Volvo Penta used the crank mounted pumps on the SBCs for years. Marine Power as well. I have had them and was pretty happy even though it took me a bit to trust it. The way they use a rubber bushing around the arm bolt takes up a lot of flex/vibration. You can change the impeller pretty easily and if you have it set up with shutoff valves, you can do that in the water. My only concern would be getting enough cooling since it looks like you will end up with a pretty high performance motor.

Brother you just hit my greatest concern. I have no idea if this will be adequate cooling.

I bought a 350,000 BTU heat exchanger and you can see my diagram below. I figure I’ll spend a small fortune in fittings and hoses but throughput is gonna be the name of the game. Assuming this cools adequately keeping it flowing is next priority.

It does have a shut off valve on 1.25” water inlet to strainer, to pump, to various fittings. I’m running the biggest hoses I can think of and utilizing both sides of elbows in/out to promote quick circulation.

I have a friend that runs the biggest cooling, refrigeration hvac (grocery stores etc freezers and a/c) for the island/state. He did some math and recommended this setup. But between us, I have no clue of this will work. Only one way to find out I suppose.

Do you have more specs than just 350,000 BTU/h? At what temperatures, flows, etc?


I have done these sorts of calculations for piston aircraft engines- I *might* be able to help.

40 GPM 4-1” ports on exchanger. Rated at 350,000 BTU. Using 1.25” hoses to feed water into and out of exchanger. See post 30 for thorough diagrams of system.

About all I know on it. 5.3 engine. 400-450hp output is my guess expect to spend most of my time 1500 rpm for trolling.

Any help greatly appreciated. I’m trusting other people on this one.

I can only offer you a modest amount of guidance based on experience with other engines.



I did a fair amount of cooling work on Rotax 912 IS sport 100hp 4 cylinder aircraft engines. These were liquid cooled heads, but air cooled cylinders. And an oil cooler.



Crucially, they can operate for a long time at or near full power, like a marine engine.


For a 100HP engine (metric HP, but close enough for what we are discussing here) they were rated at 73.5kW for 5 minutes or 72kW continuous


Go to flyrotax.com and look for the installation manual for details: d06847.pdf


They required 30kW of liquid cooling, 6kW of air cooling and 10kW of oil cooling for takeoff. Takeoff is the worst condition, especially for oil cooling because of this highest engine speed.


In my experience, this air cooling was largely unneccesary except at above 80% power.

So, if we think the GM 5.3 is more efficient than a Rotax 912 iS Sport, and it probably is, then an estimate would be 30kW of water cooling 6kW of air cooling and 10kW of oil cooling for every 100HP at the crank.


So for the estimate: for every 100 metric HP you make 73.5kW shaft power and need 46kW of cooling.

Again, the 5.3 may make less heat, it's a modern engine.



You say you cam make 400HP. That's at WOT, at maximum engine speed. Power requirements are very approximately related to the cube of speed. So at 80% speed, you will need very approximately 51.2% power. (and heat rejection). Or 200HP.


So at 80% speed at 200HP, you need 2x(30+6+10)kW cooling. Call that 92kW heat rejection.


You have 350,000BTU/h heat rejection. My online calculator and a couple of references make me think this is 102.5kW.



So. For a first guess- I think you might overheat running at full throttle at full engine speed. But you are probably fine for almost all operation.


This is just a guess- a slightly scientific guess with a reference, but just a guess. You could be OK at all speeds. I don't think this is a terrible place to start for cooling. But it doesn't seem overcooled.


Remember, this is just an opinion that you got on the internet, using a different engine as a benchmark.

EDIT: a plate to plate will not work. Much, much more cooling required. Do NOT attempt


It has occurred to me that I made an error in telling you it will only be 350k btu’s. That’s the main heat exchanger however there will be additional 50k (25k for power steering and oil each). So I’ll try to figure out what that looks like.

Heat soak is also a concern. I plan to have a bilge vent blower on the bilge exhaust side keyed to ignition so it pulls hot air out of the compartment and should draw cooler air in naturally. This blower is not to be confused with another blower I will install for venting gas fumes.

