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

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Nice build data. I finished up a very similar build about a year ago. I even used JnJ Balancing in Jupiter and can't say enough good about Johnny and his father. He assembled a solid motor for me and knew of the inherent obstacles present in a stock ls3 being bored out for a airboat.

I did a few things differently than you of course but I'm very happy with my results. I'm pretty sure you will be as well seeing that you have a whole lot more technical expertise than I do.

I look forward seeing your finished project.
 
Deano said:
While it goes without saying . . .
I'm sure I'm not the only one that appreciates your documenting your exploits along the way and pointing out which paths are better left, not taken. Don't know when I might use some or all of this info, but in any case, Thanks in advance!
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One Man Gang said:
Nice build data. I finished up a very similar build about a year ago. I even used JnJ Balancing in Jupiter and can't say enough good about Johnny and his father. He assembled a solid motor for me and knew of the inherent obstacles present in a stock ls3 being bored out for a airboat.

I did a few things differently than you of course but I'm very happy with my results. I'm pretty sure you will be as well seeing that you have a whole lot more technical expertise than I do.

I look forward seeing your finished project.
Click to expand...

I appreciate the attaboys and especially appreciate the "No Trophys Offered":whistle:

As long as I'm learning new crap and spending good money to do so, no reason everyone else can't benefit.

Deano,
My QJet days are coming to an end. Sorry!

One Man,
I have run a few engines through J&J, another waiting in the wings. I'm interested in the differences you mention, this is where the meat is.
 
Two things off the top of my head... I'm running higher pressure injectors, but I built for a possible future with forced air induction. My injectors are way down on their duty cycle with the hope that they will last. I am running 61lb of fuel pressure at my regulator. In other words, over built, underutilized. As you know, LS motors like fuel pressure. Not sure if that's a good or bad idea though, but it seems to work well so far.

I also fought with the idea of blanking off the heater lines from/ to the water pump but ended up running hoses to my expansion tank. Boat runs cool and I have never had any air pockets or coolant troubles.

I also converted my boat from a carbed 383 that gave up its ghost to holley terminator x efi system. I'm new to the efi game but from what I've seen first hand after about 14 months of riding Kissimmee, Okeechobee, and the glades loaded to the gills with either bodies, hunting gear, or both, I'm a believer. I don't recall your route, but I cut my fuel tank and installed in tank dual fuel pumps that have been flawless. Actually, aside from slightly playing with pitch, and one oil pressure sensor going out, it has been flawless. Quick note on the oil pressure sensor: I recently installed a mech guage next to it on the oil filter manifold so that there is no more wondering if the sending unit is bad or if I really have erratic oil pressure. Just a peace of mind addition for verification.

The truth is, I'm not sure if any of my approach is correct. I've read a ton and there's no general consensus on any of it and I'm not a engine builder. I am, however familiar enough with motors and other systems having spent 36 years working in the maritime industry. Given your technical knowledge and detail oriented posts, I'm listening to what you're saying and very interested in your approach.

I'm running a 2.55 box with 3 jr blades about 24-25 degrees. Turning about 5300 or so rpm on a 13.6 D Back hull with stainless rigging. She will haul 5 of us with coolers and a grill up the hill without too much effort for lunch so I'm happy. Cruise is about 25 to 30 @ 2700 to 3300 rpm. On its maiden voyage my son and I hit 51 at 5k and it was climbing pretty good. I've thought about pulling some pitch out and spinning it up but don't need it. I just feel like I built it to be all in about 6k but again, I prefer being over built and underutilized rather than running on the ragged edge and maxing out everything . ;)

Needless to say, I think I left myself some room to grow. Don't think I'll do it though. There's a lot of truth in these pages about costs being outrageous even if you're building it yourself.

I'm curious about your thoughts concerning the heater lines on these motors. Also, any comparative knowledge you or anyone else may have between a truck intake manifold and a fabricated aluminum intake from holley? I have the holley fab alum on my boat. I'm running a 102mm throttle body.
 
