him my car as a test bed. There was another company in Adelaide that played around with it but they were stumped by pressure build up in the tank from LPG returning into it after being through the fuel rails.

The guy who did the cooling system mods was brilliant but not the same person. I have seen a couple of these systems and for old style cooling systems it is a great mod but modern reverse flow systems negate the need for them.
Every job is a self-portrait of the person who did it. Autograph your work with excellence.

Fuel flow requirements calculations viewtopic.php?f=5&t=1638

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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by C3H8 » Wed Apr 10, 2019 1:49 pm

Sorry guys. That was me that mentioned Bennet early on in this post. The guy I was referring to was Dave Bennet. He lived in Minnesota in the USA. Dave developed a system in the mid 90's on Fords where he used the OEM ECU. He installed a special tank from sleegers with an electric pump to maintain a consistent delivery pressure. He also developed a special delivery line with an inner and outer fuel delivery system. Fuel ran to the engine on the inner line and back to the tank on an outer sleeve around the inner line. This kept the fuel temperature down on the return line reducing heat build up. He then developed special injectors using the Ford rail that fit directly into the factory openings but rejetted the injectors to suit liquid propane. The system was designated as Liquid Propane Electronic Fuel Injection or LPEFI. Eventually he sold the rights to a company called Schwans, a rural food delivery company running GM topkicks with 366 and 454 CI engines. They added onto his design to develop it for their trucks. Unfortunately when Schwans decided to try to market it the system would have required a retail price of approximately 12K Canadian. Unmarketable. As far as I know they did use it for inhouse conversions. Sounds unreasonable but Schwans had thousands of trucks throughout the US and Canada saved a fortune using propane and Natural gas and of course the inhouse price was substantially less. Hope this clears that up.

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Re: Adding an elec. fuelpump to an Impco vaporizer+425 setup

Post by storm » Thu Apr 11, 2019 3:31 am

C3H8 wrote:
Wed Apr 10, 2019 1:49 pm
Sorry guys. That was me that mentioned Bennet early on in this post.
There are multiple people being talked about but they have different spelling. Jono and myself are referring to an Australian with the spelling of Bennett.
Every job is a self-portrait of the person who did it. Autograph your work with excellence.

Fuel flow requirements calculations viewtopic.php?f=5&t=1638

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