PDA

View Full Version : Putting an LS1 into a 90' Prostar 190?!?


jdb11386
08-10-2010, 01:10 PM
Im new to the site but I have a 1990 Prostar 190 with a 351. Me along with my horsepower happy friends feel the ford engine isnt enough and are thinking about converting the boat to a 6.0 LS1. I was wondering if anyone has heard of anyone trying the swap or what your thoughts are on it.

DooSPX
08-13-2010, 10:14 AM
possible yes, but you can build the 351 w/ GT40P heads, intake and a small cam and be at 320hp and close to 400 lb trq and rape the 6.0 LQ4/LQ9 easily out of the hole for a lot less then swapping the GM plant in. You need... GM motor mounts, bellhousing adapter, custom linkage bracket, plum a return line for the EFI system, marine starter, marine alt., new wet exhaust manifolds and a custom tune to run Speed Density and to either run open loop all the time or a tune to bypass all factory narrow band O2's and adapt a WB O2 in to the wet exhaust riser and tune for the WB only but that can be very tricky and would need a new OS to be flashed onto the ECM. Remember that boat engines are under constant load and lots of it compared to a truck/car that has OD and a minimum of 4 gears.
I looked into this a while ago... NOT worth it.
The fords have KILLER low/mid range torque which is normally at peak around the rpm you get pulling a skier up.
BTW, this is coming from a GM die hard right here. the only ford I currently own is in my 91. then we have a chevy car, a buick, and a GMC truck. just sold a camaro a little while ago. (miss that car) though I wouldnt mind having a early 70's bronco w/ a 351W built.

east tx skier
08-13-2010, 10:29 AM
I wouldn't want to give up the Ford engine in my boat.

/obligatory engine pr0n.

http://lh6.ggpht.com/_1gl9obJSimU/Sl3oTW2nnWI/AAAAAAAACXo/ljyqpPuQP-Y/s640/GT40.jpg

DooSPX
08-13-2010, 10:40 AM
good looking furd there Doug! lol
mind if I take it and swap into my 91. lol

dummy
08-13-2010, 10:49 AM
FYI - LS1 is a 5.7L all-aluminum LS-series engine used in the 'Vettes, Camaros, and Firebirds.

Like DooSPX says, you need to do a ton of work to convert to the modern injected engine. I'd conservatively guess it'd be in the neighborhood of $5K (used engine)-$15K (new engine) for the full swap. This isn't a marine kit, but it gives you an idea: http://turnkeyenginesupply.com/Engine.aspx?pid=2&sid=13&eid=51&key=packages

You can do a lot to your 351W for that.

east tx skier
08-13-2010, 10:53 AM
good looking furd there Doug! lol
mind if I take it and swap into my 91. lol

You would probably need a new engine box. That thing is dropped way down in the bilge on that boat.

Oh, and no. They don't make 'em any more. And this one only has 240 loving hours on it. :)

DemolitionMan
08-13-2010, 11:01 AM
You can get 400 hp out of the 351 windsor. It cost me about $2,600.

DemolitionMan
08-13-2010, 11:07 AM
You can get 400 hp out of the 351 windsor. It cost me about $2,600.

It was about $4,000 total if you included msd ignition and the chrome accessories.

DemolitionMan
08-13-2010, 11:11 AM
...............

oldairboater
08-13-2010, 12:42 PM
Build your ford right and it will scream. Nothing replaces cubic inches but your not even close to getting the most out of your existing cubic inches. I have fuel injection on one motorcycle, my jeep, and my truck. FI is good when it is good but when it isn't good it is almost always a dealer item to fix. The fuel pump to maintain fuel pressure in an FI engine is a big problem. They go out with some regularity and they will not take too much abuse or stupidity. You can shorten the life of an electric fuel pump through your own stupidity. My other Harley is carbed and so are both of my boats. The boats are carbed with Holley's and the ignition is simple electronics........Almost bullet proof.

flipper
08-13-2010, 12:46 PM
You'll have to get a bell housing or tranny too which don't come as cheap as I thought they would when I was going to switch mine over to GM

get_sum
08-13-2010, 05:06 PM
LS1 = 1st gen F-body 5.7L, Vette, and 1st iteration of the new GTO
LS2 = 6.0L in Vette and newer GTO


ah well. forget it. You can get it all here anyways: http://en.wikipedia.org/wiki/GM_LS_engine

DooSPX
08-13-2010, 05:52 PM
LS1 = 1st gen F-body 5.7L, Vette, and 1st iteration of the new GTO
LS2 = 6.0L in Vette and newer GTO


ah well. forget it. You can get it all here anyways: http://en.wikipedia.org/wiki/GM_LS_engine

real break down of the most popular LS based engines...

