Pretty sweet build

[freeheel4life]

Always fun to see guys building stuff with big numbers and keeping it NA. Torque curve and high RPMs make it a not so great towboat option, but would be fun to drop into something you want to go fast in.

https://www.hotrod.com/articles/750-...roadster-shop/

[sandm]

appreciate the N/A version but if I'm going to put big $$ into a high hp boat, I want it to sound like this one.....
https://www.youtube.com/watch?v=sP3WBrVvWOU

[UNSTUCK]

I'll admit to not reading the whole article, but it seems strange to start with an LS block to convert to overhead cams. Why not use a Ford engine, or does Merc not do Ford?

[freeheel4life]

I'll admit to not reading the whole article, but it seems strange to start with an LS block to convert to overhead cams. Why not use a Ford engine, or does Merc not do Ford?

Couldn't speak to why they started with GM block vs the Ford but I'm guessing displacement in a modern package. I dont follow the Ford engine line that closely but as far as I know if you want that much displacement the only answer is getting into big block 460 territory.
I'm sure I dont need to tell you but DOHC(and overhead cams in general) have less inertia/rotational forces and less interconnected moving parts which is what allows them to run at the higher rpms vs a pushrod. Guessing that's why they went that route.

[UNSTUCK]

That's my whole point. You have a block designed for push rods and now you are left with a bunch of open holes that need filling. Then you need to build a custom front cover as well as the heads. Just seems like a very long hard way to get to that HP number. I'm sure the price tag is well over $30k as well.

[freeheel4life]

IIRC it said 32k. I think that the main thing was getting big numbers and high RPMs while keeping it in a smaller package. Short of stroking the heck out of a 351 I dont think theres any Ford gasser blocks that have those same displacement numbers. Ilmor is only pulling 522HP out of a DI GM 7.4L setup.
As far as I know there isnt a 4 valve head out there for the LS so I think that played into it as well.

Wasnt saying it was the best build ever. Just a cool concept. The zero backlash scissor gears and some other out of the box ideas are fun to me, and even with driveline losses that thing would be a beast in whatever you could fit it into. Sure you could put together a boosted LS7 and get the same power, but from what I've seen you end up doing cams and heads to get there on top of the 10-15 lbs of boost, and you have the same boosted Vette that everyone else has

[Bakes5]

$30k is a bargain. 750 hp in the outboard world will cost you about $75k. Just multiply whatever HP number you see on the back of those fancy modern outboards by 100 and you know how much they have spent on the motor alone on that boat.

[UNSTUCK]

750 HP will always be an impressive number, but at least to me it will never be worth it. My problem is that I'm cheap...dirt cheap. I can easily build a junkyard 5.3 with an LSA blower, heads and a good tune for under $5k and get 550-600 HP. To me, spending $5k for 550 HP is way better than spending $30k for 200 more HP, and you wont have to to rebuild it after every season.