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Harmonics

WarWagon

Well it hits on 7 of 8...
Messages
8,471
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3,043
Location
AZ
#41
Don' get me wrong. Yes we can have quick trucks, but quick is the key word. And I should not have said shit power but comparing it to a modern diesel like my buddies 6.7l with moderate work. Yea it's depressing .
Realistically how much power can one make with the ds4 pump. I know most people who go for power switch to mechanical injection.
:sorry: Clearly I hit too hard with attempting to point out you don't have to put up with GM's screw ups for power on the 6.5TD because others don't. You are not wrong for the OEM setup, but, we have era specific larger OEM power numbers than a 12v Cummins. Sure others are easier to turn up, but, the gloves come off then and anything goes. This was an era before the HP wars and "Where is my MPG diesel economy?"

Quick is covered by others. My build was not for a 1/4 mile, but, grades of 7% or more that go for miles while towing. This truck got me and my dad through The Great Depression V2.0 while working hard towing a trailer full of auto parts. Patch, the 1993, is retired now and a fun hot rod: for what it is.

I own a modern diesel. They are expensive to repair.
 

Will L.

Well-Known Member
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Location
Boulder City Nv
#42
@ak diesel driver and @John Romann
I wouldn’t throw in the towel on it.

I have nothing against the moose group, but I ran pumps that were more fuel than them and yes it took some “tuning” to make it streetable. Maybe 4 days iirc. But ran a few years before getting an offer for the truck I couldn’t refuse. Not sure if that guy was more rich or more stupid but either way he owns it now. This is not my 3 full race IPs. It was fully expected to go 200,000 miles but different builder.
I have been hearing about other good builders that would be worth looking towards.

When my pump was built, I did the pop adjusting on my injectors, then gave them to the pump builder and he ran the pump with my injectors on his bench to see final results. No adjustments were made from it and I helped him build a “injector tank” to see spray patterns. We compared mine to stock injectors and “Wow” was used alot.
 
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40
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21
Location
New york
Thread starter #43
My biggest thing is tools. If I go mechanical pump. I have nothing to time it nor the knowledge to do so. Plus I'd need the cable and pedal possibly to convert to manual pump.
 
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13,096
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3,218
Location
alaska
#45
My issue is more towards the hard starting. If he had trouble at +25* then what would I have at zero or below. I know some of that is from Nate's lower compression but I know someone else on here is also at 19-1 with no real issues. My old timers is kicking in here but I believe it was Darrin. Can't come up with his handle right now but Big T used his write up for his gmt800 brake mod
 

WarWagon

Well it hits on 7 of 8...
Messages
8,471
Likes
3,043
Location
AZ
#46
I forgot and now recall my extreme hard starting is a recent thing that didn't happen when I first dropped the hi-pops in. I have videos of a DB2 starting fine aka my project truck and that reminded me of 'why am I putting up with this damn hard starting SOB?'. I loose the cold advance due to the Smoke Puff limiter option that is again optional. Need time to really dig into the hard starting problem. We are down to air or injectors ruined.

DB2's don't fishbite like the DS4's do for reasons unknown or maybe checking the misfire sense. IF you can get one started it will run till it's out of fuel of looses a single 12v to the solenoid.
 
Messages
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21
Location
New york
Thread starter #47
I forgot and now recall my extreme hard starting is a recent thing that didn't happen when I first dropped the hi-pops in. I have videos of a DB2 starting fine aka my project truck and that reminded me of 'why am I putting up with this damn hard starting SOB?'. I loose the cold advance due to the Smoke Puff limiter option that is again optional. Need time to really dig into the hard starting problem. We are down to air or injectors ruined.

DB2's don't fishbite like the DS4's do for reasons unknown or maybe checking the misfire sense. IF you can get one started it will run till it's out of fuel of looses a single 12v to the solenoid.
Excuse my lack of terminology. Whay do you mean by fishbite
 

schiker

Well-Known Member
Messages
2,435
Likes
557
Location
Pendleton, SC
#48
As far as harmonics go. What others have said. How fast Diesel ignites and burns depends on how hot the combustion chamber is. The difference in flame front speed in a cold, normal and hot engine are significant comparing the extremes. The precups are needed to produce swirl/mixing with a flat top piston. DI engines have some geometry built into the piston to produce swirl/turbulence. DI engines I think are typically longer stroke or slower rpm engines. The 6.x engine platform was designed way back when to act somewhat like a gas engine with fast warm up and quicker acceleration than NA DI engines of the era.

