Another jetboater
11-15-2010, 04:11 PM
#1
On The Tree
Thread Starter
Another jetboater (please bear with me, I am still reading as much as I can)
Currently running a tired old smallblock in my jetboat. Its either stroke the old technology or do a ls swap. The price to build the old motor is way more expensive than buying a complete ls motor. The more and more I read on here, has me wanting to swap.
I called around to all the local junkyards, and nobody has a LQ9. I was leaning towards the 6.0L because of the torque it puts out.
The 5.3's seem to be plentiful and reasonably priced. Would i be disappointed in a 5.3?
Currently my boat spins up to 5300 WFO and its a all iron 355 smallblock chevy.
My plan is to:
Drop in the LS? motor
Retain the EFI
Modify the stock ECU (need to research more)The wiring should be fairly easy, I only have a tach,voltmeter,oil pressure, and water temp gauges.
I can fabricate all my own mounts, exhaust and the water inlets.
The boat has 2 aluminum fuel tanks that i made last year. since its a boat they feed from the top of the tank with a downtube. Will this present a problem?
I could run the exhaust dry to aviod the headache of tuning without the o2 sensors.
What would be the best motor to keep efi for this application? It can be either aluminum of cast because I only run in fresh water. The boat is only 16' so the weight savings of aluminum would be kinda noticeable.
Currently running a tired old smallblock in my jetboat. Its either stroke the old technology or do a ls swap. The price to build the old motor is way more expensive than buying a complete ls motor. The more and more I read on here, has me wanting to swap.
I called around to all the local junkyards, and nobody has a LQ9. I was leaning towards the 6.0L because of the torque it puts out.
The 5.3's seem to be plentiful and reasonably priced. Would i be disappointed in a 5.3?
Currently my boat spins up to 5300 WFO and its a all iron 355 smallblock chevy.
My plan is to:
Drop in the LS? motor
Retain the EFI
Modify the stock ECU (need to research more)The wiring should be fairly easy, I only have a tach,voltmeter,oil pressure, and water temp gauges.
I can fabricate all my own mounts, exhaust and the water inlets.
The boat has 2 aluminum fuel tanks that i made last year. since its a boat they feed from the top of the tank with a downtube. Will this present a problem?
I could run the exhaust dry to aviod the headache of tuning without the o2 sensors.
What would be the best motor to keep efi for this application? It can be either aluminum of cast because I only run in fresh water. The boat is only 16' so the weight savings of aluminum would be kinda noticeable.
11-15-2010, 04:17 PM
#2
TECH Apprentice
Join Date: Jan 2002
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(please bear with me, I am still reading as much as I can)
Currently running a tired old smallblock in my jetboat. Its either stroke the old technology or do a ls swap. The price to build the old motor is way more expensive than buying a complete ls motor. The more and more I read on here, has me wanting to swap.
I called around to all the local junkyards, and nobody has a LQ9. I was leaning towards the 6.0L because of the torque it puts out.
The 5.3's seem to be plentiful and reasonably priced. Would i be disappointed in a 5.3?
Currently my boat spins up to 5300 WFO and its a all iron 355 smallblock chevy.
My plan is to:
Drop in the LS? motor
Retain the EFI
Modify the stock ECU (need to research more)The wiring should be fairly easy, I only have a tach,voltmeter,oil pressure, and water temp gauges.
I can fabricate all my own mounts, exhaust and the water inlets.
The boat has 2 aluminum fuel tanks that i made last year. since its a boat they feed from the top of the tank with a downtube. Will this present a problem?
I could run the exhaust dry to aviod the headache of tuning without the o2 sensors.
What would be the best motor to keep efi for this application? It can be either aluminum of cast because I only run in fresh water. The boat is only 16' so the weight savings of aluminum would be kinda noticeable.
Currently running a tired old smallblock in my jetboat. Its either stroke the old technology or do a ls swap. The price to build the old motor is way more expensive than buying a complete ls motor. The more and more I read on here, has me wanting to swap.
I called around to all the local junkyards, and nobody has a LQ9. I was leaning towards the 6.0L because of the torque it puts out.
The 5.3's seem to be plentiful and reasonably priced. Would i be disappointed in a 5.3?
Currently my boat spins up to 5300 WFO and its a all iron 355 smallblock chevy.
My plan is to:
Drop in the LS? motor
Retain the EFI
Modify the stock ECU (need to research more)The wiring should be fairly easy, I only have a tach,voltmeter,oil pressure, and water temp gauges.
I can fabricate all my own mounts, exhaust and the water inlets.
The boat has 2 aluminum fuel tanks that i made last year. since its a boat they feed from the top of the tank with a downtube. Will this present a problem?
I could run the exhaust dry to aviod the headache of tuning without the o2 sensors.
What would be the best motor to keep efi for this application? It can be either aluminum of cast because I only run in fresh water. The boat is only 16' so the weight savings of aluminum would be kinda noticeable.
I'd go with any motor you get a deal on 5.3, ls1, ls6 or 6.0.
