Hardin Marine Cheyenne

Looks like for the marine industry the big block is going to win in the long run... If anyone puts one of these in our boats, breaking the motor will be the least of your worries...
http://blogs.hotrod.com/9-0l-dohc-big-block-crate-engine-see-it-first-91255.html
 

blazeracer

New member
Probably not. GM's most expensive and most powerful crate motor to date is an LS based 454 inch motor that makes 770hp naturally aspirated... and it's $40,000 less than the Mercury, which is a turbo motor.. haha
 
I guess what I was really trying to point out is the days of the iron block are numbered. I'm betting this is the future. An LS type aluminum block with similar architecture to the big block. I never expected anyone here to actually buy one of these, but simply was pointing out what is possible when an appropriate mix of parts is assembled.
There is a big difference between 770 HP and 1650 HP, about 114%. Therefore it is no surprise the GM crate motor is cheaper. What is interesting however is the price per HP is similar, $31.22 for the 770 vs $39.39 for the 1650. The QCV4 was designed for marine use, and comes with a 1 year warranty.
You must have a much stronger rotating assembly and good oiling for marine use than street.
I'll even point to my outboard as an example, obviously designed for marine use, hardened crank, much harder than found in any automotive application. If you gall a bearing your local machine shop will not be able to grind it. That motor will turn 6400 rpm ALL DAY LONG and has more or less done so for about 400 hours now with nothing more than an annual fuel filter & spark plug change. (5 seasons going on 6) I’ll even bet the QCV4 will turn it’s intended max RPM of 6500 all day long as well. Why? Because it was designed with the intended use in mind.
Will the LS454 hold up? Who knows? Probably. At least the rotating assembly has been forged, that I think has been the achilles heal of the previous motors used.
I know I'll be looking forward to what ever James puts together, especially if it has an aluminum block.

 

FormulaZR

New member
Matt, I think the LS is still called a small block because GM called it a small block. From GM is it designated as a Gen 3/4 SBC. It's just nomenclature, as there are obviously smaller big block GM engines out there. I assume it is a bore center/stock deck height thing? You are right, though - you can buy a 500+" LS based engine if your wallet allows.

James, if the block is ok - you could use it as a core to buy a sleeved block? Not sure it that is an option for you or not. Either way...I'm sad to hear the engine let go. I'd be willing to bet money that the engine was over-revved.

If you a building a new motor, you might look at the 4.00"+ bore engines (LS2/LS3). They open up a wide range of cylinder head options.

Also - the stock motor in the ZR1 Corvette is not a 427, it's a 6.2 which is a 376. The gen 5 Camaro SS's are also 376 ci. The only Corvette that got the 427 LS7 (not LSX, which is iron) is the Z06, the upcoming Camaro Z28 will also use this engine.

As for this quote:
Central Texas Jets said:
Turning the rear wheels in a vette just don't compare to turning an impeller in a jet pump. Hence all the problems in an engine that was designed for a vehicle.nothing can compete for longevity with the tried and true big blocks. Just sayin :smile30:

How does the differ from any other engine that is typically put into a jet boat? Was the BBC (even Mercruiser - not counting the 1350/1650 engines - though those are NOT typical jet boat engines) or BBF designed around a different purpose? The engine in my boat was designed to drive a C5 Corvette (and subsequently a Camaro SS) - should I be worried about it's longevity/reliability?


Anyone who doesn't think the LS engine can be a viable boat engine is welcome to go for a ride in my boat - which is my 2nd successful jet boat.

I'll never argue that a full tilt LS engine can beat a full tilt BBC - because it simply can't, but whats the percentage of THB members that have full tilt 1800+ hp BBC engines in their boat? And of those people who have 1800+ hp big blocks...how many use them as lake cruisers that run all day, pull tubes, etc?



