New part some might be interested in

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
26
38
64
Norco CA
www.mcratracing.com
i see were your going with this...;)


haveing a 3/8 line charged @ 12psi will flow less then a 1/2" line with came charge if the valve open time is the same


pluss the bigger line has more fluid wantitng to go through the said hole

weather or not it make more power or not... it does make current power level easier...

Wait.

The fuel flow is dictated only by the RPM of the CP3's when the truck is sitting still. Flow itself does not change unless you are starving the pump and drawing against a vacuum. At low throttle, 90% of the fuel goes back into the tank, and 10% goes into the rails. At high throttle, 90% goes into the rails, and 10% goes back into the tank. But the supply flow doesn't change.

What is important is pressure. When we launch these trucks, you must push the fuel "uphill" against acceleration. If you don't have enough "push" you start to draw against a vacuum and decrease flow.

Now, which one weighs more? A column of fuel 6' high that is 3/8" dia, or one that is 3/4" dia? It takes a bigger pump to resist the acceleration force if the fuel weight is higher.
 

MAXLLY

No Lemming Here
Aug 15, 2007
1,063
0
0
San Diego
Wait.

The fuel flow is dictated only by the RPM of the CP3's when the truck is sitting still. Flow itself does not change unless you are starving the pump and drawing against a vacuum. At low throttle, 90% of the fuel goes back into the tank, and 10% goes into the rails. At high throttle, 90% goes into the rails, and 10% goes back into the tank. But the supply flow doesn't change.

What is important is pressure. When we launch these trucks, you must push the fuel "uphill" against acceleration. If you don't have enough "push" you start to draw against a vacuum and decrease flow.

Now, which one weighs more? A column of fuel 6' high that is 3/8" dia, or one that is 3/4" dia? It takes a bigger pump to resist the acceleration force if the fuel weight is higher.

Right on Pat, makes sense to me. I think its a necesary evil though.:)

The only caveat (in my simple mind) is the new CP3's are pushing more fuel into the truck for big tunes and injectors, we should feed them with more no? When they (CP3) switch to 90% into the rail they are pushing... whats the current add for the Wicked pump you run? 40% more fuel? I need to give it what it wants/needs to maintain the add 40%, more fuel right?

If we don't then i assume we can feed (2) wicked stroker pumps offering 40% more, in the same 3/8" line that used to feed (1) stocker?

BTW- the FASS can take a washer to kick the pressure up a little to compensate for some head pressure. So could the Edelbrock no?

The fueling requirments are going to continue to increase as the pumps, injectors and air increase.
 

MAXLLY

No Lemming Here
Aug 15, 2007
1,063
0
0
San Diego
I just thought of an analogy.

I have (2) 5 gallon buckets, 50 gallons of water in a drum over each bucket... i poke one 3/8" hole for the first bucket and a 3/4" hole for the second bucket. I get more water from the 3/4" hole. Especially if i only open the hole for a moment and a millisecond later i open it again.

So each time that stroked/bigger plunger takes a slice of fuel from the big line it gets all it wants or needs. No recovery or a partial bite, its there.

Small details for sure, but they all add up.:D
 

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
26
38
64
Norco CA
www.mcratracing.com
Seems some testing is in order. What I do know currently, is that with a stock supply system + 1792 lift pump, the furthest dual CP3's can pull it down is about 6 psi. Would bigger lines increase it? Would more pressure make more power? I honestly don't know.
 

MAXLLY

No Lemming Here
Aug 15, 2007
1,063
0
0
San Diego
Cool Pat, nice to think about it with you.

When i have something to test.... I'll gladly put forth some info.
 

malibu795

misspeelleerr
Apr 28, 2007
8,133
478
83
42
in the buckeye state
I just thought of an analogy.

I have (2) 5 gallon buckets, 50 gallons of water in a drum over each bucket... i poke one 3/8" hole for the first bucket and a 3/4" hole for the second bucket. I get more water from the 3/4" hole. Especially if i only open the hole for a moment and a millisecond later i open it again.

