Building and Swapping an LSx into an Old Skier

[2014Skier]

I'll be running at the factory 58 psi. I'm gonna be using a Bosch 044 pump that I'm thinking I'll try to mount in tank to keep the install clean. The fuel rails that I'm using are generic LS3/L92 billet ones. I'm running a system with a return, so different then the GM returnless. I'm plumbing it all with AN fittings -8 in -6 return. I'm still torn on the engine management. It's down to Holley or F.A.S.T. still can't decide. The Holley system is USCG approved for what that's worth.

I feel your pain, the nickel and dime stuff never ends.

If I have any questions I'll let ya know.

Edited April 20, 2015 by 2014Skier

[ibelonginprison]

The later LS motors had returnless systems, so you just use a special corvette fuel filter that has the regulator built in and accepts the return line on one side. But you already know that - you've researched the heck out of it and it seems you've got it all under control! I'm really anxious to see the build come together.

Now I'm just asking questions cause I'm curious, lol

Drive by wire, or cable? And are you building your own harness or going to start with a standalone from somewhere else and modify? (You may have mentioned previously but I might have skimmed over it)

And I want more pics, this is going to be a sick build!

[2014Skier]

I was thinking of using and actually bought the 'Vette filter/regulator then after much contemplation decided to ditch that as I did not want any issues with vapour lock given the possibility of heat soak with the dog house and all, and I'd like to run a better filter/water separator that could also handle more flow if need be. So its more plumbing but I think I'll be happier with a return style system.

I'll be running a drive by cable setup for simplicity, not all aftermarket EFI systems support drive by wire, some do (Holley Dominator) but they are more complex then I need. I've got a 102mm throttle body mounted on my hogged out L92 intake, that whole deal is covered in the Saving an Old Square Windshield 'Bu thread. The EFI systems come with their own harness so I don't need to worry bout that. I was contemplating going with a factory ECU and modified harness and getting EFI live or the like and tuning myself, but I think the self tuning will be better and ultimately less hassle/cost with dyno time etc etc.

More pics and build info coming soon, just been busy.

[2014Skier]

So more progress, got the oil pump on, on LS motors they are driven off the crank. To put them on properly is a bit finicky using feeler gauges on the pump drive and gears to get the spacing right then snugging up the bolts. After the pump was on I put on the windage tray, which I had to shim up to get clearance for the stroker crank and rod bolts, I ended up using two washers on each stud. Then then oil pump pick-up tube went on. I measured the clearance which turned out to be just over an inch, way higher then I expected but after some research I found out that the Hummer H3 pan, which is what I'm using is supposed to have that much clearance compared to the usual 3/8" or so.

I got the pushrods made by Manton, they are 11/32" rods with 0.120 wall, so nice and stiff, and given the sustained high rpm they put 0.040 restrictors in them so the motor doesn't pump too much oil up to the top of the engine. That's why the rods have the red marking on them. Below in that pick is the rocker stands.

[2014Skier]

The LS3 heads use offset intake rocker arms to clear the larger intake ports compared to the cathedral port design. The exhaust rockers are the same as other LS motors except for LS7. The factory are nice steel pieces, very strong yet with a light tip weight. The only weakness on the factory rockers is the needle bearings, the needles aren't retained and there are cases when the bearings fail spilling small needles out into the engine. There are a few companies such as Comp Cams and Brian Tooley Racing that make upgraded trunion kits for the rockers with retained bearings and stronger shafts. So I got some Brain Tooley Racing rockers which are Cryogenically treated and micro polished with the upgraded trunions.

I installed the pushrods, rockers, rear cover, front cover and valley cover. I got an aftermarket valley cover. The older LS motors use knock sensors in the valley of the engine, which I what my block would have originally used, you can see the two bosses for them in the earlier pictures, but since I'm running my electronics based on the 58x crank and forward cam sensor the knock sensors are different and located on the outside of the block.

And there she sits for now, just gotta weld some bungs onto the valve covers for the PCV system, tap and plug some holes in the water pump, port match the intake manifold and I think she is pretty close to being all buttoned up.

[Steve B.]

Wow ! Engine technology has gone pretty far since I built my last engine. What kind of lifter system will this engine have ?

Thanks for the pics and updates on your install,

Steve B.

[2014Skier]

Yeah, these LS motors are really something else, pretty amazing. As for the lifters I'm using stock LS7 lifters, they are nothing too fancy, just called LS7 lifters cause thats the motor they debuted in but now gm uses them in everything.

[Levi900RR]

There is a 100% chance that a certain red and white 1987 Sunsetter in the PA area gets this same treatment within 18 months...

