Another Timing Thread... DD Style

bnold

bnold

Cummins. What else?
Joined
Jul 13, 2007
Messages
140
Alright guys been awhile since I have made a post over here. Truck is going on 3yrs (75k miles)since I did the conversion. Still no regrets.

I originally ran a set of John Links (RIP) 7x.014, lots of power and for the most part as log as I wasn't leaning on the throttle too hard I could control the smoke. No haze at idle unless ambient and motor pretty dang cold, no to extremely little haze at cruise (only would haze if pulling a load really). Timing was set at 18* based on plunger lift.

My only complain as I have pulled away from dynos, sleds, and the track is I would like to be able to get on the throttle more without as much smoke. Trying to clean up the trucks act a bit.

Finally after 70,000 on JL's sticks I decided it was time to downsize and try something new. After a bunch of looking around and reading, talking with different folks etc... I decided to try a set of Jamie's? (I believe) at CPP 7x.010 SAC nozzle.

In theory that should be about 50% of the fuel flow based on hole size correct?

Installed these new sticks, and still trying to get them worked out (Timing Unchanged). I have a slight haze at idle (mainly when cold) and a constant haze/puff at cruise?? Also my starts are about a revolution longer than before. This always bugs me, my truck has always been a look at the key wrong and the truck fires. Remote start friendly. No leaks that I can find anywhere. Other than what was listed the injectors really do drive nice, less smoke on acceleration etc... But, the smoke at cruise really bugs me.

Last weekend I tried bumping up the timing was aiming for 22* and hit 21* figured that was close enough! :). Actually like how the truck performs better now and the smoke at cruise may have decreased some (still there though). Only draw back seems to be a diminished off idle torque. Above 2k is extremely peppy. (which from my readings I understand is fairly normal).

So questions for CompD.
1. Any idea what John Link's injectors pop pressures are? They were built knowing this was a P7100 truck. Same with Jamie at CPP? I could call him and find out, but worth the question here.
2. What are you running for timing on a Daily Driven/Towing P7100-24V truck? Drag racing and sled pulling timing isn't what I am looking for.
3. Any ideas to my problems above? Is this the nature of a SAC nozzle on my 24V? Pop pressure related? Timing Related?

Thanks,
Brian
 
Brian my 7x12 JL's were set at 250bar from DPE and never hazed at idle or driving down the road and I'm running an s472 single turbo. I'm also running a benched 215 pump set at 500cc with .020dv's and 24* of timing with a 4k kit. Cold they would haze but once warmed up they wouldn't. I'm also an SO motor with SO pistons which have a slightly larger bowl so I'm not as apt to spray outside the bowl with high timing. I wonder if that's what's causing your hazing issue.
 
Hazed worse with the less timing though? Thought HOs were still conservatively in the bowl around 26-28* maybe more?
 
As Tyler said, with an HO you can't run as much timing as an SO and stay in the bowl.

With the VCO nozzles which I am assuming your original set was, you probably would have been in the bowl up to 20-22° depending on head gasket thickness, etc. That being said, I don't know what the spray angle is of CPP's 7-hole SAC nozzles so I can't really speculate on what timing you could run.

Your comment on "half the fuel flow" with the new sticks isn't an accurate assessment. There is more to determining how much an injector will flow other than hole size - nozzle type, internal modifications, etc. That being said, I would assume they would support less HP than the original injectors however.
 
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bnold said:
Hazed worse with the less timing though? Thought HOs were still conservatively in the bowl around 26-28* maybe more?
Click to expand...

Did you do a standard size HG when you o'ringed or not? I'm still on the stock gasket.
 
Nope marine .020... took .007 off the head. Still injector will be sitting .013 possibly high. Again, symptoms are new to these injectors
 
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j-rod said:
As Tyler said, with an HO you can't run as much timing as an SO and stay in the bowl. Agree and don't doubt it.

With the VCO nozzles which I am assuming your original set was, you probably would have been in the bowl up to 20-22° depending on head gasket thickness, etc. That being said, I don't know what the spray angle is of CPP's 7-hole SAC nozzles so I can't really speculate on what timing you could run.

