BC3 cam & follower issue

There are many guys on my crew that constantly comment how I must be super smart or how they can't believe I figured something out, that I'm a genius, I just look at them and laugh and say no, it's because I've torn it up three or four times before and I've always been too poor to pay somebody else to fix it.

Hallback said:

There are many guys on my crew that constantly comment how I must be super smart or how they can't believe I figured something out, that I'm a genius, I just look at them and laugh and say no, it's because I've torn it up three or four times before and I've always been too poor to pay somebody else to fix it.

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Growing up, times were always too lean to hire anything done unless it was something impossible for us to do on our own. In 25 years, I only recall 5 repairs in a shop. Excavator rotec, dozer transmission, a Detroit 6n-71 rebuild, and 2 engine swaps. The engine swaps only were only paid for because they were in the heart of the season and we couldn't afford to stop working to do it ourselves. Many times a year I realize how *lucky* I was to grow up that way and have to learn how to fix, even if at the time I wanted to run the machine off a cliff with myself in it.

Truck Shop said:

Yeah will every time someone notices a red spot or bump on my bald head they say looks like you bumped your head. I always reply {those are knowledge knots from the last job}.
Everyday I learn something just about as soon as I get out of bed.

Truck Shop

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Most of my knowledge knots were put there by somebody else trying to teach me when I was young and arrogant.

I do a right fine job of finding sharp objects or sharp angle cut wire ties with my noggin. Then I ask which a$$hole put that there.

Truck Shop

Ah, the age-old torture tool called an angle cut zip tie!

Truck Shop said:

I do a right fine job of finding sharp objects or sharp angle cut wire ties with my noggin. Then I ask which a$$hole put that there.

Truck Shop

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Yeah, just like the concrete wall I head-butted the other week while helping the wife stow away all the patio/garden furniture for the winter. When she offered to help I should have just said "No thanks, I'll manage by myself". At least then if I'd drawn blood I would have had no-one to blame other than myself.

Truck Shop said:

I do a right fine job of finding sharp objects or sharp angle cut wire ties with my noggin. Then I ask which a$$hole put that there.

Truck Shop

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That was one of the negatives of working the last several years in the shop by my self, could not blame anyone other than myself for those kind of things!

Is old school but a oil filled pushrod will eventually either bend or experience end cap failure, either way if left unattended long enough will allow the follower to slap the cam cannot remember any that dragged hard enough to scuff but a few did cam box roller/pin/rocker damage.

DMiller said:

Is old school but a oil filled pushrod will eventually either bend or experience end cap failure, either way if left unattended long enough will allow the follower to slap the cam cannot remember any that dragged hard enough to scuff but a few did cam box roller/pin/rocker damage.

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I always gave push rods the tap test. Just tap them on something hard like you were playing a drum and it was obvious from the dull thud which ones were oil filled. And for good measure give a tug and twist on the ends to feel for looseness!

Still could have had one fail in between. We called it Ringing them, let them slip to a vise or hammer head through the fingers, even to the shop floor if clean enough.

DMiller said:

Is old school but a oil filled pushrod will eventually either bend or experience end cap failure, either way if left unattended long enough will allow the follower to slap the cam cannot remember any that dragged hard enough to scuff but a few did cam box roller/pin/rocker damage.

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Cummins Remedy, drill 1/16" pushrod oil drain hole. I do not on inject pushrod; pushrods make okay hyd-jack handles etc.

Hallback's cam failure looks like mechanic's inject adjustment procedure caused. IMO, 75% of cam lobe failures are caused by incorrect, sloppy inject/valve adjustment procedure.

Outer Base Circle = Torquing Injector Plunger to set Pre-Load. Injector Plunger to Cup contact, requires bottoming out plunger 4-5 times to squish the fuel out. Use VS accessory drive pulley timing marks.
Old timers used short thick blade screwdriver, feeling-guessing torque. Higher tech, in-lb torque wrenches; beam, dial and best clickers type. Clicker type better? Easier to adjust all injectors equally with a calibrated in/lb torque wrench. Re-Calibrated? I do not see that often.

