how much simpler do you want? even the filter/regulator is integral. Dead head is the more recent EPA mandated design so it doesnt return heated fuel from engine side. Corvette filter/regulator is about $75 on Ebay

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I didn' t buy it, I built it.....

Thanks for the info, Pishta. Looks very nice, efficient, and affordable!

Of course, you lose the cooling effect of the fuel through the rails, which could be a problem for some of us with thick exh manifolds near the injectors.

Best,

Lou

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Home of Slant6-powered fun machines since 1988

Interesting. Is this being adopted industry wide? It certainly makes the conversion to efi simpler. You still need a pump up stream from the filter. Is the filter the pressure regulator? Do not see how that happens here.

Sam

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I'm not up to speed on all the different variations. Most, if not all of the new(er) vehicles are single line fuel systems. Everything is in the tank, pump, filter, regulator. Some systems are using pulse width modulated fuel pumps to control volume/pressure.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

I am guessing that's not a direct injected application?


Greg

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http://www.youtube.com/hyperpack

That is correct. I really don't know anything about the direct injection systems, except what they are, and they run pressures that are unreal (over 1,000 psi).

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

DI uses pressures that are above 2000 psi. You need to inject the fuel very fast (open/close time) and stop the combustion gases from puking back into the injector/fuel stream. Very different designs needed.

Lou

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Home of Slant6-powered fun machines since 1988

There are two things to keep in mind that could be drawbacks:

1. It's easier to get vapor lock if you're not careful.

2. The filter / regulator unit can't raise fuel pressure in response to boost for forced induction builds, or lower it under manifold vacuum at idle.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Thanks for those points, Matt. I did not know about the second one (no pressure reference).

Lou

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Home of Slant6-powered fun machines since 1988

Since I perform auto repairs for a living, I guess I take some things for granted- (I thought everyone knew about stuff like this ). Mechanical returnless fuel supply systems for MPFI are "old" technology- been around for about 20 years now. The fuel pressure regulator is either built into the in-tank pump / filter assembly or is part of the external filter.

Electronic returnless systems are very common now (& at around 15 years aren't that "new" either). The engine computer reads fuel rail pressure from a sensor & controls a PWM fuel pump to achieve the desired pressure.

There are a few reasons why OEM's went to returnless designs. It lowers fuel temps in the tank (since there is no return line from the hot engine) so HC loading of the EVAP emissions system is reduced. The electronic sytems reduce the electrical current draw some so alternator loading is slightly less & fuel pump should last longer. And no more ruptured regulator diaphrams to leak gas into the intake.

For most cars you don't need to reference the rail pressure to intake manifold pressure. Using a vac referenced regulator makes the pressure drop across the injector "constant" - this makes the math easy when you're programming the fuel map into the engine computer. The engineers now take MAP (or MAF) readings into consideration when figuring out the best injector on-times with fixed rail pressure, (&/or rail pressure targets on electronic fuel systems).

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63 Valiant Wagon
225 - 4 bbl