Looks Like I'ma gonna be a Caddy Guy - Now What? Stroker L92 LS3 Build

It's time for "Knot A Thunda". Say it a few times and you can sell one to anyone.

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The lifting bridle assembly weighs 24 lbs, so 504 lbs total plus headers and 1-1/2 qts of gear lube remaining to add.

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From the learn something new every day bin, it turns out I bought too new of an alternator. The alternator I bought is a 160 amp Gen 4 for the loaded 2009 Escalade the engine came from originally. It came with a 2 pin plug which I noted, but thought GM must have simplified things to sense and excite pins, nothing else. Once I got to connecting the alternator I find I was totally wrong. Gen 3 and early Gen 4 used a 4 pin internal voltage regulator. After around 2005 GM switched to a 5 volt PWM controlled regulator (alternator I bought) that used an external control module to specify alternator voltage.

I should have ordered an alternator for a 2000 ish vehicle vs. 2009. Since I don't want to add a computer to drive my alternator and it's too late to swap it, I have ordered a $25 4 pin voltage regulator off Ebay and I need to pull my alternator apart and replace the voltage regulator.

The best info I find is at the link below, instructions for regulator swap out included.
Dirty Dingo Motorsports - Pages - LS Conversion Swap Information

This link provides more good info on both the Gen 3 & Gen 4 regulator operation.
Almost ALL the late GM Alternator Information you could need!!

Alternator excitation will be through the "Lamp" pin with a 470 Ohm, 10 Watt resistor back to the ignition switch (Watt size is overkill).
Alternator "Sense" will route to the Starter.
 
Slidin Gator said:
From the learn something new every day bin, it turns out I bought too new of an alternator. The alternator I bought is a 160 amp Gen 4 for the loaded 2009 Escalade the engine came from originally. It came with a 2 pin plug which I noted, but thought GM must have simplified things to sense and excite pins, nothing else. Once I got to connecting the alternator I find I was totally wrong. Gen 3 and early Gen 4 used a 4 pin internal voltage regulator. After around 2005 GM switched to a 5 volt PWM controlled regulator (alternator I bought) that used an external control module to specify alternator voltage.

I should have ordered an alternator for a 2000 ish vehicle vs. 2009. Since I don't want to add a computer to drive my alternator and it's too late to swap it, I have ordered a $25 4 pin voltage regulator off Ebay and I need to pull my alternator apart and replace the voltage regulator.

The best info I find is at the link below, instructions for regulator swap out included.
Dirty Dingo Motorsports - Pages - LS Conversion Swap Information

This link provides more good info on both the Gen 3 & Gen 4 regulator operation.
Almost ALL the late GM Alternator Information you could need!!

Alternator excitation will be through the "Lamp" pin with a 470 Ohm, 10 Watt resistor back to the ignition switch (Watt size is overkill).
Alternator "Sense" will route to the Starter.
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On start up, my buddies alternator didn't put out (4 pin GM, late 90's, early 2000's). I finally got around to looking into it. Spent an hour researching and moved a voltage regulator into my EBay cart. When I looked at my cart it said "Last bought" in September. I thought "Oh Yah" :unsure: :unsure: Found the voltage regulator where I put it, swapped it on the alternator and now she is making 14.7 volts.

Also, the Faria Tach was going bonkers, reading high etc. Google said turn the 4-6-10 etc switch back and forth to clean the contacts. So that worked for future reference.
 
Slidin Gator said:
Welp, here we go.
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Welp, That didn't work! On the plus side, I'm getting a new engine:oops: A few more hours getting home and we might have been looking at a tow.

The Root Cause Analysis says the Iridium plugs didn't help, but the primary cause is having the engine choked down to 5,200 RPM and holding the pedal to the floor for a couple of minutes leading to excessive cylinder pressure.

Apparently the LS wants to breath and I need to tune for 6K RPM minimum on the trailer.

Appears I owe CarMotorBarge a bottle.

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Welp, looking at the detonated piston, then the busted one on the bench just kinda reminds me of a term I've used, "blueprint",,,, that engine was set up for a "luxury car" so the tolerances were set tight to keep the noise down while being a cruise vehicle and not a tow truck, I don't see any black death under the ring lands of the shattered piston, much less on the detonated piston in your hand so, the theory of "choking" it down is correct, the rings got superheated, closed the gap and seized in the bores to break the lands and the blowby added to the torching.
 
