Singleport batch fire or sequential firing

[Billyisgr8]

So if I could weld on the head and get the injectors to be right behind the valve in the short port ( not much room at all and maybe possible), do you think this would work if fired as regular sequential? cause then the fuel would be injected very close to the valve, and not be pulled into the other port. Not really wanting to do a TBI the more I think about it, and am just trying to come up with something also other than sequential siamese. So if there is not enough room to fit an injector behind the valve, what about having the injector up out of the way, with a short tube from injector tip to area behind the valve so all fuel would travel maybe down a short 1 1/2" - 2" long piece and then come out behind the valve? That would have to be about the limit cause of the injector spray pattern is then too wide. But then that also depends on spray pattern, I have seen some very narrow spray patterns on certain fuel injectors, can't remember what they are called though.

Kevin

[miniman82]

Why TF would you weld on the head, just to get this to work? Put DP heads on it, FFS!


You're nuking this, you really are. I said it once, I'll say it again: CIS and SS are your only 2 options. There are no if's, and's or but's about it, if you have siamese ports, you will experience charge robbing period. So either get DP heads and do MPFI like the rest of use, or be happy with the carb.

[Piledriver]

There is ONE way he could do it and have it work ~perfectly, but I haven't seen any GDI kits yet...
(This is something I'd love to play with)

[miniman82]

You aren't the only one waiting for that...

I can't wait to run 14:1 compression on pump gas.

[mschilling]

I guess we'll have to wait until direct injection is more common, aren't those injectors hundreds of dollars each?

[miniman82]

Not only that, but they are technically still 'under developement'. The OEMs (GM in particular) took a big leap with putting GDI in their production engines, because it's still a relatively new technology and no one really knows how well the injectors will fair in terms of how long they will last. I'm gonna give it at least another 10 years for them to work out any bugs before I try it myself, so there will be no surprises. That will also give the aftermarket time to catch up, so a viable controller will become available to drive them- which is the biggest problem we have right now keeping us from doing it with the stuff currently on the shelves.

[raygreenwood]

Not only that, but they are technically still 'under developement'. The OEMs (GM in particular) took a big leap with putting GDI in their production engines, because it's still a relatively new technology and no one really knows how well the injectors will fair in terms of how long they will last. I'm gonna give it at least another 10 years for them to work out any bugs before I try it myself, so there will be no surprises. That will also give the aftermarket time to catch up, so a viable controller will become available to drive them- which is the biggest problem we have right now keeping us from doing it with the stuff currently on the shelves.

Shoot....the jury is still out on the pistons (those with comustion chambers in them like for the direct injection diesels) and for teh entire fuel system longevity with the pressures they run.

By the way...since you are mentioning direct injection...a tangential question if you please: has anyone ever seen a picture of the high pressure direct injection that Bosch ran on the Mercedes and Junkers inverted 12 cylinders in WW II? Not the fuel distributor and hose system...but the actual injectors and ports? I have never actually seen those parts. I understand they actually injected through the side of the top portion of the cylinder wall and not the heads. Not to steal the thread...but just wondering. Ray

[Billyisgr8]

Your right Mini, why waste my time...I have a knack for allways trying to overthink something. SS will probably be the way I go. Will see how the winter plays out with extra time.

Kevin

[Alexander_Monday]

Sorry, stupid idea that I see why it wouldnt work.

.

[K-Roc]

Kevin, On a draw through Turbo setup like yours is setup now, or like Dilleys, the fuel being sucked through the Turbo Vaporizes and actually drops your intake charge Temperature quite a bit. ( that's why Dilley can run 28 Lbs boost with no intercooler )

If you do switch to EFI with the injectors at or near the heads be sure to put an intercooler on it or you will actually make less power.

Cheers.

[Piledriver]

Not only that, but they are technically still 'under developement'. The OEMs (GM in particular) took a big leap with putting GDI in their production engines, because it's still a relatively new technology and no one really knows how well the injectors will fair in terms of how long they will last. I'm gonna give it at least another 10 years for them to work out any bugs before I try it myself, so there will be no surprises. That will also give the aftermarket time to catch up, so a viable controller will become available to drive them- which is the biggest problem we have right now keeping us from doing it with the stuff currently on the shelves.

Shoot....the jury is still out on the pistons (those with comustion chambers in them like for the direct injection diesels) and for teh entire fuel system longevity with the pressures they run.

By the way...since you are mentioning direct injection...a tangential question if you please: has anyone ever seen a picture of the high pressure direct injection that Bosch ran on the Mercedes and Junkers inverted 12 cylinders in WW II? Not the fuel distributor and hose system...but the actual injectors and ports? I have never actually seen those parts. I understand they actually injected through the side of the top portion of the cylinder wall and not the heads. Not to steal the thread...but just wondering. Ray

To add to the off-topicness...

GDI covers a lot of ground.. there's more than one way to do it.

There are/were GDI kits--- for 2 cycles ... basically for scooters, using low pressure compressed (~400 PSI) air systems.

I forget who invented them, but later version of the system it was (is?) used on production BOAT engines. (Yamaha/Mercruiser or such)

Given the existence of compressed air powered cars, the thought of tapping a little of that air for a GDI setup is a no brainer.

The high pressure type of system GM etc are trying to use (capable of multiple very finely timed/sized squirts to shape each combustion phase even) is new.
(similar to common rail diesel)

The low pressure compressed air systems can pre-emulsify the fuel, which IS an advantage vs. conventional port FI, less of an advantage when the newer DI systems provide really tiny droplets--- Low pressure or at least air driven probably the way to go if you are rolling your own.

