LS vs Big Block
03-24-2013, 08:21 AM
#31
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I will put a ls based motor up against a big block torque for hp any day I have hade 450 cubic in aluminum block
Motors in my cat for 5 years still going strong getting 2 miles per gallon no one has touched on the fuel mileage of these things put a big block to shame my two cents worth I just ran a ls7 which is 427 cubic in with the ls9 blower from gm on 93 oct gas 12pounds boost made 850 hp at 6600 rpm and 825 torque at5300 rpm this monster made 800 ft lbs at 3500 rpm and will fit under a corvette hood will post pictures and Dyno sheets tomorrow
Motors in my cat for 5 years still going strong getting 2 miles per gallon no one has touched on the fuel mileage of these things put a big block to shame my two cents worth I just ran a ls7 which is 427 cubic in with the ls9 blower from gm on 93 oct gas 12pounds boost made 850 hp at 6600 rpm and 825 torque at5300 rpm this monster made 800 ft lbs at 3500 rpm and will fit under a corvette hood will post pictures and Dyno sheets tomorrow
03-24-2013, 08:37 AM
#33
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I will put a ls based motor up against a big block torque for hp any day I have hade 450 cubic in aluminum block
Motors in my cat for 5 years still going strong getting 2 miles per gallon no one has touched on the fuel mileage of these things put a big block to shame my two cents worth I just ran a ls7 which is 427 cubic in with the ls9 blower from gm on 93 oct gas 12pounds boost made 850 hp at 6600 rpm and 825 torque at5300 rpm this monster made 800 ft lbs at 3500 rpm and will fit under a corvette hood will post pictures and Dyno sheets tomorrow
Motors in my cat for 5 years still going strong getting 2 miles per gallon no one has touched on the fuel mileage of these things put a big block to shame my two cents worth I just ran a ls7 which is 427 cubic in with the ls9 blower from gm on 93 oct gas 12pounds boost made 850 hp at 6600 rpm and 825 torque at5300 rpm this monster made 800 ft lbs at 3500 rpm and will fit under a corvette hood will post pictures and Dyno sheets tomorrow
03-24-2013, 08:47 AM
#35
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The exhaust was stock ls7 corvette I just did a test yesterday on a ls7 stock motor except for a little larger cam and valve spring change we made 660 hp at 6600 rpm and 560 ft lbs at 5200 rpm we put on a set of headers and the stock ls7 corvette manifolds no difference this was a bone stock motor pump gas you can put a fast intake on this motor and pick up 20 hp the motors are just fffffffuuu cool when was the last time they redesigned the big block never the ls7 motor is the motor of the new millennium just get it
03-24-2013, 09:57 AM
#36
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OK I'm very open minded on this subject and want to share an experience. I am 60 and grew up building hot 327's/350's as a kid and remember when the MK IV 396 came out in '65 in a few Impalas and Chevelle's...427's in '66 and the rest is history. I had an LS6 460 Horse SS 454 Chevelle in 1970 and it was hard to beat.
The BBC has been the architecture of choice for go fast marine propulsion as well as large cruisers 40' and under. One of Sea Ray's best sellers ever was the 34' & 39' EC with twin 454/330 horse BBC's on BW transmissions. A 34 EC will make about 35 MPH with that power and suck gasoline like you wouldn't believe!!!
Up until 2010 I had a Sea Ray 40' EC with twin 400 horse Cat 3208's that ran 30 fairly easily and used roughly half the fuel that a 34' w/454's or 502's would. One day I was at my marina in North Palm Beach when a very nicely restored '89 Sea ray 34' EC pulled in. It caught my interest so I did what we all do...I got a closer look. The owner was more than happy to share what he had done. i went aboard and he opened the hatches in the cockpit floor to reveal a pair of marinized LSA Small blocks!!! He had them mated to a pair of Hurth/ZF transmissions with 2" prop shafts!! The LSA'a are set up closed cooling and I have to tell you...in a 12' beam boat they looked lost in the bilge!!
My first question was how does it run? The owner was a retired engineer and knew his stuff. He explained that you have to understand he saved 1000 lbs of weight in the boat and almost doubled the power and torque....so let's go for a ride!!
We left the dock, pulled out into the ICW and idled thru the "No Wake" zone. Once we cleared he offered the helm to me which I couldn't get to fast enough. I eased into the throttles with tabs down and this 7 ton beast jumped on plane like a ski boat. Trust me...getting all that iron out of the bilge of that boat makes a huge difference. I saw 40 with the tabs still all in at 3800 RPM. I got out of the tabs and the 34 jumped to 45 without touching the throttles. I looked over and he gave me the nod so i let it all out...56 MPH at 5200 RPM!!! I backed off to about 4800 and held 52~53 no problem..Flow Scan showed 30 GPH TOTAL!!
He confessed that he spent just north of $40K on the boat in the re fit but there was a large portion of that total in new upholstery, electronics, etc.
In summary...I was sold on the LS idea that day. That boat accelerated like an out board ski boat and was a full 20 MPH faster than it had been with the original power...using considerably less fuel!!
I know the 34 EC isn't a hull that any of us would choose as a "Go fast" set up but imagine this set up in say a Formula 370 SS with steps!!??
I think we are in the midst of a "Paradigm Shift" in Marine Propulsion and the LS architecture has taken a strong lead.
The BBC has been the architecture of choice for go fast marine propulsion as well as large cruisers 40' and under. One of Sea Ray's best sellers ever was the 34' & 39' EC with twin 454/330 horse BBC's on BW transmissions. A 34 EC will make about 35 MPH with that power and suck gasoline like you wouldn't believe!!!
