adding CAC to existing dt466 motor

[444-4D]

Originally Posted by LMJD

Right, what's that saying, a guy with experience beats a guy with a theory every time?

I'd be surprised if experience wins every time, but it may. Theories are good foundations for new experiences. Or maybe experiences are a good foundation for a theory, you decide. However, there probably needs to be some defining of theory and experience. Use this comment as an example. "With intercooler, ambient temps will have minimal effect on EGTs."
Is this experience or theory.

[hemivolvo]

i totally agree with experiance over thery. i have proved with my first milage test im getting equall to or better than what i got before, WHY efficiancy, an engine thats efficiant will out do one thats lugging and not up to its potential. a guy that got a caculator for christmas wont come up with the same result as a guy that has 40 yrs exp working with engines, period. i still am wondering how the ''ideal gas law'' was going to help me ,I could do the math --figure out my increase in air flow mathamaticaly-- and end up just turning the screw to increase fuel with out a mathamatical formula to know HOW much fuel to increase. i still just depened on expereiance and gauges to get it right.
i am still a little in the dark [because of lack of experiance ] on how ambiant temp will affect my EGT, to me stands to reason that 50 degree vs 100 degree temp will cause EGT to go up, ill wait and see . the fact remains i have a GAUGE and now have the experiance to adj according to results this summer when temps go up.
this has been a wonderful time of learning for me, i am a VERY technaical guy and feed off USEFULL information, not so much thery and maybes. FACTS are whats important.
I wont get my test this weekend as the weather has gone to, well you know, its 36 deg tonite and suppose to rain and snow locally, but be sure first chance i get im gonna hit the road for a 300 mile test.
thanks for ALL the input and ill post results SOON

[drcampbell]

Engines don't "lug".

"Lugging" is a result of the driveline behaving like a ~10Hz tuning fork.

If you put an engine on a dynamometer, you can put the pedal to the metal at 900 rev/min without any "lugging". Why? Because the driveshaft on a dyno is much shorter and stiffer than one on a vehicle; it doesn't resonate at 900 rev/min and it's the vehicle's driveline, not the engine, which initiates "lugging".

Lugging should be avoided because it can break just about every component in the powertrain, but running at low rpms and high torque settings is where gas and Diesel engines are the most fuel efficient, not the least.

- - -

If you run the same speed, you will get the same mileage. (see my earlier post on the topic)
If you take advantage of the extra power now available and run 14% faster, you will burn 40% more fuel per hour and 23% more fuel per mile.

I just thought you'd be happy to know that your work has resulted in 40% more power being available. Bragging rights and all that.

It has nothing to do with engine efficiency. It has to do with that fact that a faster-moving vehicle needs more power to overcome aerodynamic drag, and the fact that engines consume more fuel in order to develop more power.

- - -

Did these facts come from theory or experience? Both. First, we get experiential data from road, dyno and wind tunnel tests. Then we compile the data and develop a hypothesis to try to explain the data. When we get a good enough hypothesis which not only explains all the data on hand, but also accurately predicts the results of future tests, then that hypothesis graduates to a theory.

Too many people use the word "theory" when they really mean "hypothesis". (or just as often, "clueless guess" or "wild speculation with no basis whatsoever") But in science and engineering, a theory is a robust thing.

[LMJD]

"With intercooler, ambient temps will have minimal effect on EGTs."
Is this experience or theory.

Experience. Anyone who's ever driven truck knows that whether 0 degrees winter or 110 in the summer, EGT rises at the same rate and reaches the same max temp on the same grade pulling the same load. My post was meant to agree with you and compliment Evel486. His posts always reflect knowledge from experience, not just repeating crap whether right or wrong that's been picked up from a forum or theory invented while behind a desk.

"Lugging" is a result of the driveline behaving like a ~60Hz tuning fork.

Case in point, any mechanic who's spent years replacing scored liners and pistons due to lugging would be highly amused to finally learn it's caused by or defined by a tuning fork driveline.

[Evel486]

Wow, I really opened a can of worms with my comment about ambient temps & egt's.
I didn't say it has no effect, I said it was minimal. Hemivolvo will be able to tell all about power increase, egt's & fuel economy when he has some 'experience' under his belt. Proof will be in the pudding.
Hemivolvo asked what time it was. I said it was 6ish. I didn't tell him how to build a watch.

[hemivolvo]

thanks for the help evel486 for a while there i needed to know
''what time it was''
now i think i can keep track on it. i have a good handle on it now thanks again

[hemivolvo]

hey evil486 havent had time to make an extended milage test ,,,,but thinking about your earler post i DO have white smoke on cold start up seems to be a little worse now you mentioned timing on the pump might help,,,, what do you suggest? im off to mexico for 4 wks soon so cant deal with it now but id love some info for the spring, ive looked it would be tight but do have room to adj timing if it would give me any advantage, ive been told smoke on cold start is some what nornmal.. thanks for any input

[Evel486]

Adjusting the timing is rather easy on these engines. Remove the cover plate from the pump drive. The gear is slotted- 3 bolts IIRC. The correct way to set timing is remove the top side cover of the pump & you'll see a pointer. Rotate the engine by hand until a mark lines up with it. Then I believe on the balancer there will be degree marks & a pointer. Loosen the pump gear bolts and rotate the engine until the desired timing. Should be stamped on an engine tag somewhere. If not, set to 20 deg btc.
This is all from foggy memory- it's been many years since I've done it this way. Now I use a diesel timing light.
White smoke when cold on an older engine is normal but it should clear up quickly. Even if you simply advanced the timing a few degrees it might help. Do as above except don't worry about the pump marks. Just set the balancer at an easy to read mark, loosen the gear bolts and back the engine up 2 deg and tighten the gear bolts.

[Skidlyman]

Originally Posted by Evel486

Your minimal boost increase on the third try may be due to the fulcrum lever now hitting on the max speed screw. I would suggest at the very least you adjust your max speed screw to get 3100 rpm with no load. This will insure you get full fuel at 2600 rpm & will probably feel much better driving.

so I was told on another site how to get more fuel out of this pump and ended up backing out the droop screw instead of the maximum fuel screw on the very top. it did raise the rpms and seems like an increase in power but after looking at the exploded view decided to put droop screw back where it started and back out maximum fuel screw. then i set hi idle to 3100 does this sound correct ?

Now I want to set timing to 19 btc but can't find the timing marks on pump. any help would be appreciated . pictures and drawings REALLY HELP me. thanks

[Skidlyman]

anyone help me here ?

[hemivolvo]

sorry i havent gotten back till now been gone for 35 days salmon are in been fishing.. home for a week or so then off for BIG trout.....
a quick note to evil486 boy am i happy all the power i EVER expected and between 8 to 9 mpg. thank you for your input could have never done it with out help
as to skiddys post sounds like your on right track max idle up then max fuel till you get temp up,,,, do you have an egt gauge? if not better get one or you could melt down
as for timing on the pump rotate engine till out side mark on crank is at 19 before tdc remove plug on side ofpump look for mark inside if id does not line up loosen pump and rotate till mark lines up then tightn pump down,,,, find some safty info on correct procedure as in fuel shut off so it dont start wnen you crank it over
do you have turbo or cac do you have early ambac pump?
good luck