hows a hot screw work?

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hows a hot screw work?

Postby Joecochrane » Sat Jan 18, 2014 11:06 am

Curious about a hot screw will the longer screw allow more fuel without runaway? Right now my pump is about a quarter turn away from run away. So if I can get a lil more out of a hot screw than sign me up.
The driver 02 2500 ho 6 speed 2wd lil lift 35s edge cts hot some injectors and a fass

The toy 87 f350 39.5 tires 180 bus motor 727 trans maxed pump ground pin bumped timing 366 spring hx35 and a lot more in the works.
Joecochrane
fuel screw!!!!
 
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Re: hows a hot screw work?

Postby CumminsPower59 » Sat Jan 18, 2014 11:33 am

No. You are just about there already. A longer fuel screw works well with some of the 184 and 205 pumps, as many won't hit run away with normal mods. I found this to be the case with a NOS 205 pump I ran for a bit. Got to be careful with the longer screw, as damage to the fulcrum lever might happen.
Ike

91 W350 SRW, 3.07's, NV4500, 370's, THD LPPP, Super HX40, 2nd gen IC swap, BHAF, Isspro's, 2" lift, 285's on 3rd gen 17"'s.
04 VW Jetta Wagon TDI 5speed
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Re: hows a hot screw work?

Postby RCCUMMINS89 » Sat Jan 18, 2014 12:51 pm

The longer fuel screw (hot screw) is not beneficial on pumps that can hit runaway. As stated above... IT IS ALSO LONG ENOUGH THAT FULCRUM LEVER DAMAGE CAN OCCUR. It was made this way, because there are a very few pumps out there that you can modify the fulcrum lever slightly and turn the screw in further. But again.... every pump is different and one really needs to know and understand runaway and its affects before installing the longer screw.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
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Re: hows a hot screw work?

Postby Joecochrane » Sat Jan 18, 2014 1:25 pm

I took my pump to runaway and the brought it back untill the throttle stoped hanging up when I would lift. I'm less than a quarter turn from runaway so I guess I won't be buying a hot screw.
The driver 02 2500 ho 6 speed 2wd lil lift 35s edge cts hot some injectors and a fass

The toy 87 f350 39.5 tires 180 bus motor 727 trans maxed pump ground pin bumped timing 366 spring hx35 and a lot more in the works.
Joecochrane
fuel screw!!!!
 
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Joined: Thu Jan 16, 2014 9:21 am
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Re: hows a hot screw work?

Postby RCCUMMINS89 » Sat Jan 18, 2014 1:39 pm

Nope, no need to.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
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Re: hows a hot screw work?

Postby Sutter1stgen » Sat Jan 18, 2014 9:16 pm

Joecochrane wrote:I took my pump to runaway and the brought it back untill the throttle stoped hanging up when I would lift. I'm less than a quarter turn from runaway so I guess I won't be buying a hot screw.

How high did you free rev the engine to see if it would or wouldn't get runaway. I found that revving it up to 2-2500 rpm wold not induce a runaway condition. But when I Dyno my truck I run it till it defuels or just about. So I made sure to rev my truck up to about 3k with a board ready. It took about 1.5 turns out more than I had it originally set at, before it was safe.
Not saying yours isn't safe, but just some things I noticed when messing around.
Eric

91'w250 with a new pump. This one doesn't chase itself around in a circle.
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Re: hows a hot screw work?

Postby Joecochrane » Sat Jan 18, 2014 9:40 pm

Probably only about 1500 I better look into that. Thanks
The driver 02 2500 ho 6 speed 2wd lil lift 35s edge cts hot some injectors and a fass

The toy 87 f350 39.5 tires 180 bus motor 727 trans maxed pump ground pin bumped timing 366 spring hx35 and a lot more in the works.
Joecochrane
fuel screw!!!!
 
Posts: 69
Joined: Thu Jan 16, 2014 9:21 am
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Re: hows a hot screw work?

Postby lineman » Sun Feb 02, 2014 1:38 pm

CumminsPower59 wrote:No. You are just about there already. A longer fuel screw works well with some of the 184 and 205 pumps, as many won't hit run away with normal mods. I found this to be the case with a NOS 205 pump I ran for a bit. Got to be careful with the longer screw, as damage to the fulcrum lever might happen.


Where are the pump numbers located? I screwed fuel screw in all the way till it bottomed no run away. How do I make sure I don't damage fulcrum lever with the longer screw?
93 w250 A518 4x4 white new to me
lineman
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Re: hows a hot screw work?

Postby RCCUMMINS89 » Sun Feb 02, 2014 1:40 pm

You can't damage the fulcrum lever with a factory screw. If you have a longer screw, and then it feels like it bottoms out.... it is a good possibility that the fulcrum lever is touching the afc top.
89 RC on shortened 92 diesel frame - NV4500 w/dual disc/4.10s on 37s. - Self built pump, "hot screw", lots of timing, True high volume low pressure lift pump, 62fmw/68/.7gated, 77lpm SAC Inj., Studs/O-rings,- 423/1220 Mustang - 11/16/2013 http://www.TheHungryDiesel.com full line dealer, if you don't see it please ask.
RCCUMMINS89
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Re: hows a hot screw work?

Postby CumminsPower59 » Sun Feb 02, 2014 1:52 pm

lineman wrote:
CumminsPower59 wrote:No. You are just about there already. A longer fuel screw works well with some of the 184 and 205 pumps, as many won't hit run away with normal mods. I found this to be the case with a NOS 205 pump I ran for a bit. Got to be careful with the longer screw, as damage to the fulcrum lever might happen.


Where are the pump numbers located? I screwed fuel screw in all the way till it bottomed no run away. How do I make sure I don't damage fulcrum lever with the longer screw?


On the side of the pump that faces the left fender. There is a bunch of numbers, one is the part number and the last three digits usually tell what it is.
Ike

91 W350 SRW, 3.07's, NV4500, 370's, THD LPPP, Super HX40, 2nd gen IC swap, BHAF, Isspro's, 2" lift, 285's on 3rd gen 17"'s.
04 VW Jetta Wagon TDI 5speed
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Re: hows a hot screw work?

Postby lineman » Sun Feb 02, 2014 3:01 pm

RCCUMMINS89 wrote:You can't damage the fulcrum lever with a factory screw. If you have a longer screw, and then it feels like it bottoms out.... it is a good possibility that the fulcrum lever is touching the afc top.


Ok got ya on that you would go by feel.
93 w250 A518 4x4 white new to me
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