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Originally Posted by 242LS
(Post 4677721)
You almost want to go straight to a museum so it doesn't get dirty. Beautiful.
BTW - Does anyone have the dyno sheet/numbers for a stock Merc 330 or 420? I'd love to see how the torque numbers compare. close to a merc 420. Also a LS3 crate. Similar hp, different torque curve for sure. https://cimg3.ibsrv.net/gimg/www.off...47cb822f61.jpg |
Btw. I will be doing a b testing on the coolant system. Both are setup with 160 thernostat. One has 2 holes drilled. One has 3. I will be running them monitoring temperature stability and water pressure when we do get out and about. Figured it would be a good idea so people know what to expect when the give this a go |
Originally Posted by 242LS
(Post 4677721)
You almost want to go straight to a museum so it doesn't get dirty. Beautiful.
BTW - Does anyone have the dyno sheet/numbers for a stock Merc 330 or 420? I'd love to see how the torque numbers compare. |
Originally Posted by 242LS
(Post 4677721)
You almost want to go straight to a museum so it doesn't get dirty. Beautiful.
BTW - Does anyone have the dyno sheet/numbers for a stock Merc 330 or 420? I'd love to see how the torque numbers compare. |
I took MILD THUNDER's 454HO chart, eyeballed the actual numbers and plotted against my LS3 and 509/AFRs/cam (the LS looks just fine for torque now):
https://cimg4.ibsrv.net/gimg/www.off...7c5da20cd.jpeg |
The LS3 crate is 10.7:1 static, where the 454HO is 8.75:1. I can see where the big block would shine , in the lower rpm and acceleration department.
Suprised the 6.2L LS3 doesnt make more torque, a 6.4L hemi makes around 475ft lbs. |
Originally Posted by 242LS
(Post 4677737)
I took MILD THUNDER's 454HO chart, eyeballed the actual numbers and plotted against my LS3 and 509/AFRs/cam (the LS looks just fine for torque now):
I personally will not build high RPM boat engines again. To achieve my PK HP and speed I was spinning my engines ~6500 RPM that pushed my "legit" cruise speed to 5000 RPM's. There was never a real balance in prop pitch selection. Either spin the s#it out of them with a small wheel or load the engines with a bigger prop. Engines ran great, but running engines 6000+RPM's for miles that you hand built with your hard earned money just makes your guts pucker. |
Originally Posted by mggdoors
(Post 4677727)
Dirty. That would be my gto currently. Redoing turbo plumbing at the same time as this build. Its a f******ing mess right nowhttps://cimg3.ibsrv.net/gimg/www.off...34cd668e4.jpeg |
Originally Posted by 242LS
(Post 4677737)
I took MILD THUNDER's 454HO chart, eyeballed the actual numbers and plotted against my LS3 and 509/AFRs/cam (the LS looks just fine for torque now):
https://cimg4.ibsrv.net/gimg/www.off...7c5da20cd.jpeg
Originally Posted by 14 apache
(Post 4677768)
be carful plastic hose on wastegates it will melt off if you run it hard enough at least in a boat it will. Came back from a ride in my vdrive and nothing was hooked up and making big boost. Lo |
Originally Posted by Rookie
(Post 4677755)
Nice numbers.
I personally will not build high RPM boat engines again. To achieve my PK HP and speed I was spinning my engines ~6500 RPM that pushed my "legit" cruise speed to 5000 RPM's. There was never a real balance in prop pitch selection. Either spin the s#it out of them with a small wheel or load the engines with a bigger prop. Engines ran great, but running engines 6000+RPM's for miles that you hand built with your hard earned money just makes your guts pucker. |
Originally Posted by Rookie
(Post 4677755)
Nice numbers.