LM7/L33- 5.3/5.3 HO (there are more 5.3's but in fwd)
LS1- 5.7 (vette, F-body, 04 goat)
LS6- 5.7 (01-04 ZO6 vette, earlier CTS-V)
LS2- 6.0 (05-06 goat, vette, TBSS, SSR)
LQ4- 6.0 (truck 2500-3500HD)
Lq9- 6.0 (Caddy trucks, Denali's, SS Silvys)
LY6- 6.0 (truck)
L76- 6.0 (G8)
L92- 6.2 (truck)
LS3- 6.2 (vette)
LSA- 6.2 supercharged (cts-v)
LS9- 6.2 supercharged (ZR1 vette)

I have tuned or setup about all of the above for street/strip or RR

from a 14 second tuned 5.3 ECSB 5400lbs (mine) to a 10 second LS1/2/6/3 vettes f-bodies)

While I love MPFI, I have had a few carb vehicles- a 84 MCSS 350 carb (this car got 22mph from FL to MD and was a mild vortec build), a 79 Camaro Z28 350 carb, and my 91. set up the carb right and it can make you very happy. and a proplerly tuned carb can make the same or sometimes more( though not likely) top end HP

DooSPX
08-13-2010, 05:55 PM
oops

double post.

1redTA
08-13-2010, 06:10 PM
I think it would be easier to buy a boat with the ls1 engine already in it. Although a ls1 engine would be neat to see in that boat

DooSPX
08-13-2010, 06:17 PM
BU put a Indmar LS1 in their boats for a bit and it didnt turn out too great. It made lots of topend power, but suffered really BAD slap (which is relatively common on LS1s, though I never had one do it) but being in a boat, the constant load on the engine made things worse.

1redTA
08-13-2010, 07:56 PM
An iron ls block ( 6.0L ) with a 4 barrel manifold set up to run the coil packs with a carb would be easier. Chevy > Ford HE HE HE

DooSPX
08-13-2010, 11:42 PM
It would be easier than running the ECM, tuning, fuel return. but you still need mounts, bellhousing, linkage bracket, marine items.
and while I would agree with you about GM > Ford, but you cant discount the 351W, it is one of the best motors they ever built IMO. a grand in parts and you can have 400lb ft trq at like 3000-3400 rpm.
A carbed LQ9 with its flat tops and higher CR should hit 400 lb ft trq but at 4500 or so. The one area where EFI shines in the terms of power is under the curve power. I have never seen a carb match what a tuned EFI system will do is in hp/trq below peak.

1redTA
08-14-2010, 10:36 AM
I agree with you Doospx, I just wanted to see some lively discussions about brand loyalty over the engines. The LT1 makes a better engine for a tow boat than a LS1

Hoosier Bob
08-14-2010, 10:59 AM
Not really getting the GM>Ford when comparing 351 to the 350. Low and mid torque was always easier to get from the Ford 351 right? I have owned many 350's and agree in a vehicle it rocks but never had the same feeling being pulled in a boat. 351 is an easy fix, and produces torque where you need it.

jdb11386
08-14-2010, 02:43 PM
I should have been a little more specific about what im doing. This is going to be a winter project involving people that work with, let me be politically correct here, ls or lsx style engines, specifically people that have built high horsepower vehicles such as a 1000 hp sierra denali that was a daily driver. Were not the smartest people in the world but when it comes to getting power out of an ls engine were on top of our game. I know there will be a lot of test fitting parts and plumbing things but the main thing I was wanting to know if anyone had tried it, just to give me a heads up on something if they had. We will make it work and there is no way you can compare a 351 ford to a ls style engine, simple things like geometry of an ls dont even compare to a ford, especially if you compare the amount of money invested to get power out of each engine to get equal power, but I wont get into that. We're mainly doing it just because we like to spend money immaturely and to say weve done it. Also if anyone has any info on parts suppliers, that would be appreciated, i know of a few but im sure there are lots more out there.