Thanks for doing all this math. There really is only one way to find out for sure. It will have a ps cooler and an oil cooler.

If needed a bigger exchanger is not the end of the world. But we will see. I’ll get up on plane and get going fast on rare occasions but majority is high speed trolling. 13mph. Give or take conditions.

So it’s been a lot of hurry up and wait here. Not sure I posted this but all 3 of my kids tested positive for COVID. And per Hawaii law, all of us (me, wife, and kids) were quarantined for over 20 days.

Wiring-

I did end up getting a LS1 stand-alone harness. I couldn’t find a gen 4 stand-alone. Turns out the 2008 was an oddball Ls due to connectors etc.

https://www.ebay.com/itm/313583141284

I did have to cut off and replace the ev1 to ev6 injector connectors. From old harness. This was free for me. I’ve read mixed reviews on adapters and this way it’s permanent.

The map sensor I had looks compatible but if you do this double check that
I did have to order some older style O2 sensors denso 234-4337
The coil brackets, coil harnesses, and coil harness extenders have finally come in this week. Took about 3 weeks to get those. And the flexible oil dipstick says oct-nov to arrive.

My harness came with compatible parts id’s. I ordered a maf sensor. Will probably need an ait sensor as well.

My pcm came in from lt1swap.com Brendon was great and super fast to work with. very close to being ready to start this.

Must have a ligenfelter trg-002. The Holley terminator x’s are still not in stock.
Need a 4pin to 2 pin alternator connector. I’ve thought about wiring it up myself but still reviewing harness diagrams. I do have a resistor here and maybe I can make that setup work. We’ll see. The ict billet 4pin to 2 pin waalt30-6 is only $30.

Will be ordering gauges soon. Think I’ll be going with Faria Chesapeake in black.

https://www.boatid.com/faria-beede-i...iABEgJ8SPD_BwE

And need fuel system. Mainly a pump. Anyone have suggestions for inline fuel pumps? I’m thinking about an inline pump from summit and keeping an evil energy from Amazon onboard as a backup.

It’d be pretty pricey to put in tank pumps in and really a pain if they failed.

Glad to here your out of quarantine and since you didn’t add anything I assume everyone is doing well!? God help anyone else that might try and work on it down the road😀but sure sounds like you’ve got it figured out! Hope the Lava isn’t a issue . My step daughter in Capt. Cook is ok

I’m never parting with this boat. I hope I’m happy with performance. Family is all aok. The lava is all in the volcano park a good bit away. A few years back it was flowing and within 10 miles of me.

I live in HPP. You step daughter should know where that is diagonally NE from her to me roughly. Rainy season is starting here I got to get a cover up ASAP.

I put another order in with summit

This ones for the fuel pump, ligenfelter converter trg-002, 4 pin to 2 pin alt harness, and msd custom plug wire kit.

That’s gonna get me really close to firing it up. I need to order some gauges, fuel hoses, regulator, and some other stuff but nothing too major left on the engine.

I can’t wait to fire it up, or at least try to. I’m sure I’ll have some issues to work out.

It’s a boat OF COURSE. There will be issues——-lol
Amazon must be a God send over ther, we wanted metal cooler cups for our vacation but didn’t want to drag them there in the baggage looked and had them ship a 4 pack there thru Amazon for like $26-28 then left the set for her there, no issues with what do you have in the bag?

Yeah Amazon prime is a must here. Real nice of you to give to others. Yard sales and second hand everything is pretty normal here. Amazon’s shipping has gotten slower, sped up, and is slowing down again. But they did open a warehouse in Hawaii so that did help some during COVID but I think the supply chain is really messed up getting stuff to them.

Summit is still lightning fast with very reasonable 2 day air prices.

So far no issues (that I’m aware of) But I won’t really be able to fine tune until I get it firing. But as is all things engine. It’s one thing to bolt it together. It’s another to make it run and keep it running.

