Highest Naturally Aspirated Torque? BBC
 

Who has some really high N/A torque numbers from a Big Block and with what combo to make it? HP is no object Torque is king for this post.....

I,ll start. This may be weak to your standards but this is my torque / 510 cid / 625 hp / 615 FPT
http://s265.photobucket.com/albums/i...t=ef5e67a0.pbr

Certainly not the winner but I'm in the lead since I'm the second post :).

500 efi's coverted to 540's with heads, added compression, etc. Made 630 hp, and 699TQ fully dressed(seawater pump to wet CMI's) on the dyno.

A buddy has some carb'ed 615's making upper 800's HP and TQ (can't remember exactly)

My buddy Ken's 634 made 932lbs/ft. Big Duke heads, single Dominator, Torque Monster!
:food-smiley-007:

How about this?

http://www.dragracingonline.com/tech...-sonnys-1.html

1100 Hp, 1100 Tq naturally aspirated and on pump gas.

Chris

Nice work!
What heads did you use on the 540's? 699 fully dresses should be good for some consistent high speed numbers.
I am not really asking about the highest so everyone is a winner here. I think that if the build focuses on torque the boat will run better in the end than going for a big hp number on the dyno.

That is cool but I am sure the price is stratosphere ++. Imagine a pair of them in a medium sized Skater ( fill her up with 87 ):eek:

Call BIG Daddy DEAN GELLNER :ernaehrung004:

Dart 308 Iron Eagles (ported), Monoblade TB from ASM, a modified 741 cam with the intake lobe [email protected], 9.75 compression, 55# injectors. Except for the larger air breather these look like stock 500's....but they don't SOUND like them!!!

Motors are in a 2002 382 Formula. Ran 30P 5 blade Maximus yesterday 5,250 at 83mph (cruise 3,500 at 56-57)....all GPS speeds.

peak HP 629 @ 5,200
peak TQ 699 @ 4,300

carb's would have made more power since the plenum is holding back air-flow.

BTW: I agree, we set out to build TQ, not hp. I'm proping the boat for cruise speeds too, I borrowed a set of labbed 30P Bravos that were about 3 mph faster WOT but slower in mid-range rpms.

Not always.

Many builds that concentrate on torque from low to midrange power trip over themselves trying to get a good high speed #. On the reverse, many builds that concentrate on too high of an rpm power peak, trip over themselves in the low to midrange power.

Depends on what exactly you are trying to pinpoint here.

Can you tell us more exacts of what you are thinking and what you are trying to achieve and with what ?

and ck out those oval ports on sonny's engine !!!

I kinda did the same as t500 hps . 502 mpi converted over to a 540 with a carb. 630hp @5300rpm. 700 lbs tq. Crain 741 cam. Dart Iron Eagle heads with some port work.
My numbers were with dyno headers, no accessories.

My 540 made 667ft/lbs of torque at 4600 and 665 hp at 5800 through wet exhaust and running all accessories. The motor was speced by Bob Madera aka RMBuilder.

Chris

I guess it really depends on the application. In my boat, I can blow out the prop with the torque I've got at any speed low enough not to be in the power band, so I'm not at all concerned with torque, and wouldn't mind trading some for more top end power.

Remember, it also depends on what RPM that torque is at, and to be honest, that's why HP is really what matters. HP is what moves the boat (contrary to popular belief). An engine that make 800ftlbs at 7000rpm is not going to run the same as one that makes 800ftlbs at 3000rpm.

666 ci 980 torque and 900 HP ,N/A on pumpgas @ 5500 RPM.

beat that can built new for 25 K.

If i had the $ i would race one of these myself.:party-smiley-004:

The highest i ever seen was 1400 HP and around 1300 fpt on a N/A motor with 110 octane fuel and 632 ci. @ 7500 RPM

Very good power,

My builder knew what he was doing!! :)

548 cu in,640hp @ 5500,677 tq @ 3900 pulling all accessories and wet headers.Custom cam by Cam Motion in BatonRouge,La.,Machine work by Al Pitre of Pitre Race engines,EFI set up and dyno by Mark Boos of Percision Marine,assembled by me.

The highest torque numbers I've ever seen were Bigyellowcat's turbocharged engines at 2000+. It used to be in the archives but I can't find it now.

Sounds like a strong long life motor!!!!

I am in the process of building a new 598" motor and looking for some good ideas to make the most of each cubic inch but not by twisting the thing to the sky RPM wise. I am interested in what can be achieved in big torque because I think that it allows more upper midrange efficiency in the fact that you can turn a bigger pitch prop with a given gear ratio. What torque does a Hawk 750 572" motor make and at what RPM? for example.

If you were to build a 598 with small port but high flowing heads like AFR 315 cnc and a small cam like a 741, you'd probably end up with about 700hp and 775lbs of torque with out revving high.

Remember that big ci usually delivers big torque (650-700+ lbs) from 3000-4500 RPM. This torque is what breaks Bravo drives. If you hold ci to the 500 ci range, you can hold the torque to 550-650 lbs and still make 600 HP at 5250...650 HP @ 5500 RPM and 750HP at 6000 RPM....all with under 650 lbs torque. We have a lot of boating hours from 3500-6000 RPM and have never broken an XR style Bravo drive. We also see zero gear wear on the magnets.
If you up add up the total cost of mantaining the drive train you may find the 540+ ci may not be low life cycle cost for the entire drive train.

motors
 

So if you have a clean sheat what do you build for a modertly preforming 40 v bottom say 70 to 80 mph range . All the torque you can ? Or cut back on trq. and build some hp.Also keep in mind some type of longjevity probibly not allot of rpm. Im runnig TRS and Borg W. trans.

Start with a pair of Konrads. Any amount of hp is going to cause expensive drive problems. Last year I broke an upper, this winter I have to rebuild a lower.

Here ya go...get you a peek at this dyno printout sheet on a motor I did last Easter. Notice the HP and torque at 5300 rpm. This was done on a single Holley carb. This pic is the motor that made the power.

My 540s reach max torque at 5000 rpm. We went after hp since I wanted to keep the Bravo drives.