DooSPX
08-14-2010, 10:27 PM
Well, if you guys are so good then go for it. what are you going to use for the ECM to control the fuel? custom OS with no O2's in open loop, or custom OS with WB?
I am a LSx guy, but I know whats smart and what is not. Also, sherlock, with the price of a bone yard LQ4-9 w/ ECM to to get 400lb ft trq compared to the motor you ALREADY have, let me know if you can get the motor and make 400lb ft at 3400 rpm for 2K or under.

btw, what heads, cam, intake, ECM, what power adder and what cid was the motor in the denali? what injectors and what was the duty cycle? kpa MAP? AFR?

Give me some real info so I can believe that you or your "friends" really know about the GenIII/4 platform, not what you read on LS1Tech/ls1.com, etc and I will shut my trap. Sounds like your "friends" should either already own a LSx based shop/tuning or need to get in the business, because they can make some serious mula.

One last thing, you said, and I quote "We're mainly doing it just because we like to spend money immaturely and to say weve done it." if you like to spend big money, why not get a newer 190/197 w/ the LY6 and mod it? the LY6 is a great motor and makes killer power. Even the wealthy do not like to blow money for no reason. well, let me rephrase that, the people with common sense.
And please do not come across like you know it all and have a do what I want anyway attitude, you will lose the respect from those who where trying to help you so you do not waste your money.
about your parts, any MC dealer can get you the mounts, bell housing, trans adapter, etc because MC currently uses a Gen4 platform in their current models.

DooSPX
08-14-2010, 10:29 PM
I agree with you Doospx, I just wanted to see some lively discussions about brand loyalty over the engines. The LT1 makes a better engine for a tow boat than a LS1

The LT1 w/ a slot is a BAD boat!!!

1redTA
08-14-2010, 11:04 PM
A claim for that hp really deserves some backup. Got a vid of said Denali on a dyno with a chart? You get a truck like/from Parish?

Hoosier Bob
08-14-2010, 11:06 PM
Remember 20's with spinners can throw off a dyno! I know! I seen it!:DA claim for that hp really deserves some backup. Got a vid of said Denali on a dyno with a chart? You get a truck like/from Parish?

DooSPX
08-14-2010, 11:21 PM
Remember 20's with spinners can throw off a dyno! I know! I seen it!:D

spesshh!!! 20's. thats so old skool. now we role on 34's ridin' HIGH like planes. LOL :D:D

Bert
08-14-2010, 11:22 PM
Well, if you guys are so good then go for it. what are you going to use for the ECM to control the fuel? custom OS with no O2's in open loop, or custom OS with WB?
I am a LSx guy, but I know whats smart and what is not. Also, sherlock, with the price of a bone yard LQ4-9 w/ ECM to to get 400lb ft trq compared to the motor you ALREADY have, let me know if you can get the motor and make 400lb ft at 3400 rpm for 2K or under.

btw, what heads, cam, intake, ECM, what power adder and what cid was the motor in the denali? what injectors and what was the duty cycle? kpa MAP? AFR?

Give me some real info so I can believe that you or your "friends" really know about the GenIII/4 platform, not what you read on LS1Tech/ls1.com, etc and I will shut my trap. Sounds like your "friends" should either already own a LSx based shop/tuning or need to get in the business, because they can make some serious mula.

One last thing, you said, and I quote "We're mainly doing it just because we like to spend money immaturely and to say weve done it." if you like to spend big money, why not get a newer 190/197 w/ the LY6 and mod it? the LY6 is a great motor and makes killer power.
And please do not come across like you know it all and have a do what I want anyway attitude, you will lose the respect from those who where trying to help you so you do not waste your money.
about your parts, any MC dealer can get you the mounts, bell housing, trans adapter, etc because MC currently uses a Gen4 platform in their current models.
Wow, jdb11386just got burned:D I know nothing about these engines other than my little 351 pulls good;)