A longer version of what was mentioned early in the thread.

Once average ECT gets above 215/220F in the IDI 6.5 (And other factors indicate high heat ie EGT, IAT, oil temp -overall hot engine/ hot combustion precups etc and when heavy fueling) I believe the combustion temp can vary some cylinder to cylinder. Repeating that the dash guage is an averaging ECT pre balanced flow water pump and other head issues there are different localized temperatures in the head. This causes differences in pressure rise in the cylinder near TDC. This stresses the crank and lower end with "fatigue harmonics" on a relatively light duty high speed V8 engine. It's not necessarily unbalanced as the same amount of fuel is injected into each cylinder and will normalize over a few degrees of rotation. It's not enough to nail because it's not pre-igniting like low octane gas before TDC as the IP injection event is still the same start time. Its a pressure rise increased rate closer to TDC than normal temperature operation.

Keep the heat load balanced and not too hot it seems to live. Better metallurgy helped too. The last version of water pump is the best balance flow water pump (spin on fan).

You shouldn't go cooler than 180F thermostats. Its not going to stop an overheat but they might get you over a small hill. Leroy I think sells them or get robert shaw stats.
 
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3,218
Location
alaska
#49
ds4s a noted for a slight bucking which got termed fishbite kinda like having a fishbite on your bait. No known positive answer for the fix. Most seem to think it's a fuel supply issue or air intrusion but I've seen it chased for a long time
 
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Location
New york
Thread starter #50
ds4s a noted for a slight bucking which got termed fishbite kinda like having a fishbite on your bait. No known positive answer for the fix. Most seem to think it's a fuel supply issue or air intrusion but I've seen it chased for a long time
My truck has a stumble every once and a while. It usually when it goes from cold to warmed up just idling in a lot. Once it reaches operating temp it will blip like a hickup and run perfectly fine. Does it like clockwork every ime it's idling warming up when it hits temp
 
Messages
13,096
Likes
3,218
Location
alaska
#51
so another take would be diesel is ignited by heat (generally compression induced) if the precombustion chamber gets too hot it would start igniting the fuel before compression heat is achieved similar to preignition.
 

Will L.

Well-Known Member
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7,301
Location
Boulder City Nv
#52
Sometimes I come across as a jerk- never my intent. But having been nicknamed sarcasmo by a couple people...

I cant really speak to cold start relations but I really think if it were that bad on a db pump the military would have abandoned the 6.2 before the 6.5 was ever made. So stock fueling starts ok for uncy sams ok.

So hopped up pump the issue? Problems to be overcome for the starting issues maybe a wabasto heater? Or running the baby soft injectors?

Now, the hopped up pumps for volume when combined with higher pop pressure injectors- there is a ratio of say 5:2 (5,000 psi pump and 2000 injector) on stock setups but if the pump builder doesn’t know how to rasie the output pressure along with the volume, then your pressure is going to fall- BECAUSE he doesn’t know how. New ratio-??? 4.4:2.3 maybe 4:2.3 who knows?
So now lower the pop pressure like he wants and you get back that ratio 4.250:17 is same as 5:2 It wont atomize as well but more volume gets through.
Maybe that ratio make atomization closer to stock?

When I wanted a pump “bumped up” it was a couple hundred. But my psycho pumps were a couple thou each, labor costs only. Starting with a new pump not included here. My point is like my thread about the cheapy wmi I am looking at- yeah it works, kinda but with issues. The right way is just way more money. Could be the issue?

Wanna pressure gauge on those pumps vs a new stock one yet?

So the builder was recommending way lower than stock pop pressures. So maybe Yes more fuel, but lessAtomization. Again think of wmi. What you want is volume AND pressure.

Yes in the harder starting cold areas, I would hesitate too until a pump builder could explain details of why the problems and show how it is solved. Maybe focus on return-ability of the pump if it cant handle the cold starts. Dont swap everything over until that is known.

