jworm49

I would like to upgrade the stock prop but I don't know what size to get. The boat comes with a nice Prather prop but I would like to try the next size up to see if I can get some more speed and see if the boat will come up on plane any faster. Thanks.

rcflyertwo

My Feedback: (3)

[8D] The boat comes with a prather 230 prop, its 1.90 dia and 3.0 pitch the next size up in a prather prop would be a 235. You might want to try a polished and balanced 230 stainless steel prop first. Have you taken the extra head gaskets out of the motor yet?? If not try that also , should give you a little more power to swing a larger prop tooo. Also I took off the exhaust header and took a dremel tool to it, enlarged the exhaust flange opening and smoothed out the inside at the header a bit, mine had some big gobs of weld inside, not good for the airflow. the best prop is going to be a sharpened, balanced and polished stainless steel prop I think there are a few places online that sell them that way too, a few bucks more but well worth it if you don't know how to do it yourself. Let me know how you make out and what if any gains you have made. Butch in Niagara Falls.

Ron Olson

My Feedback: (1)

I'm surprised that it can turn the 230 in the first place! I have a 220 in my .21 mono that has a ton more power and RPM than the Dynamite .32 does. I'd try going down a size or two if you want more speed. Try an Octura X442 or X445 if you think that it can really handle it. The X445 or M445 are real close in size to the P-220.

rcflyertwo

My Feedback: (3)

The rated power of a smaller motor comes from its high rpm, a 21 size will not have the torgue of a 32 size so of course it won't swing as large a prop. I find the 32 spins the prather 230 with no problem at all. also the 32 size boat is larger than the 21 size boats hence the need to swing a larger prop, i think if you try using a smaller prop at higher rpm you run the risk of prop cavitaion problems. just my guesstimate. [8D] My friends that run gas boats almost always go to bigger props, also differnt pitches and most have thiers cupped to push more water. Butch

Ron Olson

My Feedback: (1)

2.9 HP @ 38,000 RPM for a Rossi Niagara/Pirahna. I swing props that most .21's can't! What's the rating on the Dynamite .32?
A MAC engine for instance is a high RPM engine but not a lot of HP. I saw John Brown only turning an X437 at last years Internats.
Gas boats are high torque engines with lower RPM but that is slowly changing too so that's why they turn higher pitched props.

jworm49

Ron, Fist off thanks for the input I am still new to this. I think that the Dynimite .32 is rasted at like 1.3 hp but it does swing the 230 prop no problem, I got my boat on gps at 34 mph it does take a bit longer than I would like to come on plane though. I may be wrong but to my the 230 looks small thats why I thought I should go up a size. If I could ask you another qwestion I want to get a new boat, I want something that will do 50mph or better. I would like to stick with a deep V if possible I like there looks as well as the stability. But I don't know if I should go electric,nitro or gas. I don't have a preference besides that as far as I know the run time with most fast electrics sucks. I'm just woundering how I could make this happen while spending the least amount of money. I know that it won't be cheap but I don't want to get something and then wish I had chosen another route. Thanks for the advise. Jereme, NH

Ron Olson

My Feedback: (1)

It's not that the prop is too small, the hull is actually a little big for that motor, HP and RPM wise. I just answered a posting a minute ago on upping the motor size. Drop a decent .45 in there and the speeds would go up another 15-20 MPH, depending of course on a lot of factors.
Only you should decide what route that you want to go next. YOU are the one that has to be happy in the end. No use buying a boat then deciding that it's not exactly what you wanted. Do a lot of looking around, go to any races in your area, look at race results then make your choice. Races can be decieving also depending on how good or bad the boat setup is, how the driver is, etc. Think of what you want the boat for, playing around, racing, both?
Most good .21 powered monos are now in the 50 MPH range, a .45 will get you over. Speed is relative to how deep your pockets are. I don't even want to think of how much that I have into the .21 mono that my son races or my 7.5 mono. My .12's would scare you for the amount of money that I have wrapped into those little creatures!

Ropper

Anyone know of any boat races and where in Washington state? I live on a lake perfect for it but don't ever see anyone at the boat launch with boats. My buddy has the shockwave 55' and I have the shocwave 36' and had the Bud 1/12(nice boat for looks,but I guess I run my boats to hard,the thing fell apart on me)

Ron Olson

My Feedback: (1)

For R/C boat racing in Washington State, most of the races are NAMBA sanctioned there, www.namba.com .

jworm49

Ron Iwas wondering if I put a ,45 in my boat would the hull handel the speed? with my trim tabs bent up i can hit 35 now but I get a lot of chine walk, if i bend them down this will stop but I lose speed. So if i put a larger motor in the boat i would have to bend the tabs way down. So are you saying that with the extra power I would still hit 45-50 even with the tabs bent down?

Ron Olson

My Feedback: (1)

I haven't seen the Shockwave 36 in person yet, a LHS is supposed to have one but haven't been there in a few weeks so I don't know how heavy the 'glas lay-up is.
Use some of the other tips that I have posted elsewhere in here.
The trim tabs should only be adjusted just a little at a time, I'm talking in as little as 1/16" at a time and if the tabs are even with the hull bottom, move them up 1/16" also. It's suprising that 1/16" doesn't sound like a lot but it really is to a model boat.

jworm49

OK Ron I'll try that, also I was wondering my boat runs faster and has much better throtel responce with the lid off. the lid is very light so I would have to guess that the fact the carb has more air is the rason for this. I was woundering about either drilling a few holes in the lid or just one so that I could run some tubeing through it directly to the crab since I don't like to run with the lid off. Do either of thouse sound like good ideas to you? Also you said that most good .21 monos run in the 50mph range. Could you give me the names of a few or a site that I could look at some. All I seem to find are gas powered such as Enforcer. They look awsome but I would think they are a lot more money that the boats your speaking of. Thanks a lot for all your help it means a lot to me there aren't many people in my area into boats and I am fairly new to this. -Jereme- in New Hampshire

Ron Olson

My Feedback: (1)

You're right, the engine will run better with the cover off. You are running into the same thing that other boats such as the Nitro Hammer, Grey Thunder and many others that have covers over the motors. You are drawing in hot air from around the exhaust and not getting cool outside air in. Remember cowl induction and hood scoops on race cars? The same thing. A hole over the carb will help immensely or leave the lid off if you want to.
I've got a Speedmaster 21 myself that my son drives and we love it. Most modern hulls such as the Seaducers should have no trouble hitting the 5-0. It's a lot of things that get them there though, a good motor, fuel, prop and some time to dial everything in.