turning the barrels?

haha... I wonder how many motors and pumps i would have saved if i never asked about turning my barrels. thanks guys for clearing all this up for everyone.
 
bubba_pa said:
You can make a scribe mark on the top of the pump case where the barrel hold-down bolts go as a reference. Loosen the injector lines then loosen the two hold-down bolts and turn clockwise. Then run the truck for a while and wonder why it doesn't idle quite as smooth as it used to and then take it to a pump shop to be balanced correctly :bang
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I have a motor here to put in the truck. Just need to do a few touch ups to the motor and it'll be ready to go in. I wanted to play with turning the barrels.

Just like the guys with the gassers who start spraying there motors on an engine dyno to see where it blows.... Lets see what happens. I have a 600cc 5k gsk pump ready to go on when this kicks the bucket, and I have another fire ring'd, 14mm studs, balanced, etc, etc. etc. motor to go in when this one breaks a piston ring, or blows a headgasket, or whatever.

Merrick
 
I would think tuning it by egts would balance it out even better than pump stand.
 
gunracer1 said:
I would think tuning it by egts would balance it out even better than pump stand.
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How exactly how would this be done? The flow between b/p's will vary as the pump temps change, so this being said, to tune by temperature the engine would need to be at operating temp to be properly adjusted, also the exhaust manifold transfers heat so small differences will not be as easily detected as flow rates will be on a test stand.

I've also seen pumps benched that will fluctuate in opposite directions with rpm change.

Here is a chart to explain. (ignore the dashes)
215 pump off a '98 12 valve with 225k
The engine only idled rough and the owner wanted it fixed

Flow in cc's at low idle, cold looked like this.
#1----#2----#3----#4----#5----#6
-8----9-----9.2----9.4----9.1----10

Flow in cc's at high idle, cold looked like this.
#1----#2----#3-----#4----#5-----#6
647---641----640---639----640----630

Flow in cc's at high idle, hot looked like this.
Low idle flow remained relatively the same hot and cold.
#1----#2----#3-----#4----#5-----#6
651---640---640----640----640----620
 
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so if i wanted to go this route and have a performance shop do this would my truck still be somewhat street driveable and how much would this run me in price also can it still be almost as reliable or should i just wait and do this after i have something else to drive?
 
I'll be giving the barrel turning a try in a bit.

On another note, do yall remember the guy on TDR years ago that was telling everybody to run without a plate? (Something like, Run Plateless, or remove your plate!!) I feel like I'm in his shoes, LOL

Merrick
 
Hammer said:
:thankyou2::clap::clap:

I am amazed at how many feel that they know more than the pump shops.
Wonder if they have ever seen a truck who had a home tuned pump that had a lean cylinder and it melted down?.
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Diesel engine always run lean, so a lean cylinder will never melt. Too much timing advance could crack a piston, to long injection could melt a piston but never you can melt a piston with a lean mixture.

It's not a gaz engine !
 
Just turned 'em. I'd say SOP, a 30-50HP improvement? Noticeable, and to me impressive for a free mod. I'm sure with some 370's there would be a fair amount more power, but on the OE injectors, I'm sure the pump is complaining, along with the injectors, LOL.

The midrange was impressively stronger, but my OE GS's pull the fuel way to early, but I'm sure the OE turbo is just fine with that, LOL. The bottom end, seemed like it had more response, without more smoke... Felt like it. Was chirping the tires easy in corners without smoke, where it needed a nice haze before... Imagined?

Only thing I did notice was a hanging idle? Wanted to idle at 1,200rpm when coasting, 1,000 in park, and the normal 800RPM in D.

I might try dropping the idle in D a little bit. Before with a stab of the throttle, anything less than 800rpm resulted in a motor that needed re-started.

Suggestions for the idle? Or, explanations on the 'cause? GS's can't meter the fuel properly anymore?

Merrick
 
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If the nozzles is bigger is normal than the engine run faster, the idle screw is on the throttle lever so the pump doesn't see the difference. Adjusting need to be done !
 
MCummings said:
I'll be giving the barrel turning a try in a bit.

On another note, do yall remember the guy on TDR years ago that was telling everybody to run without a plate? (Something like, Run Plateless, or remove your plate!!) I feel like I'm in his shoes, LOL

Merrick
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Don't remember his first login name, last one was Cummins Corvette......turns out he was right in a way, it was the next year that the Rack Cap was born....like 03'.

Jim
 
Jim Fulmer said:
Don't remember his first login name, last one was Cummins Corvette......turns out he was right in a way, it was the next year that the Rack Cap was born....like 03'.

Jim
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haha, Yup. That's him. Wow, he was good at gettin' people stirred up!

Jim, what's your opinion on the "soft" idle? Think if I toss a 4k gsk in it, it'll firm up? Of just toss my big balanced pump, and send this one off?

Merrick
 
I still remember all the hell I got when. I told people to grind their on plates.
 
Diesel engine always run lean, so a lean cylinder will never melt.
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I disagree with that comment....

Too Lean or too rich can cause the same damage with any type of motor.
 
Jim Fulmer said:
Break that down for me (Soft Idle)

Jim
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Start truck, idles at 800 cold. After it warms up a bit, it's at 1,000rpm. Drop it in gear, it's at 800rpm.

Take it for a quick drive, say get up to 30mph, and when you let off the throttle, the R's fall to only 1,200rpm, and the engine is actually "running" at that rpm. Not until the converter can pull the motor down, will it go below 1,000. If it's in gear, and your coasting (the converter is unloading the motor slightly), it idles at 1,200. In Park/Neutral, it's at 1,000rpm, and in gear, stopped it's at 800.

Compared, to before turning the barrels, it was dead set at 800rpm. In Park, A/C on or off, and when coasting in gear, it would try it's best to pull down to 800rpm before adding fuel. Now, the fuel sneaks in real slow, from 1,200 down to 800. Kinda like a gasser with a vacuum leak....

Merrick
 
fnschlaud4620 said:
So how is the idle quality once you get it adjusted back down to a reasonable rpm?
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As far as idle quality, in gear, nothing that makes me perk up my ears... It's definatly not balanced, but, it's not way off. When it's cold, it has a little stutter, but even before turning the barrels it had a little stutter, it's just ever so slightly exaggerated now. Maybe that's just a quirk of a 215 motor with a tight auto behind it?

I can hear one cylinder hitting just a tad harder than the others, but only inside the truck, nothing alarming. Outside, it sounds exactly the same as before.

Throttle response is much better, and it takes way less throttle to hit the same RPM as before. About an 1/8 throttle and it's at 2,000rpm in neutral.

I like it, and if you are looking for power, I'd recommend it. If you are already running plateless, and without an AFC, this mod might be for you, but, if you are into the fine tuning of things, you might want to try to balance the pump somehow, either with EGT, fuel volume, or benching it, but, with my truck, a plateless toy, I like it. Just the funky idle has me goin' right now... hmmm. I'd like to atleast find out why it's idling weird.

Merrick

EDIT: Thanks for the props. The power is definatly up. Before, it was struggling to spin the tires in 2nd locked (WOT from a stop, it would spin through 1st, hit 2nd and halfway through 2nd it would catch traction), now, it wants to do a rolling burnout if the TC is locked at 1,500RPM and you nail it in 2nd gear, or from a stop, WOT, once it breaks the tires loose, in about 20 feet, I lock the converter, and it pretty much goes straight to the top of 2nd gear, and spins the tires until it's time to shift to 3rd... Put a smile on my face everytime :)
 
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