Pump, lines, add a bicycle brake cable into the cab and some backyard bailing wire to the existing pedal just for testing and add it on the truck aduring know cold streaks. If all is good, then do the correct install. If it doesn’t work out and you get back all but a couple hundo, now you know. Sometimes gotta pay to play.

Or hit up heath for his merlin, just ensure return warranty if it doesn’t live up to the hype.

The two built pumps here are moose jr. At what was it 155cc? Remember they make a Bull moose at 200 cc.

You CAN NOT HIT 120 On ds4. 110? NOPE. Be the first Show me an uninterrupted video of one on a bench putting 105 through injectors and I will drop $40 for you congrats drink in an envelope to you for the new world record you set.
Want big power AND a ds4, ok. Just mount the Ford db2 on the other side of the timing cover and some
Lines going to the injectors feeding through the glowplug holes. Cummins air heater works nice for your intake with some tig welding. Why not 2 ds4? Because the pmd can’t handle 2 pumps, and you cant run twin pmds.

Tools for Db2 are not to different. There is a bar to use instead of prybar for fine pump adjustments, or make your own from 1” flat bar and 2 bolts. Replace your scanner with a paper clip and a diesel pulse adapter. Most people like the snapon that also has the eye that goes in the glowplug hole. I am content with my Mac ET18DPM in the picture that needs any inductive timing light hooked to it. Maybe buy the one of the hundreds of military type ones being auctioned off- I never used one of those, but shouldn’t be to bad.

Instructions very slightly based on tool, but mine is put clamp on injecton line, put ground wire on same injection line. Put timing light pickup (sparkplug wire clamp) on red metal loop. Power up timing light. Start engine and aim timing light at timing tab/ balancer mark just like old school gas engine.
58E0743F-2E10-43F4-9ACA-968979161C4D.jpeg
CC605A52-560F-4693-B3E9-885DF41D26FF.jpeg

IMPORTANT: turn engine off before adjusting pump. Lock down 1 of 3 nuts and start engine to recheck timing. Repeat 4-5 times when you learn how, then it is usually 2-3 engine starts after that now that you have a better feel for it.

All the info is here in this forum, including the how to convert manual. Invest some hours reading all the stickies and search the stuff you are missing.

But really you should dyno so you have an accurate reference. Do 0-60 time, maybe 1/4 mile. Then- what do you want it to be? Now the key- how much $

Did you balance the lower assembly of your optimizer? How many miles on the rubber band timing chain? Tons of questions- what heads are you running and how much work was done to them for flow? Guessing you are punched out huge if your thinking precup modification next?
 
Messages
40
Likes
21
Location
New york
Thread starter #53
Sometimes I come across as a jerk- never my intent. But having been nicknamed sarcasmo by a couple people...

I cant really speak to cold start relations but I really think if it were that bad on a db pump the military would have abandoned the 6.2 before the 6.5 was ever made. So stock fueling starts ok for uncy sams ok.

So hopped up pump the issue? Problems to be overcome for the starting issues maybe a wabasto heater? Or running the baby soft injectors?

Now, the hopped up pumps for volume when combined with higher pop pressure injectors- there is a ratio of say 5:2 (5,000 psi pump and 2000 injector) on stock setups but if the pump builder doesn’t know how to rasie the output pressure along with the volume, then your pressure is going to fall- BECAUSE he doesn’t know how. New ratio-??? 4.4:2.3 maybe 4:2.3 who knows?
So now lower the pop pressure like he wants and you get back that ratio 4.250:17 is same as 5:2 It wont atomize as well but more volume gets through.
Maybe that ratio make atomization closer to stock?

When I wanted a pump “bumped up” it was a couple hundred. But my psycho pumps were a couple thou each, labor costs only. Starting with a new pump not included here. My point is like my thread about the cheapy wmi I am looking at- yeah it works, kinda but with issues. The right way is just way more money. Could be the issue?

Wanna pressure gauge on those pumps vs a new stock one yet?

So the builder was recommending way lower than stock pop pressures. So maybe Yes more fuel, but lessAtomization. Again think of wmi. What you want is volume AND pressure.

Yes in the harder starting cold areas, I would hesitate too until a pump builder could explain details of why the problems and show how it is solved. Maybe focus on return-ability of the pump if it cant handle the cold starts. Dont swap everything over until that is known.