So each time that stroked/bigger plunger takes a slice of fuel from the big line it gets all it wants or needs. No recovery or a partial bite, its there.

Small details for sure, but they all add up.:D

and less chance of foaming at said pump... this is what i was aiming for....


foaming in the tank is another problem in and of itself...

also electric pumps hate sucking fuel... they just plain suck at sucking fuel. thus putting a bigger suction line help them preform better. and i would think same principle would help the cp3 as well
 

malibu795

misspeelleerr
Apr 28, 2007
8,133
478
83
42
in the buckeye state
Wait.

The fuel flow is dictated only by the RPM of the CP3's when the truck is sitting still. Flow itself does not change unless you are starving the pump and drawing against a vacuum. At low throttle, 90% of the fuel goes back into the tank, and 10% goes into the rails. At high throttle, 90% goes into the rails, and 10% goes back into the tank. But the supply flow doesn't change.

What is important is pressure. When we launch these trucks, you must push the fuel "uphill" against acceleration. If you don't have enough "push" you start to draw against a vacuum and decrease flow.

Now, which one weighs more? A column of fuel 6' high that is 3/8" dia, or one that is 3/4" dia? It takes a bigger pump to resist the acceleration force if the fuel weight is higher.

i see your point.. in a stock tank style pick you are fighitng roughly 3' of verticle lift from the bottom of the tank to the cp3.

one could say i have gone to a sump style tank... if fact i do.. the pick-up is ~1" above my bed floor with ~60 gallons on top of that. doing so i have cut the suction head by some 30"

as for the accelerating forces dotn know if it helps or not...
 

McRat

Diesel Hotrodder
Aug 2, 2006
11,249
26
38
64
Norco CA
www.mcratracing.com
On a 1.91 sixty foot time, you are exerting over 1 g forward acceleration. That is just like your truck being at a 45° in the air. So the "lift" required is closer to 6 or 8 feet.
 

MAXLLY

No Lemming Here
Aug 15, 2007
1,063
0
0
San Diego
and less chance of foaming at said pump... this is what i was aiming for....


foaming in the tank is another problem in and of itself...

also electric pumps hate sucking fuel... they just plain suck at sucking fuel. thus putting a bigger suction line help them preform better. and i would think same principle would help the cp3 as well

Doesn't air need be present or space for air, for foam to present itself? So i am on the same page with you, are you talking about foam at the back of the CP3 or at lift pump inlet/tank?

You must mean the lift pump side? Isn't air/foam lighter than diesel fuel and therfore flaoting on top? With pickups at the bottom, assuming decent fuel level, we never suck air right? We have some entrained air but the FASS filters get most of that no?
 

malibu795

misspeelleerr
Apr 28, 2007
8,133
478
83
42
in the buckeye state
Doesn't air need be present or space for air, for foam to present itself? So i am on the same page with you, are you talking about foam at the back of the CP3 or at lift pump inlet/tank?

You must mean the lift pump side? Isn't air/foam lighter than diesel fuel and therfore flaoting on top? With pickups at the bottom, assuming decent fuel level, we never suck air right? We have some entrained air but the FASS filters get most of that no?

"air" does not need to be "present" to foam... there is oxygen in fuel. put enough vacuum on it and it will apper... weather that be that be for a short tenth of a sec or longer...

and on both cp3 and lift pump suction sides. it is less llikely to foam at the cp3 inlet with a positive head pressure there... but posible.

IMO opinion i would rather have 6 psi of fuel pressure on a 3/4" line then a 3/8" in the simmilar example pat gave. the fuel will naturally want to fill a small cavitiy faster then the smaller line.

if you watch a vlv open and shut with fluid medium flowing through it in slow motion there is a wave/wedge that flows in a the said space that it is connecting too... not a solid cylinder of fluid. and i am sure there is "dead" fuel in the plungers of the cp3...much like there is "dead air" in and engine..... like any pump it is not 100% effcient...

one of the many reason when mounting a pump of any type it is sugjested to mount as close to the bottom of the tank as possible it make the pump the most effcient as possible. weather that be a lift pump ona vehicle or a well pump for ground water... or transfer pump on a tank.


did i make sense on that?
 

