Random Questions . . . .

[BC847]

Hey folks. I've been tinkering here and there under the hood and wonder if any of you know:

- Where one could find an economical source of a pull-cable (ideally push/pull) that has a round knob or T-handle (threaded/removable so as to allow passing through a mounting hole. RE: Dash) on one end.
And a threaded metal sleeve holding a 1/4" pin on the other end. The threaded sleeve would mount through a plate. The 1/4" pin would need to move about 1/2" at the most. The cable would need to reach from the dash right there at your left knee, to over at the engine air filter plumbing.

- A means of indexing the throttle shaft with a working range that's slightly shorter than a regular 3200rpm governor spring would have. I'm overshooting peak throttle pull put to the mechanism downstream of the gov spring. I'm not sure how to go about it other than a dyno or ET. I can't tell by the seat-of-the-pants gauge anymore.

- How are you dealing with hot fuel at the drag-strip? You run as little fuel in the tank to keep the weight down, but with repeated runs and cool-down time, the fuel gets hot. I'm trying to sort-out a historic issue of my mess having it's best pass of the day, being the first pass.
After each pass, I allow my mess to idle long enough for not only the EGTs to drop, but also the transmission fluid temp (by way of a fan assisted auxiliary cooler). In my mess, 100*F warmer trans fluid temp adds .1 second to an 8th mile pass. I can change nothing and with very consistent engine and transmission temps, I can have an ET drift up to a quarter of a second. Ambient air temps and humidity don't alter this issue.
> One night recently, during a cool-down after a pass, I put my hand on the fuel pressure regulator and Daggum! That boy was just this side of HOT!
Could my ET drift issue be as simple as dropping fuel density? I've thought about cooling the fuel by pulling the plug on the fuel heater on top of the filter. It only recently dawned on me that thing runs all the time . . . ? I've also thought about getting a power steering fluid cooler from a bigger car or truck and install it in the fuel circuit somewhere. What'cha reckon?

- What about a under-hood mounted enclosure for a bunch of electronics (Head light relays, cab heat/AC blower relays, fuses replacing fuse links, cool-down timer, master gauge controller and other stuff). Perhaps as big as a standard shoe box or so. All the stuff mounted on a plate with the wiring underneath. The box would only need to be rainproof (dripping from the hood) and would be mounted where the grid heater relays currently reside.


Stuff like that.

[lectro_static]

I would look into morse cable for your cable, both ends are threaded and then you can get the handle from about anywhere if you look at some of the sandrail stuff they have a long rod that has holes thru it for throttle pedal adjustment.

Cooling your fuel, if I recall correctly you have a couple write ups on another board and have upgraded your fuel system alot. Have you thought about running a "cool can" on your return line that would cool the fuel before it goes back to the tank keeping the temp lower, or run it just before the pressure regulator that would cool both into the motor and keep the fuel in the tank at a lower temp. They claim there is no loss of volume or pressure thru them but with a regulator even if there is you can turn it up.

Hope my novel made some kind of sense and helps you out abit

[PToombs]

You should be able to get a cable at most any auto parts store. Usually you have to feed the cable from the dash out because the handle is fixed. Unless you get a PTO cable, but they are large and heavy.
As for fuel heat, I just looked in the FSM, and the heater is on all the time! Just unplug it, should work better then.
For cooling, maybe you can rig a cool can with ice to run the fuel line thru or put around a filter on the way to the IP. That should cool it off. Or you can add a trans cooler or something like that where the air can hit it.
The regulator is what's making the heat, because it's running past a relief valve and getting compressed on the way.

[Richie O]

I know my quickest run was mid day. It was sunny and hot then a cloud bank came by and cooled down about 10 degrees. The next runs were in the sun and the time went back up. I was told by someone that warmer fuel actually gains volume. I would assume that to mean that as the fuel warms it must contain more air.???

[BC847]

I know my quickest run was mid day. It was sunny and hot then a cloud bank came by and cooled down about 10 degrees. The next runs were in the sun and the time went back up. I was told by someone that warmer fuel actually gains volume. I would assume that to mean that as the fuel warms it must contain more air.???

Let me show you what warm and cool air do for my heap at the 1/4 mile track . . ..

At 70*F:




And at 50*F:




These two passes are at the same track, a week in between. Nothing was changed on the truck.