Pump, lines, add a bicycle brake cable into the cab and some backyard bailing wire to the existing pedal just for testing and add it on the truck aduring know cold streaks. If all is good, then do the correct install. If it doesn’t work out and you get back all but a couple hundo, now you know. Sometimes gotta pay to play.

Or hit up heath for his merlin, just ensure return warranty if it doesn’t live up to the hype.

The two built pumps here are moose jr. At what was it 155cc? Remember they make a Bull moose at 200 cc.

You CAN NOT HIT 120 On ds4. 110? NOPE. Be the first Show me an uninterrupted video of one on a bench putting 105 through injectors and I will drop $40 for you congrats drink in an envelope to you for the new world record you set.
Want big power AND a ds4, ok. Just mount the Ford db2 on the other side of the timing cover and some
Lines going to the injectors feeding through the glowplug holes. Cummins air heater works nice for your intake with some tig welding. Why not 2 ds4? Because the pmd can’t handle 2 pumps, and you cant run twin pmds.

Tools for Db2 are not to different. There is a bar to use instead of prybar for fine pump adjustments, or make your own from 1” flat bar and 2 bolts. Replace your scanner with a paper clip and a diesel pulse adapter. Most people like the snapon that also has the eye that goes in the glowplug hole. I am content with my Mac ET18DPM in the picture that needs any inductive timing light hooked to it. Maybe buy the one of the hundreds of military type ones being auctioned off- I never used one of those, but shouldn’t be to bad.

Instructions very slightly based on tool, but mine is put clamp on injecton line, put ground wire on same injection line. Put timing light pickup (sparkplug wire clamp) on red metal loop. Power up timing light. Start engine and aim timing light at timing tab/ balancer mark just like old school gas engine.
View attachment 52028
View attachment 52029

IMPORTANT: turn engine off before adjusting pump. Lock down 1 of 3 nuts and start engine to recheck timing. Repeat 4-5 times when you learn how, then it is usually 2-3 engine starts after that now that you have a better feel for it.

All the info is here in this forum, including the how to convert manual. Invest some hours reading all the stickies and search the stuff you are missing.

But really you should dyno so you have an accurate reference. Do 0-60 time, maybe 1/4 mile. Then- what do you want it to be? Now the key- how much $

Did you balance the lower assembly of your optimizer? How many miles on the rubber band timing chain? Tons of questions- what heads are you running and how much work was done to them for flow? Guessing you are punched out huge if your thinking precup modification next?
I'm not asking to set records what I'd like to know is what' the most achievable power you can hit with a ds4
 

Will L.

Well-Known Member
Messages
8,080
Likes
7,301
Location
Boulder City Nv
#56
Hmm, good question! I just turned a blind eye so long ago that I don’t have a clue.

Been about 15ish years since I last owned one so my numbers would be horrible guessing at this point.

Somebody start the bidding with your number. No disrespect intended. There are some respectable trucks I’ve rideen in or saw on YouTube. I would say if no dyno number then a good 0-60 time maybe? Where are you at John?
 
Messages
6
Likes
4
Location
Midwest
#57
I've seen chassis dyno numbers in the upper 220's from sources I trust.
I've also seen claims of much higher numbers, but typically these do not show the actual printout, or photo of the dyno screen, or any indication of what modifications have been made or whether propane or WMI is being injected. None of the higher power claims I have found so far seem at all credible.
I think there is a youtube video of a DS4 truck making 290HP. But with no details. It could be a mechanical conversion.
Hoping to get mine on the rollers in the next few weeks. Will be interesting to see what it does. Then I plan to start playing games with the pump.
 

Will L.

Well-Known Member
Messages
8,080
Likes
7,301
Location
Boulder City Nv
#60
Oh yeah! Most people will never spend the $ on dyno. That’s why I was saying an option of 0-60 time.

If person x has a dyno of say 250/500 and 0-60 is say 7.5 seconds.
Person y has same gearing and trans with similar weight, and does 0-60 in 7 seconds, a ball park could be done.

There is a calculation where weight, 0-100, 1/4 mile time, etc can ballpark it.

We know unless a manual trans is in place, dyno run is only theoretical unless they hit the 5252 rpm cross point to ensure operator did his math right. So most dyno runs can be skewed, even by accident.
 
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