Those look like the engines they use in those British formula cars. Real neat looking engines if they had more displacement they would be a good boat motors

Boatless you are correct ,They use these Hartley Enterprises V8 in Britisch cars for road racing and or uphill climbs etc.

[QUOTE=professor_speed;3865987]No Its hyabusa heads on custom block etc. looks to be way short on torque.

For such a small high reving engine isn,t it normal to produce torque numbers like this ?

I agree, that toque it is not bigg if you look it with engine rpm, but this is normally. I am convinced, that you must compare torque on the prop shaft and this is at least the same like at the best marine engines with comparable output power. I see the biggest benefit on the torque curve. From 4.500 to the 10.000 rpm it is almost on same level. It is like from 2250-5000 rpm on bigg block engines.
Aniway, we will test it if it worth and offer this or Ilmor 6,2 V8, perhaps even orange Ilmor. In any case we will try to destroy this engine with classic ride like with other engines and same time we hoope that it will survive this 300-400 really hard hours which we will try to made in this year. If will work will work, if not will forgot it.

you are correct if you can gear it low enough and make it up with RPM then it should work.

So, what about getting a few more mph out of surface drives. Is this proven? I've read you can pick up some speed from less drag. I'm going to be upgrading my panther drives sooner or later, and I wanna have some real stout drives. I was thinking kamma or ameson, but I haven't looked at other options.

How well do the ameson 6 hold up under say 700 or so hp.

The #7M's are rated at a very conservative 850 hp

Hello;


New questions for experts.

1.) In Z drive (Mercury XR for example) you have cca 8% more mechanically losses than with straight surface drive.

2.) If you use Z drive like clear surface drive with notched transom, you have same hydrodinamic efficiency like at classic surface drive. Correct?

3.) In 550 hp range it is classic surface drive (with transmission gear box) cca 200 pounds more heavy like Z drive.

4.) If I put in BAM calculator BHP datas for surface drive and 8% less power for Z drive, I recive almost same results for both, becouse of less weight with Z drive.


Please comment, I am really curious what is thruth there.

Where do you get that weight? I know the #7M is 5 lbs heavier with the cast iron transmission than a Bravo on a box. With 550 hp and use of the aluminum velvet drive the surface drive would save 32 lbs over the Bravo

I take it from tech datas:
- Bravo 120 #
- ZF 63A 100#

And Bravo do not need ZF. Arneson need it?
Probably I am miss something (I hope, I am "stick drive" fan!)? Perhaps 120# at Bravo1?