DOHC 7.0 is Merc engine SB4 750hp
 

google ''sb4 merc marine''

or go find the ''march 2019'' issue of ''super chevy'' magazine ,a good read and heads and intake are made by edelbrock

both cover the new small block dual over-head cam 750hp crate engine

could this be the new GM ZORA c8 engine?

https://jalopnik.com/this-750-hp-ls7...l-s-1823828455

http://www.mercuryracing.com/automotive/

https://www.hotrod.com/articles/750-hp-dohc-ls-based-mercury-racing-motor-roadster-shop/

it only make 750hp-560ft lbs of torque at 7500rpm

if you need something bigger theres a 9.0 liter that makes 1750hp

Not a chance.

This was just merc showing off their engineering department. It's cool but it is a joke compared to their twin turbo racing stuff. The race stuff is also around 8:1 compression so that it can run on pump gas. Their racing department is no freaking joke. I was never there but dad was when they still tested on lake X and you had locked doors and men in lab coats running around. They are very good at what they do.

IIRC it started life off as an ls7 block that they modified for the heads. Intake design emulates that of the original LT5. Very cool project but I doubt gm would go out of house again. Plus the 1350/1750 is absolutely gigantic.

the 9.0 is a ''VERY'' large even bigger type of the BBC[but nothing but a few bolts from a BBC fit]

this sb4 eng [ive seen it run and driven 1 in a twin eng boat]

,was supposed to be an over the counter add-on 6-8 years ago,then it faded away for a couple and came back as a new boat eng,and was put in a car as a design study,then somebody at GM saw it

kind of cool that edelbrock is casting the heads and intakes,

these are emissions ready,no matter what you read

I met one of the engineers who designed the double overhead cam small block at SEMA. I was really surprised at how few people they had to design the engine, only two or three guys as I recall. He really knew his engines. Very talented.

Was the 9.0l based around the 496 architecture? That I don't recall. Yes it is huge though. And really heavy.

I didn't know they ran the sb4 in the boats. Wonder what kind of fuel they were running? Unless it had modified tuning and compression or something like that. Unless times have changed. Last race engines are now approaching 20 years old so...

am I thinking of the 525 then?

And I've stood next to them. They are gigantic. And they sound gigantic in the staging area for the offshore races too lol. They weigh something like 1000+ each no?

What small block?

9.0 is a whole MERC built eng,nothing BBC in it

sb4 is their smaller boat eng,about $30k each,they are the same as the crate car eng and ran on reg gas,,merc is trying to go their own way on eng's

Read "All Corvettes are Red," by McClelland. I owned a 93 ZR1 which I took to Europe. It lives in Munich with the second owner. When GM bought Lotus in '86, Lotus had just built their Etna V8. GM acquired 70 lotus engine engineers. Tony Rudd designed the Gen.1 LT5, much to the chagrin of the Chevy engineers. It was manufactured and assembled at MM who specialized in low volume race engines. The engine was a disaster because the bean counters wanted the heads to be interchangeable with the cast iron small block and the bore centers had to be the same. Rudd and McClelland left under a cloud. Graham Behan, one of the Lotus engineers revised the design, adding two extra bolts to the mains and brought the heads to OBD2 smog standards on the Gen.2 LT5. They gained 30HP. A gen 3 engine was been designed by Behan when GM pulled the plug. The english engineers knew the game was up when they saw the LS prototype engine. Lingenfelter bought (was given ) all the LT5 stuff from GM including the Gen.3 LT5 prototype engine which got 475 HP at 7200 rpm but couldn't meet smog requirements achieved at Lingenfelter LPE IN. Behan came with the deal. The GM engineers redeemed themselves when the LS6,7 and the 3 proved their worth. Their cylinder blocks are almost identical to the Gen.3 LT5 engine.
I put 5000 miles on my ZR1 in Europe and got 180 mph on a daily basis.

That sounds right. I know that they have been going that way for a while now too. They did that 4.5 v6 last year was it? I'd imagine the stuff dad saw at lake x was the M drive prototypes. The time line is right. Late 90s or so. Stuff he worked on was the blackhawks. Way before LS was a dream.

I'm not seeing anywhere where it mentions marine usage? Only the n/a 6.0 is in the slot where the sb4 would be. Unless they don't have it on their website yet?

I thought I had read an article about a car that has had the Gen 3 LT5 in it. Either way the specs on that engine were going to be crazy. I love the MM ID tag on those LT5's, way ahead of their time and man they really run!

IIRC lingenfelter as the only revised lt5 I know of. Made something like 450 horsepower in 96 or something along those lines. GM axed it because it was big and heavy. Also because they couldn't build it in house and it was expensive. The LS matched 85% of the characteristics of that bad boy, albeit it took 10 years.

You pay for that mercury racing/marine badge on an engine but for the most part, it's going to work. The companies roots are in racing and engineering. There is a reason kiekhaefer had well over 200 parents. (And won back to back nascar titles...) and everyone worked for him at one point lol.

There is an old story, goes something like this. During mercury setting the endurance record for an outboard at lake x, kiekhaefer was changing spark plugs on the outboard. He used nothing more than a wrench. One of the engineers told him he should torque the plug to spec. His response was "check it." And as the story goes, the rest is history. :rofl: