07:20:46pm, Thursday, April 18, 2024
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Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
There have been several attempts to introduce entry level diesel classes at a local level with restrictions on injection pump type, turbocharger, tires etc. Inevitably the class rules escalate to allow the use of better pumps, better turbochargers, better tires etc. The one idea I haven't seen is to limit fuel flow with an orifice on the inlet to the injection pump. A properly sized orifice would limit the amount of fuel available to the pump regardless of the supply pressure, this is called choke flow and would be a hard limit for fuel flow. The orifice could be purchased as a "pill" by the association and changed at every pull, or be safety wired in place or be changed randomly by officials.
Ok tell me why this wouldn't work. Rich |
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Re: Fuel Flow Limit
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Registered: 03/31/2008 Posts: 762 |
From Wikipedia
Choked flow in liquids If the fluid is a liquid, a different type of limiting condition (also known as choked flow) occurs when the Venturi effect acting on the liquid flow through the restriction causes a decrease of the liquid pressure beyond the restriction to below that of the liquid's vapor pressure at the prevailing liquid temperature. At that point, the liquid will partially flash into bubbles of vapor and the subsequent collapse of the bubbles causes cavitation. Cavitation is quite noisy and can be sufficiently violent to physically damage valves, pipes and associated equipment. In effect, the vapor bubble formation in the restriction prevents the flow from increasing any further. I don't think we want the diesel cavitating before it enters the injection pump. The principal you are talking about works better for compressible fluids (air) and is one of the ideas Doug Roberts had for the SSD class. If you read Wikipedia though, choked flow of air doesn't occur thru a nozzle until the downstream pressure is 53% of the upstream pressure. That would be equivalent to the turbo pulling a vacuum of 7 psi on the restrictor which seems pretty high to me. It would definitely limit HP, but there would probably be performance to be gained by turbo wheels designed to pull more vacuum. |
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Re: Fuel Flow Limit
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Just my 2 cents
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I'm not very smart. However I do not think 7 psi in what I would consider a vacuum. |
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Re: Fuel Flow Limit
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xxx
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come on boiz,please give some slack,he means even with some pressure on the lesser side it will be a "VACUUM EFFECT" with such a restriction,think a little before we all comment like the brain is dead. |
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Re: Fuel Flow Limit
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Just my 2 cents
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My brain is not dead. Deere puller said "turbo pulling a vacuum of 7 psi" And 7 psi is not a vacuum. Vacuum is measured in inches, microns, torr. Not psi. |
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Re: Fuel Flow Limit
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Chewie
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Your statement proves the proposed restriction would work. You may not like how it works but it would work. Don't want cavitation? Don't try to use more fuel than the orifice will pass with out causing cavitation. Funny how that limit works |
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Re: Fuel Flow Limit
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how about this
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How about instead of another failed bandaid fix we fix the real problem. The op mentioned rules being put in place to limit something only to be changed shortly thereafter to allow a part which increases cost and power, traction, etc. Would it possibly be more intelligent to enforce and stick to the rules instead of constantly changing them? Will adding another limiting rule not be subject to change? ie adding an orifice size rule then voting in a larger orifice. How about people understand and abide by the rules of competition and if those don't satisfy the competitors hunger for power or what have you he/she can move up to the next class.
Enough with the bandaids, history has proven they don't stick for long 
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
The idea was to have a "limiting" function that could be easily monitored, similar to the RPM chips that are used with ignition systems. |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
The point about cavitation is a good one, I will have to give that some thought, pressure drop through the orifice might cause air to come out of solution or create a pressure below the vapor pressure of the fuel. |
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Re: Fuel Flow Limit
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Registered: 03/17/2019 Posts: 65 |
Just limit plunger size |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
That is an approach, unfortunately the only way to know plunger size is to disassemble the pump. |
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Re: Fuel Flow Limit
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Registered: 03/19/2018 Posts: 662 |
Restriction "pills" are a regular part of turbo alky setups and have been for decades. Surely any cavitation issues would be known about by now?