11-15-2010, 04:45 PM
#3
On The Tree
Thread Starter
Well i live in the same area as you. called every auto wrecker in SD today. not one single 6.0L. Ramona has 5.3's for $600 Am I not looking hard enough?
11-15-2010, 04:55 PM
#4
Get a 6.0 LQ4, relatively low compression, lots of torque. If you need log exhaust manifolds, let me know. I have a pair of 351C aluminum logs that fit LS/LQ motors.
Oh yeah, if you need a GTO, front sump oil pan, I've got one of those too. An Olds 442 ended up in my driveway before a boat.
Oh yeah, if you need a GTO, front sump oil pan, I've got one of those too. An Olds 442 ended up in my driveway before a boat.
Last edited by garys 68; 11-15-2010 at 05:02 PM.
11-15-2010, 05:00 PM
#5
On The Tree
Thread Starter
Im looking for one... It seems however in california these things must be made out of gold, because if they have one they want like 3 grand for the thing
11-15-2010, 07:12 PM
#7
On The Tree
Thread Starter
ill check it out.
If you wanna kill some time and see all the crap i've done to this boat since 2009, you can see all the build pics and story here
http://www.socaljetboats.com/boat-sh...et-69-schiada/
If you wanna kill some time and see all the crap i've done to this boat since 2009, you can see all the build pics and story here
http://www.socaljetboats.com/boat-sh...et-69-schiada/
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11-16-2010, 12:32 AM
#9
On The Tree
Thread Starter
Well I have been researching the lq4 and think this would be a great motor for my boat. The problem is the drive by wire setup. I don't think that is going to work for my boat. Electric throttle in a boat environment just spells disaster like a prius running out of control on the freeway. With the bare bones ECM and wiring of my project would it be possible to connect the cable operated throttle body?
11-16-2010, 09:30 AM
#12
On The Tree
Thread Starter
I know the system is good. But it is less than ideal for the boat environment. A throttle for the boat is a foot throttle and most of the time when you get in to drive it you're wet. Also it is better to have a stiffer throttle when the water is choppy.
11-17-2010, 10:40 AM
#13
On The Tree
Thread Starter
still going back and forth on the 5.3 or 6.0. the 5.3 is half the price of the 6 and would allow more money for the swap. i just dont want to lose performance over my current old SBC. i dont know my hp/tq numbers of my current motor. that would make this alot easier.
The RPM's that i run are fairly high. I cruise at 3500 rpm and my max rpm right now is 5300. under 1800-2500 rpms is not even on plane.
The RPM's that i run are fairly high. I cruise at 3500 rpm and my max rpm right now is 5300. under 1800-2500 rpms is not even on plane.
Last edited by sandeggo; 11-17-2010 at 10:55 AM.
11-17-2010, 11:03 AM
#14
With efi, the midrange on both motors will put your old sbc to shame. I dont know the specs on your old motor, but you're looking at 300+ hp with either engine and a cam/valvesprings can make a big difference.
My choice...well no one ever wished they had a smaller engine....6.0.
My choice...well no one ever wished they had a smaller engine....6.0.
11-17-2010, 11:20 AM
#15
On The Tree
Thread Starter
Well i just got off the phone with a buddy of mine that knows my current motor very well and he estimates the HP to be around 300-330. His is a pretty accurate guess.
11-17-2010, 11:39 AM
#16
Well if you're happy with your current top speed, a 5.3 will get you there. If you want a little more, swap out the cam for an LS1 cam (really cheap), or LS6.
There was a 5.3 build on here a while back that showed really good dyno numbers.
And honestly, unless you go with high dollar headers, the exhaust may limit hp much beyond 350hp.
Oh, and I still have a GTO oil pan and 351C exhaust manifolds for LS motors.
There was a 5.3 build on here a while back that showed really good dyno numbers.
And honestly, unless you go with high dollar headers, the exhaust may limit hp much beyond 350hp.
Oh, and I still have a GTO oil pan and 351C exhaust manifolds for LS motors.
11-17-2010, 11:44 AM
#17
On The Tree
Thread Starter
Well if you're happy with your current top speed, a 5.3 will get you there. If you want a little more, swap out the cam for an LS1 cam (really cheap), or LS6.
There was a 5.3 build on here a while back that showed really good dyno numbers.
And honestly, unless you go with high dollar headers, the exhaust may limit hp much beyond 350hp.
There was a 5.3 build on here a while back that showed really good dyno numbers.
And honestly, unless you go with high dollar headers, the exhaust may limit hp much beyond 350hp.
the cost savings of the 5.3 allows extra money for tunes, cams, etc.
11-17-2010, 12:12 PM
#18
ill check it out.
If you wanna kill some time and see all the crap i've done to this boat since 2009, you can see all the build pics and story here
http://www.socaljetboats.com/boat-sh...et-69-schiada/
If you wanna kill some time and see all the crap i've done to this boat since 2009, you can see all the build pics and story here
http://www.socaljetboats.com/boat-sh...et-69-schiada/
