RcFlyer06

My Feedback: (4)

Does anyone know if you can use airplane or car engines in boats if they're modified with a water cooling head?

malicent

car motors your can! heck ive done it with no cooling head added

matt420

Stay away from the TZ's ,those engines are turd's !!!!

Dan S

That's the funniest one I have heard about the OS TZ engine.

what do you base your claim on?

Dan.

RcFlyer06

My Feedback: (4)

Pardon my ignorance but whats a TZ engine??? So I guess the airplane engines in a boat are a no go? I figured the porting would effect the engine performance but I didn't think it would change the power so much!

Blackout

I have an O.S. .40 SF airplane engine in a Dumas 30" long mono. It works pretty good with an Octura X447/3. Not real fast, but fast enough to have fun. I bought a Dumas flywheel from my local hobby shop and wrapped soft copper tubing around the head for cooling. I'm using the stock airplane muffler and have the exhaust routed out the transom with rubber tubbing.

The car engines will work with no water cooling because they have a large heat sink on the head. Just make sure the engine is getting air.

misshydro

Hate to brake your hart there Matt420.. There not turds!!!! Alot of guys are using them in there boats!! If you mod one out it will realy fly big time!![X(] I should know theres a Proboat Miss Bud 1/12 scale own&built by Johnny from A-ZRacing with a mod O.S.18TZ went 55MHP!!!!!!![X(]O.S.18TZ is a turbo car motor....[8D]

Hydro Junkie

One thing to be remembered about aircraft engines is that they are low RPM engines compared to purpose made car and boat engines. Since aircraft use large diameter props to get bigger bites of air, they have to be kept at lower speeds to prevent the blades from going supersonic, where the prop is basically ineffective. In a high performance boat, higher RPMs are required over the ability to swing a 9" plus prop

RcFlyer06

My Feedback: (4)

But now who says I'm looking for extreme performance? Just looking for the sunday cruiser . On the other hand though, could you not tune the engine with the prop more or less? I had an OS46AX that I pushed WAY beyond it's general rpm range on a pylon racer by putting a high pitch low diameter prop on...I guess it's a bit diferent but the point being you can change props to match the engines power?

Ron Olson

My Feedback: (1)

Maybe I'm one of the few that have run air-cooled car and truck engines in boats, mostly if not all the .12 sized ones. As long as the heat sink can get cooling air, you're all set. There are good and bad engines that will work in boats and I've found by trial and error a few that do work and others that didn't.
I've had good luck so far with OS and Trinity/Picco. The stock carbs leave a lot to be deisred but will work. The problem is that the engines were made to comply with ROAR and IFMAR rules that only allow 5.5mm bore carbs. They really wake up with a larger carb adapted to them. Even Andy Brown made some MAC engines with air-cooled heads which was no big deal as he also made the MAC's for 1/8 scale buggies. Most of those were used on the OB conversions.
Here's my OS .12 in my Wild Thing .12 mono. The heat sink head gets so much cool air that I could remove at least half of the fins but I'll wait until I can find another before hacking away. These engines were made to be run in hot, dusty conditions without a lot of air under a Lexan body.

Blackout

While no one expects high boat speeds from an airplane engine, there is more to the speed equation than just rpm. A motor with more torque, but less rpm can spin a bigger prop with a higher pitch, which will also contribute to higher boat speeds.

It sounds like there are some airplane guys trying to get into our boat hobby. They have these engines laying around, so let's give them some help...

Dan S

I believe there are quite a good number of people that are using plane engines in their boats just for playing around.

you won't be able to get the same amount of rpm but with their higher torque you should be able to spin a bigger prop or a prop with more pitch.

no, you cannot tune the engine with the prop on sitting on the table, no load on the engine. do a rough rich setting on the table and launch the boat, retrieve and tune again accordingly if necessary.

Dan.

RcFlyer06

My Feedback: (4)

Well I know that I can't dry tune a boat, I'm not a COMPLETE noob to boats (although I'm pretty close ). I was just making an analogy to planes. You can select different props to get the engine to run in different power bands...and also get different "bite" out of the prop depending on the type you have. Onthe same note...I'm an aspiring aero engineer so I know just the TINIEST bit of prop theory...but this could all go out the window being that we're talking water now...I know that technically a 2 blade prop is more efficient than a 3 blade being that the blades cut through the disturbed air/medium of the previous blade and there-for have reduced efficiency. Do boat props work similiar or would it be recommendable to attempt to make the most of my engine's torque and try a three blade? The hull I have is a christmas gift for my GF who is getting into this with me so once christmas passes I'll start posting pictures of the project. Thanks to all!

matt420

Hey Dan i base my claim on havin one in my vegas, note: my thread My outlaw/sport20 vegas its way back there to my guess of the stickers i had on my sponsons and the thing never runnin right , thought it was just me but my dad had the same issues along with everyone else in the club iam in, no one runs em anymore because of it, my stocker put out more than that engine, they belong in trucks and cars, where they need to stay. As to you misshydro your not breakin any hearts here, i run with Johnny at the races, seen the boat in person along with many other of his screamin boats, so no need to school me on that subject, some have luck with em some don't, but like i said when i put my stocker in and blew it away, i think there turd's ,just my opinion wich are like a@#holes everyone has em !!!!!!!!!!!!!!

