Theoretical Motor Build Up!
 

I'm bored and sick of winter! So lets have some fun and kick around some ideas and theories for something different. Here is what I am thinking. 1000 HP naturally aspirated marine engine. It can run on 110 octane and can be 632". Max RPM can be 6700 RPM and it must be able to idle at 1000 RPM. Assume full length headers and it must be capable of 20 hrs between lifter / spring changes and 200 hrs on the bottom end. I am thinking a good start will be a 12:1 compression 632". Which heads? AFR, Dart Big M, Big Chief? What about induction and cam specs? This is only a BS motor for now, but this is something I think would be very cool in my 23' cat. :drink:

Craig

Re: Theoretical Motor Build Up!
 

How about you start with the new 10.6 Dart block so you can have a decent rod to stroke ratio. Make 9.0 compression so you can run pump gas, use Big Duke 388cc runner heads to keep your bottom end. Use EFI so you can run a 280/ 288 @ .050 110ls cam that will idle around 900rpm. and blow your outdrive at will. HP would be over 1000.

Re: Theoretical Motor Build Up!
 

With the 10.6 block what kind of cubes are we talking? Probably looking at some custom dished pistons, but that is no big deal. EFI would be sweet and allow good idle quality. 1000 HP NA pumped gas motor would be pretty sick!! Paint it blue and call it a stock HP 500! :D

Re: Theoretical Motor Build Up!
 

I figured stay at 632 and use a 7.1 rod so you can turn it up, I think you would end up with around a 43 cc dish in the piston. The block isn't available for a little while yet, but it could be fun. I guess you better look into a sheet metal tunnel ram and a couple of 1600 cfm throttle bodies. A Weldon 2025 fuel pump and a set of 72 lb injectors should do the job.

Re: Theoretical Motor Build Up!
 

That cam is too big for a 632" GPM :rolleyes: since were going to keep the r's around 6500 a hydralic roller would be the ticket.....call Crane and get a 651! :p :p :D :D Besides these big inch motors are not good boat motors and you can't make power without a blower Wette Vette.....

I got another idea Vette...sit those flat tops on the shelf get a set of 13:1's coming from JE, oh yeah and a little more cam...Wholah 1000+ on 110. Your minimuim idle restriction would be the toughest nut to crack :drink:

Re: Theoretical Motor Build Up!
 

No wimpy hydraulics in the imaginary motor, I ran the solid roller 280/288 in my 598.

Re: Theoretical Motor Build Up!
 

Exact same cam I ran in my 632 except it was on 115 to give it a chance to idle with a tunnel ram. This big HP fuel injection is finally getting there it seems.

Re: Theoretical Motor Build Up!
 

The one I ran was in a blown application so it was cut on a 112, with the EFI it idled at 1000 rpm. It was a little big for the 598 so I cut back to a 276/284. I would think the 4.75 crank could use the larger one. What are the other specs on your cam?

Re: Theoretical Motor Build Up!
 

Are the big chief type heads that superior to conventional that 1000+ HP could be expected at 9:1 compression? I have seen a 632 make 900 HP with 10.5:1 compression at 6600 RPM with fully ported Dart 360's. That is why I thought it would take at least 12:1 and a couple of dominators on either a custom sheet metal intake or at least a fully hand ported tunnel ram. The stick I like for this application is one that Erson advertises as "easy on parts" for marine race use. 276/284 @ .050" lift with .731" lift on a 114 with a 4/7 firing order swap. Now for another debate. Is the EFI or dual dominators goning to make more peak HP? The benefits of EFI speak for themselves, but I feel the wet manifold may actually make more peak HP and be better for a motor intended primarily for high RPM use. Aren't the Pro Stock guys still running carbs? :cool:

Re: Theoretical Motor Build Up!
 

Yes Pro Stockers are still running carbs. The last I heard, they were running them split in half. I believe this was to spread the carbs out enough to straighten the intake runners.