Standard 300 V8 vs 300R V8

[Steve J]

Hey guys
I am building a offshore center console fishing boat that really needs twin 350's. Problem is nobody is making a 350 that I want.

The Verado 350 L6 does not have the low end torque the boat needs. The Suzuki is out because they can not keep them running.

So I was planning on putting the Mercury 300 V8 on it, because I am told it has more low end torque than the Verado 350 L6 and I would only lose about 2MPH over the 350 L6 on top end.
Then somebody recommended putting 300R V8's on it. Telling me the 300R has 330 to 335 HP and would probably out preform the 350 L6.

My only concern is in my reading Mercury says the 300R has shorter intakes to improve middle and top end torque /HP.
Will the 300R have as much torque on the low end as the standard 300V8?

Has anybody ran the standard 300V8 and the 300R that can compare the two?

Thanks
Steve

[mr fun]

Hey guys
The Suzuki is out because they can not keep them runnin

Thanks
Steve

where did you get that information ? I liked the platform they presented , duo prop , 10-1 compression ratio, pretty stout.

[Steve J]

I have owned one and have several friends that own them. We have had multiple failures of the heads cracking and lower unit problems.
When they run they are good, But Suzuki has to get the problem fixed before I would buy another one.

[Steve J]

No body?

[Chaz]

I have owned one and have several friends that own them. We have had multiple failures of the heads cracking and lower unit problems.
When they run they are good, But Suzuki has to get the problem fixed before I would buy another one.

No body?

There were a handful of motor's , models , configurations mentioned .. you would more than likely get an answer if you were more specific.

[engineermike]

According to the CARB offroad database, there are 3 different power levels that the 300 v8 is offered in, as listed below:
316 hp at 6250 rpm, 311 ftlb at 5000 rpm
296 hp at 5500 rpm, 313 ftlb at 4500 rpm
276 hp at 5500 rpm, 298 ftlb at 4500 rpm

For reference, the Verado 350 consumer:
340 hp at 5800 rpm, 320 ftlb at 4500 rpm

Verado 300:
296 hp at 6100 rpm, 284 ftlb at 4500 rpm

350 SCi:
344 hp at 6500 rpm, 318 ftlb at 4000 rpm

300 XS:
296 hp at 5800 rpm, 297 ftlb at 4500 rpm

Suzuki 300 4 liter:
296 hp at 6000 rpm, 253 ftlb at 4500 rpm

Suzuki 300 4.4 liter:
296 hp at 5800 rpm, 294 ftlb at 5000 rpm

Suzuki 350:
345 hp at 6000 rpm, 319 ftlb at 4500 rpm

And finally the Yamaha 350 5.3 liter was:
350 hp at 6000 rpm, 334 ftlb at 4200 rpm

[Rak Rua]

Is the middle level 300 ^^^ the Pro-XS?

It’s the lightest of the 3 (only slightly) but doesn’t have the AMS/power steering like the R version. A few more rpm’s than the standard but the R has a few more again. Has a torquemaster gear case, no HD or speedmaster option.

Pro-XS sounds like a sensible compromise unless you’re chasing outright speed.

RR

[engineermike]

Yes, I believe so.

[Steve J]

Thanks Mike
That is good info
I am assuming the top one is the 300R, middle is 300XS, bottom is the 300 V8 Verrado?

316 hp at 6250 rpm, 311 ftlb at 5000 rpm
296 hp at 5500 rpm, 313 ftlb at 4500 rpm
276 hp at 5500 rpm, 298 ftlb at 4500 rpm

[engineermike]

I believe top is 300r, bottom is 300 seapro (commercial), and middle is everything else.

[Steve J]

Surly somebody has a real life comparison between the 300R V8 and the standard 300 V8??