Torquing Rocker Adjustment Screw Locknuts. Another variable; you can alter inject adjustment or valve clearance by over-torquing the lock nuts. Remedy use Snap-on type Cummins torque wrench adapter. Later model engines', lock nut are not hardened and lose torquing ability after repeated usage > replace with OEM part.

Inner Base Circle = Measuring injector's plunger travel @ 19deg BTDC for each cylinder. Injector plunger is @ 0.2035" above cup-tapered angle; i.e. stroke distance to travel injecting fuel. Requires 2 engine revolutions to adjust all injectors/valve clearances. More accurate injector adjustment; i.e. visually reading the actual plunger travel to 0.001" accuracy. Still requires bottoming injector plunger out 4-5 times to squish the fuel out.

Altering Static Injection Timing to Prolong Camshaft Service Life:
Fast Timing = Advanced; fuel is injected while the piston is lower in the cylinder; injector plunger travel 0.2035" @ 19deg BTDC plus injector roller-follower travel = 0.00 inches. Say 0.034" Increased mechanical-hydraulic pressure required to push the fuel through the injectors' orifices = increased roller-to-cam lobe pressure.

Slow Timing = Retarded: fuel is injected while the piston is higher in the cylinder: injector plunger travel 0.2035" @ 19deg BTDC plus injector roller-follower travel, say 0.056" Decreased mechanical-hydraulic pressure required to push the fuel through the injectors' orifices (longer stroke = longer duration) = decreased roller-to-cam lobe pressure.

Cylinder pressure is higher @ retarded timing. Piston's crown-bowl is closer to TDC; important to use injector cups with the correct orifice angle and cup protrusion. Cylinder block-height; shaved block (below spec) also changes the relationship, piston-crown bowl to TDC distance. Squirting fuel toward the upper-outside of the cylinder = shortening engine life, excessive smoke etc.
Good machinist will stamp shaved valve on the deck 0.007"-0.015" etc. If you're assembling block with low-deck height (measured) use thicker head gaskets to establish 'as new' distance.
Part 1 ______________________________________

And while we are talking about oil filled push rods, do not cut one with a torch or even a chop-saw. I was shown pictures many years ago at a Cummins school I went to where a guy had done just that and the oil flashed and caused the push rod to burst and burned the guy's hand bad.

I seldom fine oil filled pushrods and use hand hacksaw or die-grinder cutoff wheel to cut for other uses. If the socket is loose, remove, clean and re-braze.

Compression release equipped, for Calif on-highway usage (later engines, not NH200 or earlier with single-double disc fuel pumps) discard compression release control shaft and exhaust pushrods.
1) control shaft is softer than the pushrod bonnet and shaves away steel causing oil-particle contamination.
2) bored drivers play, using compression release to smoke their buddies; causes damage.

petepilot said:

a400 magnum diy project. i got little over 435 out of a sc that stayed together for a162k miles that i ran it. sold the truck and then lost any further contact with the buyer so don`t know how long it lasted after

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Part 2
How long could petepilot DIY Mag-435 last? How about 24 years, average 74K miles per year (+1,750,000mls) regional hauls, drivers paid hourly? Small Cam OEM Magnum 400Hp CPL 695 updating using BC parts is a good example of using ‘retarded injector timing > 0.056”, low pressure PTD injectors > 181C and low pressure PTG pump > 154psi to extend engine and camshaft service life.

Corona Clay New 1972 KW#2-W900-NTC SC-350-13 speed, Jake, single stack muffler-exhaust, no A/C, no fan/clutch, pwr-str, 750 luberfiner, standard fuel filter...S. Cal Truck-Pup regional hauling, plant-to-plant, on-off road / product delivery, drivers paid by the hour.

Maintenance intervals: 3750.00mls oil-filters, fuel-filter, air-cleaner Delo-series 3-30wt...switch to 8,000mls Delo-series 3 15-40wt change intervals. Chevron diesel, truck yard pump. Random: Inject/Valve adjustments > procedures: Used OBC-72lb/in, 0.014”/0.027” and IBC-Dial Indicator Plunger Travel / 0.011”/0.023” <aluminum upper rocker boxes, Jakes removed.