Fuel system and cooling system are next on the list.
Need: fuel water separators, fuel hose, -an fittings, c5 regulator, return hose setup.

Cooling: All my fittings and hoses for the cooling system. Power steering cooler, oil cooler.

So yet another order for parts

Ict billet 5’ spark plug wires.

https://www.amazon.com/ICT-Billet-Un...omotive&sr=1-2

Faria Chesapeake black gauge set.

https://www.amazon.com/Faria-KTF003-...28983850&psc=1

Ls oil drain valve

https://www.amazon.com/EZ-Oil-Drain-...motive&sr=1-12

Fuel regulator /filter

https://www.amazon.com/EVIL-ENERGY-F...NsaWNrPXRydWU=

AIT sensor for LS1 harness

https://www.amazon.com/ACDelco-213-2...omotive&sr=1-3

Holley Term X is back in stock. So do I try to return ligenfelter trg (if can-it’s unused) and go Holley? or do I stay with what I have? Bear in mind that’s $800-1200.

Holley all the way. Love my 12.3 display with the dominator ecu. The Term X is a much better value though. Lot of good support for the Holly stuff and you will be happier in the end...

Kind of what I figured.

I’m going to get the engine going, outdrive rebuilt, gimbal housing ordered. I should have some money leftover and then I’ll do term x.

I’m not doing Holley gauges they look great but crazy expensive. I’m going old school Faria black Chesapeake on teak wood background. I’ll either leave a space for the handheld to mount between the gauges or just make a new one altogether when I do that upgrade. Having tools and wood makes it pretty easy.

I just got a truckload..literally of curly Koa wood. Too bad I’m only using teak but boy is this stuff gorgeous.
These 2 pieces cost me about $100
https://i.postimg.cc/xqjKwLh4/24728B...988BD3EE0F.jpg
Got a much better deal…
https://i.postimg.cc/NLN1B5wf/80-ACA...76-C3-D0-E.jpg

Just one of my woodpiles… I need a barn
https://i.postimg.cc/YLSYQwQH/396D1A...9E9F8609D5.jpg

https://i.postimg.cc/rKK5mM8G/85A864...B63FD18820.jpg

For those wondering..,denatured alcohol, mineral spirits, or water will give you an idea of what it will look like varnished. I like alcohol dissolves quick, cleans the wood surface, and won’t dry it or wet it.

So I’ve found another flaw in my plan. I had that fancy cooling setup figured out. But notice the no clearance issues. I’m not even sure I can get an elbow in there.

So I’ll have to plan to go the traditional setup.

https://i.postimg.cc/hJJwk9G6/71977F...55AAB9AF54.jpg

But the plug wires and some other misc stuff finally arrived. I’m locating cooling hoses and have some fuel lines to take care of. Expansion and overflow tanks are planned out. Feel like I’m getting close to firing it up.

I think they make a 3 or 4 inch riser for that. And for many installations on 25s it's desired.

So I got these from Hardin marine. I don’t see where I can get risers. If I’d gotten crusader or pcm I could have done that but I was trying to avoid iron.

Maybe another brand would work in between or I have another idea with a friend who I think has a mill…let’s get this closer along and we’ll revisit it.

https://www.hardin-marine.com/p-1045...-53-60-62.aspx

This needs a bigger heat exchanger. At this point, I might as well get an appropriate marine heat exchanger. Given the price of fittings and cooling needed it’ll be cheaper and simpler to go that route.

Now for full closed or half closed is next question.

New plan:

https://i.postimg.cc/VrPhJTL9/5-D92-...-CCBC2-B2.webp

This cost is about $1300. I spent about $800 on brass fittings and 200 on the plate to plate. Fortunately I can return the other stuff. It’s not much difference to do it in a better way. Hope this helps others dealing with this.

I’ve found that crusader (also pleasure craft marine I believe they are under the same parent company) use a LS based engine in some instances (6.0). I know Ilmor and I believe Indmar utilize the LS. However, I’m excluding them for this conversation. My preliminary research shows crusader is the least expensive and most readily available.

