Rally Sport w/ V8 OMC

[Dargo]

Just picked up a Johnson 3.6L GT300 for my Rally Sport project. Wondering how much setback I should be running. I have heard these hulls like quite a bit (around 18"). Is the 18" number on a hull with the notched transom though? My RS does have the notch.

Also, any recommendations on props I should be trying first? The motor I bought comes with a 15x22P. I'm assuming I'll need more pitch than that.

Thanks!
Chris

[mercpunk]

21ft or 18ft ????

[Dargo]

Sorry, 21'. A Challenger/Shadow copy.

[cutwater]

If you do a search on here, Wildman has set up alot of Rally Sports, and shared that info. If memory serves, 18" sounds like the right number, but he was running Merc 300PMs...don't know how that will compare weight wise to the big Johnny. I think the Rally's were built heavier than the Challenger / Shadow / Superboats...

[Dargo]

Cool. I sent him a PM for some pointers. I thought I read somplace that his RS did not have the notch. If that is the case, I'm wondering if I could get away with 8 or 10 inches of setback instead of the 18 since there is quite a bit built in with the notch.

[THE HOSER]

I have had a v-8 on my superboat for years
what you need is no more then 12" of set back
and the best wheel for that is a 14 1/4" -27 srx prop

here's what i hand

[leading edge propeller]

Just picked up a Johnson 3.6L GT300 for my Rally Sport project. Wondering how much setback I should be running. I have heard these hulls like quite a bit (around 18"). Is the 18" number on a hull with the notched transom though? My RS does have the notch.

Also, any recommendations on props I should be trying first? The motor I bought comes with a 15x22P. I'm assuming I'll need more pitch than that.

Thanks!
ChrisHi Chris. My dad was the founder and owner of Rally Sport Boats, Growing up Years ago we had many of the 21's as our personal boats, and one of the last one's we had was one with a 3.6 V8,and the best prop we found to work was a 14.25 x 24 4 blade, with a bob's 6" setback, with a merc we ran 10" setback but with the weight of the V8 the boat didn't need that much setback. A modded chopper ran well to but the 4 blade carried the boat better and was a little faster. Please Feel free to call me if you have any questions. Rich 941-720-0710

[Dargo]

Hey, thanks for the tips guys! Great to get some prop feedback as I had no idea where to start. Hoser, Rich, do you remember any motor height #'s? I can't imagine it will be real high. a couple inches below the pad maybe? I do have a LWP. Lots of different setback estimates the more I ask.....hmmmm. I'll have to roll the dice a bit on that one. Thanks again for the info and Rich, I'll definately give you a call in the near future.

[leading edge propeller]

[QUOTE=Dargo;1904411]Hey, thanks for the tips guys! Great to get some prop feedback as I had no idea where to start. Hoser, Rich, do you remember any motor height #'s? I can't imagine it will be real high. a couple inches below the pad maybe? I do have a LWP. Lots of different setback estimates the more I ask.....hmmmm. I'll have to roll the dice a bit on that one. Thanks again for the info and Rich, I'll definately give you a call in the near future.[/QUOTE Iam not real sure on engine height but i do know it wasn't that high, my brother had a new 21 Rally Sport about 5 years ago that he got from the new owners with a mercury 200 2.5 carb motor and we played with height alot and it was easy to find the spot were it started to slow the boat down when the motor was to high and that spot wasn't very high, you just start to lose the leverage to carry the boat, this was with a worked big ear chopper and they offer alot of bow lift. As far as setback he started with a bob's 6" and then went with the 10" setback and the boat drove better but believe it or not it didn't gain 1 MPH and this boat was a little liter layup than most of them. Hope this helps a little, give me a ring anytime. Rich

[THE HOSER]

the best the boat ran was 88 mph with a 30" lab cleaver . Put the nose cone 11/2" below the bottom

[JamesGang]

Just picked up a Johnson 3.6L GT300 for my Rally Sport project. Wondering how much setback I should be running. I have heard these hulls like quite a bit (around 18"). Is the 18" number on a hull with the notched transom though? My RS does have the notch.

Also, any recommendations on props I should be trying first? The motor I bought comes with a 15x22P. I'm assuming I'll need more pitch than that.

Thanks!
Chris

Hey Chris
Post a couple pics of your project. Would love to see how its coming along.
Jim

[Dargo]

I have been slowly accumulating parts over the last month or two. I think I have everything now! I am planning on hanging it the weekend of May 7th. Suprisingly, alot of my buddies want to be there to help (the size of the motor alone is generating alot of interest). So, it should be quite a show. A rig like this is quite an oddity up in my neck of the woods so, it will be fun to hit the water with it this summer.

[JamesGang]

Good luck with it, and don't forget the pics as it starts to come together.