Last GM Big Block

[BajaMike]

The 8.1L Vortec V8 Was GM's Last-Ever Big Block Engine

The Vortec 8100 represented the final link to Chevrolet's roaring '60s muscle car motors.

www.drivingline.com

 

[Angler]

That engine likes to drink oil...

 

[J&k beer can]

Yes they love oil and drunk the

quick..

 

[MK1MOD0]

Last ever......... unless you count the 454, 502 and 572 which are all STILL in production.

 

[glamis0812]

Great motors, they definitely burn some oil when you work them but very reliable.

 

[Dalton]

Yes they love oil and drunk the View attachment 1020431 quick..

my old uber driver used a rare 8100 avalanche, he just drove for fun

 

[spectras only]

The all aluminum 6.2 in my son's Cadillac Escalade is a better option. I prefer the 6.2 Merc engines in my boat too.

 

[MK1MOD0]

The 6.2 boat motors now make 450 hp. The 496 never made that much hp in marine trim.

 

[Bigbore500r]

The 6.2 boat motors now make 450 hp. The 496 never made that much hp in marine trim.

Its not the HP, its the torque........
That 496HP is cracking well over 500ftlb of tabletop flat torque from 2500+, and that's gonna let you plane the heavy boat full of people

 

[Bigbore500r]

The all aluminum 6.2 in my son's Cadillac Escalade is a better option. I prefer the 6.2 Merc engines in my boat too.

The newer 6.2's rip, but the power curve is insanely different. They don't need the 8.1 in gas trucks anymore because they have 10 speed transmissions. But back in the day of the 4 speed auto.....that low rpm grunt of 500+ ftlb starting at 2000rpm and continuing as flat as a table top is what got you up the hill without having to downshift to 2nd and rev 4500+ at 45mph

 

[MK1MOD0]

Its not the HP, its the torque........
That 496HP is cracking well over 500ftlb of tabletop flat torque from 2500+, and that's gonna let you plane the heavy boat full of people

Owning a 6.2 motor in a heavy boat, I’ll just say, the boat planes instantly with a boat load of people. No difference than it would with a 496. The fact that the 6.2 is much liter is not to be discontinued. Having been in countless 496 boats, and now the new gen 6.2 ......... I’ll take more hp and a liter package 6.2 over a stock 496 every time.

 

[Bigbore500r]

Owning a 6.2 motor in a heavy boat, I’ll just say, the boat planes instantly with a boat load of people. No difference than it would with a 496. The fact that the 6.2 is much liter is not to be discontinued. Having been in countless 496 boats, and now the new gen 6.2 ......... I’ll take more hp and a liter package 6.2 over a stock 496 every time.

What boat?

 

[DRYHEAT]

The newer 6.2's rip, but the power curve is insanely different. They don't need the 8.1 in gas trucks anymore because they have 10 speed transmissions. But back in the day of the 4 speed auto.....that low rpm grunt of 500+ ftlb above 2000rpm is what got you up the hill without having to downshift to 2nd and rev 4500+ at 45mph

What is this four-speed auto you speak of?

 

[Bigbore500r]

What is this four-speed auto you speak of?

How soon we forget....lol

 

[MK1MOD0]

Another note. The 496 is dead in the marine world. Merc, indmar, Volvo have all killed it. Either they went to the LS, or to the 502.

 

[MK1MOD0]

What boat?

I‘ve been in a ton of boats with both the 496, and 6.2. Presently, the wife has a 24MXZ. it a heavy boat for sure. But, even when loaded down with a bunch of people, these LS motors work amazingly Well. With the supercharged versions now over 600hp, they are certainly part ofthe future.

 

[Bigbore500r]

I‘ve been in a ton of boats with both the 496, and 6.2. Presently, the wife has a 24MXZ. it a heavy boat for sure. But, even when loaded down with a bunch of people, these LS motors work amazingly Well. With the supercharged versions now over 600hp, they are certainly part ofthe future.