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One Man Gang said:
Two things off the top of my head... I'm running higher pressure injectors, but I built for a possible future with forced air induction. My injectors are way down on their duty cycle with the hope that they will last. I am running 61lb of fuel pressure at my regulator. In other words, over built, underutilized. As you know, LS motors like fuel pressure. Not sure if that's a good or bad idea though, but it seems to work well so far.
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On the injector subject, the final injectors are 100 lb/hr when I need maybe 50, fuel pressure is set at 58 PSI. I still have to build the boat but have been thinking about dual in tank pumps. The tuner is arguing for a pickup pump on the main tank to a ~1 gallon tank with the HP pump to make sure the engine is getting fuel with a tank near empty. I am thinking about using the Holley Hydramat with in tank pumps as the solution.

https://www.holley.com/products/fuel_systems/hydramat/

One Man Gang said:
Also, any comparative knowledge you or anyone else may have between a truck intake manifold and a fabricated aluminum intake from holley? I have the holley fab alum on my boat. I'm running a 102mm throttle body.
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I am using the truck intake from the L92. This fits the 92 mm throttle body I am using. For comparison look at the green line on the torque curve I posted. The green torque curve is a Motor Trend 416 with a FAST intake and 102mm throttle body. My engine came in (hit 500 ft-lbs) 500 RPM earlier than the Motor Trend build and lost by 5 Hp at 6,300 RPM. Adding the K&N filter brought my engine in even sooner. Seems like the 92 mm throttle wins here.

Motor trend did a test of 20 different intake manifolds on a LS3.

https://www.motortrend.com/how-to/giant-ls3-intake-manifold-dyno-shootout/
 
My injectors are 80lb, fyi.

I have the hydra mat duals in my tank. Knock on wood it has been flawless.

I was concerned about my intake being too big at 102mm. I wouldn't mind trying a truck intake like yours. I rolled the dice when selecting size and type, and so far I'm happy, but as with a lot of things I always wonder what if I tried this.

Any thoughts on the heater block off or routing? Also, in case I missed it, how much compression are you running?
 
One Man Gang said:
My injectors are 80lb, fyi.

I have the hydra mat duals in my tank. Knock on wood it has been flawless.

I was concerned about my intake being too big at 102mm. I wouldn't mind trying a truck intake like yours. I rolled the dice when selecting size and type, and so far I'm happy, but as with a lot of things I always wonder what if I tried this.

Any thoughts on the heater block off or routing? Also, in case I missed it, how much compression are you running?
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Regarding expansion tank, I am nowhere near on a boat build, but my thinking is to run the inner port on my water pump (The Hot Side) to my expansion tank and leave the outer port plugged (vs. the dual hoses you mention).

11.3 compression, nothing crazy vs. stock 10.5, just planning 93 full time. The Texas Speed cam sheet and dyno run on the standard stroke 6.2 are below.

Regarding intake and throttle body, this subject has been discussed on Southern Airboat excessively. But even planning 5,500 run out, we are building pickup trucks not Ferraris. The factory configured the L92 I started with to power the Escalade and make power/torque to 5,500 RPM.

The stock throttle body is 87 mm and the intake manifold opening is ~94mm. The stroker adds 10% more displacement, so the optimum throttle body is about 10% more area (not accounting for cam). Geometry as it is, the optimum throttle body is 87*(1.10^0.5) = 91 mm.

Now, this is strictly based on displacement and assumes the cam adds similar. In reality we are all building for more torque through more airflow, so sizing beyond that is where the magic happens. For me, I would be happy to move the torque curve down from 5,500, plus Johnny gave me a 92 mm throttle body which bolted right up. So, the 92mm was a no brainer. Going larger in the market involves aftermarket intake manifolds, which are all tuned for making maximum Hp at 6,000 RPM Plus and use 102mm and larger throttle bodies which are (102/87)^2) = 137% or larger (in area) than stock to make beyond 600 Hp.

Unless you are turning the engine (regularly) to 6,000 RPM and beyond the 102 mm throttle body and Holley intake are too big. They hurt your performance/torque at normal operating range (2,500-4,500 RPM). Top end power at 5,000-5,500 is likely similar.

Cam Specs 2.jpg

Texas Speed L92 Stage 2 Curve.jpg
 
I was actually concerned I may be going too big with my intake and throttle body for NA, but it is in place and working good so I will leave it for now.

I almost plumbed my heater lines exactly like you're thinking. That's the one area I did not make and run AN hoses and fittings so plugging the "cool" side wouldn't be a problem. I pulled the factory nipples and tapped the holes so a plug would screw right in. That would be a simple thing to try and see if there's any improvement or difference.

I'll see if I can dig up the fuel pumps part number and specs for you when I get off my tugboat, but I do know they are from Rhodes(sp?) Racing, and they're overkill for my build.

Thanks for all the technical numbers and your feedback. Moving from the old school, carbed, SBC to the fuel injected LS platform, and doing it myself was a eye opening learning experience. Not difficult, but I've definitely seen the light. Fwiw, it's good to hear you steered away from the holley injectors. Thankfully all of my resources told me that was not the way to go before I pulled the trigger.
 
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