Hoosier Bob
08-14-2010, 11:27 PM
Back in my day we rolled on teens! Caps and rings baby! If you really rolled a set of Crager Super Sport 15's were the ticket to getting any 18yo in your Goat!:Dspesshh!!! 20's. thats so old skool. now we role on 34's ridin' HIGH like planes. LOL :D:D

DooSPX
08-14-2010, 11:45 PM
Back in my day we rolled on teens! Caps and rings baby! If you really rolled a set of Crager Super Sport 15's were the ticket to getting any 18yo in your Goat!:D

lol... 8p:D

DooSPX
08-15-2010, 08:38 PM
maybe we scared him off...
oops.... :(















HAHAHA! trying to be something your not is very immature. :D:D

TLR67
08-16-2010, 10:33 AM
You tguys are Harsh...LOL....

On a serious not I heard awhile back 20 Years ago or so.... That the Hull design of MC's will only let them get up to so fast... Is that true for the entire boat or just the Prop pocket? I could never get rid of my Carburated 351 Inmar... However this Head upgrade you speak of has me thinking now...

callaway_1
08-16-2010, 11:49 AM
really harsh:(

back in the 1980's I grew up in a chevrolet, olds, buick, and pontiac dealership. We were also mastercraft dealers from 1987-1990.

I love my '93 Stars and Stripes and have always planned to replace the engine (351 285hp.) with a GM should the day come that I have to do that.

I was reading this thread with a lot of interest.

I read it and reread it trying to understand why some guys act like jerks????

Some new guy comes here to ask questions, to ask for help and he gets this crap? This behavior is counter productive to the basic concept of a "Forum".

Who cares if some guy wants to spend a boat load of cash building up some hot rodded pro star that may not out perform the same hull with a slightly modded 351?

Just to be clear, I have no idea who the original poster is, or if he is full of it or not? either way it's no way to treat a newbie.



Back to the Hull design and effect on speed, it definitely impacts the top speed. We had a 450hp 454 in a 1990 PS190 and while it was a beast it only had a couple mph over a 1:1 PS190 with a 351.

Barefooter92
08-16-2010, 12:09 PM
jdb:

Welcome to Team Talk!

Love your project idea. One thing we all require here is lots of picures of your journey through your boat and motor project. If you don't provide photos we can no longer be friend here on TT!:toast:

DooSPX
08-16-2010, 12:40 PM
really harsh:(

back in the 1980's I grew up in a chevrolet, olds, buick, and pontiac dealership. We were also mastercraft dealers from 1987-1990.

I love my '93 Stars and Stripes and have always planned to replace the engine (351 285hp.) with a GM should the day come that I have to do that.

I was reading this thread with a lot of interest.

I read it and reread it trying to understand why some guys act like jerks????

Some new guy comes here to ask questions, to ask for help and he gets this crap? This behavior is counter productive to the basic concept of a "Forum".

Who cares if some guy wants to spend a boat load of cash building up some hot rodded pro star that may not out perform the same hull with a slightly modded 351?

Just to be clear, I have no idea who the original poster is, or if he is full of it or not? either way it's no way to treat a newbie.



Back to the Hull design and effect on speed, it definitely impacts the top speed. We had a 450hp 454 in a 1990 PS190 and while it was a beast it only had a couple mph over a 1:1 PS190 with a 351.

no one was being harsh till he came back saying we are the kings at the genIII/IV platforms, making bogus clams about 1000hp trucks, etc. and saying we will do it anyway because we like to spend money and brag. everyone was giving him hints that it was SO much easier to build the ford that was in there. after everyone's advice to build the 351 the OP got a ridiculous attitude and ran his mouth with claims he knows he cannot back up. If you would have noticed, I mentioned my love for the GenIII/IV stuff as well as the old school genI 350's.
maybe you should re-read it one more time

callaway_1
08-16-2010, 12:44 PM
I certainly didn't read it that way.

I read it as a guy who has done other types of hot rods and now is looking into doing a boat.

I guess my glass is half full.

DooSPX
08-16-2010, 12:51 PM
he claims to have done other GenIII builds. but having known someone who has actually built a 1000+ REAR wheel hp TT 408 in a chevy single cab short bed, and seeing what it took to get there and trying to make it civil on the street. of course, I know guys that think if the car starts and drives with out cutting out its a dd. the claim of a 1000hp truck needs to be proven. I would love to see a graph, a vid and the info from the tuning done. I will shut up if he can back it up.
IF he wants to put 7K or more plus tons of hours to get something that will not perform go for it. I would like to see pics of that as well.