View attachment 1020506

I agree that the LS motors crank out power. I think your application is a bit different though.

Your boat is engineered to holeshot, plane quickly and tow weight. Its a bit different when you have a 28' deck boat full of people, and the boat is propped to run 60+. The N/A smaller displacement motor makes the HP necessary, but doesn't have the torque production between 2000-3000rpm to roll the boat over and get it on plane. If it can't plane, it can't get past 3000rpm to where the horsepower lives. That's why you don't see larger single I/0 cats and V bottoms rigged with the smaller displacement options, unless it's a pair of them. No matter how good the newer motors are, the old "no replacement for displacement" comes into play down low, nothing short of compression or a twin-screw or positive displacement supercharger can add power down low where needed to shore it up and make up for the lack of torque in that application.

And this....is why Merc keeps making 8.2L motors with the "same" HP as the 6.2 offerings

 

[Wedgy]

What is this four-speed auto you speak of?

Missed it by one year. 1990 State of the Art!
TBI G30 EXT. MK4 7.4L T400 3.42 . 12 pass + tow 5000 of gear like nothing. Slow and Steady. Van On!

 

[MK1MOD0]

I agree that the LS motors crank out power. I think your application is a bit different though.

Your boat is engineered to holeshot, plane quickly and tow weight. Its a bit different when you have a 28' deck boat full of people, and the boat is propped to run 60+. The N/A smaller displacement motor makes the HP necessary, but doesn't have the torque production between 2000-3000rpm to roll the boat over and get it on plane. If it can't plane, it can't get past 3000rpm to where the horsepower lives. That's why you don't see larger single I/0 cats and V bottoms rigged with the smaller displacement options, unless it's a pair of them. No matter how good the newer motors are, the old "no replacement for displacement" comes into play down low, nothing short of compression or a twin-screw or positive displacement supercharger can add power down low where needed to shore it up and make up for the lack of torque in that application.

And this....is why Merc keeps making 8.2L motors with the "same" HP as the 6.2 offerings

i knew you were going to say that. my boat is currently propped to run 55. Not 37 like the factory. And yes. There are many other brands starting to run the LS platform. If you think most boats need to go WOT to-get on plane, I’m going to completelay disagree. Almost NO ONE slams the throttles all the way forward to plane. In fact, if you slammed the throttles to the firewall all the time to get on plane, the drive wouldn’t last . My guess, you haven’t been on a boat with the newer 400 hp plus LS power. They work very well. And not just on a ski boat. While I love the 502 in all its incarnations, I was never impressed with the 496. While it ultimately became reliable, the first years were a mess and I couldn’t tell you how many I seen being towed in. Most fuel related problems. Simple fact, the LS makes more power and is liter than the 496 ever was.

 

[DRYHEAT]

How soon we forget....lol

Didn’t forget I’m still driving a three speed. TH400

 

[MK1MOD0]

I agree that the LS motors crank out power. I think your application is a bit different though.

Your boat is engineered to holeshot, plane quickly and tow weight. Its a bit different when you have a 28' deck boat full of people, and the boat is propped to run 60+. The N/A smaller displacement motor makes the HP necessary, but doesn't have the torque production between 2000-3000rpm to roll the boat over and get it on plane. If it can't plane, it can't get past 3000rpm to where the horsepower lives. That's why you don't see larger single I/0 cats and V bottoms rigged with the smaller displacement options, unless it's a pair of them. No matter how good the newer motors are, the old "no replacement for displacement" comes into play down low, nothing short of compression or a twin-screw or positive displacement supercharger can add power down low where needed to shore it up and make up for the lack of torque in that application.