Stamp it.

[TRBenj]

This may be a little forward thinking, but how are you planning to prop the boat?

[martinarcher]

There is a 100% chance that a certain red and white 1987 Sunsetter in the PA area gets this same treatment within 18 months...

Stamp it.

[maroon88iroc]

There is so much awesome in this thread. Really impressed with your work!

I am in the process of swapping a LS1 into my 1969 firebird, once I get it in and running I will be picking up a 6.0 & LS3 top end (like you) to throw in it eventually. You really cant beat the LS series engine. You will have an awesome boat in the end.

[ibelonginprison]

There is so much awesome in this thread. Really impressed with your work!

I am in the process of swapping a LS1 into my 1969 firebird, once I get it in and running I will be picking up a 6.0 & LS3 top end (like you) to throw in it eventually. You really cant beat the LS series engine. You will have an awesome boat in the end.

Based on your signature you not only drink the LS koolaid, you bathe in it.

That's what's up. *fist bump*

I have a broken exhaust manifold stud that I have to get removed before I slide the motor in my truck this week. *sigh*

[maroon88iroc]

Based on your signature you not only drink the LS koolaid, you bathe in it.

That's what's up. *fist bump*

I have a broken exhaust manifold stud that I have to get removed before I slide the motor in my truck this week. *sigh*

Haha ya you could say I am an extreme GM enthusiast. The LS based engines are fantastic. My '02 Z06 (LS6) with an MS3 cam & full exhaust runs high 11's @ 120 MPH in the 1/4 & my wife's bone stock daily, '05 Z51 (LS2) runs mid 12.5x's @ 110 mph. Strong cars that can easily be daily driven with fantastic reliability & fuel mileage.

LS SWAP THE WORLD

[ibelonginprison]

I've almost swapped an LS into my G so many times. But I have 4 friends that have done that in their G/Z - and it's sooooo much of a headache.

Just not worth it. When I wrap this thing around a tree or it finally catches fire and burns to the ground, LS3 powered C6 with a procharger and be done with it.

[rennis]

this thread is awesome.

[maroon88iroc]

I've almost swapped an LS into my G so many times. But I have 4 friends that have done that in their G/Z - and it's sooooo much of a headache.

Just not worth it. When I wrap this thing around a tree or it finally catches fire and burns to the ground, LS3 powered C6 with a procharger and be done with it.

This, but go for the Grand Sport!

[ibelonginprison]

This, but go for the Grand Sport!

If I go that far, then I'm headed straight to Z06-land.

[2014Skier]

Hey guys, thanks for all the comments, love the LS enthusiasm. Hope your swap is going well IBIP. The more old school 'Bu's with LS power the better. As far as the prop is concerned I really don't know. I have yet to call ACME, my guess is something around a 13x14, that way I'll still get a good hole shot and with the revs that I should be able to turn I'll get the top speed that I'm looking for. I'm hoping for 60+ mph at this point, might be a pipe dream but....

Not much physical progress lately, more stuff being worked out in my mind etc.

I've got the water pump mounted, I'm using a LS1 pump from a Camaro, most common engine accessory drive system spacing. I tapped and plugged the heater core inlet/outlet holes using 1/2 npt and 3/8 npt plugs. The Alternator is on, using a billet alternator mount was the easiest way to put the F body alternator onto the cast iron block. Only kind of issue I ran into was I had to drill and tap a hole in the block for the upper alternator mount bolt. All this stuff is available off of e-bay. I got a billet manual belt tensioner too, also e-bay, with F-body spacing, the LS tensioners mount to the water pump housing. Nothing too crazy going on with the accessory drive, I'm trying to figure out what to do for the raw water pump drive right now, I'd like to reuse my old one and make brackets for it, but haven't had a chance to mock it up yet.

I've installed the motor mount plate adaptors, they simply convert the LS style four bolt pattern to the SBC style three bolt pattern. Because the boat originally had a Ford in in, I've had to order the engine side of the font mounts for the SBC bolt pattern form SKIDIM. They should bolt onto the adapter plates already on the motor now.

Nothing special with the harmonic damper, just an F-body one, I really wanted to spring for a ATI of Fluidampr but just can't swing the money right now, hard to beat $70 for a stock GM one, at least to get me up and running.

Waiting on some more parts, but I'm very close to mating the engine and transmission together on a stand.

[oldjeep]

That doesn't look like a marine alternator, I can see the windings. Make sure to use ignition protected parts- starter and alternator so that it doesn't go boom.

