0820Outlaw

Hi guys, just joined up and looked around a little. Doesn't seem to be many 20 Outlaws on the forum. So I'll try my luck with the big boys.

I have an '08 20' Outlaw, bone stock save for some nice add-ons (dual batts, trim tabs, balanced/trued 23P 3 blade, and straight through tips) and like everyone else, would like a bit more power. The boat has the 260 5.0L, Gen II Alpha and will hit a flat 60 w/ a small chop, 59.? when flat on GPS with one rider. I'd like to bump the power to around 300-310. Before I do that, I figure I'd better see what's under the hood before I dick around with it. For 305 c.i. and 260 hp, I figure the little thing is fairly hot to start with. I'd like to put on the Thumper exhaust, new cam, and mess with the computer (if I can) and possibly switch to aluminum heads. I probably have Vortec-style heads, but what cc are the chambers to give me the 9.4:1 compression? And if I do go to a hotter cam (stock 350 Mag or 377 Mag?), at what point is reversion a factor? I'd like to also switch to a 4 blade prop to cut down on hellacious bowlift and a better cruise rpm (can't stay on plane at 2500 rpm). With increased power, will this put too much strain on the Alpha? Any help you give is greatly appreciated.

By the way, those of you who do have this boat, do you notice a port list with anything more than 20 lbs in the passenger seat? This boat seems to be terribly balanced, even 12" X 9" tabs don't really help.

Plowtownmissile

Just saw this post and don't know if your still here or not but here goes...

I haven't seen anyone do heads/cam on our boats yet. I also haven't seen anyone who offers a computer upgrade for the 260hp 5.0L MPI engine. 20 Outlaws love props with bow lift to run fast. My prop recommendation for a good all around performance (55mph top speed/fuel efficient/decent holeshot) is the 21p Mirage Plus. I don't have tabs but I've never noticed the port list you mentioned. Our boats are extremely light and very susceptible to weight placement in the boat.

jctexas07

...

Irishtornado

You want to prop your boat between the recommended RPM's of your engine. I'm not familar with these on a SB marine engine. If your lacking in rpm's contact Bblades Propellers I'm sure he can get you running at the optimum setup you want.

Plowtownmissile

+1

Brett set me up with my 23pitch Lazer II (which is the fastest prop for a stock 260hp 5.0 20 Outlaw). That prop labbed will give you the best top speed but it sucks for holeshots with more than 2 people on board and drinks alot more gas than my 21 Mirage+ does.

0820Outlaw

Hey guys. I am still here and now have even more prop questions. I researched the forums here and Mercury Prop Selector and had convinced myself the Rev-4 was for me.....even at 14.625" and the same pitch. So I called Peter at Propco and asked his advice where he convinced me to buy one of his Slingshots. Now the factory Laser II measures in at 13.75" X 23"P 3-blade, comes out of the hole (18" X 12" tabs now help) at 3500 rpm, maxed out at ~5100 rpm at 59.1 gps. The Slingshot came in at 15" X 23"P 4-blade(right??), comes out of the hole at 2000 rpm, maxed out at 4400 rpm at 55 mph indicated. After arguing with Peter and calling each other bad names over the exchange charge, I now have a 14.25" X 21"P 4-blade, coming out of the hole at 2600 rpm, and building quickly, maxed out again at 55 mph indicated but I can easily turn 5200 rpm at neutral trim and could probably get 5500 rpm aired out.

So today I called a trusted mech. He said get your diameter down to 13.75" to 14.25" to improve your hole-shot, get your pitch up to 23" to 24" to get your top rpm down into the 4600-5000 rpm range and hope for the best speed as all you want is a good cruise and great hole-shot. That rpm range was a source of our argument, but it turns out we were both wrong. The mechanic explained this little motor does not have a great deal of low end torque so you have to get the R's up out of the hole.

So now what do I do? Use the Rev-4 or the VenSura? Anyone successfully run a 4-blade on a 20 Outlaw?

And glad to know the port list is not unique to my boat. I was about 3 days away from sending down to get the hook removed.

Thanks again

0820Outlaw

Does anyone have any experience using the 14" X 23P Vensura prop on this application? Seems to fit right in with what the mechanic says.

jctexas07

I just upgraded to a Mirage plus 23 pitch and am turning right under 5000 mid 60's when smooth. I looked at a four blade prop and decided with the 3 blade since most of what I read stated four blades are great to ski with or for high powered rigs. I guess it is a matter of preference for some, but love my 3 blade. I beleive a 23 would be great, but you can expect a little prop blow out when taking off. It takes mine a bit to get on top of the water, but when I do, I can cruise at 37 mph at 3000 rpms and get some top end, too.

A.O. Razor

I've run a Vensura on a 212 Islander with a 350MPI. I think it's the same bottom as the 20OL. Also on a 19' Stingray LX. In both cases, it was a great prop. On the Baja, we tried a comparison with the Laser, and it was about as fast, but a little better out of the hole. there was a tiny bit more prop torque that could be felt when turning, but in no way anything major. I can't remember if it was a 21" or 23", but hey, should not make a diff. On the Stingray, it was way better than the M+ he had on it, in all aspects. Personally I think it's an awsome prop for the 18'-21' runabouts and an overlooked prop. I would love to see what a labbed Vensura could do on this type of boat.

obnoxus

sell the 305 and find a used 350 mag.

Probably cheaper,,,,,absolutly less aggrivation