And this....is why Merc keeps making 8.2L motors with the "same" HP as the 6.2 offerings

And just to show you I dig Big block chevys. Here are the TWO in my last boat

 

[Bigbore500r]

i knew you were going to say that. my boat is currently propped to run 55. Not 37 like the factory. And yes. There are many other brands starting to run the LS platform. If you think most boats need to go WOT to-get on plane, I’m going to completelay disagree. Almost NO ONE slams the throttles all the way forward to plane. In fact, if you slammed the throttles to the firewall all the time to get on plane, the drive wouldn’t last . My guess, you haven’t been on a boat with the newer 400 hp plus LS power. They work very well. And not just on a ski boat. While I love the 502 in all its incarnations, I was never impressed with the 496. While it ultimately became reliable, the first years were a mess and I couldn’t tell you how many I seen being towed in. Most fuel related problems. Simple fact, the LS makes more power and is liter than the 496 ever was.

Disclaimer - I'm a huge LS fan, and have built over 100 of them in the last 15 years.

I agree they can make great power per CI of displacement, and it can be done cheaply using factory parts to boot.

But.....

Heres the thing - it doesnt matter how far you advance the throttle (you referenced that "nobody slams them all the way forward) - The motor can only injest as much air as it can use for a given RPM (naturally aspirated.....) - So effectively, the motor can only produce as much torque at a given RPM as it is cable of producing, regardless of throttle angle beyond a certain point. Every driven a motorhome up a grade? That's what your boat is doing getting on plane. You can push the sticks as far forward as you want, but beyond a certain point your pushing the load as hard as you can and you may have alot of throttle available, that gives no results.

So pushing throttles 1/2 way to get on plane, can be the same as pushing them 100%, until the motor "catches up" and begins using more air and increasing RPM to where it can continue to utilize all of the air available at 100% throttle.

Your boat is a tow boat, and it planes easy (ts designed to....). It's propped in a manner that it can run a smaller displacement motor and get it up into the RPM range where its making torque, so plaining isn't an issue. And once its there...it can scream to redline and make as much (or more...) power than the 496 you referenced.

You won't see a single 450HP 376" CI N/A motor pushing a 28 magic, or a Fundeck, or a ...you name it....because when weighted down it wont plane. You could prop it way down and it will plane, but then it wont run the top end numbers. So if you want both options, your gonna run either A - more cubic inches, B - a blower, or C - prop it / gear it down and buzz it 6000+ to get your speed back on the top end (which you probably can do, as its still pulling at 6k...). But, nobody does option C cause Bravo's dont like to run beyond 6k for extended periods, and neither do commonplace marine engines.

That's all I got.

 

[Bigbore500r]

Didn’t forget I’m still driving a three speed. TH400

Well the 4L80 is only like a .78 overdrive, it helps but it ain't that great lol

 

[DRYHEAT]

Well the 4L80 is only like a .78 overdrive, it helps but it ain't that great lol

I’m kind of waiting to see what kind of aftermarket development there’s going to be for the 10 speed transmission, I’d like to upgrade my 400 but it would probably be more than the truck is worth.

 

[Bigbore500r]

I’m kind of waiting to see what kind of aftermarket development there’s going to be for the 10 speed transmission, I’d like to upgrade my 400 but it would probably be more than the truck is worth.

I mean, a 4L80 is still a great upgrade that can be done cheaply, but it doesn't do much for the gear spacing, other than give you a lockup converter and that .78 overdrive. 1st, 2nd and 3rd are still the same as you TH400, and you still have that steep (numerically shallow) 2.48 1st gear.

Seen these before? TCI makes a 6 speed version that works with their stand alone controller, it will bolt up to BBC's.
I've never seen somebody run one, but it's clever and has a nice gear spread...
Not cheap though either!