malicent

matt yours was a turd lmao!!!!!!!!!!!!!!! but your dads is pretty quick if he can stay out of corners lol!

malicent

No matter what forum i go to you are always dropping names. yea johnny's boat is fast, btw me and matt both are in the club with him so im going to start dropping his name every three posts like you do. anyway out of the 5 people i personally know 3 tz were crap 1 was so touchy it wasnt worth running and 1 well is your best buddy johnny's and we know how it goes after he had to rebuild it a few times.

matt420

Ya his is quick when it runnin right, he just a driver on the ragged edge, but he strippin her down and the stocker goin in, after the last race in open water he couldnt get it goin like it should, johnny was helpin him and couldnt figure it ,but it seems they only run when there extremely modded and still there picky little motors !!!!!!!!!!!

A-ZRacing

Hey guys this is KC not Johnny. They are right I hear a lot of people have problems with the TZ engine. Its no secret. However once you mod them they seem to run great. Ha and yes Johnny runs on the edge, with both his boats and his mods. Thats what he does, which saves our customers the problems. He tests everything to the limits so we know where they are. His motors being blown and rebuilt serves a purpose. However the engines we sell to people once broken in and tuned (which is not that hard with these mod engines) start up everytime and run great. So everythign I have read in this topic is very true. Some poeple have problems with stock tzs... Johnny pushes everythign to the max, so you dont have to. Hope everyone is having great holidays and enjoying all the snow. We actually were going to go run boats this next week but every body of water is frozen over ha. I guess a sheet of ice will keep us from running. Damn weather ha

chief3452

Hey Ron,

I have been curious about how the little car/buggy engines perform in a boat. I would like to know more about your setup in Wild Thing mono and what your thoughts are on using one to power a hydro. Take care,

Scott

Ron Olson

My Feedback: (1)

They seem to work pretty well. Like I said above, you have to find the right one. The middle-of-the-road ones seem to work best in the boats. The high RPM ones appear to need smaller props.
For an outrigger hydro, this video: http://www.rcflix.com/photopost/show...=500&ppuser=15 was a maiden voyage for this boat so it was basically untuned and a guesstimated prop, a Prather 215.
At the Flint record trials back in October, there were quite a few there that were running in the 60 MPH + range.
I'm working on putting together a Sport 12 hydro and heading down in a few minutes to do some more thrashing on it. The problem with that one is that an air-cooled head won't fit under the cowling but maybe in another type of hull like a Thunderboat style would work better.
For a 'rigger, so far the plans that Tom Moorehouse has on his site, www.firefighterboats.com he has the Cheese plans and that boat is a very good one if you like to put them together from plans. There are more .12 'rigger boats coming out at a surprising rate lately as this class appears to be quickly catching on.

chief3452

Thanks Ron,

I was thinking of building a Finlay round nose and trying a .12 or .18 in it. There seems to be a lot of buzz about the smaller engine classes and I am interested in racing so I thought this might be the ticket. Could you post a pic of your Sport 12 hydro? Is there a sanctioning body or rules in place for the class? take care,

Scott

Ron Olson

My Feedback: (1)

There is a propsoal now before the IMPBA for a Sport 12 class, it's in the Roostertail at www.impba.net .
The Findlay hull would be a good choice as I think that's what the person who outlined the rules, Glenn Quarles is using for his.
I just came up from mounting the rudder linkage and servo but these aren't the latest shots. I'm using an Octura strut, Speedmaster mini-rudder, Grimracer Miss Vegas turn fin (which looks really huge on this hull so it will probably get cut down), a 4 oz. Grimracer?Power Surge fuel cell from when Mike had his own little company. The servo mounts and engine rails are carbon fiber angle. Rudder servo is now a Hi-tec HS82-MG (new product from them) and I'll use an HS81-MG for the throttle. Radio system I'm not sure of yet as I've got a few laying around. Octura also made the 3" motor mount.
The engine sitting in there is just an old Trinity/Picco that I used for checking where everything else has to go. An Andy Brown/CMD Racing CNC'ed prop is just hanging there for now.
Oh yeah, the hull is a Delta Force Vortex. The Pennzoil decals are a temporary thing as I want to build it as a Miss Stanley Tools (hypothetical boat) U-2L.

chief3452

Wow Ron,

Sweet looking rig. I bet it will be a screamer. Thanks for the link to the rulebook, I'll check it out. Keep us posted on the progress of the Miss Stanley Tools. Take care,

Scott

Ron Olson

My Feedback: (1)

No problem. If you have anything else that I can help you with, let me know. I built my first .12 mono about 8 or so years ago, back when it was a lot harder to find parts. Thanks to all of the RTR boats out now it makes things a lot easier today.

matt420

ya KC, the ponds bein frozen sucks , there's a fun run on the 1st at waughop if the weather good, you guys should come out , if i ever go back to the TZ definitly hiittin you guys up but for now my stockers works great and i was talkin about my dad bein on the edge,when he in the water i'am the boat stand !!!!!!!!!