CP |
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Re: Fuel Flow Limit
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Just Another Nobody
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DO they work similar to the "pills" on an Ederle injection system? If so, aren't they a restriction on the return fuel back to the tank, that only flows once the pump makes enough pressure to open the check valve? Kinda their only method of tuning? Maybe the restriction could be just to limit line size? Say on the charge pump inlet? |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
On the charge pump or supply pump might be a good approach, it should help reduce the cavitation issue. |
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Re: Fuel Flow Limit
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Ken
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If you want to limit a class on fuel, why not just mandate a factory sealed pump by 1 supplier. |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
Different engines use different pumps and making everyone change their engines to use the same pump would be prohibitive, in my opinion anyways. |
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Re: Fuel Flow Limit
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Enforce rules
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Yall are way over thinking this. If they would just stick to strict turbo limits and strict cubic inch limits. The fuel issue would be resolved on it's own. A given sized turbo in and out will limit the amount of fuel an engine can burn. Then you dont chance causing problems with fuel pumps and injectors because of starvation and cavitation. I like what ntpa did with turbo restrictions on the light pro class. That is a step in the right direction. They probably will still have problems holding them together at over 3000 hp with stock blocks. But at least they are trying to put reasonable limits on these beasts. |
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Re: Fuel Flow Limit
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Agreed
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I agree with the strict turbo control. A perfect example is the Super farms. Look at how these 640 ci engines are limited because of the turbo rule. I'm not saying that you cannot find more power with them however the 3x3 turbo has really been a true limiting factor that has slowed down the rate of hp gains over the last few years as opposed to the gains experienced in the light pro class with no turbo restrictions until now. Just saying that it appears the best and easiest way to place Performance limits on a puller is to limit the airflow by turbo restrictions. |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
Turbo rules and limits are fine, but those are routinely defeated and end up with expensive hybrid turbos. |
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Re: Fuel Flow Limit
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Registered: 03/17/2019 Posts: 65 |
Why are you so afraid of pump plunger limits make the consequences of cheating suvire enough that if you are caught twice your out period. Why are we so scared of enforcing a decent set of rules |
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Re: Fuel Flow Limit
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Agreed
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Not afraid of enforcement of the rules. I'm all for good rules. The reason the turbo rules are defeated in rcps words are because the turbo rules are too grey in many organizations. That's why some are clarifying the rules better to help eliminate these issues. As for plunger size, it's not as easy to check as a turbo check, besides I for one wouldn't want to have the top of my pump pulled open in a field environment. If the turbos are properly enforced then again the fuel side will take care of itself. You can only put so much fuel to a given amount of air. Anything above and beyond you are going the wrong way. Keep the rules simple a d clearly spelled out then enforce them and a lot of problems will go away. Not saying that all problems will disappear but many will. Too many rules are never a good thing, because it just adds more items for tech crews to have to monitor therefore a greater chance of something getting missed. |
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Re: Fuel Flow Limit
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Registered: 03/17/2019 Posts: 65 |
If plunger size is relatively unimportant as you suggest why do most super farms want to run bigger pumps a 13 will provide more than enough fuel for that class. They want to shorten duration of delivery we keep coming back to cost of equipment and the falling numbers of tractors is it so difficult to see. If you don't have as much fuel to burn you can only go so far. These smaller classes need to stay smaller classes so the average puller can still pull |
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Re: Fuel Flow Limit
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Registered: 12/01/2018 Posts: 108 |
Trim state super field class has box 3lm rule. They are tore apart, and inspected before season. Also have a claimer rule on the turbos. You can only burn so much fuel, so fast with very limited air. |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
The advantage to the orifice method on fuel is the simplicity of enforcement, no measuring required, pick a pill from the tub and put it inline with the fuel supply, no muss no fuss. |
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Re: Fuel Flow Limit
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Agreed