I prefer Crusader die to the full closed cooling design. The Hardin Marine setup only does half closed (block only not exhaust) and costs $1600. https://www.hardin-marine.com/p-7409...per-brass.aspx

Here is a link to the Crusader parts manual. Throughout the drawings reflect LS architecture.

Please see:
pic on p1
Pic on p8 of water pump diagram
Pgs 32-41 diagram the closed cooling and detail the setup for the 6.0

https://www.crusaderengines.com/wp-c...03/L510018.pdf

Here’s another view of the cooling diagram

https://macombmarineparts.com/pages/...tem-components

Parts required:
Heat exchanger- RA0147048a

Marine parts.us:
Heat exchanger Thermostat housing and splitter - r025038- $65.35

Perf protech:
Heat Exchanger Bracket- r090258- $137.15
Degas bottle- r146001-$75.38
Degas cap- r034045- $23.36
Degas bottle bracket?

Various suppliers:
Water pump inlet and threaded port- R025036 $44.27 p8 of crusader diagram

Searching for:
Water pump tee- R025035a

Misc hoses and clamps.

I’m still searching for the water pump Tee r025035a. I already made my own out of brass fittings and reducers. I used a 1.25” brass tee with 1.25” hose barb fitting inlet and reducers to 1” hose barb outlets. I suspect the crusader part r025035a would be much less expensive.

Per our first call, I learned that 1hp =2,500 BTU’s. However that number does not include the cooling requirements of a full closed system. Maybe you can back into it from the information provided.

Closing notes in exhaust manifolds. I bought these from Hardin Marine https://www.hardin-marine.com/p-1045...-53-60-62.aspx

I wanted to keep iron out of the boat in my salt water environment. However, I did not consider that I might need exhaust riser spacers. I am now faced with definitely needing spacers and will probably have to fabricate them myself. I would tell others to buy the crusader or pcm exhaust elbows and risers if they might need spacers. Perforate h has a good article about this.

So it’s been a while but all the heat exchanger parts are in. I’ve started installing the parts and wiring up gauges etc.

The stand-alone harness is nearly finished with wiring. The instructions what little came were wrong so it took extra time to sort it out. I think everything is nearly ready. I need to go over every connection just to double check everything but the engine should be ready to fire up soon.

I’m using Sae 30 to break it in. I’ll probably switch over to 10w-40 once I’ve started it and let it run for awhile. Probably 20-30mins on initial startup. Then change to conventional 10w-40 and after 25 hours probably switch to full synthetic (royal purple is a favorite of mine).

Volvo recommends 10w-40 in the dps based Ls systems
Crusader recommends 15w-40 in their 6.0 Ls system.

Any suggestions always appreciated

I ended up ordering one of these for my front splitter out of the LS water pump into bottom manifolds. I’ll post pics when I can. It’ll be a lot lighter and cheaper than this brass setup below

https://www.hardin-marine.com/vsearc...rchTerm=300373

Before

https://i.postimg.cc/zLmfBrmR/6-E094...-E17-C8-B5.jpg

After. Might make it a little cleaner yet. But big thing is weight in the hose out of the pump. It’s much lighter.
https://i.postimg.cc/XZwYBz31/A1138-...E70-AD5-EC.jpg

Ps yes that is masking tape holding the maf on until I get the right coupler shipped in.

Just a note about oils: The 2003-2013 5.3 LS motors used oil pumps rated for either SAE 5w-30 or 5W-20. Later motors ALL had pumps rated for 0w-20 oil. In my 2014 Silverado the dealer said I could safely increase the 0w-20 to 5w-30 for long distance towing but not to ever use a higher viscosity than that as thicker oils put excessive strain on the pumps. Not knowing anything different or better, I've followed those guidelines with regular 5K full synthetic LOF schedule, and just turned 337,000 miles. Just something to consider.

So good points frank. What rpm is your engine pulling on long haul towing? Over 4K? The big concern I have is the results of pulling 3-5k rpm for extended time.