TCI Auto 271700 TCI 6x 6-Speed GM 4L80E Automatic Transmissions | Summit Racing

Free Shipping - TCI 6x 6-Speed GM 4L80E Automatic Transmissions with qualifying orders of $109. Shop Automatic Transmissions at Summit Racing.

www.summitracing.com

 

[DRYHEAT]

I mean, a 4L80 is still a great upgrade that can be done cheaply, but it doesn't do much for the gear spacing, other than give you a lockup converter and that .78 overdrive. 1st, 2nd and 3rd are still the same as you TH400, and you still have that steep (numerically shallow) 2.48 1st gear.

Seen these before? TCI makes a 6 speed version that works with their stand alone controller, it will bolt up to BBC's.
I've never seen somebody run one, but it's clever and has a nice gear spread...
Not cheap though either!

TCI Auto 271700 TCI 6x 6-Speed GM 4L80E Automatic Transmissions | Summit Racing

Free Shipping - TCI 6x 6-Speed GM 4L80E Automatic Transmissions with qualifying orders of $109. Shop Automatic Transmissions at Summit Racing.

www.summitracing.com

Interesting, I hadn’t seen that before. It’ll be interesting to see what the future holds I honestly don’t really need it I don’t haul anything real heavy anymore but I like to drive my old square body. Would be a nice bonus if I got better than 8 or 9 mpg and turning 3000 RPM plus going down the freeway slower than the rest of the traffic.

 

[ka0tyk]

Gt45 turbocharged 8.1l here.

 

[bonesfab]

I’m kind of waiting to see what kind of aftermarket development there’s going to be for the 10 speed transmission, I’d like to upgrade my 400 but it would probably be more than the truck is worth.

Better be ready to cut the floor out. the 10 speeds are huge.

 

[MK1MOD0]

Disclaimer - I'm a huge LS fan, and have built over 100 of them in the last 15 years.

I agree they can make great power per CI of displacement, and it can be done cheaply using factory parts to boot.

But.....

Heres the thing - it doesnt matter how far you advance the throttle (you referenced that "nobody slams them all the way forward) - The motor can only injest as much air as it can use for a given RPM (naturally aspirated.....) - So effectively, the motor can only produce as much torque at a given RPM as it is cable of producing, regardless of throttle angle beyond a certain point. Every driven a motorhome up a grade? That's what your boat is doing getting on plane. You can push the sticks as far forward as you want, but beyond a certain point your pushing the load as hard as you can and you may have alot of throttle available, that gives no results.

So pushing throttles 1/2 way to get on plane, can be the same as pushing them 100%, until the motor "catches up" and begins using more air and increasing RPM to where it can continue to utilize all of the air available at 100% throttle.

Your boat is a tow boat, and it planes easy (ts designed to....). It's propped in a manner that it can run a smaller displacement motor and get it up into the RPM range where its making torque, so plaining isn't an issue. And once its there...it can scream to redline and make as much (or more...) power than the 496 you referenced.

You won't see a single 450HP 376" CI N/A motor pushing a 28 magic, or a Fundeck, or a ...you name it....because when weighted down it wont plane. You could prop it way down and it will plane, but then it wont run the top end numbers. So if you want both options, your gonna run either A - more cubic inches, B - a blower, or C - prop it / gear it down and buzz it 6000+ to get your speed back on the top end (which you probably can do, as its still pulling at 6k...). But, nobody does option C cause Bravo's dont like to run beyond 6k for extended periods, and neither do commonplace marine engines.

That's all I got.

If ya want to cherry pick a tiny segment of the performance boating community, that’s fine. A 28ft, single engined barge loaded down with 12 people may not be the very best fit for an LS. But seriously, who routinely goes out with 12 people in a boat........ as for the planning , I’m guessing all designers build their boats to plane easily. The longer the boat... generally the slower to plane. As far as running rpm’s, the Bravo has zero issues running at above 6000 RPM as long as it has a proper drive shower. I would run mine above that for literally miles and miles at times, and never had a heat related issue, and that was with 800hp on tap. I totally understand that there is no perfect motor for all boats, but I just say, the 496 was not a great engine. It was in a ton of boats because it was cheap, and therefore affordable for someone who wanted a performance “ like” boat. Cast crank, rods and pistons do not scream performance. Personally, glad the Merc and the other big brands have gone back to the 502 . Much better basis for any build.