1st in-frame Aug 77, 369,378mls [5 yrs in-frame service]; oil cooler seal failure-cam lobes damaged (running with coolant-oil mixed). Cyl-kits, bearings etc. Injection timing 0.046”

2nd in-frame Dec 85, 960,382mls [8 yrs in-frame service], worn ring packs, #4 cam lobe fretting damage. Update to Magnum 420-440Hp @ 2250 governor cut off; PTG + 20% (185psi). Reused connecting rods-original 2-bolt-nut type, cyl block counterbore ledges machined for 0.010” shims. Original aftercooler, Holset HT3B turbo, Cummins pulse manifold and demand flow cooling, oil pump, oil cooler housing, modified coolant housing, steel pan, large damper. Before inj/valve adjustments; oil-coolant were warmed using 2 block heater for 48hrs. Engine was running or using block heaters for the 1st year usage.

3rd in-frame Jun 09, mileage unknown [24 yrs in-frame service]; 85 yr old owner Gerald D called questioning his service records, “2-inframes”? “That is correct, 1st @ fuel slab, Freddy V driver pestering, NO shade (hot) and my wife totaled new Vette in parking lot, LOL. 2nd my dad died Dec 31st, 85 easy to remember events without digging into invoices". KW#2 and (6 more KWs) service-operation stopped by CARB regulations 2011 [39 yrs service]

KW#2 is the only KW with original engine; 2 other Cummins KW powered had engine swaps, 1 to 3406B, 1 to BC-350Hp. 4 Detroit powered KWs, 8V92 430Hp, replaced with 8V92 Silvers. 1-8V92 KW#1 remaining-retired early, the rest repowered with take out Cummins; 8V92s cannot pass scale snap idle test.

Cummins Turbo-Manifold Pressure: 4psi lowers exhaust temp 100 degrees approx. 400Hp plus req’s 28-34psi gauge; higher is better, burn injected fuel instead of wasting as exhaust black smoke. Pyro temp, hot side 1250degs max, cold side max > minus 200degs. Twin stacks, not req’d. Twin air cleaners, helps or large cfm single.
To be continued maybe

Stans note on deck height is important, probably more so than fast or slow timing. The biggest problem today is the fact that the engine in this discussion hasn't been in
production for on road since 1992. Most blocks are not straight on deck surface plus the water ports are eroded and counter bores are toast. Some years back I was
long blocking 855's for a diesel machine shop at a shop I worked at. I did somewhere in the neighborhood of 90 long blocks and probably 30 of those were completes.
The reason for setting injector timing on cylinders #1, 3 & 5 is to get them even and the only way that's done is with different thickness of gaskets shimming the
follower boxes. One of the reasons for this is that the blocks were not bored for cam exactly straight from the factory.
The decks on any blocks I assembled were marked on the rear of the deck with a -3, -5 and so on for amount removed from deck surface. This day and age it's
totally plausible that a block could have been decked twice maybe even three times but really rare at three. On any I assembled I stamped my initials on the deck also.
Set injector first then valves. Outer base or inner base method is great just get it right the first time around then bar through it again and recheck your valve settings.
Next thing is the counter bores, IMO any block that has repair sleeves installed to save the block is on borrowed time, wasn't worth doing to begin with. Cummins
started installing repair sleeves as a last ditch effort to salvage there pile of junk cores. Cummins was running short on good blocks for their Cummins Recon engines
so they installed the repair sleeves in blocks that had cracked and previously over bored for 20-40 liners. The problem with the repair sleeve was one was cut into
the adjacent repair sleeve leaving no actual block material between counter bores. Very weak repair, those blocks should have been scraped. But it got bad enough
that Cummins started using new blocks in the Recon line-up. So you could have bought a Recon that had a new block.

