Riggers from Japan

[Hammerhead]

Hey! I know what you mean. I can spend all day polishing and balancing just one prop. Do you think I should even bother going out and buying an H48? I think the H45 has a 7inch cup, so I don't even want to bother with that one.

If I can turn a 38 do you think I will be able to turn a 48?

Let me know.

Hammer

 

[Twin_k90]

How easy did it pull the 38?? i would see if you can borrow a 48 off somebody and try one,

my twin pulls 38's like there is no tomorrow and the 48's easy as well, so maybe you would pull a 48, there is only one way to find out and thats to try it!!,

the H45 has only a small blade area compared to a 38 or 48, usually the less blade area means they are easier to pull, but ill let you know about these ones!!!

BTW i just sent you a email as well,

 

[Hammerhead]

Hey Dale! I was looking at Marty's Prop charts, and it says that the H45 has a 7inch cup. That sounds like an awful lot of pitch. Have you ever tried one?

Right now, I'm pulling the H38 with know problem. I guess I can borrow an H48 this weekend and try it out.

Thanks Hammer

P.S. I'll go check my mail.

 

[Twin_k90]

It has 7" cup but not a lot of blade area, im going to try mine on the weekend ill let you know how they run, if your pulling a 38 easy move up to a 48!! if your pulling that you will be moving!!

 

[Hammerhead]

Hey Dale! Do you think if I have my H38 cupped a bit more, will it stop cavitating on the launch. If so, How much should I have it cupped. 5inches or so?

Let me know what you think.

Hammer

 

[Twin_k90]

I wouldnt worry about the cavatating on launch, my mono cavatated really bad, it lets the boat get going before it loads up the motor, we have pitched up some 38's and they worked well, dont have a pitch guage so i cant tell you how much they were,

 

[MikeP]

Hammer,

I notice the riggers you run over there have adjustment holes for the turn fin. Can you tell me what happens when you move it back or forward? Is that something you move often or leave alone.

-MikeP

 

[Hammerhead]

Hey Mike! Brilliant observation. Yes, we do play around with the turn fin. It depends on what turn fin we decide to use depending on the water conditions. For really mirror like water surfaces, we use a turn fin that has a very big back angle, so we will have to move it forward on the turn fin arm to compensate for the CG (center of gravity). If it is really rough, we use a turn fin like the one your using. They are almost 90 degrees. We have to move it back to compensate for the CG here, too. We try to keep the leading edge of the turn fin at CG.

By the way, I had to put center of gravity in (), I know that you know what CG is, but I found out that my mom has been reading my thread, so I have to keep it in laymans terms for her ;D.

I would go with K-90s advice on the screw, too. I will get back to you on the type of anvle you should use. I heard of a good one that doesn't cost as much as it does to have Andy do it for you.

Hammer

 

[Hammerhead]

Here you go Mike!

It is called the Little Rock welding Prop anvil. International Waters just happens to have some literature on it.

www.intlwaters.com/iwrc/www/Interview/feb98.html

 

[Hammerhead]

This doesn't seem to work. I know I got the URL right, but the Internet explorer says that you have to go to intlwaters first then look for it. Help Tom!

Hammer

 

[MikeP]

I think I would like to learn how to do my own prop work. That's just the way I am. I hate waiting on someone else, these endevors usually end up coasting more money and alot of time but it's more rewarding and I learn more. I found a phone number for Little Rock welding . 812-897-4638.

MikeP

 

[Twin_k90]

Guys, we are going to be selling pitch guages in about 4 weeks we should have the first order, they will be around the $150au mark with shipping, they are the Advanced Racing Tech ones and come with a dial guage and insturctions

 

[Mark Sholund]

Dale,

I'm sure your Twin K-90's run nice but how do you do your

props without a pitch gauge?You must guess really good.

When you finally get your ART gauge then that should really

help you.Then you will know what pitch you have.Happy

Boating!!!!!!