I personally will not build high RPM boat engines again. To achieve my PK HP and speed I was spinning my engines ~6500 RPM that pushed my "legit" cruise speed to 5000 RPM's. There was never a real balance in prop pitch selection. Either spin the s#it out of them with a small wheel or load the engines with a bigger prop. Engines ran great, but running engines 6000+RPM's for miles that you hand built with your hard earned money just makes your guts pucker. |
Originally Posted by JRider
(Post 4677795)
One thing he has going for him is that these are going into a 28 Daytona, efficient hull for sure. I had a 6300rpm BBC motor in my old 28 Profile cat, took some propping for sure. Small prop and still had to ventilate the prop to get it on plane, tried tubes like a #6 boat at first then found out the prop vent holes were enough to let it spin up to get it on plane. With twins he should not have as much of a problem as me planing. I always thought twin LS motors in a 28 Daytona would be killer, taking out a 1000lbs from big block weight would do that hull wonders as far as balance.
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Engine get dropped at dyno Saturday. Should be dynoed by end of following week Will be ran on a Superflow 901. For comparison im gonna try to get some sheets from Larry of hp500 and 525 that have also been ran on hos dyno for apples to apples. |
I admit I have not had a chance to read your entire build thread. I was surprised early on to see you were using LS3 style heads. I have contemplated an LS build for years for either my current boat or preferably a better boat. I however would use a cathedral port head, most likely one of the aftermarket heads like a TrickFlow or AFR. I have seen several dyno shoot outs of max effort builds using both style heads and while the square port always takes the top number, it also is always sacrificing numbers down low and to me the peak number does not justify that short fall. I realize these are not max effort/max budget builds, so perhaps that was why you chose the stock LS3 heads over perhaps a stock cathedral head. At any rate I look forward to seeing your results and still plan to read the rest of your build. Good Luck. One last thing, I just had a memory post up of this build on my F/B wall and thought I would share it with the group.
https://www.enginelabs.com/news/vide...00-horsepower/ |
Originally Posted by fastestbowtie
(Post 4679125)
I admit I have not had a chance to read your entire build thread. I was surprised early on to see you were using LS3 style heads. I have contemplated an LS build for years for either my current boat or preferably a better boat. I however would use a cathedral port head, most likely one of the aftermarket heads like a TrickFlow or AFR. I have seen several dyno shoot outs of max effort builds using both style heads and while the square port always takes the top number, it also is always sacrificing numbers down low and to me the peak number does not justify that short fall. I realize these are not max effort/max budget builds, so perhaps that was why you chose the stock LS3 heads over perhaps a stock cathedral head. At any rate I look forward to seeing your results and still plan to read the rest of your build. Good Luck. One last thing, I just had a memory post up of this build on my F/B wall and thought I would share it with the group.
https://www.enginelabs.com/news/vide...00-horsepower/ |
Originally Posted by mggdoors
(Post 4679140)
Dyno pull is Friday. We are utilizing dual plane intakes to still maintain maximum low mid torque with a loss of 10-15 hp around 6-6200 vs single plane. My builds are very close to what you are talking about without spending buku bucks on heads |
Originally Posted by mggdoors
(Post 4677890)
Im teally hoping the weight loss helps this baby get on plane easier. It can be a real pain. Was literally impossible with 4 blades. Had a good enoigh bite but then boost on old engines would kick in and blow them loose. Even dragging tunnel tab. Hopefully heavier nose now will help force her over |
Originally Posted by Wildman_grafix
(Post 4679179)
I have dyno sheets for HP500EFI's and 525's from our guy here if you want them. Shoot me a PM with your e-mail and I can send them out.
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Originally Posted by JRider
(Post 4679192)
Did you have shorty drives? My friends 28 tall deck had standard drives with no tab and twin 502 Mags, he never had an issue planing. I drove it a few times.
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If I wanted more torque I would have went with Big Block engines. I’m still running the 1.65 Blackhawk drives. I’m after top end power at 6000-6500. My thoughts are a future update on drives and installing LSA superchargers. I like the broad power and of the 6.2 with its heads. I still should have more power and torque at any rpm range than compared to the MPI 350’s I had.
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Originally Posted by mggdoors
(Post 4679207)
I am looking for dyno sheet specific to the dyno we run on to get a valid comparison. Different dynos show different #s |
Well???? Looking for results.