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I never said larger plungers didnt matter. I said if you limit the air and cubes. You can only burn so much fuel. R Hall understands exactly what I was talking about. Try putting a 16 mm pump on that stock, boxed 3lm, let us know how that works out. I think a good rotary will run as good, most likely better than a over sized pump. Also the claimer will keep people from putting a lot into a pump. You can buy used and reman p pumps on Ebay all day for under 1500 bucks. Have a 1500 dollar claimer on the injection pumps. I guarantee you if anyone can buy anyone else pump for 1500 dollars there is no one gonna spend big money on a big money pump. One other thing I think if someone claims a pump or turbo, they should have to forfeit their pump or turbo to whomever they claimed the parts from. This will keep people from frivolous or nuisance claims. Also if you don't allow water injection, that will deter big fuel as well. As for the orfice or pill I've never heard of such a thing as a fuel control device. Especially in the diesel world. I think it is a bad idea. Just my opinion. |
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Re: Fuel Flow Limit
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Registered: 10/30/2018 Posts: 749 |
PUT A CLAIM ON THE ENGINE I've been pulling 35 years and never seen anything inforced clubs leave everything up to a protest which should not be all vehicles should be checked once and random there after and actually checked rules are know better than the paper they are wrote on if not enforced .And nobody wants to be the Ass who protest something |
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Re: Fuel Flow Limit
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Agreed
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I agree with Lewis too on enforcement of the rules. However we are missing the big picture here. Many are worried about someone getting an advantage over someone else. I do believe in good rules and standards to be followed and enforced. However, if we are so worried about a puller getting an advantage over the others then why not do what someone else said in a post way back. Why dont we all just show up and pull the same tractor like they do in pedal pulls. This would prevent anyone from getting Something figured out that others haven't thought of yet. We all have the same machine to compete with. Same tractor from top to bottom. But wait that wouldn't work either because someone would complain about this or that. Why cant we just have some good old fashioned competition like what competition used to be. Fords against the Chevrolet and Dodge . John deere against Allis Chalmers and Ford and IH. I think like Lewis and 5488. I think power plants should match brand of sheet metal no matter what color. |
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Re: Fuel Flow Limit
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shut up
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Why not just claim the whole damn tractor? And let's make it a $50 claim rule while we're at it......you make no sense at all Lewis. What the hell good is a claim rule anyways? If you believe it to be "illegal", then what good does claiming do you? You still can't run it either. Stupidest rule idea ever. |
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Re: Fuel Flow Limit
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Not how it works
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Claims have nothing to do with being illegal, |
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Re: Fuel Flow Limit
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Missing the point
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Shut up you are missing the point. The claimer rule is to prevent someone from spending big money on parts to compete. Which in turn keeps the class in check and affordable for the average person. That's what it is for. If one gets caught cheating he should be thrown out. But it someone puts 10k in a pump and turbo and someone claims it for 1500, he is out alot of money. See how it works? |
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Re: Fuel Flow Limit
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Registered: 10/30/2018 Posts: 749 |
SHUTT UPP lots of racing has claims be stuppid and spend lots on your crap if i can't use it your broke can't pull any more and if it's illigal your exsposed and .i DONT HAVE TO TAKE IT that's how it works.S0 NOW WHAT O YOU HAVE TO SAY |
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Re: Fuel Flow Limit
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Registered: 01/23/2011 Posts: 241 |
Claim rules have been tried in local motorsports, but it doesn't work there, either the guy refuses to agree to the claim in which case he is baned from further competitions with that group. Another approach is to have something no one else wants, why would an IH guy want an Oliver engine or a fuel pump that work on his engine? |
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Re: Fuel Flow Limit
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Registered: 10/30/2018 Posts: 749 |
Didn't think of SOME OF that RCP GOOD POI NT |
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Re: Fuel Flow Limit
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Registered: 07/11/2008 Posts: 326 |
I"m afraid you would end up with the same issue..
You will have to limit the charge pressure also. 15psi is going to flow a lot less than 700 psi.. I think you will just end up with really high charge pressures to try to compensate, which cause pump issues and or special pumps to be built. It is a simple idea. |
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