Engine/Transmission (1994 - 1998) Various Plate characteristics

[DPinkston]

I know there has been lots of questions and answers about the various plates available. TST has a chart that gives HP and torque numbers for their plates, but from what I understand there are more differences between the plates than just their power potential. Differences mainly in where they fuel heavily or where they defuel (if they defuel at all). I thought defueling was a function of the governor. Am I understanding this correctly? Is there any comprehensive spreadsheet comparing these characteristics? I am going to eventually plate my 180 pump and I was considering a #8, but everyone seems to favor the #10. Just trying to make an informed decision.

Danny

 

[bmoeller]

You've pretty much got it figured out. There is an arm that part of the governor, and it hits the plate. It moves up and down the plate, following the profile of the plate. The more to the rear of the pump the arm moves, then less fuel is delivered.



You can see it in this cut-away below-



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[TMitch]

I asked the same question about fueling characteristics in a different thread yesterday with no answer yet. I understand the power potential as listed in the TST site etc but I am more interested in the particular fuelling characteristics of the various plates and how the forward/back adjustment of the plate affects the fuelling characteristics of each particular plate. It may be obvious to most people but I need a little help to understand these things. I guess if I had a picture of each plate then I could probably interpolate (big word!!) what I am trying to figure out but I don't.

Further to bmoeller's excellent picture, then is it correct to assume amount of fuel delivered at any particular time is directly related to engine rpm and the position of the arm along the profile of the plate? And thus the profile depth controls volume of fuel at a particular rpm? So what I really want is a verbal description of the profiles of the different plates.

Merry Christmas

Terry

 

[LandShark]

Maybe this will help.





Stock plate from 1995 auto trans.

 

[LandShark]

Tracing of plates. OEM is from 1995 Auto, #6 is from PIers.

 

[Cummins4Life]

Home ground from a stocker.



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[DPinkston]

So is the lower part of the plate for low rpm and the upper portion for upper rpms, or does it work that way? Is it true that a profile allowing the arm to move farther forward (in the direction of the front of the engine) provides more fuel?

Danny

 

[Cummins4Life]

Yes the farther up the plate you go the higher the RPM, the farther forward the arm travels the more fuel.

 

[Forrest]

#4 & a stock plate

 

[DPinkston]

So the different profiles provide more fuel or less fuel at different rpms. That was the crux of my original question. Is there a chart that tells you where in the rpm range that a particular plate will really be fueling, or do you just have to visually compare the profiles and take a guess? When the governor starts cutting back the fuel does the arm travel back down the plate until rpms decrease? What keeps the arm from hanging on the sharp corners that some of the plates have? I have read that certain plates increase the upper rpm EGTs while others do not. I would assume that these are the ones that provide a lot of fuel at the top. It seems that there are several factors that must be considered when choosing a plate. One is the engines ability to add enough air to control EGTs, another would be the intended purpose of the truck. An aggressive plate may work fine in a truck used primarily as transportation or a toy, while use of the same plate in a truck used for heavy towing would produce excessive EGTs unless more or cooler air can be introduced.

Yeah, lots of questions. Just trying to get a good understanding on all of this.

Danny

 

[Cooker]

It is correct that the farther forward (toward the front of the engine) that the arm moves the greater the fuel delivery but the movement of the rocker is not directly proportional to RPM. The rocker is affected by the load of the engine as well. It could provide maximum fueling at 3000 RPM's or is could provide little to no additional fueling at 3000RPM's (such as reving up the truck in neutral or easily strolling easily down a street in 1st gear). Also on this same note the arm could travel up and down on the plate at the same RPM's (such as coming to a hill while maintaing close to the same RPM's the rocker will provide additional fueling due to the increase load even though there may have been little if any increase in RPM's).



You are correct that some plates are better for hotrodding and some are better for towing. The #10 is a good towing plate because it cuts back on the upper end fueling so towing heavy up a hill it would be better than a #4 (assuming you are a bit short on air), but some guys dislike the #10 for performance reasons because they don't want the fueling to be cut back on the upper end.



Clear as mud right

 

[Forrest Nearing]

Home ground from a stocker.



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good lookin' plate...



see my photo gallery to see my home ground plate

 

[blkdragon]

So if you ground a stock plate from the top notch all the way down would you get all the fuel possible at all the RPM's while still not sacrificing pump safety?

 

[Forrest Nearing]

you could probably grind it deeper, but flat w/ the top puts out quite a bit of fuel... I think the AFC arm is my stop right now... I've slid my plate back a little, and I'm still seeing the same boost/EGT.



Forrest

 

[BPonci]

Forrest that doesn't look like a #4 plate compaired to the ones i have seen or the one i have. What brand is that. Looks more like a #6.

 

[Forrest Nearing]

the 6 and 4 look similar, but I don't think a 6 goes in that deep as it comes off the nose...



Forrest

 

[BPonci]

The #4 that i have from tst looks to have less nose area and cuts in deeper with no defuel on top.

 

[Jim Fulmer]

It's not a #4 or a #6 TST unless they have changed the design since I have had both and still use the 6.



Jim

 

[Cooker]

Here is my $. 02



It is not a #6 or a #5, although the nose looks very similar to a #5. I don't have a pic of the #4 I had but it does resemble it????



BPonci do you have a pic of a #4?

 

[Forrest]

#4 & a stock plate

The #4 @ it deepest point is deeper than the #0, but comes back to a little less than a #0.