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mtnrider 06-30-2022 12:41 PM

any progress with this build

articfriends 07-01-2022 06:43 AM


Originally Posted by mggdoors (Post 4767590)
Do yourself a favor and pull the intercoolers and gusset them. Also run the zl1 lid if possible. Good for 20 or so hp and intercooler is more efficient. Port them as well. I did mine. Pay close attention to the area right above the gasket area that mates to head. Youll notice square edges. Round those out and open them up. Injectors I would decap the zl1 injectors and have them cleaned and flow matched. Good for 105lb/hr. And cheap. Last but not least a nice little trick if you dyno them and your ecu has capability is to fire injectors the second the intake valve opens or 0-5 degrees before and stop them at or before the valve closes. Easy BIG hp gain and does let fuel pool behind calve/cleaner afr etc. I actually showed my dyno guy this and he couldnt believe the gains. Over 40hp in my case. If you have overlap and can get enough fuel in within the valve event I suggest injecting after the overlap event. But only if you can get adequate fuel in by the time it closes.

Where did you see the '40 hp" gain from timing a port injected injector rpm wise? Im skeptical as I own a dyno and high end injector machine and have never found a single hp gain form sequential or timed injectors in a port vs batch fire OR a difference in AFRS whatsoever off of idle. Heres the reason WHY I disagree with the 40 hp gain: at say 6000 rpm, the intake valve is opening and closing 3000 times a minute. The injector is also firing 3000 times a minute. at a typical top end MS of say 13 MS, the injectors firing for .013 seconds (keeping deadband out of discussion which is minor) , extrapolating the data out to 3000 times minute, .013 x 3000+ 39, thats 39 seconds, so of in a minute of valve opening and closing 3000 times, the injector has sprayed fuel pretty much steady for 39 of those 60 seconds, so about 70% of the whole time. this is assuming the injector is NOT set to double fire and is only firing every 4 stroke revolution. When you see a injector on machine at anything over than equivalent to 2500 rpms, its a steady spray so i disagree 100 % with the 40 hp gain, you may have made other tuning changes and saw a gain but after a certain rpm your injector is spraying a giant stream/fog of fuel, Smitty
Now a direct injected engine, especially a diesel, yeah, I can see by advancing injector timing there can be a power optimization

PODUNK RACING 03-18-2023 04:06 PM

Good information!

mtnrider 03-19-2023 01:52 PM

Did you ever get the boat back in the water

hogie roll 01-17-2026 10:54 AM

Just reread this one. Wanted to say thanks for all of the posting and data. I know we gave you a hard time.

I think if going NA with LS engines for a boat a guy would want to utilize all of the 9.3” deck height and get really aggressive with the stroke, like a 4.125” if possible. Better yet a sleeved aluminum block or aftermarket block with a big bore too. But then the budget comparisons to big blocks have really gone out the window.

Utilizing stock take off blowers like you did is really the smartest move.

mggdoors 01-17-2026 03:30 PM


Originally Posted by hogie roll (Post 4941586)
Just reread this one. Wanted to say thanks for all of the posting and data. I know we gave you a hard time.

I think if going NA with LS engines for a boat a guy would want to utilize all of the 9.3” deck height and get really aggressive with the stroke, like a 4.125” if possible. Better yet a sleeved aluminum block or aftermarket block with a big bore too. But then the budget comparisons to big blocks have really gone out the window.

Utilizing stock take off blowers like you did is really the smartest move.

no worries, my engines are still up and running great. We have Sens converted them in the last two years over to LSA ported Blowers and blah blah blah and we have them up to just over 1000 hp. Each different cam specs, of course. I can say this my 28 tall deck hauls ass and I can hold 6500 RPM’s as long as I want. We generally run them 5 1/2 pounds of boost. They make 767 hp each and about the same torque. Notice on the diner run we stopped at at 6400 RPMs even though we are still gaining over 20 hp per 100 RPMs that was our final tune for how we run it in the boat 90% of the time to try to keep the drives alive.
https://cimg3.ibsrv.net/gimg/www.off...28acef908.jpeg

hogie roll 01-17-2026 05:54 PM


Originally Posted by mggdoors (Post 4941602)
no worries, my engines are still up and running great. We have Sens converted them in the last two years over to LSA ported Blowers and blah blah blah and we have them up to just over 1000 hp. Each different cam specs, of course. I can say this my 28 tall deck hauls ass and I can hold 6500 RPM’s as long as I want. We generally run them 5 1/2 pounds of boost. They make 767 hp each and about the same torque. Notice on the diner run we stopped at at 6400 RPMs even though we are still gaining over 20 hp per 100 RPMs that was our final tune for how we run it in the boat 90% of the time to try to keep the drives alive.
https://cimg3.ibsrv.net/gimg/www.off...28acef908.jpeg

You dynod to over 1000hp with those blowers?

mggdoors 01-17-2026 06:30 PM

Correct

Originally Posted by hogie roll (Post 4941603)
You dynod to over 1000hp with those blowers?



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