TLR67
08-16-2010, 01:13 PM
Back to the Hull design and effect on speed, it definitely impacts the top speed. We had a 450hp 454 in a 1990 PS190 and while it was a beast it only had a couple mph over a 1:1 PS190 with a 351.

And thats what I thought.... So what are you actually going to Gain from all of this anyway??? If a 351 Cant get you up you better consult with Jenny Craig not GM....8p

DooSPX
08-16-2010, 01:17 PM
And thats what I thought.... So what are you actually going to Gain from all of this anyway??? If a 351 Cant get you up you better consult with Jenny Craig not GM....8p

thats a good one! lol :D

1redTA
08-16-2010, 01:25 PM
I went through the same idea as him; putting a junkyard 5.3 or 6.0 into my boat. I was really down on my Windsor's points distributer and carb till I rebuilt the carb and put a petronix II conversion in my boat. I like the he!! out of it now.

Mind you I have a 96LT1 Trans Am with a 350 putting almost 400hp to the tires with 350ft/lbs of torque from 2500-5300rpm running rich, we bottomed out the wideband oxygen sensor at There is more power in this engine with some computer tuning.
I am sharing my knowledge of GM to let people know I am not trying to keep any one away, just wondering how you daily drive a 1000hp vehicle

DooSPX
08-16-2010, 01:30 PM
ask parish... its not easy to even get anywhere near that point.

I think an LT1 in any pre 91 hull would REALLY rip your arms out. they have much less wetted surface and are lighter.
put the LT in your 81 and tell us how it goes! lol





that would soo nice...
*day dreaming about a built LT in my 91*







*SLAP*
there is reality:rolleyes::o

callaway_1
08-16-2010, 01:49 PM
Hooking up that kind of torque and HP becomes the issue. The prop just starts cavitating.

It was great for pulling 5 barefooters at once! I miss that boat!

Bert
08-16-2010, 04:07 PM
And thats what I thought.... So what are you actually going to Gain from all of this anyway??? If a 351 Cant get you up you better consult with Jenny Craig not GM....8p
Don't care who you are... That there is funny:D:D:D

jdb11386
08-18-2010, 06:18 PM
I didnt intend to offend anyone but everyone was telling me not to do it, and I wasnt bragging about how much money we have, because I have to watch my budget just like everyone else, I was just saying that we like to do the things that everyone else says you cant or shouldnt do, i.e. putting an ls engine in a 20 year old boat, and from everyone's feedback it sounded like I shouldnt do it and just take the easy way out. We dont consider ourselves the gods of the ls engine or anything like that, we among thousands of other people in the country enjoy this engine and are pretty proud of the things we do with them. Getting out of the water isnt a problem and no we dont need Jenny Craig (one of my buddies might) but just looking to replace that tired old 351 which has been a great engine. The main thing is we are looking a good challenge and from the sounds of it I might have one with this boat engine. And here is the proof of the truck, (this is a 6.0 lq9 block, it made the 1000 rwhp with an lsx block) http://www.youtube.com/watch?v=4RtzsAcLKqA

east tx skier
08-18-2010, 07:51 PM
Before you make any block changes, double check your clearance under the box. For all that has been mentioned, you might as well check this, too. It's your boat. Enjoy it how you like, I say.

DooSPX
08-21-2010, 12:20 PM
I didnt intend to offend anyone but everyone was telling me not to do it, and I wasnt bragging about how much money we have, because I have to watch my budget just like everyone else, I was just saying that we like to do the things that everyone else says you cant or shouldnt do, i.e. putting an ls engine in a 20 year old boat, and from everyone's feedback it sounded like I shouldnt do it and just take the easy way out. We dont consider ourselves the gods of the ls engine or anything like that, we among thousands of other people in the country enjoy this engine and are pretty proud of the things we do with them. Getting out of the water isnt a problem and no we dont need Jenny Craig (one of my buddies might) but just looking to replace that tired old 351 which has been a great engine. The main thing is we are looking a good challenge and from the sounds of it I might have one with this boat engine. And here is the proof of the truck, (this is a 6.0 lq9 block, it made the 1000 rwhp with an lsx block) http://www.youtube.com/watch?v=4RtzsAcLKqA