Up until 2010 I had a Sea Ray 40' EC with twin 400 horse Cat 3208's that ran 30 fairly easily and used roughly half the fuel that a 34' w/454's or 502's would. One day I was at my marina in North Palm Beach when a very nicely restored '89 Sea ray 34' EC pulled in. It caught my interest so I did what we all do...I got a closer look. The owner was more than happy to share what he had done. i went aboard and he opened the hatches in the cockpit floor to reveal a pair of marinized LSA Small blocks!!! He had them mated to a pair of Hurth/ZF transmissions with 2" prop shafts!! The LSA'a are set up closed cooling and I have to tell you...in a 12' beam boat they looked lost in the bilge!!
My first question was how does it run? The owner was a retired engineer and knew his stuff. He explained that you have to understand he saved 1000 lbs of weight in the boat and almost doubled the power and torque....so let's go for a ride!!
We left the dock, pulled out into the ICW and idled thru the "No Wake" zone. Once we cleared he offered the helm to me which I couldn't get to fast enough. I eased into the throttles with tabs down and this 7 ton beast jumped on plane like a ski boat. Trust me...getting all that iron out of the bilge of that boat makes a huge difference. I saw 40 with the tabs still all in at 3800 RPM. I got out of the tabs and the 34 jumped to 45 without touching the throttles. I looked over and he gave me the nod so i let it all out...56 MPH at 5200 RPM!!! I backed off to about 4800 and held 52~53 no problem..Flow Scan showed 30 GPH TOTAL!!
He confessed that he spent just north of $40K on the boat in the re fit but there was a large portion of that total in new upholstery, electronics, etc.
In summary...I was sold on the LS idea that day. That boat accelerated like an out board ski boat and was a full 20 MPH faster than it had been with the original power...using considerably less fuel!!
I know the 34 EC isn't a hull that any of us would choose as a "Go fast" set up but imagine this set up in say a Formula 370 SS with steps!!??
I think we are in the midst of a "Paradigm Shift" in Marine Propulsion and the LS architecture has taken a strong lead.
03-24-2013, 11:16 AM
#37
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Location: Mound, Louisiana
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Interesting thread. Having just bought an LS Camaro several years ago, I suggested the same thing over on Performance Boats forum. Even though it seems the membership is mostly comprised of smaller boats owners, I was greeted with "boos and hisses, bad idea, it'll never work" ,etc.
I'm laughing about it now!
I'm laughing about it now!
03-24-2013, 11:21 AM
#38
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03-24-2013, 11:25 AM
#39
Well said! A LS based engine can be a great package for most boats. I'm not going to say they would replace a 1500hp Sterling. Just because I don't want to pretend to know that level of power. Any thing under 800hp the LS based power plant can out shine a BBC. Wether fuel consumption, HP to weight or just unbelievable HP/Torq youll find something. Not in every aspect but overall if you mess with these motors you will be amazed. Ask the Ford guys more LS powered Mustangs at the strip than you see Ford powered (JKing). Breath breath ford guys
I have two 588's that I was freshing up to put in my boat. I started doing the math and some lightly boosted LS3's will be 600hp easily. They will also be EFI and the Stock ECM will work in this application. Then guys are running these motors at 15-18PSI of boost on stock bottom ends and stock head gaskets. They are doing this on 91 and Meth Inj. Some guys have played with E85 but I think they have went back to Meth because of lots of negative things about E85. I'm not sure about using Meth on a boat but I'll find out. (If you have tried it I would like your opinion on Meth Inj). I'm not saying that boost levels or stock bottom ends will work in a boat but LS's DO work in boats.
Now the comment that Mercury tested the LS motors and they weren't strong enough? Might be more politics then anything. I tow my 34Ft boat with a 6.0L that pulls it 80mph. I couldn't have towed it with a 7.4L with out lots more fuel and overheating it. I never had a 454 that went over 125k that wasn't desperate for a rebuild. GM removed the 8.1L from its line up because the reliability and better Hp/Torq/Mpg of the 6.0L. These motors are so strong they are effecting ever form of Motorsports that they are allowed in.
I have two 588's that I was freshing up to put in my boat. I started doing the math and some lightly boosted LS3's will be 600hp easily. They will also be EFI and the Stock ECM will work in this application. Then guys are running these motors at 15-18PSI of boost on stock bottom ends and stock head gaskets. They are doing this on 91 and Meth Inj. Some guys have played with E85 but I think they have went back to Meth because of lots of negative things about E85. I'm not sure about using Meth on a boat but I'll find out. (If you have tried it I would like your opinion on Meth Inj). I'm not saying that boost levels or stock bottom ends will work in a boat but LS's DO work in boats.
Now the comment that Mercury tested the LS motors and they weren't strong enough? Might be more politics then anything. I tow my 34Ft boat with a 6.0L that pulls it 80mph. I couldn't have towed it with a 7.4L with out lots more fuel and overheating it. I never had a 454 that went over 125k that wasn't desperate for a rebuild. GM removed the 8.1L from its line up because the reliability and better Hp/Torq/Mpg of the 6.0L. These motors are so strong they are effecting ever form of Motorsports that they are allowed in.
03-24-2013, 11:36 AM
#40
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I still think when it is time for my HP500EFI motors to be rebuilt I will look at the cost of the LS motors.
Even if I get the same power dropping 600 or more pounds out of the back of my 7200 pound boat would have to make a huge differance.
Even if I get the same power dropping 600 or more pounds out of the back of my 7200 pound boat would have to make a huge differance.