- Notice with the warmer 70* air (thinner air), I got a good 1/4 mile ET and trap speed.
- Notice though with the cooler air (thicker air), the 1/8 mile was notably improved but the 1/4 ET and speed was much slower.

I think the warmer, thinner air let the truck aerodynamically move faster. The cool, thicker air made more power (as shown by the 1/8 mile data), but slowed the truck in the 1/4. I never got the truck above 100mph that day.

The regulator is what's making the heat, because it's running past a relief valve and getting compressed on the way.

I think it's more of the Walbro electric fuel pump and the IP itself that are heating the fuel.

- I don't believe the regulator's contributing to the heat. If there were any compression of the fuel prior to the IP, it'd be by way of the lift-pump, however subtle. If the fuel were in fact compressed, passing through the regulator would have the fuel expand and cool as it moved to the lower pressure side (standard "change of state" physics stuff).

[Ace]

Pic of fuel cooler plumbed into the return line:

http://stuff.is-a-geek.net/PhotoAlbum/1 ... TD_228.jpg

[Mark Nixon]

I was told by someone that warmer fuel actually gains volume. I would assume that to mean that as the fuel warms it must contain more air.???

No, in a perfect world, there is no air in diesel fuel.

It's like this, as a liquid warms or cools, it changes density.
Warmer makes it less dense, thereby it grows, or expands, once it cools, it contracts, or condenses.
Cooler fuel is denser, like cooler air is, when taken in at it's coolest possible temperature, say 40 degrees, then is subjected to heat ,say 400 degrees +, it then expands at a higher exponential rate than fuel (or air) at, say, 80 degrees would.

A good way to see this effect in action is heat a pan on the stove for a minute or so, then drop a small amount of room temperature vegteable oil on the pan and watch how it appears to puddle up, then spread out as it gets to the pan's temperature.
You'll also notice that it appears more "runny", or less viscous, this is due to heat expansion.
Cool it down quickly and it becomes denser, more viscous, and it contracts.

This is also how some truck stops make extra money on diesel fuel in summer, they have been known to intentionally sell what is called "hot fuel", as it changes volume and fools the metering devices on the pumps.

Mark.

[AHineman]

http://www.jegs.com/p/JEGS/JEGS-Push-Pull-Cables-and-Accessories/763983/10002/-1

I bought a 4' push/pull cable from Jegs for my fuel shut off. I used a clamp/shim on each end and a stainless swivel to attach it to my pump. I got the knob for the end at Lowe's for cheap. The cable is pretty stiff though, so it may not work for you if it has to be snaked though a really tight area.

Just a thought with your throttle problem...If its rotating too far couldn't you adjust the high idle screw (or reinstall it) to keep it from over rotating. This may be too coarse of an adjustment for what you're doing, but if your throttle is indexed to idle fine, and you can go past full throttle, it could be a free throttle stop.

[BC847]

Thanks for the input folks.

[AHineman]

Do you have room for a battery box? One of those would fit the bill for your electronics enclosure.

[GO OVRIT]

I cut a factory fuse and relay box out of a Dodge neon to use in my Jeep. It takes a little time with a multi meter tracing wires, but it made a clean job. I had relays for all my kc lights, fuel pump, ignition, cooling fans, and had a couple left over. I didn't do any research to find a better box, so you might find just what you need. And its already water resistant.

[fatty]

Your transmission/torque convertor could be slipping causing your first pass to be the fastest..

[BC847]

Your transmission/torque convertor could be slipping causing your first pass to be the fastest..

The torque converter is of the non lock-up type meaning, it slips.

If the trans were slipping, it'd be toast by now! LOL!

It's been freezing or raining big-time. I havent done crap.

[dpuckett]

Daivd- I have noticed the same thing regarding thinner air and performance. When I lived in Colorado, I always got 2mpg better in whatever truck I had than I did here at sea level. I figure the lesser aerodynamic drag offset the less dense air.

[BC847]

It's my understanding that it's pretty-well established that everybody's MPG goes down in the winter due to the cold denser air.

Speaking of denser air, I'm fixing to replace the HX35-Hybrid (secondary) with a 62/65/14 S300. Even with the big IC and cam, the EGTs are still a little on the hot/smokey side at the top of the 1/4. I'm hoping it'll gain a little more power with more air.

We'll see.