Lil Dog

I was over at the TDR yesterday and found that Ol Smokey is up to his tricks again...LOL<br><br>He has been working on another design for the fuel delivery pin with a re-worked cone design. Something similar to the design of the fuel plates in the P7100 pumps. We will wait to see what his results are for his rig. <br><br>I am thinking this will be sensitive to the type of mods you have done. Interesting none the less.<br><br>FYI <br><br>J-eh

Lil Dog

This post should be in the 12V section I would guess..OOPS.. :-[ :-[<br><br>Anyway here is the post..TDR - Fuel delivery pin design.<br><br>J-eh

Monty

This should be very interesting. Lots of things have been coming out of the woodwork for the VE pumps. A year ago 300 hp was what everyone thought the limit of this pump was. We know now that is not true. Keep up the good work guys. ;D

Old Smoky

I will let you guys know how this turns out. I might even be making one or two extras, if anyone is interested. <br><br>Mike <br>

Alec

I have been thinking about this ever since I max'd my AFC eccentric.<br><br>There are two modifications that I think should be made to the AFC:<br><br>1) the depth of the notch in the eccentric can be increased to allow for more maximum fuel delivery.<br><br>2) The shape of the notch (cone as stock) and the stiffness of the spring can be tuned to allow for a different fuel to manifold pressure curve.<br><br>One big problem with the AFC as stock is that it only operates over a range of about 4 to 6 psi. E.G.: you can set it so that it takes 2psi of boost before the diaphram starts to move, but at around 8 psi you have maximum fuel delivery; if 4psi is the minuimum, then 10psi is maximum. If you turn in the stop screw in the top cover then you limit its operating range even more. Stock, my truck was set so that fueling was not increased until about 4 psi and boost maxed out at about 12 psi, so the operating range of the AFC was pretty adequate, but now I want to control fueling from 2psi all the way up to 20 psi.<br><br>The psi range over which the pin actually travels is determined by the diaphram size, the pin (eccentric) length, and the constant (stiffness) of the spring (how much force it takes to compress the spring a certain amount). Adjusting the &quot;Star wheel&quot; only changes the pre-load on the spring, not its constant. (That is how you set the point at which increased fueling starts, by determining how much manifold pressure is required to start moving the eccentric.)<br><br>I would like to see a stiffer spring and an eccentric with a steeper slope. This would allow one to set the pump up so the stop pin (the little sliding pin) was all the way in with no boost, and at maximum extension at say 15-20 psi. The adjusting screw could then be used to set the no boost fueling to your smoke tolerance levels, and as boost increased, the AFC would continue adding more fuel over most of the pressure range.<br><br>As of yet, I haven't taken any precise measurements, or calculated what I think the appropriate eccentric shape or spring constant should be. (Though stock both the eccentric shape and spring constant are linear).

Old Smoky

These are some good thoughts, asilitch. My pin will have a slightly &quot;steeper&quot; slope, and allow for maximum fuel delivery. There was some discussing on spring tension, preload, etc, on the TDR with myself and a few others a while back. That is about as far as it went, though. I don’t think anyone experimented with different springs, that I know of.<br><br>Do you think controlling the fueling is really necessary up to 20psi? With my setup, the smoke is gone way before that. I guess that depends on intake, exhaust, timing and turbo, too. It will be even better after I finish the hybrid turbo I am working on today. Keep the ideas coming. <br><br>Mike<br>

Alec

&quot;. . .up to 20psi? With my setup, the smoke is gone way before that.&quot;<br><br>Which means that, EGT's aside, you could be burning more fuel with all of that air. That is what I was trying to describe with the operating range idea. At 2psi I want more fueling than at 0, at 20 psi I want more fuel than at 10psi. But with the stock set up I can either have the same fuel from 0 to 14 psi (obviously not a good idea) or the same fueling from 8 psi on up.<br><br>So currently I smoke too much below about 3psi, and could be giving her more fuel at 10psi.<br><br>With a stiffer spring and steeper cam, I could inject less fuel at 0psi and more fuel at 20psi. I could also set up the pump so that both the AFC AND the &quot;power screw&quot; adjustments were maximized. Currently I have excessive smoke at 0psi, and I haven't even touched the screw.<br><br>Let me know what you think,<br><br>Alec<br>

Old Smoky

I don’t think it sounds like a bad idea. You might even learn something new by experimenting with it. If you do the mods that your signature shows you are planning on doing, your smoke issues/EGT's will be significantly reduced. <br><br>I think what you mean by maximizing the power screw is that you would have acceptable power, smoke, EGT's, etc. I just want to be sure you don’t mean cranking it all of the way in. From what I have heard, chances are if you do that your engine will run away on you.<br><br>Let us know how it turns out.<br><br>Mike<br>

Old Smoky

Here it is:





I forgot to install the stud into the top before taking the pictures. Though the cut may look curved, it is liner. I haven’t had a chance to test it yet as I am working on my hybrid turbo. I will make sure my modified stock pin and the new fuel pin produce the same #'s. Testing should be done in about a week. They will be available at that time for $85, which includes instructions with pictures. This increases power from low through high range, and can be fine-tuned with the star wheel and smoke screw adjustments if necessary. Fueling at 0 boost will be the same. I would be happy to answer any questions.

Mike

Monty

Mike, I added the first pic into your post for you. Here is the side pic.

Old Smoky

Thanks. I just got posting pics on the TDR all figured out. I guess I’m not doing so well over here. : <br><br>Mike