I did put in a good after market pump (not a high volume to avoid draining the pan). Also a major problem from mid 2000’s on is that DOD garbage. Under the valley plate is a series of sensors and stuff that shuts off the lifters at certain rpm. A major issue are those lifters collapsing.

https://i.postimg.cc/jD809mNm/A8E08F...C9A1233F69.jpg

Vs the ls7 lifters here

https://i.postimg.cc/zyDYx8LT/2299FA...4195C00D66.jpg

This is why DOD deletes (LOMA, AFM- all same thing) are so popular. In addition, vvt and a cam phaser can be part of this but my gen 4 didn’t have vvt.

So what they told you makes sense for a stock engine (with DOD and VVT) running in cold weather. As 5w and 0w are the measurements for how it will flow at colder temps. Here in Hawaii as in FL it’s pretty warm all the time.

What’s got me scratching my head, there doesn’t seem to be a standard-Crusader has one and VP has one -they are both using LS now are calling for much thicker oils over GM’s factory specs. I actually called Royal Purple to discuss this but couldn’t reach anybody. There are even some guys running VR-1 a race oil at 20w-50 in boats and race cars with great results. However I’m not sure a standard volume pump can handle that. I’ll do some more research on that.

My engine still has the Active Fuel management, but I've noticed that in Trailering mode, it does not activate, even at slower speeds.

I turn about 3000 rpms at about 63-65 mph on the highway pulling either my boat or my 20' drop-tail trailer with my Jeep on it. I get about 13.5 mpg hauling the Jeep, which on the trailer with my old BMW motorcycle together weighs about 6,300 lbs.

Without the trailer and in trans normal driving mode I turn about 1700-1800 rpms at the same speed and get about 19.8 mpg.

Hey, hey. Look what came to me today!

https://i.postimg.cc/MvXtpN8P/3695-F...A18955-C07.jpg

https://i.postimg.cc/9zLJVVsw/E330CE...6053FC4D55.jpg

Custom riser spacers… now to paint and install

Here is the test fit. Should be installing tomorrow and getting it started soon I hope.

https://i.postimg.cc/30XsFNwr/82850B...9FDA8C87CF.jpg

So today we tried to start it up. Crank no start. The ligenfelter trg-002 is blinking all red indicating no crank shaft input. I did reuse that sensor. I purchased a new one this evening and will be installing and go for start tomorrow.

I told wife I should just fire it up at 9pm tonight and was given a very stern no… especially as she teaches the police officers kids who live 2 doors down from me.

Oh well. Morning is coming. Maybe 0600?

Good luck! I have a new 454 in my 1978 23' Sceptre that has not been run yet myself (waiting for boat to be finished from a project that has taken WAY too long). Please post pictures and I'm sure the neighbors will understand.

Sounds great water rat. Still no joy yet. I’ve got to double check spark and some wiring issues from this harness. I think I’ve identified the issue.

On the plus side the crank position sensor turned the trg from blinking red to all red. Meaning not talking to pcm. I think the pcm has a power supply issue from this harness. Another day of trouble shooting ahead.

Ugh, I feel your pain. I'm sure nothing that several hours and a few ounces of blood and sweat won't cure. Good luck and keep us posted.

It’s alive! I feel like Frankenstein…

I don’t care how many you’ve done until it’s running you’re scared…or it’s somebody else’s money.

https://i.postimg.cc/XB8pf1CW/F1EF25...66BD9897C3.jpg

https://i.postimg.cc/64w8GxTz/3CE68F...6C7A64ED1F.jpg

I’ll try to make a vid of it running…it sounds awesome. Deep and throaty. I love it. Still working on the idle but it’s figuring it out.

Congratulations! Would love to see some video and hope to be reporting similar news myself soon.

Awesome! Hope you get to dip her soon!

And here is a short video of it idling. Nothing special but it’s nice.

https://youtube.com/shorts/BgZwQZmeAmw?feature=share