 

[Bigbore500r]

If ya want to cherry pick a tiny segment of the performance boating community, that’s fine. A 28ft, single engined barge loaded down with 12 people may not be the very best fit for an LS. But seriously, who routinely goes out with 12 people in a boat........ as for the planning , I’m guessing all designers build their boats to plane easily. The longer the boat... generally the slower to plane. As far as running rpm’s, the Bravo has zero issues running at above 6000 RPM as long as it has a proper drive shower. I would run mine above that for literally miles and miles at times, and never had a heat related issue, and that was with 800hp on tap. I totally understand that there is no perfect motor for all boats, but I just say, the 496 was not a great engine. It was in a ton of boats because it was cheap, and therefore affordable for someone who wanted a performance “ like” boat. Cast crank, rods and pistons do not scream performance. Personally, glad the Merc and the other big brands have gone back to the 502 . Much better basis for any build.

I would say cherry picking would be using a 24' wake boat as the litmus test for performance boat engines.....

I think your missing my point - Im not a 496 fan. I also prefer a 502 platform for many reasons, but the fact that an 8.1 uses cast components doesn't have a bearing on what i'm saying.

And what I am saying is - Small displacement + larger performance boat (weight) = won't plane when propped for an acceptable cruising / max speed.

Go out on the lake, it's full of 26'-30' single I/O performance boats, boat Cat and V bottom. They need to plane with 80+ gallons of gas, 2 coolers, and a load of passengers in 115 degree heat. I wouldn't call that a small segment of the market. Id call that a huge portion of the market. You'll see a 6.2 in some 24' boats. You'll see it in a few of the 255 Howard VTX's that have rolled off the line. You wont see a single one powering a performance boat bigger than 26', unless there is a pair of them, or if it's blown. The smaller boats (or boats that are designed like yours, with pulling skiers and sports in mind) can get away with them, and once on plane they can get to the sweet spot and reach power. But the bigger boats can't, or it is extremely difficult. A 2-speed trans could make it happen, but now were just exploring stuff that costs $$$ and is outside of the average setup.

If Merc could ditch the BBC and only offer the 6.2, they would. They can't, cause there is a plethora of other applications out there that require more low end torque to get the job done.

 

[MK1MOD0]

Not a litmus test at all. Just one option. As for the boats rolling off the line, more and more performance boats are going the LS route every year. A lot of them are faster with the LS than a low hp BB. If your looking for over 500 hp, then it’s a no brainer. Under that, the much much liter LS is a real contender.

 

[RCDave]

I'll chime in. I had a 25' Shockwave Tremor. 24 degree deep v bottom. No way I would have opted for a small block. It would have been a dog out of the hole and thru the mid range. Low end torque moves heavy loads

 

[dribble]

That engine likes to drink oil...

When I took my boat with the 496 out the first time , I broke it in by screaming down river at 5000 rpms for 20 miles to get a buddy’s dog to a vet hospital because he swallowed a big fish hook and had a lot of blood coming out his mouth and nose. The engine literally had one hour on it. 19 years and several hundred hours later the engine still doesn’t use a drop of oil

 

[Bigbore500r]

Not a litmus test at all. Just one option. As for the boats rolling off the line, more and more performance boats are going the LS route every year. A lot of them are faster with the LS than a low hp BB. If your looking for over 500 hp, then it’s a no brainer. Under that, the much much liter LS is a real contender.

You're leaving size out of it, and that's my point! Lol

If you're looking at 22' decks, 21' V bottoms, 24' wake board boats, Chapparrals, etc.........ding ding ding - Those have a small block, 6.2, LS, etc.

26' or over single I/O performance boat, naturally aspirated - Show me one?