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Tomorrow. The single plane did not make it in on time so I bought another dyno day for ****s and giggles. Trick flow single plane. The edelbrock dual is not playing well with side to side afr. Also we are pegging 106psi of oil pressure lol. Losing quiet a bit of hp (5-8hp per 10psi). So Im going to have them dump the 15-40 and go to 5-30 which is what llmor runs in his ls marine engines. We are set at .0026 mains .0023 rods so the lighter oil will be adequate. The dyno pulls are in full marine trim (alt, wp, swp) minus exhaust. Exhaust used is the small 1 3/4 schoenfield stepped circle track headers. Tested no spacer, open 1”, open 2”, 1” 4 hole. No spacer sucked. Gained 20 by adding spacer. 4 hole sucked too although it had most consistent afr side to side. 22-30 timing. Final ser at 26 as 26-30 only seen like 8hp. Safety tuned. 10x3 gaffrig air cleaner in place on all pulls. Dyno is very greedy according to the gentleman running the dyno. Says he has had customer run cars on chassis dyno and make 20rwhp more than is shown on engine dyno. That is here nor there. Also will be posting egt data. Tq fluctuates only 87ft lbs from 2600-6200. Very flat. Will post tomorrow once data with single plane comes in. |
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Cool. Looking forward to seeing the results and thanks for all the details.
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Were you also planning on trying the marine exhuast and see if there is any change? |
Originally Posted by Wildman_grafix
(Post 4679756)
Were you also planning on trying the marine exhuast and see if there is any change? |
Ok. Here we go. Just to recap. Keep an eye on the ugly afr on the dp. The sp was much cleaner but swappedlean banks. Weird. Stock ls3 heads. Stock rockers. 408 stroker. 11:1 1050 4150. Full marine trim minus exhaust. J607 correction in Tucson AZ. Not max timing runs. 30 degrees showed max power but I had them reduced to 26 to beconservative and safe. The 237/237 114lsa single pattern that I designed meets the anti reversion qualities of my exhaust but as you can see flattens out at the top due to poor exhaust flow on the exhaust port. Makes good solid power all the way through but as my budget does not allow headers at this time I stayed conservative to prevent reversion. I did do a b testing for you guys ( thank my pocket book later) with single and dual plane intakes. Keep in mind that the operator before even running it stated it is very greedy. Believe me, dont believe me. I dont really care. We will be a b cam testing in the next month. Will be adding in split and reducing intake duration. Possible porting. Holy oil pressure. Lol The last shot is dual plane with direct carb mount vs 1”. It did not like the direct mount. Dyno operator and I do not particularly care for these carbs. Both flowed and ran the same but finicky and require drilling bleeds as bleed jets are oversize to standard. Not a fan. Ran decent once tuned. Idled at 800. Medium choppy idlehttps://cimg7.ibsrv.net/gimg/www.off...440884796.jpeghttps://cimg8.ibsrv.net/gimg/www.off...c7ca23a2e.jpeg https://cimg9.ibsrv.net/gimg/www.off...517e48973.jpeg https://cimg0.ibsrv.net/gimg/www.off...efbc2faf8.jpeg |
Dual plane vs single plane. Sp run is not our best run. 10hp shy. Just for comparison sakehttps://cimg7.ibsrv.net/gimg/www.off...4ab8363797.jpg |
Pull showing from 2600 on dual plane with 2” spacer 26 timinghttps://cimg7.ibsrv.net/gimg/www.off...2632a2e194.jpg |
pretty damn good,,way back when,,I had my oval port,single plane,9.3-1 comp,230/236 ls110 454 made 527hp,517tq.I love the light power plant you have.my tq curve was pretty flat to,2 tq peaks at 4100 and 5200 rpm.
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You said that you may have data on a 525 ran on the same dyno? Were you able to get those?
So what Intake have you decided to go with? |
FWIW, I wouldnt reduce the intake duration anymore than it already is. I would add exhaust duration, like at least a 10* split, maybe even a little more due to those heads. I agree that your lack of exhaust flow, from the port itself, and the exhaust valve duration, is hurting top end power. Sure it may lose a little down low, but I think it will more than make up for it up top. Right now, that powerband is typical of a 1990s mercury HP500 engine. By going from 5200, to 5800, youre gaining a whopping 11HP over 600RPM. The engine is dying off, and the BSFC's show the ineffiency there. I'd expect the problem to be worsened, had it been dynoed with a marine manifold like a stainless marine. One of the nice things about an LS, is its valvetrain. Seems like a waste to run it where a old big block has proven to live hundreds of happy hours without issue.