But in a previous thread about the stupid repetitive mistakes that companies make Cummins and the 855 had one great big flaw.
{The engineers at Cummins refused to correct the real problem, {BORE SPACING} no meat between the counter bores was the inherent problem with the 855.}
If the block had been redesigned with 3/4 of an inch more deck surface the engine would have had less counter bore head gasket issues. But later on with the
NT88 and lower press fit liners part of that did get better. IMO

Truck Shop

Hallback said:

Hopefully we can get it straightened out as it is my favorite truck that we have in the fleet. It is going to retire to just my hobby truck I believe.View attachment 189036

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thats a good lookin b

StanRUS said:

Part 2
How long could petepilot DIY Mag-435 last? How about 24 years, average 74K miles per year (+1,750,000mls) regional hauls, drivers paid hourly? Small Cam OEM Magnum 400Hp CPL 695 updating using BC parts is a good example of using ‘retarded injector timing > 0.056”, low pressure PTD injectors > 181C and low pressure PTG pump > 154psi to extend engine and camshaft service life.

Corona Clay New 1972 KW#2-W900-NTC SC-350-13 speed, Jake, single stack muffler-exhaust, no A/C, no fan/clutch, pwr-str, 750 luberfiner, standard fuel filter...S. Cal Truck-Pup regional hauling, plant-to-plant, on-off road / product delivery, drivers paid by the hour.

Maintenance intervals: 3750.00mls oil-filters, fuel-filter, air-cleaner Delo-series 3-30wt...switch to 8,000mls Delo-series 3 15-40wt change intervals. Chevron diesel, truck yard pump. Random: Inject/Valve adjustments > procedures: Used OBC-72lb/in, 0.014”/0.027” and IBC-Dial Indicator Plunger Travel / 0.011”/0.023” <aluminum upper rocker boxes, Jakes removed.

1st in-frame Aug 77, 369,378mls [5 yrs in-frame service]; oil cooler seal failure-cam lobes damaged (running with coolant-oil mixed). Cyl-kits, bearings etc. Injection timing 0.046”

2nd in-frame Dec 85, 960,382mls [8 yrs in-frame service], worn ring packs, #4 cam lobe fretting damage. Update to Magnum 420-440Hp @ 2250 governor cut off; PTG + 20% (185psi). Reused connecting rods-original 2-bolt-nut type, cyl block counterbore ledges machined for 0.010” shims. Original aftercooler, Holset HT3B turbo, Cummins pulse manifold and demand flow cooling, oil pump, oil cooler housing, modified coolant housing, steel pan, large damper. Before inj/valve adjustments; oil-coolant were warmed using 2 block heater for 48hrs. Engine was running or using block heaters for the 1st year usage.

3rd in-frame Jun 09, mileage unknown [24 yrs in-frame service]; 85 yr old owner Gerald D called questioning his service records, “2-inframes”? “That is correct, 1st @ fuel slab, Freddy V driver pestering, NO shade (hot) and my wife totaled new Vette in parking lot, LOL. 2nd my dad died Dec 31st, 85 easy to remember events without digging into invoices". KW#2 and (6 more KWs) service-operation stopped by CARB regulations 2011 [39 yrs service]

KW#2 is the only KW with original engine; 2 other Cummins KW powered had engine swaps, 1 to 3406B, 1 to BC-350Hp. 4 Detroit powered KWs, 8V92 430Hp, replaced with 8V92 Silvers. 1-8V92 KW#1 remaining-retired early, the rest repowered with take out Cummins; 8V92s cannot pass scale snap idle test.

Cummins Turbo-Manifold Pressure: 4psi lowers exhaust temp 100 degrees approx. 400Hp plus req’s 28-34psi gauge; higher is better, burn injected fuel instead of wasting as exhaust black smoke. Pyro temp, hot side 1250degs max, cold side max > minus 200degs. Twin stacks, not req’d. Twin air cleaners, helps or large cfm single.
To be continued maybe

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keep it up you just recounted a job almost to a t done in1981 ooops make that83

How the hell did this thread go from a problem on a BCIII follower/cam to a small cam magnum that cummins only produced in 87. There was a reason the small cams
were discontinued and big cams arrived on the seen. But even that has no bearing on Hallback's problem.