MAXLLY

No Lemming Here
Aug 15, 2007
1,063
0
0
San Diego
"air" does not need to be "present" to foam... there is oxygen in fuel. put enough vacuum on it and it will apper... weather that be that be for a short tenth of a sec or longer...

and on both cp3 and lift pump suction sides. it is less llikely to foam at the cp3 inlet with a positive head pressure there... but posible.

IMO opinion i would rather have 6 psi of fuel pressure on a 3/4" line then a 3/8" in the simmilar example pat gave. the fuel will naturally want to fill a small cavitiy faster then the smaller line.

if you watch a vlv open and shut with fluid medium flowing through it in slow motion there is a wave/wedge that flows in a the said space that it is connecting too... not a solid cylinder of fluid. and i am sure there is "dead" fuel in the plungers of the cp3...much like there is "dead air" in and engine..... like any pump it is not 100% effcient...

one of the many reason when mounting a pump of any type it is sugjested to mount as close to the bottom of the tank as possible it make the pump the most effcient as possible. weather that be a lift pump ona vehicle or a well pump for ground water... or transfer pump on a tank.


did i make sense on that?

Absofreakinlutley crystal :D

Thank you. I love this place.
 

JOHNBOY

< Rocking the Big Single!
Aug 30, 2006
2,159
0
0
Saegertown, Pa
Do you own the lates you run? Didn't think so.

Yes...he has lathes in his shop.

To the original point you made though....do you really need a perfect finish on something that's going on the bottom of a truck ?
OOR....are you just shooting your mouth off over her like normal instead of over there where the guy you're talking crap about will see it ?
I run lathes owned by another for a living. Do I own a Lathe? Yes sure do and some other machine tools. My point was that part far from the quality that I have come to see from Hellman. I commented here because you posted here. I post just as much on your site as I do here.

You obviously don't know Joe or his history in this sport. Most people in diesel motorsports just WISH they had his reputation or abilities.
He takes more pride in everything he does than anyone I know.
I do know. That is why I was suprised to see that.
This is the post I read as bashing Joe. Of course like I said...he doesn't have the balls to post that on CompD. Her has to hide here and bash stuff from our site like he always does.

At least I come to y'alls house when I have something to say about any of y'all.

Are you daring me now????? You should know better. Being your so worried about my man parts I will say that I have two young sons and another one on the way. Medical proof my package is just fine. You make it sound like all I do is bash stuff on CompD. What else have I bashed? The truth is my comment struck a nerve with you. Why? Two reasons. One you have a good deal of respect for the work Joe has(as do I). Two I was not afraid to confront you on your site. http://www.competitiondiesel.com/forums/showthread.php?t=40376 I am just as helpful on your site as I am here. I post tech and help out there to. I like your site. I have learned a good deal from it and its members. I have no problems with the website. The problems between you and me are personal. If you want to end this give me a call. Check your PMs you will find my number.D



I will reply to this later this morning. Do to a death of a loved one and a very sick pregeant wife I have not been on much. Sorry Rich I have had far better things to do. You better call Ms Cleo back because the info you have on me is very wrong. ;)

I will not be apologizing.

Reply in red added after I got home.
 
Last edited:

UNBROKEN

New member
Mar 30, 2008
565
0
0
I run lathes owned by another for a living. Do I own a Lathe? Yes sure do and some other machine tools. My point was that part far from the quality that I have come to see from Hellman. I commented here because you posted here. I post just as much on your site as I do here.

I do know. That is why I was suprised to see that.


