EFI TURBO 302 GMC

[SPARKY]

GH,  How many  injectors are you planning on using on your "JIMMY"?

[landracing]

Sparky,

I assume you are referring to a 6 cyl application, as I found this post
http://www.landracing.com/forum/index.php/topic,3528.0.html

GH, also curious what type of EFI unit will be controlling this... I happen to have a Great EFI system for sale that can control that can control 12 injectors plus a fair amount of data logging.

Jon

[Sumner]

Sparky,

I assume you are referring to a 6 cyl application, as I found this post
http://www.landracing.com/forum/index.php/topic,3528.0.html

GH, also curious what type of EFI unit will be controlling this... I happen to have a Great EFI system for sale that can control that can control 12 injectors plus a fair amount of data logging.

Jon

I'm about sure it will be MegaSquirt as that is what he is using on the Stude now and what he told me he was going to use, but he'll probably come on here sooner or later 

Jon do you have yours listed in the 4-sale area??  I think our web master has an area like that  8-) .

c ya,

Sum

[GH]

Sparky, Jon and Sumner, as Sumner said, I will use MegaSquirt, 2 injectors per intake port, 6 injectors total. Not sure on the size of injectors just yet. We are installing MegaSquirt on the #1950 green Buick for datalogging only as we speak.

[Sumner]

The most recent picture from Gary.................

............. and the man himself a couple years ago.

What is he driving (the car with the trunk open)??

c ya,

Sum

[panic]

           -

[Sumner]

Where are they being placed?

[panic]

.

[Sumner]

Thanks - I take it that's as close to the port as you can get them?
Not to un-ravel your work so far, but even though the port ID may not stand a big change, there's some argument in this case to use a port face contour scalloped away for injector body insertion like Honda, etc. here's one borrowed from Larry Widmer's site http://www.theoldone.com/:


This has several positive effects:
1. doesn't obstruct the area of the manifold or port as much since most of the injector is in the inletted section
2. may allow more choice of angle of attack of the injector discharge (more parallel to port align), since the body need not intrude as much
3. less induced bias or swirl due to flow striking exposed injector parts
4. probably not useful here due to turbo, but allows the injector to be closer to the valve - which means less atomization, between the injection point and the valve seat (any vaporized fuel displaces much more air in the charge than droplets). This is useful when the port efficiency isn't high.

Good info.  I've been reading more and more where some of the cars (I think like IRL, Formula 1??) are moving the injectors or maybe just a second set, can't remember, further up the runners.  In fact quite a long ways up the runners to try and help atomization.  I don't know if it has to do with the very high rpm's they are running and the velocity of the air charge vs. time to get the fuel atomized with the air so that you have a fully atomized charge in the combustion chamber or what.  I'll see if I can find one of the mentions of it.

c ya,

Sum

[maguromic]

Like Panic mentioned Larry Widmer knows his stuff.  I remember him working on the Boss 429 program for Bob Glidden and he was able to make monster Hp with that head.  My set up is very similar to this for my GMC. Actually took some of the ideas from my IRL motors.  When I am finished with it I will post some pictures.

[GH]

Sumner, the black car with the deck lid open is a 1958 Chevrolet delray 2 door sedan, 283 V-8, lowered with a tube grill, had that car when we got married in 1962. We were on our way to Mo-Kan dragway in Joplin MIssouri to race my Henry-J with an Olds 303 engine. That was the first race Sandy had been to.

[panic]

.

[SPARKY]

OK I will show my ignorance---what is a stipple---I take it to not be a stiff _ _ _ _ _ _.

[panic]

.

[ddahlgren]

Quoted..
This has several positive effects:
1. doesn't obstruct the area of the manifold or port as much since most of the injector is in the inletted section
2. may allow more choice of angle of attack of the injector discharge (more parallel to port align), since the body need not intrude as much
3. less induced bias or swirl due to flow striking exposed injector parts
4. probably not useful here due to turbo, but allows the injector to be closer to the valve - which means less atomization, between the injection point and the valve seat (any vaporized fuel displaces much more air in the charge than droplets). This is useful when the port efficiency isn't high.
End Quote...

In all due respect for someone elses opinion..
It works a lot more like this in real life or at least every efi engine I have tuned in the last 20 years...
If someone has dyno shets to prove otherwise I would love to see them.

1. A properly installed injector does not protrude into the port..
2. At WOT it does not really matter where you aim them Buick indy lights had them aiming away from the valve.. They ran just fine. Kinsler has a lot of them 90 degrees to the port they run just fine.. A lot of passenger cars aim them almost paralell to the port they run just fine... If the port is so lazy that it can not move one thirteenth of it's weight around you have a serious problem other than injector placement or angle. Do not lose track that it is air/fuel ratio by weight not volume...
3. See #1...
4. What?? A pound of fuel contains x atoms period... The heat of vaporization will cause cooling of the intake charge that will make more room available.... You do not want liquid fuel in any manifold if possible... As a side note any well developed racing engine has the injectors as far away as possible from the valve. They are put closer in passenger cars because they run closed loop. The added distance of moving the injector adds a delay and the loop is harder to keep closed and not hunt all over the place..

Dave