EFI straight eight Buick

[4sfed]

4s fed, what are your thoughts on multiple -squirts per engine cycle?   (not sure if you've read all the megamanual) but one thing that might help us here is, since this engine only runs to ~5000rpm, we have enough time to get "2 squirts" per cycle. 

I wouldn't expect the timing or number of "squirts" to make much difference as long as the A/F ratio comes out right.  When VW came out with the first production EFI we installed one of them on a six cylinder Opel engine . . . just adding an additional injector to each driver (two drivers) for a total of 6 injectors . . . no change in injector timing.  There was only a 1% improvement in hp when we finally built a three-driver system and timed the pulses 240° apart instead of 180°.

or it's possible we could just feed all the fuel upstream of the blower, since the manifold is a wet design anyways.

comments/thoughts? 

You can always inject upstream, but manifolding will play a more important part in even fuel distribution.  I'll look for you guys next year. 

Jim

[Buickguy3]

Gary Hart, The Salt Cat is on the same road. It should be ready for road testing in about three weeks.[The red-neck chassis dyno]. We'll let you know how it went after the test.[Or when I get out of jail]. By then we should have snow to simulate the salt.

[GH]

Buickguy3, you said you are on the same road. Did you mean you were injecting fuel in the intake ports like we are talking about?

[Buickguy3]

Yes, At this point we are leaving the ports siamesed and using two injectors close to the cyl. head. We understand the problems, but will reserve modifications to the manifold and electronics until we run it and see what problems we encounter. There's a lot of Budweiser engineering to be done this Winter. [I hear it's going to be long and cold]. Good luck with your project, it sounds like you have some engineering to do also. DG.

[GH]

JD Tone, are you reading any of this? Have you mechanically injected any of your JIMMY 6s, by injecting directly into the ports, near the head?

[Buickguy3]

GH, Not mechanically injected. We are using TEC3R system.

[dieselgeek]

I think we have a fix if it becomes necessary.  We'll definitely report our progress!

[RichFox]

I mechanicaly injected my Plymouth 4 near and far from the ports. ran 113.75 with the long tube big plenum intake, ran 113.75 with the short intake. The plugs looked pretty much the same all the way through. #1 exhaust valve would start leaking first so I guess it was running leaner.

[jimmy six]

GH, I have run mechanical injectors with my stock head. Because of "theory" I choose not to stay with them on gasoline. On the GMC cylinders 3 and 4 are the only 2 with even pulses between firings ie: the fuel "puddles" the same amount of time between those 2. The others 1, 2, 5, & 6  all have either more or less pulses between firings. In theory with a constant flow mechanical injection this mean you have 2 cylinders lean, 2 cylinders rich and 2 cylinders with the correct mixture. Odds are not good enough for me I still need all 6.

This can be masked with multiple nozzles and butterflies and is currently being done with quite a bit of success by a few racers just not yet by me.

The Buick is far worse in my opinion for constant flow mechanical fuel injection. Just look back at the message with the firing order and you will see what I mean. The shared intakes are separated by 1 pulse, then by 6. A lot of flowing fuel to puddle while 6 other cylinders fire.

I run vintage classes only so EFI is not an option. If it ever becomes one on vintage engines you won't see me any more. I kinda like Pro Stock and Nascar for these reasons.

I personally believe the placement of the nozzle on injected engine is dictated by the type of fuel. Methanol and nitro low and gasoline higher.  EFI seems to be low on all my modern cars.....Good Luck

[GH]

Here goes, I shrunk a photo of the Buick engine in question.

[GH]

Here is a photo of the aluminum rods that are used in the straight 8 Buick. I just learned how to make photos small enough to post on here.

[Milwaukee Midget]

Looks like a pretty stout con-rod.  Does this monster have 9 main bearings?  The reason I ask is that I'm wondering why you're limiting your RPM to ~5000.  Cast crank?  Head design?

Chris

[Stan Back]

Could it be the 10-inch rod?

[Buickguy3]

Don't know about GH's rod, but we stretched ours to 9 inchs so that we could shorten up the 4 ring piston. As a result, we took 1 pound 3 ounces off of each throw. The crank is forged. Hope the attachments come through. DG

[GH]

Doug, our rods are actually 8.875" long, center to center, Venolia had them made for us in 1999, we think GRP made them.