Truck shop

Worked Continental Engine Rebuilders for a short time, they INSISTED on installing upper bore sleeves mainly to pay for the damned machine to do that as was seriously expensive. They had a grand time explaining away the coolant seeping nightmares they sent out, I left after a short/long three months. Also had problems getting the Foreskins to accept replacing MORE parts in the RT9509s and RTO9513s we were rebuilding, most were slop togethers on the cheap and did NOT last. SQHP, SQ100s were the typical third members we saw, had a few odd Eatons a few fewer yet Corn Queen and nobody would work them except me as I had time on all of them, Riveted ring gears scared the hell out of some of the guys I worked with, I would NOT accept the bolting kits knowing they routinely failed where rivets if done properly out lasted the gears.

Truck Shop said:

How the hell did this thread go from a problem on a BCIII follower/cam to a small cam magnum that cummins only produced in 87. There was a reason the small cams
were discontinued and big cams arrived on the seen. But even that has no bearing on Hallback's problem.

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Truck Shop,
The reason for Magnum was so Cummins could get rid of small cam engine cores. petepilot, myself DIY Magnums preceded Cummins; not brain science just using BC parts on small cam engines. Also work with NTC335s, non aftercooled for 400Hp, narrow nose Pete butter-fly hood type.

Cummins camshafts/roller followers regardless of Small Cam, Big Cam do have a bearing on Hallback's problem. ALL share a common failure mode; failures by sloppy/wrong adjustment procedures.
ALL share a remedy to help prolong cam service life; i.e. retarding timing and using lower pressure high flow injectors, PT pumps with lower pressure.

Prolonging liner-ledge service life is also a benefit of using retarded injector timing. My reason for including KW#2 example; timing new per CPL spec 0.0325"-0.036", per 1st in-frame 0.046", per 2nd in-frame 0.056"

Advanced timing rattles liners, wearing liner ledges. Retarded timing is like a slow hard push; per dyno tests = increased torque/hp, per off-road torque converter equipment specification, engine using PTR pumps. Also per driver's seat of pants, pulls like a tractor; i.e. increased lugging power.

FYI crowned roller followers and cam lobes are not a 'silly idea' but based upon sound engineer design. Follower rollers are crowned to prevent edge loading; steel deformed under load ditto camshafts. Crowning is used by most major OEMs, high-perf off road, aircraft engines.

ADT AR855 Stainless Pulsed Manifold

Designed by James J. Fueling and Garry Shidner, patented reverse flow flange design, mileage increase 0.7th. Cummins changed exhaust port design; smaller increasing velocity; i.e. killed the AR855 manifold

Hallback's BCIII cyl-block if produced after Sept 87 has increased upper deck thickness, 1.0" to use LPF liners.
LPF liners were a design carry over from KT-series engines.
Advantages of LPF liners
1) the liner press fit is increased over the circumference area [more sq-inches]
2) held more securely lower in the block [approx 3/8” lower]
3) being held more securely in the block helps eliminate seeping head gaskets [increased support reduces liner movement @ circumference-liner ledge and ledge to top of counterbore]
4) extends liner-ledge service life [increased liner support lower in cyl-block with increased surface area]
5) helps eliminate cavitation corrosion-pitting caused by liner movement [combustion forces cause expansion-contraction, bubbles > cavitation corrosion-pitting]
6) reduces ring-blow-by [reduced cylinder distortion > caused by combustion forces; piston compression ring moved upwards > improved liner support in the highest cylinder pressure areas @ TDC]
7) helps prevent head bolt thread cracking [lots of cracked threads are mechanic’s error; i.e. did not clean out coolant-oil before installing the head, causes hydraulic pressure cracking]
note; 4) above: Cummins-Cat use/recommend using a stainless shim allowing polishing-wear to occur to the shim, instead of liner ledge wear
note; 6) above: emissions > combustion gases trapped between the upper compression ring-cylinder wall increase No2.
Hopefully Hallback can connect dots and question whomever repairs his retire-toy truck if he doesn't do the engine repairs himself.