For an engine that is expensive, bulletproof, and makes stupid power - you need to look at a turbine. A turbine offers the absolute most power you can buy in the smallest package possible - with unmatched long term reliability - and run silly high revs. For the rest of us who are looking at engines that are $10k and under for our cruisers...the LS engine isn't the only choice, but it is a good engine to consider. As with any engine, it's important to educate yourself to the correct way to build, run, and tune one. Before we throw rocks at James' used LS for breaking, lets remember that my Liberator had a "newly rebuilt" 454 BBC when I got it...10 hours later I had a "newly rebuilt" 454 BBC with a hole in the oil pan and a rod sitting below it. Must be because that Mercruiser 454 was based on a design that was originally put in a Corvette...unless of course it was it was because it was a used engine of unknown history.
 

blazeracer

New member
Ditching junk yard motors... Picking up a custom pro built real LS1, new... Wednesday. Gonna put the AFR heads and LG Motorsports 5G3X cam in it and not look back, except to see where the other guy is. haha
 

Crusader

Moderator
blazeracer said:
Ditching junk yard motors... Picking up a custom pro built real LS1, new... Wednesday. Gonna put the AFR heads and LG Motorsports 5G3X cam in it and not look back, except to see where the other guy is. haha

Good job James!!
 

TMoore

New member
Knocking on wood... my junk yard ls 5.3s have been doing pretty good.
No problems yet, again knocking on wood!

I have yet to see another boat with stock junk yard engines be as fast as mine, especially stock JY BBCs.

There are times and places for both the LS series engines and the BBC, pick what YOU want to run and have fun with it. :smile17:
 

blazeracer

New member
TMoore said:
Knocking on wood... my junk yard ls 5.3s have been doing pretty good.
No problems yet, again knocking on wood!

I have yet to see another boat with stock junk yard engines be as fast as mine, especially stock JY BBCs.

There are times and places for both the LS series engines and the BBC, pick what YOU want to run and have fun with it. :smile17:

You gonna make Yugo? Tom's got a little ole tunnel jet with a junkyard 5.3 on twins. It'll cook.
 

TMoore

New member
We'll be there Saturday.  Drive up Saturday morning and drive home that evening.
It's right at 100 miles 1 way for me.

I want to see that 5.3 tt run!
 

blazeracer

New member
Didn't even occur to me that this was possible, but the part of the oil pan gasket the has the o-rings for the block to pan seal was missing. Probably responsible for two blown motors.  It's fixed right now and I have great oil pressure. Now I need a little break in time then a few hard runs to get the tune right and the RPM max'd out, then see EO to get my impeller cut. Looking to tune the pump to 6,200 rpm on motor leaving a little room for spray.

Holding at about 40 psi on idle, almost 70 at anything above idle.
 

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Patchman

Administrator
Staff member
That's because someone used silicone and not a gasket. :smile20: Sucks about the motors! :smile18:
 

blazeracer

New member
I went and checked an old truck pan I have here. It's got that piece on it and it broke right off without barely touching it. A new pan gasket was $35 at the dealer and fixed it. Learned something new. The gaskets are all one piece and riveted to the pan. There's no way silicon would hold there. It's under pressure. If it was a high mileage motor the piece probably fell off when they pulled the pan from the motor.
 

Devilman

Well-known member
Good that you caught it in time. Look forward to hearing how it runs out for ya when you start dialing it in. :smile17:
 

blazeracer

New member
Had it on the water yesterday for the first of the shake down run. Went 71 mph @4,800 rpm with two of us in the boat plus a cooler and a tool bag. Carb was stumbing all over the place and seemed like it was running out of fuel. Air cleaner ended up at the bottom of Lavon somewhere.

Boat pulls real hard, love this hull.
 

blazeracer

New member
Scored a set of Rewarder headers from ole Jake for the LS1. Also got some color on the scoop, added 1/4 turn fasteners and a Harwood scoop plug. Shot some color on the valve covers also. Still gonna wet sand, clear, and polish the scoop today. Then this sucker should be close to done.
 
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