[maroon88iroc]

Hey guys, thanks for all the comments, love the LS enthusiasm. Hope your swap is going well IBIP. The more old school 'Bu's with LS power the better. As far as the prop is concerned I really don't know. I have yet to call ACME, my guess is something around a 13x14, that way I'll still get a good hole shot and with the revs that I should be able to turn I'll get the top speed that I'm looking for. I'm hoping for 60+ mph at this point, might be a pipe dream but....

Not much physical progress lately, more stuff being worked out in my mind etc.

I've got the water pump mounted, I'm using a LS1 pump from a Camaro, most common engine accessory drive system spacing. I tapped and plugged the heater core inlet/outlet holes using 1/2 npt and 3/8 npt plugs. The Alternator is on, using a billet alternator mount was the easiest way to put the F body alternator onto the cast iron block. Only kind of issue I ran into was I had to drill and tap a hole in the block for the upper alternator mount bolt. All this stuff is available off of e-bay. I got a billet manual belt tensioner too, also e-bay, with F-body spacing, the LS tensioners mount to the water pump housing. Nothing too crazy going on with the accessory drive, I'm trying to figure out what to do for the raw water pump drive right now, I'd like to reuse my old one and make brackets for it, but haven't had a chance to mock it up yet.

I've installed the motor mount plate adaptors, they simply convert the LS style four bolt pattern to the SBC style three bolt pattern. Because the boat originally had a Ford in in, I've had to order the engine side of the font mounts for the SBC bolt pattern form SKIDIM. They should bolt onto the adapter plates already on the motor now.

Nothing special with the harmonic damper, just an F-body one, I really wanted to spring for a ATI of Fluidampr but just can't swing the money right now, hard to beat $70 for a stock GM one, at least to get me up and running.

Waiting on some more parts, but I'm very close to mating the engine and transmission together on a stand.

Looks like an nnbs intake but shaved, those flow really well. I would have preferred the alternator in the higher mount area, as those brackets are also available. With it being a boat there will be a lot of moisture down by the oil pan & plenty of room around/above the valve covers.

Also fyi I would definitely consider using the ARP harmonic balancer bolt, I had an issue with the GM balancer "wobbling" & ultimately backing off the crank which is common on the LS engines. I took it a step further and bought a better quality powerbond brand pulley (around $100), got a crank pin kit from ebay ($60 used to pin balancer to crank to prevent movement), also used the ARP balancer bolt ($38) and torqued it to spec. a lot more vibrations in a boat than a car so it may be something to think about.

[2014Skier]

For now the alternator is not a marine one, I may change that later. Given that it's fuel injected I'm not too worried about fuel vapour. The intake is a L92 intake that I cut the top off and cut out that restrictor inside and opened up the ports in the plenum. Then plastic welded the top back on. I covered That whole process in the saving a square windshield 'bu thread. I am using an ARP crank bolt, torqued to 235 ft lbs, I've heard of the balancer problems, I really want to upgrade the balancer but this will have to do for now.

[formulaben]

For now the alternator is not a marine one, I may change that later. Given that it's fuel injected I'm not too worried about fuel vapour. The intake is a L92 intake that I cut the top off and cut out that restrictor inside and opened up the ports in the plenum. Then plastic welded the top back on. I covered That whole process in the saving a square windshield 'bu thread. I am using an ARP crank bolt, torqued to 235 ft lbs, I've heard of the balancer problems, I really want to upgrade the balancer but this will have to do for now.

A carburetor is not the only place a fuel leak may develop...

[TRBenj]

A few of us have taken down the 60mph barrier... I don't know LS engines all that well but if your heads can support the cam you've chosen and the hp levels you're talking about then I think 60 is a pretty safe bet. Hull is the big question, I'd recommend a life jacket and a safety lanyard until you're familiar with how it runs at high speeds.

Regarding prop, I think you're right about the 13x14 based on cubic inches and a reasonably efficient hull, but that would be a traditional hand finished size. The acme equivalent would be a 13x13 (the 13x12 acme is the stock replacement for the traditional 13x13). Then spin it up. If you have a 1" shaft then I've got a prop you'll want to try- it's not enough for my 502 that's rev limited to 5050rpm but it would be perfect for what you want to do, I suspect. Email me: [email protected]

[shawndoggy]

alternator = bad place to cheap out to avoid

[2014Skier]

Man you guys are a tough crowd with the alternator...I'll get it sorted, I just got caught up in wanting to take the easy way out for once. It's not even really a cost thing, marine alternators in a similar style to what I have for 77 bucks. I order one up and make it fit. Thanks for the head shake.

Good to hear I'm on the right track with the prop, I'll email ya about the one you've got.