Mark Sholund

 

[Twin_k90]

Thats the problem we dont know what pitch we are running, we just add pitch slowly till we get it right, with the anvil you can get the blades pretty close but its still not 100%, i will let you know what we run when we get them setup,

at the end of the day it doesent matter what pitch each boat runs but it is nice to say i pull a H50 with 7" pitch!!

 

[Hammerhead]

Hey Dale! I tried the H48 today. My motor could spin it, but it was really choppy today, so I couldn't really tell if it was any better than the H38. I got a video of it running with the H48. I think my engine needs to have an over haul. Especially the bearings. I have run about 10 gallons of fuel through it since I got it in April. Doesn't seem to have the get up and go it used to have.

When I get the vid up on my site, I will post the URL.

 

[Twin_k90]

Execlent, it will be moving!!! the H48 is my choice for heat racing its a very good prop cant wait to see the vid!!

next time out throw a H50 on the back and see what it does,

Check the piston and liner the fit might be getting a bit loose and worn out,

 

[Hammerhead]

Hey Dale! I just pulled my engine apart, and I found the problem. The connecting rod is rattling. There must be a half millimeter of play if you add the bushing wear of the crank shaft and the wrist pin together. I think I will just change the connecting rod and the wrist pin and see what happens. My AAC piston and sleeve still fit tight, and they're still shiny. I can't see any reason to change them. And my bearings are still in ok condition as far as I can tell. When I pull on the flywheel it doesn't have that much play. When I try to wiggle the

flywheel up and down, it has no play at all. I think they are still good.

My engine just doesn't have the punch it did before. I wonder if just changing the con-rod and the wrist pin will be enough.

I don't really need a pitch guage. I'm like Mike, when it comes to building boats, but I prefer to leave the prop jobs to the proffesionals, myself. I can't afford trial and error when it comes to props. If I mess up on a boat, a piece of plywood or a meter of carbon is just pennies.

Hammer

 

[Twin_k90]

That would cause loss of power and potentially wreak your whole motor, change any worn parts you find, while you have it apart it wouldnt hurt to throw a new set of bearings in it.

is there any play in the piston where the wrist pin goes through?? maybe you should try a brad christy titnaum rod that should stop this from happening again

 

[Hammerhead]

Hey Dale! I checked and there wasn't any play where the wrist pin goes through the piston. There is play where it goes though the connecting rod and also where the crankshaft goes through the connecting rod. My guess is that the copper ( or what ever they are made of ) bushings in the connecting rod are worn. Being that the bushings are the softer of the two metals, I would imagine that they are what has worn. I might be able to get away with just replacing the connecting rod. I have a spare RPM titanium rod. I think I will order a wrist pin just for the sake of doing so before I replace it. I have never replaced bearings myself. I would have to send the motor in to do that. Do you change yours yourself? If so, is there a fail safe way of doing it. It costs 120 for parts and labor over here to have it done. If I had 250, I could buy a new engine. I would like to learn how to do it myself without making things worse. I heard that if you don't do it right, you will end up spending more money than if you had the factory do it for you. What do you think? Any suggestions or advice will be appreciated.

Thanks, Hammer

 

[MikeP]

Hammer,

I have changed several sets of bearings for myself and others. If you do it right it's a piece of cake. Cost of bearings was about $35.00 us. Here is how I did it.

Use a heat gun and heat up the case, you can tell when it's hot enough when the old oil starts to smoke. Use some kinda punch and push out the front bearing. To get the rear bearing out tap the case on a piece of wood. I wear a leather glove on one hand to hold the case. To install the new bearings heat it up again until it smokes and insert the front bearing, slide the rear bearing on the crankshaft and slide it in using the front bearing as a guide to get it in straight. When it cools down a little you should be able to slide the crankshaft in and out of the bearings without binding, if a bearing is not in flat the crank will bind. If it does heat it up and tap a little to seat the bearing flat.

The bearings should fall into place. No Hammers allowed.

Maybe someone else could add something to help.

Mike