 

[MK1MOD0]

You're leaving size out of it, and that's my point! Lol

If you're looking at 22' decks, 21' V bottoms, 24' wake board boats, Chapparrals, etc.........ding ding ding - Those have a small block, 6.2, LS, etc.

26' or over single I/O performance boat, naturally aspirated - Show me one?

Well..... since I’m not anyone’s secretary , I’ll pass on the Internet task, but thanks I’ll just add, Calling a 28ft boat with a single 496 a performance boat is a bit of a stretch. A nice family boat, and a custom boat... I can see those definitions. A performance boat, not so much. .....then again, that’s just the opinion of this old hillbilly.

 

[Bigbore500r]

Well..... since I’m not anyone’s secretary , I’ll pass on the Internet task, but thanks I’ll just add, Calling a 28ft boat with a single 496 a performance boat is a bit of a stretch. A nice family boat, and a custom boat... I can see those definitions. A performance boat, not so much. .....then again, that’s just the opinion of this old hillbilly.

I guess we'll agree to disagree.

I know you see my point, but you can dance around it like the best of them!

Have a good 4th!

 

[MK1MOD0]

I guess we'll agree to disagree.

I know you see my point, but you can dance around it like the best of them!

Have a good 4th!

If your point is, a 496 is a good motor for a slow 28ft boat. Then yes. I agree

 

[MK1MOD0]

And saying a 6.2 that pushes a boat into the low 40s a powerful engine choice is pretty funny!!!!

Where did ya get that ?

 

[Bigbore500r]

If your point is, a 496 is a good motor for a slow 28ft boat. Then yes. I agree

This is the part where I smile and wave....cause we're not even talking the same sport at this point

Have a great 4th

 

[MK1MOD0]

Post #16

Ohhhh. Yea it’s actually 55. And certainly no performance boat. Just a family boat. Not designed or intended to be fast. But ok. Ok ok. I give. The 496 rules!!

 

[MK1MOD0]

This is the part where I smile and wave....cause we're not even talking the same sport at this point

Have a great 4th

But I am. Your cherry picking a tiny segment. 28 -30ft single engine boat. You win. Long live the 496 !

 

[77charger]

I know the old style small block 6.2 was impressive but torque is gonna get the big boat moving .Now in a smaller boat say 22-23ft and under 6.2 all day over a big block.Big block will not work as hard either theres a reason big cubic inches win races!

 

[Bigbore500r]

But I am. Your cherry picking a tiny segment. 28 -30ft single engine boat. You win. Long live the 496 !

 

[FRSCKE]

Here's my BBC a 93' G30 454/4L80E 4x4 EXT ...

 

[MK1MOD0]

View attachment 1020814

Ahhhhhh. Isn’t that cute.

 

[Shlbyntro]

I'm just going to jump in and break this up. Yes the market is slowly shifting towards the LS platform.
But 49 out of 50 boats out on the water today are still Vortec powered. No single line of engine has had such a successful and dominantly long run in this world than such. That would include 4.3, 5.0, 5.7, 6.2, 7.4, and 8.1L engines

The LSs have their strengths for sure and we will see more and more of them. But they have about 20 years to go before its a competition.

The 8.1s are great motors, you just have to care for them. LSs don't push 40 foot cabin cruisers around. 8.1s and 8.2s do

 

[MK1MOD0]

Lol. Need some radar or GPS to prove up that tall tale

???? Hmmm? Not sure why that’s hard to believe. The boat came with a tiny 15P prop from the factory. I’ve since changed it for a 20P. Not for top speed, which is pointless in this boat, but for cruising. Its made approximately a 15mph difference. Now it comfortably cruises in the high 30’s instead of 22-25. Also much nicer when pulling my wife on the slalom ski.

 

[Yoshiro]

This is an interesting discussion to read and I see both points of view here.

A good analogy would be Ford and their V6 turbo engines vs Dodge and their V8s.