okay, I will shut up now. 8p
you are coming across MUCH more reasonable now! thank you for that.
thank you for the video... 800+ is still stout as all get out. would like to see a vid of the lsx block.
what was the AFR? any injection? I prefer meth inj. myself as does everyone that I know or work with. how much boost? any chance you logged your EGT's?
If you do go with it, please post progress with pictures. also, any idea what you are going to do with fuel control? Open loop, custom w/ WB? what is your tuning software? (being serious btw, really would like to know) personally, if I were to do it, I would like to try a custom os on the ecm and run a wb as primary lookup for fuel.
If I win the lotto...

of course I need to play first! :rolleyes:
Would love to hear more details now if you can provide them in the manner in which you replied above.

jdb11386
08-21-2010, 12:59 PM
18 lbs of boost on that engine with meth on both setups, video of the lsx block never made it to the internet and ill have to see if i cant get it, but that setup only lasted about six months in the truck before he sold it and put the truck back stock. Just a headsup i see that your in the southeast, if your ever are in the market for an 05 denali be careful, that truck was cut up pretty good underneath with all the aftermarket parts:purplaugh.
Havent really started thinking about tunes or anything like that for the boat yet, i have a block and thats it right now. Gonna have descent parts nothing to crazy just want something reliable and probably go with a set of l92 heads, only looking for around 400hp unless another boat ends up in the pond then the sky is the limit for the prostar, a lsx block in a ski boat could be alot of fun, especially with a 200 shot to go ahead and get the slolam skiers out of the water:D. Im wanting to avoid running a carb setup if at all possible. Who knows what will be the end result, like I said it will be alot of testing parts and customization ill probably end up naming the boat frankenstein.

Patrick Hardy
08-21-2010, 01:19 PM
[QUOTE=DooSPX;702460]

I think an LT1 in any pre 91 hull would REALLY rip your arms out. they have much less wetted surface and are lighter.
put the LT in your 81 and tell us how it goes! lol


I can see the point of having fun on a boat / engine project, but I do not see the point in taking the best water sports boat on earth and making it a go fast boat and or a monster HP boat. Wasn't that a recent tread on its own (go fast boat bashing)? All I know is that with my 1996 PS190 LT1 with a powerslot transmission, I have all of the HP/torque to pull the arms off of anyone on the end of the rope.

DooSPX
08-23-2010, 03:00 PM
thats a good looking boat! have any other pictures?

Patrick Hardy
08-23-2010, 04:15 PM
Thanks, it has been an awesome boat to own. I have had nothing but great times with it in the 13years that I have own it. I have a lot of photos of it in my members gallery page under the showroom section.

Midnightrider
08-04-2013, 10:17 AM
I get a good chuckle out of the hecklers doubting this guy about 1000+ rwhp trucks. Its easy to do with a stock iron 6.0. Ive built more than a few that way. I realize this is a old thread but its how I found this site. Im also interested in a LS swap in a Ford powered MC. I hope this site isnt like Corvette forum where there are more know it alls and Dbags than guys who want to help other enthuiasts out.

CantRepeat
08-04-2013, 10:31 AM
I get a good chuckle out of the hecklers doubting this guy about 1000+ rwhp trucks. Its easy to do with a stock iron 6.0. Ive built more than a few that way. I realize this is a old thread but its how I found this site. Im also interested in a LS swap in a Ford powered MC. I hope this site isnt like Corvette forum where there are more know it alls and Dbags than guys who want to help other enthuiasts out.

I don't think you are going to run into too many know it alls. Moreover, there are going to be lots of TT users here that would love to see you swap an LS motor into any older MC. Just take lots of photos and start a swap thread.

Midnightrider
08-04-2013, 10:53 AM
Im no guru but I would love to give it a good try. I probabaly wouldnt go FI but more like a similar setup i had in my Z06. Big cammed LS7 with a good power curve.

CantRepeat
08-04-2013, 11:09 AM
Well, for me, if I was going to do a swap of this type it for sure would be EFI. I don't think it you need to go crazy on the cam in a ski boat.