Youve got a 10.8:1 compression engine there, throw some cam at it. Worried about reversion, convert the tails to dry, drill in a couple pizzer holes at the ends, and run some mufflers or turn downs. If youre dynoing with pump gas, and it likes the timing, to the tune of 14HP more on top, I'd run that. The engine is telling you what it likes. Its telling you that you were firing the plug at the right time in the combustion process. Im more worried about timing advance in the lower rpm range. Almost every engine i've datalogged watching things like spark knock/short term retard, has almost always happened in the lower to mid rpm. Rarely does it occur at peak hp area. Firing the plug later, on a marine engine, can be detrimental just as firing it too soon. It puts a ton of heat into the exhaust valve, and itself can cause detonation, tuliped/fatigued valves, etc. In a car, that only sees full throttle blasts for short times, the heat buildup from retarded timing isnt all that great. A boat engine, that may be held WFO for 10 minutes, I'd rather keep the combustion events going like a swiss watch. Great build, thanks for sharing the results, looking forward to the cam swap results. |
Originally Posted by Wildman_grafix
(Post 4679980)
You said that you may have data on a 525 ran on the same dyno? Were you able to get those?
So what Intake have you decided to go with? |
Originally Posted by MILD THUNDER
(Post 4679998)
FWIW, I wouldnt reduce the intake duration anymore than it already is. I would add exhaust duration, like at least a 10* split, maybe even a little more due to those heads. I agree that your lack of exhaust flow, from the port itself, and the exhaust valve duration, is hurting top end power. Sure it may lose a little down low, but I think it will more than make up for it up top. Right now, that powerband is typical of a 1990s mercury HP500 engine. By going from 5200, to 5800, youre gaining a whopping 11HP over 600RPM. The engine is dying off, and the BSFC's show the ineffiency there. I'd expect the problem to be worsened, had it been dynoed with a marine manifold like a stainless marine. One of the nice things about an LS, is its valvetrain. Seems like a waste to run it where a old big block has proven to live hundreds of happy hours without issue.
Youve got a 10.8:1 compression engine there, throw some cam at it. Worried about reversion, convert the tails to dry, drill in a couple pizzer holes at the ends, and run some mufflers or turn downs. If youre dynoing with pump gas, and it likes the timing, to the tune of 14HP more on top, I'd run that. The engine is telling you what it likes. Its telling you that you were firing the plug at the right time in the combustion process. Im more worried about timing advance in the lower rpm range. Almost every engine i've datalogged watching things like spark knock/short term retard, has almost always happened in the lower to mid rpm. Rarely does it occur at peak hp area. Firing the plug later, on a marine engine, can be detrimental just as firing it too soon. It puts a ton of heat into the exhaust valve, and itself can cause detonation, tuliped/fatigued valves, etc. In a car, that only sees full throttle blasts for short times, the heat buildup from retarded timing isnt all that great. A boat engine, that may be held WFO for 10 minutes, I'd rather keep the combustion events going like a swiss watch. Great build, thanks for sharing the results, looking forward to the cam swap results. |
The more and more I look at this dyno chart it makes me question the cam timing. I had a buddy install the cams and am questioning his install at this point. The way the power falls off at 5400 and hangs out tells me we are either way advanced or retarded. Comparing to a 236/236 we did (almost identical) it pulled through and peaked at 6400. Time to play doctor before we throw another cam at ithttps://cimg3.ibsrv.net/gimg/www.off...f945290fe.jpeg |
Seems to be close to on par with a merc 500efi |
Originally Posted by Crude Intentions
(Post 4680532)
Seems to be close to on par with a merc 500efi |
Was the 236/236 cam in the same engine? Same cube/stroke?
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Originally Posted by MILD THUNDER
(Post 4680540)
Was the 236/236 cam in the same engine? Same cube/stroke?
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