Chris1530

So im new around here.. Im planning on getting started with lsx engines.
Im lloking at putting a LS engine into a Jet boat. otheres have already done it.

Im not looking to spend gobs of money doing it either.
Im just lookn for prolly around 350 HP 380 Ft lbs more or less.

Looking at the used 5.3 Engines are cheaper about 750 shipped
with harness, ad ECM.
versus 6.0 shipped 1400 with harness and ECM

I am looking at just a stock engine with a Cam for now..
Will be Ran with Open Headers

Question #1
So if I drop a Cam in the 5.3 Engine will I have any problem reaching 350 HP or more ?

Question #2
How much more HP wll the stock 6.0 with a cam make over the 5.3 ?

Question #3
Can some Tune the Ecm based on the info I give, and what is the price range.

Question #4
Relates to above, Hp tuners and EFI Live tuning software is it better to spend the money and tune myself, or send the ecm to be tuned ?

Hope i have givn enough info for you guys to help with answers.

Thanks

ULTIMATEORANGESS

iTrader: (4)

jets boat huh?

sounds like fun. im not much help but my friend has a chevy 350 in his boat and hes very happy with it. i think its carbed though.


id still go with bigger cubes but i know **** about boats lol.

Lanaue

iTrader: (3)

If you want power go with the 6.0. You can get 350hp from the 5.3. 400hp should be easy from the 6.0. Go with your heart, You can't go wrong.

Chris1530

Well the main thing i wanna know HP wise.
is How much more will a stock 6.0 with a cam make over
a stock 5.3 with a cam ? and if it isnt enough to offset the price difference
being that the 6.0 is double the price.

Anyone have info on the other questions ?

01ssreda4

iTrader: (96)

I would say hp of a camm'd 5.3 vs. a camm'd 6.0 would be likely a 50 hp difference. You could run a slightly bigger cam with the bigger cubes and have better power and torque in the lower rpms.

Most tuners I know use HPTuners. There are a few guys here that will tune you based on the specs you give them. Frost is one of them. I think the price is around 100 or so. You mail him your ECM.

Camaro_94

iTrader: (5)

If 350hp is your goal, then I'd say go with the 5.3. If you want more power, you can always do a head/intake/big cam setup on it.

Chris1530

Yeah 350 is the conservative goal.
it had a BBC about 300 HP in it when i bought it. oil pickup came off..
Yanked it put the SBC in it out of my Mud truck only about 300HP.

So i figure if i go 350 at the flywheel im good for the Year. Then the year after i can look at other options, maybe a conservative turbo setup.

and im looking at flywheel HP bcuz theres no drivetrain. just the Jet

Thanks for the Help so far.

Oh and I got the Idea from "Compressor Surge" on here and "Wasted Income"
on Performance Boats.. I read the article on both sites

Chris1530

Also anyone i can talk to on cam specs ?

need something with good low and mid range torque. like 2000 up to around 5500

When i do a cam swap. do i need to change springs, and pushrods. or des it depend on the amount of lift the new cam has ?
Thanks
I know older sbc, but ls is new to me and im not really sure how much lift the stock springs can take.
Seems alot of ppl here change the valve train with a cam

01ssreda4

iTrader: (96)

Springs and pushrods in these motors are barely adequate for the stock cam. So yes I would recommend them. As far as cam specs, you can call up Cam Motion, Thunder Racing, TSP, or EPS. either of those will get you going the right direction.

topspeed7

iTrader: (1)

im planning to do the same thing but boats like high rpm so my project is turbo 4.8,
the 4.8 revs much more than a bigger cube engine and it can easily handle 500 plus on stock crank and rods.

Chris1530

So would these be a good spring to upgrade to ?

http://www.summitracing.com/parts/LUN-73925K1LUN/

says supports up to .660 lift ..

4.8 Turbo project what kind of boat ?

JohnFrazee02SS

iTrader: (23)

yes a 5.3 cammed will make 350 flywheel i have a 02 z28 with one that puts down 340 rwhp on a .563 lift, its very responsive and has alot up top.

Chris1530

Nice to know..
Its been a boring day so ive been reading....
And seems alot of you guys are turbo'n these 5.3's in pretty stock form.
Might do that,
would a turbo like this support 8-10 PSI on a stock 5.3 with upgraded springs and cam and make 500ish HP ?
or would I need to upgrade other parts.

http://cgi.ebay.com/ebaymotors/GT-45...Q5fAccessories

Turbo flange = T4 inlet Flange 4-bolt exhaust flange
Type of Bearing - Wet Float Bearing
Type of Wastegate - External Wastegate
Compressor:
Inlet: 4 3/16" / Intake (ID/OD): 2.25"/3.25"
Inducer: 68.7mm / Exducer: 97.8mm
Trim: 69 / A/R: 0.66
Turbine:
Outlet: 4"
Downpipe flange: 3.5" V-band
Inducer: 87.4mm / Exducer: 77mm
Trim: 92 / A/R: 1.05

Chris1530

seems some of the threads i read here ppl were runnin 15psi on stock bottom ends ? would

I be safe with the above stated items.

5.3 with springs/cam.
GT45 turbo @ 8-10 lbs
do i need different injectors ?

thanks

LCW

iTrader: (6)

If you go with the turbo for your 5.3 setup and want to run 15psi you will need to drop to compression ratio to be safe. However I believe you will be fine on 5-8 psi in stock form. If you don't want to deal with the computer business you can grad a 6LS from MSD and toss a carb up top. Carbs aren't bad with turbos either.. I have seen a guy make 1200 whp through a carb at 22+ psi. His motor was built very well though. Best of luck. I have been looking into this also. Thinking of stroking my LS6 to 383 then swap to a carb.

71chevytruck

Trick flow has a package that will give u 550 hp and stock internals. Im looking into it myself for the 6.0. I am building a carbed 6.0 for my 71 chevy truck. U will get better performance and reliable delivery if u upgrade injectors, but at around 8 psi, u should have no problems. Weight may be an issue to think about also. 5.3 would b aluminum, 6.0 is prolly cast. At the hp u r looking at, reliability wont b an issue.

71chevytruck

part number for that kit from trick flow would be tss-k 306-550-470. Good luck. Hope to see the boat on here soon.

nick2334

iTrader: (2)

what size boat are we talking about? Also how fast do you want to go on the water? One more thing to think about if you don't get the correct lower unit in a boat the motor doesn't mean anything. Its kind of like the rear end of water.

lemons12

iTrader: (71)

All you want is 350 HP? That can easily be achieved with only a bolt on 5.3..

I like power.. the 6.0 at any stage is going to make around 50 more HP with a better curve and more tq. I would do the 6.0 with a 228 cam or so.. that will put you well over 350 HP
6.0 1300
Cam 350 or used 200
Springs 200
Push rods 110
Timing chain and oil pump.. been a while sice I have bought either, check Texas-speed.com for price on these.. all you need is an ls6 pump, don't waste money on a double roller or anything.

If you end up needing more power pull the heads and get them ported and milled..

no replacement for displacement.. for the money there is no reason to not go with a 6.0

Typed from phone hope it was understandable and helpful..