Ray:

The Deutsches Museum in Munchen is your kind of place if you ever get over there... Might have some info on their website? They had cut ways of all sorts of stuff, including an actual ME-262 with a cut away engine on one side. The actual cross section of an 747 (or airbus?) fusealage is pretty neat too. (Not a scale model, think really, really big band saw)

Also, from Wikipedia---"The first automotive direct injection system used to run on gasoline was developed by Bosch, and was introduced by Goliath and Gutbrod in 1952. The 1955 Mercedes-Benz 300SL, the first sports car to use fuel injection,[citation needed] used direct injection. The Bosch fuel injectors were placed into the bores on the cylinder wall used by the spark plugs in other Mercedes-Benz six-cylinder engines (the spark plugs were relocated to the cylinder head)."

Complete page on GDI at Wikipedia:
http://en.wikipedia.org/wiki/Gasoline_direct_injection

[Billyisgr8]

The reason for wanting to possibly try FI is so I can drive to the tracks which are at 4300 and 1000 feet without having to re-tune especially going up to the high elevation track and the loooong hill climb. The 2 closest tracks are 2 1/2 and 3 1/2 hours away. The one disadvantage is an intercooler forsure....more plumbing, but there are pros and cons for a race/street car . I still have a holley 600 here which driving to the track would only be on the front 2 barrels, so could jet the fronts for street driving, and use the adjust ajet on the rear with a tuned vacuum spring so I only have to turn the screw for fuel adjustment, might not be that simple, but sounds good.

Lots of planning if I want to go this FI route, may just try the holley first, then FI.

Darren, I can't imagine if I ran 28 psi boost what kind of a number I would run, thats 10 more psi boost. That would put me very close to a 128+ mph run.

Kevin

[miniman82]

IMO, 3300 ft is not enough to matter at all. I've made 9000 ft changes without changing a jet, though it does start to run rich up that high. And BTW if it's altitude adjustment you're worried about, you'd need Megasquirt with the dual map sensor mod and real time baro correction.

[Piledriver]

IMO, 3300 ft is not enough to matter at all. I've made 9000 ft changes without changing a jet, though it does start to run rich up that high. And BTW if it's altitude adjustment you're worried about, you'd need Megasquirt with the dual map sensor mod and real time baro correction.

Or just turn it off for a moment, and it will reset the baro reference.
(Hey, I built it into mine, but it's just as likely to be used for fan housing pressure balance testing or turbo backpressure as baro...depending on how I set it up that day)

[raygreenwood]

Not only that, but they are technically still 'under developement'. The OEMs (GM in particular) took a big leap with putting GDI in their production engines, because it's still a relatively new technology and no one really knows how well the injectors will fair in terms of how long they will last. I'm gonna give it at least another 10 years for them to work out any bugs before I try it myself, so there will be no surprises. That will also give the aftermarket time to catch up, so a viable controller will become available to drive them- which is the biggest problem we have right now keeping us from doing it with the stuff currently on the shelves.

Shoot....the jury is still out on the pistons (those with comustion chambers in them like for the direct injection diesels) and for teh entire fuel system longevity with the pressures they run.

By the way...since you are mentioning direct injection...a tangential question if you please: has anyone ever seen a picture of the high pressure direct injection that Bosch ran on the Mercedes and Junkers inverted 12 cylinders in WW II? Not the fuel distributor and hose system...but the actual injectors and ports? I have never actually seen those parts. I understand they actually injected through the side of the top portion of the cylinder wall and not the heads. Not to steal the thread...but just wondering. Ray

To add to the off-topicness...

GDI covers a lot of ground.. there's more than one way to do it.

There are/were GDI kits--- for 2 cycles ... basically for scooters, using low pressure compressed (~400 PSI) air systems.

I forget who invented them, but later version of the system it was (is?) used on production BOAT engines. (Yamaha/Mercruiser or such)

Given the existence of compressed air powered cars, the thought of tapping a little of that air for a GDI setup is a no brainer.

The high pressure type of system GM etc are trying to use (capable of multiple very finely timed/sized squirts to shape each combustion phase even) is new.
(similar to common rail diesel)

The low pressure compressed air systems can pre-emulsify the fuel, which IS an advantage vs. conventional port FI, less of an advantage when the newer DI systems provide really tiny droplets--- Low pressure or at least air driven probably the way to go if you are rolling your own.

Ray:

The Deutsches Museum in Munchen is your kind of place if you ever get over there... Might have some info on their website? They had cut ways of all sorts of stuff, including an actual ME-262 with a cut away engine on one side. The actual cross section of an 747 (or airbus?) fusealage is pretty neat too. (Not a scale model, think really, really big band saw)

Also, from Wikipedia---"The first automotive direct injection system used to run on gasoline was developed by Bosch, and was introduced by Goliath and Gutbrod in 1952. The 1955 Mercedes-Benz 300SL, the first sports car to use fuel injection,[citation needed] used direct injection. The Bosch fuel injectors were placed into the bores on the cylinder wall used by the spark plugs in other Mercedes-Benz six-cylinder engines (the spark plugs were relocated to the cylinder head)."

Complete page on GDI at Wikipedia:
http://en.wikipedia.org/wiki/Gasoline_direct_injection

Thanks Piledriver.....yes...oddly enough I just found a cutaway pic of a DB 605 on wiki. With a bit of magnification and looking at several other drawings I believe the injectors either were in place of the plug holes you see on the outside moving injectors inboard...or were in the same pocket. Either way they injected into the cylinder side wall at the top...just in front of the intake valves at about 1100 psi. Still an amazing engine. Cylinder liners screwed into the head from the inside and locked by knurled rings. 3 compression rings and two oil control rings...one down on the skirt below the pin.
http://upload.wikimedia.org/wikipedia/c ... utaway.jpg

Dude...if you don't love watching this...someone stole your balls! turn up the volume!

http://www.youtube.com/watch?v=4ZzvKCQwWj0
Ray