Are you daring me now????? You should know better. Being your so worried about my man parts I will say that I have two young sons and another one on the way. Medical proof my package is just fine. You make it sound like all I do is bash stuff on CompD. What else have I bashed? The truth is my comment struck a nerve with you. Why? Two reasons. One you have a good deal of respect for the work Joe has(as do I). Two I was not afraid to confront you on your site. http://www.competitiondiesel.com/forums/showthread.php?t=40376 I am just as helpful on your site as I am here. I post tech and help out there to. I like your site. I have learned a good deal from it and its members. I have no problems with the website. The problems between you and me are personal. If you want to end this give me a call. Check your PMs you will find my number.D



I will reply to this later this morning. Do to a death of a loved one and a very sick pregeant wife I have not been on much. Sorry Rich I have had far better things to do. You better call Ms Cleo back because the info you have on me is very wrong. ;)

I will not be apologizing.

Reply in red added after I got home.


If I read it wrong I'll be the first to apologize.
Fair enough ?
 

Burn Down

Hotrodder
Sep 14, 2008
7,092
28
48
Boise Idaho
I was just thinking about the bigger feed line idea. Doesn't the 1792 flow 160gph @ x psi? If casper has twin wickeds & can still hold 6 psi @ wot, I Don't see were your gaining anything with bigger lines. If the factory fuel line and modded pickup was a restriction it would have no pressure. Just my thoughts, let me know if I'm missing something.
 

Dura-Ration

You Shoulda GotA Diesel
Jun 20, 2008
128
0
0
66
Escatawpa, Ms.
x2

I was just thinking about the bigger feed line idea. Doesn't the 1792 flow 160gph @ x psi? If casper has twin wickeds & can still hold 6 psi @ wot, I Don't see were your gaining anything with bigger lines. If the factory fuel line and modded pickup was a restriction it would have no pressure. Just my thoughts, let me know if I'm missing something.

Yeah, why modify what works for one CP3 when the Stock draw straw works for two Wicked CP3's. Save time & money for something else.
Steve
 

sweetdiesel

That's better
Aug 6, 2006
10,390
0
0
52
Thailand
Pat are you saying that if someone was to put say 1" line from the tank to the cp3 with a like size pickup within the tank, it would do no good? Reason I ask is, I thought Simon once said he had large line(7/8" or 1") and was planning on doing the same.

Thanks

I have a 10 gal fuel cell! I need big lines for more volume between fill ups:joker:


Im thinking though with higher volumes and circulating pressures that we would see higher fuel temps:( Unless you account for this with better cooling.
 

slowlmm

New member
Mar 2, 2008
2,582
0
0
45
so cal
I have a 10 gal fuel cell! I need big lines for more volume between fill ups:joker:


Im thinking though with higher volumes and circulating pressures that we would see higher fuel temps:( Unless you account for this with better cooling.



Thats wht i was wondering as well. Right now with my dual cp3s stock lines and lift pump i dont see temps over 120F and i belive 120-150 is the sweet spot. .?
 

MAXLLY

No Lemming Here
Aug 15, 2007
1,063
0
0
San Diego
I was just thinking about the bigger feed line idea. Doesn't the 1792 flow 160gph @ x psi? If casper has twin wickeds & can still hold 6 psi @ wot, I Don't see were your gaining anything with bigger lines. If the factory fuel line and modded pickup was a restriction it would have no pressure. Just my thoughts, let me know if I'm missing something.

I am modding the back of my CP3's to accept a larger fitting. Currently we have a 1/4" feed line into the back of the pump, purdy easy to increase that to 5/16" ID. I wanted to know what happens when you increase line size and bump up the feed fitting to jive... ie Feeding the CP3 with a 3/4" line and have a 3/4" feed fitting into the CP3 as well. Will this not allow more fuel at less pressure? Does not a larger body of liquid lose less pressure when purged that a smaller body of liquid? I spose.

It may be a waste of time, but i wanna try. I agree, feeding 3/4" worth of fuel into a 1/4" nipple is kinda silly, feeding 3/4" into a 3/4" fitting at the back of the pump is kinda silly as well, unless you mod the back of the pump to take advantage of it.

The mod needs some support to be viable. I'm just farting around with it. We won't know for sure until somebody tries it.:) We made the fittings (still need a 14mm thread) I just need to finish it up.:rolleyes: