1/8 scale offset/center mtr well

[Mark Anderson]

If the full scale has offset, build the model with the engine and strut offset to the left. This will help control the torque effect by giving the right side more leverage. Then add any weight needed to the left tip. Watch boats run, when they blow off they lift the left side first especially in the corner due to reasons already stated. I also angle my strut to help with prop walk.

 

[Hydro Junkie]

So if the turn (with bottom curl) ic holding down the rt sponson why offset the engine away from the left sponson needing weight in the turn? Just trying to understand the weight thing

Okay, let's try to make this easy:
1) Four things are affecting the boat in a turn; torque, prop paddlewheel effect, rudder & turn fin and air flow
2) Torque from the engine and prop, as well as the prop's paddle wheel affect, will lift the left side of the boat due to the counter-clockwise rotation. Adding weight to the left side of the boat will offset some of this as it makes the torque have to overcome more weight and inertia
3) Offsetting the motor and/or engine bay is used to reduce the amount of weight added to the hull by changing where the boat's CG is located, left to right.
4) The turn fin becomes the pivot point of the boat during the turn, thus anchoring the boat from sliding sideways as well as holding the right sponson down. Just one added thought, not all boats perform well with hooked fins. Some boats work better with a flat fin that is mounted at an angle, bottom closer to hull.
5) As I stated in my previous post, air can lift the boat. If the torque/paddle wheel effect lifts the left sponson, the boat is very likely to blow over.

 

[daveberari]

Guess I’ve been lucky so far cuz none of that has happened now I have to believe I’m not going through the turns as fast as I thought I have a centered engine and not a huge fin

 

[daveberari]

Guess I’ve been lucky so far cuz none of that has happened now I have to believe I’m not going through the turns as fast as I thought I have a centered engine and not a huge fin

I seen most blow overs down the straightaway don’t think racing in district 2 should be any different than any other districts

 

[Mike Cathey]

Why would want to add weight to the left sponson?

Be careful how much weight you add. I don't start with any in my new boats. You can tape down the foam backed strip lead (leave the backing on so you get adhesive on your deck) on the deck on the left side as you are tuning the boat ride. Sneak up on it and move it fore and aft until you get the ride you are looking for. Later you can go back and drill a 1/4" hole in the sponson main where you need the weight and mix some birdshot and epoxy and use a paper funnel to get it in the sweet spot.

You are looking for the minimum here. Excess weight will kill the performance.

 

[daveberari]

Be careful how much weight you add. I don't start with any in my new boats. You can tape down the foam backed strip lead (leave the backing on so you get adhesive on your deck) on the deck on the left side as you are tuning the boat ride. Sneak up on it and move it fore and aft until you get the ride you are looking for. Later you can go back and drill a 1/4" hole in the sponson main where you need the weight and mix some birdshot and epoxy and use a paper funnel to get it in the sweet spot.

You are looking for the minimum here. Excess weight will kill the performance.

Now I like that nifty way of settli

 

[daveberari]

Now I like that nifty way of settli

Now I like that nifty way of settli

Nice easy way to find that sweet spot at WOT. Thanks Mike Will definitely do this

 

[Mike Cathey]

Nice easy way to find that sweet spot at WOT. Thanks Mike Will definitely do this

If you decide you need some in the sponson tips get some wax paper to lay down. A friend of mine did this and leaned the boat against the wall with the sponson tips on his new living room carpet and there were a couple of places the West Systems seeped through some glue joints and he epoxied his boat to the carpet. To say his wife was upset is an understatement.

 

[daveberari]

If you decide you need some in the sponson tips get some wax paper to lay down. A friend of mine did this and leaned the boat against the wall with the sponson tips on his new living room carpet and there were a couple of places the West Systems seeped through some glue joints and he epoxied his boat to the carpet. To say his wife was upset is an understatement.

Thanks been done that. Built myself a detached work shop to handle the fumes/chemicals/ all the sawdust. life is better!!!

 

[Paul Cooper]

"You want the boat to balance on the leading edge of the fin,but you only want about 20 Oz of strut weight. West System type scales work good for checking strut weight. As far a offset it wont matter as your going to add weight to balance heavy on left sponson IMHO "

Sorry I'm new to this. Any chance of photos or a video on how this is done?