Zazzy
08-04-2013, 10:58 PM
You could build (or buy) a non-aspirated, carbureted, 9:1 CR, small block Ford (358 ci) and easily get 650 hp. You'd have to run race gas and it would be fun to start up and idle out of the no wake zone. After that, I can't imagine that it would be any fun. The power tends to be a bit violent.

1redTA
08-05-2013, 02:07 PM
I hope this site isnt like Corvette forum where there are more know it alls and Dbags than guys who want to help other enthuiasts out.


This forum is full of people who are more than willing to help any
one out and will support most any projects on your boat ( no tower on a Stars and Stripes though) I would be interested in seeing it done

And as far as Vette owners, whew, you nailed it for the most part!

WFO MasterCraft
08-05-2013, 04:44 PM
I went through this thought process already. I have an '85 S&S with the 351 Windsor. It had 2 dead cylinders and I having grown up a Chevy man on the streets I wanted to get that "Ford POS" out of my boat. The first thing I looked at was a motor out of the LS series. I found that it is possible to get an ECM for this purpose "Check". There are marine parts that fit on the motors "Check". I have the skills to do it "Check".

So, I went ahead and rebuilt the 351W. Why you ask? I decided against the swap because like you I like stupid power in awkward places just because. After I found an LS motor, did a cursory inspection, and tracked down parts and machine work, on paper the damn thing was going to make around 480hp/500lbft. That exceeded my 1.57:1 power slot's capabilities by ~80hp/100lbft. So, I started looking for a tranny that would handle it. There were all different types of stern drives that will handle those numbers. Direct drive/v-drive trannys use hydraulic clutches to transfer power and not gears. The v-drive has gears but after the clutches. More power requires heavier springs, higher pressures, and better disk material. A new/rebuilt power slot at the time was $2600 and that wasn't "built". So, a "built" one will most definitely cost 1.5-2 times that if you are lucky. I never researched it because I wasn't willing to pour the boat's "best" resale value into a boat that wasn't designed to use that HP effectively. I did however, think about an aquatic stump pulling business that I would use it for. (Food for thought)

I spent $2500 on the following and my boat damn near rips the driver seat off the floor when I give her the onion from a stop.

Bored 30 over
Decked the block for flatness
Milled the heads for flatness
Mild crane "torque" cam
New hypereutectic pistons
Edelbrock performer intake
Rebuilt stock 575 cfm carb with +1 size jets
3 angle valve job on the stock heads
Heavier springs
Stock length lifters
Double roller timing set
Intake Port matching.
I think it was around 11:1 comp ratio
It does not like less than premium fuel. It pinged like a *****. So much in fact, I pulled the heads and checked the valve train and piston tops. I've run the boat now for 3 years pretty hard on premium and hasnt done it again. Also, I can run all weekend on the stock tank of fuel because of the relatively small carb.

On paper I'm making ~395hp/400lbft. I have a 13x18.5 three blade nibral prop and a new/rebuilt tranny. If the water is real turbulent the prop will "break free" and cavitate but otherwise it hooks up like a pair of slicks. I'm looking at getting a 14" prop to fix that.

I took the assembled long block to the machine shop because he preferred it that way and I got back a short block.

Like you have said before. You are willing to "See if we can do it" and I am there with you. They make all kind of adapter plates and I'm sure you can bolt an LS to a washing machine but, for me the practical side of me won out. By the way, LSs are longer and you might be hitting the floor panel in front or the bilge floor behind the tranny to you maintain the correct engine/tranny angle so it will mate up to the prop shaft. I'm a mechanical engineer and writing this post got me thinking and the prop shaft is another place where that Bad-A LS can show its might by twisting it in two.

"Anything can be done with the right amount money and the right amount of persistence"
-Me

Good luck and if you do take this on, PLEASE post progress pictures.

Cheers and we'll see y'all on the lake!

WFO MasterCraft
08-05-2013, 04:52 PM
Hell, how about you and I get together and put an LS with a 4L80E transmission, a 4x4 transfer case with the output switched to the back (to create counter rotating shafts) in my '85 Stars and Stripes and we'll have the only twin prop ski boat with selectable gears in the world. :)