John Fenner said:
Welp, looking at the detonated piston, then the busted one on the bench just kinda reminds me of a term I've used, "blueprint",,,, that engine was set up for a "luxury car" so the tolerances were set tight to keep the noise down while being a cruise vehicle and not a tow truck, I don't see any black death under the ring lands of the shattered piston, much less on the detonated piston in your hand so, the theory of "choking" it down is correct, the rings got superheated, closed the gap and seized in the bores to break the lands and the blowby added to the torching.
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Pistons are forged, none shattered piston and the engine didn't seize up, 2 hours of run time after failure with lot's of blow by out the catch can. The piston in my hand was the primary failure. The bench shot shows the crank bearings starting to score. The bores have since gotten an 0.005 over bore/hone for clean up.

The conclusion is that the cylinder temp burned up the plugs and then things went to hell. The piston had a good bit of porcelain embedded in it.

Same piston, different view.

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Total optical illusion with the bench photo and piston.
I get the bearings getting scored, the material goes somewhere.
 
kwanjangnihm said:
SG is the plan just to remove pitch and use same prop? Less than 20 degrees is where you may end up to be 6K+
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The plan is this engine is being rebuilt and pickled for a year or two so my son and I can focus on the hull it is destined for. Prop for that boat remains TBD. In the meantime, all of the accessories, starter, flex plate, 2.68 gearbox and 3 blade WW EX are moving over to an iron 6.0 and back on the boat this engine was on.

For future reference, this link is a related thread covering the failure and related prop damage:
Gear Box Dowel Through Prop

This thread will come back to cover the 6.0:
LS 6.0 Lockup Fail

This pic from earlier showed the prop at max 25 which choked the stroker down to 5,200 on the trailer. It was originally pushing past 6500 somewhere between 15 and 20 where it was originally running on the 6.0. The revised version of the 6.0 should be around 500 Hp vs. 600 for the stroker.

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It looks like this thread has reached conclusion, at least for a while. In the meantime, the O-540 boat and storage tank are fueled up with cheap A$$ AV gas I bought for $3.85 a gallon back in January. It's time to burn some fuel.
 
For good measure I clicked the AI summary. Seems reasonable enough to decide if I want to read 9 pages or not :giggle:

The user is planning to build a high-performance L92/LS3 engine with a 4.00" stroke for an airboat. Key goals include 450-500 HP at 5,500 RPM, strong low-end torque starting below 3,000 RPM, forged internals, EFI, and upgraded injectors. They are seeking advice on components like the valve train, cam, porting, and ECU options (mentioning Holley), while prioritizing low-end torque over top-end power. Research includes following recommended bearing clearances of 0.0025" from other forum threads.
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Slidin Gator said:
For good measure I clicked the AI summary. Seems reasonable enough to decide if I want to read 9 pages or not :giggle:
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Really curious as to how the tune looked as far as timing. I have a similar setup that is choked down and we have held it to the floor longer than I’d like to admit. 😂
 
smythts said:
Really curious as to how the tune looked as far as timing. I have a similar setup that is choked down and we have held it to the floor longer than I’d like to admit. 😂
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I will have to dig that up, but it is not a super aggressive tune, but it does assume 93 octane fuel, which is an open question? I told the tuner to be conservative on the 93, he could push the E85 timing. On the 6.0 I asked him if I could proceed with cutting the knock sensors out of the harness since we didn't use them before ("they don't do anything") and he said let's leave them in and try them out. YOU THINK :giggle:

When we talked about putting nannies into the tune he kept saying "the way I understand airboats is sometimes if you lose power you sink". I had to admit that is true, but the boat was not about sink on that particular dry trail 😬
 
I would venture to say that the knock sensors are kinda critical with the safe tune of the engine, having true delco or Delphi units, what else curbs the timing back when a spark knock is present running a high performance engine as a "tow truck" over loaded up a mountain and not detonate?
 
John Fenner said:
I would venture to say that the knock sensors are kinda critical with the safe tune of the engine, having true delco or Delphi units, what else curbs the timing back when a spark knock is present running a high performance engine as a "tow truck" over loaded up a mountain and not detonate?
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Yep.
 
John Fenner said:
having true delco or Delphi units, what else curbs the timing back when a spark knock is present
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John,

To be clear, on my stuff the "system" is Holley and "We" control all the tuning/timing/decision making. Delphia/Delco provide the cam/crank position sensors, that's about it.

The knock sensors are more info, period.
 
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