Your comment on "half the fuel flow" with the new sticks isn't an accurate assessment. There is more to determining how much an injector will flow other than hole size - nozzle type, internal modifications, etc. That being said, I would assume they would support less HP than the original injectors however.
Click to expand...
With a 50% reduction in hole area at the same given pressure I'm going to assume they are flowing less fuel as well. 'Rated' at 150ish as opposed to the 300ish the 14s were at. Smaller hole size and less flow shouldn't be causing additional haze and incomplete burn. Spray angle, pop pressures, timing could?
 
Took .007 off the head and installed a .020 headgasket. Wonder how much you dropped your compression by. Iirc sac nozzles are dirtier than voc as well.
 
BgBlDodge said:
Took .007 off the head and installed a .020 headgasket. Wonder how much you dropped your compression by. Iirc sac nozzles are dirtier than voc as well.
Click to expand...

Back when that head was done that was the idea to drop the compression some on the HO motors when running a fair amount of boost... Still 65-70psi on this rig.

What the thought is now... No idea! :)

As far as the sac nozzle choice wishing I would have stuck with what worked for me in the past.
 
Give me a call. I'll send you whatever you want to try. I'm not hard to get along with. I refuse to have a unhappy customer.:Cheer:
 
cummins724 said:
Give me a call. I'll send you whatever you want to try. I'm not hard to get along with. I refuse to have a unhappy customer.:Cheer:
Click to expand...

I will, just curious to what the masses thought. Whether setup related or otherwise.

Thanks
 
I've sent out alot of these injectors and you are the first I've heard having smoke issues with 7x.010 sac. I'd like to know more about your setup and what you are seeing for boost etc. Might be smokey because they aren't hitting the fuel hard enough. When you call me, I'll give you a phone number for my turbo guy. He can help you diagnose the issue and we can get you fine tuned in.
 
My 6 hole sac nozzles start a little harder than the 7x14s(vco) that i was running. These injectors are quite dirty compared to the 7 hole nozzles as well, but for me the power is worth it. If your looking for a clean running truck, i would personally try a set of 7x12(or even a 7x10 depending what power you still want) vco nozzle with the pop pressure around 290bar. Seems to be a pretty clean running setup for most people

FYI, i run 24* and its my dd.
 
cummins724 said:
I've sent out alot of these injectors and you are the first I've heard having smoke issues with 7x.010 sac. I'd like to know more about your setup and what you are seeing for boost etc. Might be smokey because they aren't hitting the fuel hard enough. When you call me, I'll give you a phone number for my turbo guy. He can help you diagnose the issue and we can get you fine tuned in.
Click to expand...


Going to make me dig up some notes on what's under the hood... Been a long time since some of that was thrown in there!! (think twins originally went in 2006/7?)

Primary is the S400 from Rip at Source from back when I ran at HX35-14. Which does he use 75/93/1.3? Is that right?
Secondary is I believe a BD Super B S300

I would tend to agree that the smaller sticks could in fact cause more smoke on acceleration only because less fuel is on tap. However, that would not explain my smoke at cruise.

I will pay some more attention to boost numbers in the morning on the way to work. Cruise/WOT, will do my best to give you a call tomorrow. 6-10s are wearing on me! 2-3hr round trip commute not helping matters! :)
 
Good on boost leaks

Tried to get a bit of info between traffic on the way into work this am. At cruise holding speed.

1850rpm ~65mph 6th gear 9psi total 2psi primary
2600rpm ~65mph 5th gear 10psi total 3psi primary
2100rpm ~75mph 6th gear 10psi total 3psi primary

5th gear WOT spurt (again traffic not much room) 63psi total 25psi primary around 2800rpm. I'd have to check but my pressure relief valves are probably set pretty loose, 50-60psi so I'm sure I was bleeding boost.

Normal acceleration shifting around 2100 rpm (normally a couple lengths behind my neighboring auto car to give you an idea of speed)
Out of 2nd 5psi
Out of 3rd 11psi
Out of 4th 15psi
 
Pulled my new SACs on Sunday and put in my old JL VCOs. All symptoms now gone, no smoke at idle, no smoke at cruise. Less smoke on acceleration. So something isn't quite happy between these injectors and my setup. As soon as I can get the address to send these back to Jamie I will get them sent off to be checked out. Thus far Jamie has been good to work with and seems to want to make it right, appreciated. Hopefully we can get it worked out.
 
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