learning,.. fun, learning!!!

[anthony_marquart]

Tested this morning... good stuff

My .21 rigger design is proving good... (yes,.. alot like a JAE) I think I'm getting close to peak performace now with my NR 5port.. As I get my boat running real well I find things that happen only at this level of performance.. One of them was the water line blowing off.. Well I fixed it inside the hull.. was runing great again.. proped back up and really ran strong... noticed water shooting up... now it blew off the rudder!!!! The .050 hole in the head is really packing water in now that it's running so much better. Just looking over the boat between test runs,.. rudder bolts coming loose!!,.. never happened before.. never ran this fast before.. I did shorten the pipe to 2.75 in,.. measured from the center of the head to the first line on the S pipe.. added some rpm, still launching all the prop I've got... which is a crazy high, 3.75 1445,.. at about 46mm.. maybe it's time to try a little more diameter.. it's coming unhooked a bit..

I start think,.. man.. It's almost perfect,.. better stop running before I loose a bearing or a P/L fit.. plus I'm about out of 65% FUEL... Tough to get in small quanitity...

On future testing.. THe things I think of are more props,.. shorter pipe... I just built a boat for Kevin,.. (nitrosniffer) It's what I call my "ultralight" version. Depending on how he finishes it I bet it comes in around 3.25 lb.. Eventually I will build one for myself...

Man I love this stuff. Just wish there was a person or two around to run with...

Next challenge is my kids .12 wildthing mono. powered by a RB concepts v12,.. I plan to lift the sleeve .030 and get the head to about 8-10.. run 50%,.. GR has some good props for this application. I've got the .12 pipe from zipp for it.. I keep saying I'm not really concerned about performance on it but that realy isn't my nature. still need a few parts for it... I think I'll focus on that and not burn nitro in the rigger for nothing.

Anyone around CHarlotte,.. we have a great place to run here in Concord.. I'm going to ask if we can add bouys soon...

 

[shoboat]

Tony,

7 5/8" on the S-pipe. Or 2 5/8" your way of measuring.

You may need to get the H-7 or 1450's out soon.

I hope you have a 90 degree water fitting on that rudder?

It is the only way to go.

Let Me Know If I Can Help You,

Mark Sholund

 

[anthony_marquart]

The 1445 @ 3.75 TE pitch is running faster than the H7 @ 3.6. Maybe I need t send some props back to you for mod or exchange..

Don't have the 1450s ,.. My partner in Indiana got those I think.. I'm thinking maybe I can use something around the 48mm area.. about 46 now. Another paypal coming your way Friday.

Looks like I can got anther 1/8 shorter with the pipe... I'm pretty sure the boat is right about 70mph now.

Thanks again for all your help.. what would you recomend for the .12 mono?

The lighter boat build idea is starting to sound good... Not ready to back into building mode though...

Tony,

7 5/8" on the S-pipe. Or 2 5/8" your way of measuring.

You may need to get the H-7 or 1450's out soon.

I hope you have a 90 degree water fitting on that rudder?

It is the only way to go.

Let Me Know If I Can Help You,

Mark Sholund

 

[mtruex]

The 1445 @ 3.75 TE pitch is running faster than the H7 @ 3.6. Maybe I need t send some props back to you for mod or exchange..

Don't have the 1450s ,.. My partner in Indiana got those I think.. I'm thinking maybe I can use something around the 48mm area.. about 46 now. Another paypal coming your way Friday.

Looks like I can got anther 1/8 shorter with the pipe... I'm pretty sure the boat is right about 70mph now.

Thanks again for all your help.. what would you recomend for the .12 mono?

The lighter boat build idea is starting to sound good... Not ready to back into building mode though...

Tony,

7 5/8" on the S-pipe. Or 2 5/8" your way of measuring.

You may need to get the H-7 or 1450's out soon.

I hope you have a 90 degree water fitting on that rudder?

It is the only way to go.

Let Me Know If I Can Help You,

Mark Sholund

anthony,

way to go, fun when things get faster..one of these days i will have to come check out the place you found and do some running with ya..just need some time!!!

you should definently step up to a 1450 about 46mm 3.75 is a good start..

 

[anthony_marquart]

Well, tested again today. Not so good. Maybe the last times I tested I thought I was doing better but I wans't.. a radar guns tells all.

I post these test results for a few reasons,.. to report results to the guys who help me,.. and hopefully to help people like me trying to learn.. Everybody doesn't do it.. if it's boring or bothering anyone let me know and I'll share it privately.

A couple changes from the last radar poven testing. .. last time.. 66mph steady.

Previous setup,..

NR 5P, AB parobolic @ 7.3, 65% Odonnel, H7 w 3.6cup and 45.8mm JAE style hull. Odonnel OD9 plugs (great plug) 66mph on radar,

Changes,

- switch to a NR header, no abrupt changes in direction.. old header from zipp had sharp angle at the engine.

- switched to a S pipe from AB parabolic. This APPEARS to be a lower volume pipe. started at 3in and the tried 2.75 and back to 3.

-ended up with the same prop.

Barely got to 66 MPH today. Ate a plug every run. Pulled the pipe back to 3.0, plug lasted longer but speed dropped.

I made a hull change also. I shortened the ski about 1/2 inch. I think the rear of the boat was poping up going over wakes. That DID improve and the prop stayed hooked up better.

I'm pretty much out of the 65% Odonnel so I'll be seraching for fuel soon. The GR 50% runs great but the .21 seems to respond well to high nitro!

THe boat was running pretty clean. THe change to the rear may be creating a touch more spray on the rear of the boat. I may try a standard type strut.

As usual.. all suggestions and comments welcome..

Burned up about 5 plugs today trying to get this right. I think I'm going to go back to the AB pipe and try to the place I was before. Then try more prop. I have a couple to try,,, no use today. (thanks Mark!!!)

Also, thanks Jim Allen.. I AM listening.. and trying to retain as much as possible!!!! I'm holding the phone in my hand waiting for your call on that pipe!

Moral to todays story,..

-only radar gives accurate results.

- The age old reccomendation of changing only ONE thing at a time holds true.

-.21 engines do respond to high nitro. I tried some 50%, them 65%, gained 5mph.

-listen closely to those who have data to back up there advice!(J.A.)

 

[Chris Wood]

Before u try a different pipe try a.1450 46.5 to 47 mm with about 3.4 cup and see whay that does

 

[moparbarn]

anthony, i was having some of the same issues as you with plugs & speed. i went up in prop, seemed to cure the problems. i had always believed that you start small & dial in the boat & engine, then go up in prop. well, i just ate plugs & wasn't happy with the speed. i've ended up with a 1450 at 48.5 diameter with 3.75 te cup. the engine cleans out like a chainsaw in the heart of a tree, sounds MUCH happier, has stopped eating plugs for lunch & the speed went up. try loading it up some more & let us know what happens.

 

[Jim Allen]

I think it is very fair to say that any setup that works well on one particular engine boat combination, may not work as well on a similar or same engine boat combination.

If we only consider the marine type of engine there are very few, if any manufactures, who are bench testing each manufactured engine before it is sold to the public. One manufacturer that I am very familar with, Mike Langlois of Aero Percision who manufactures .40 size Nelson long strokes, takes the time to bench test each motor before it is sold. Even though these engines are machined to very tight tolerances, engine performance figures of HP & RPM vary over a wide range. Engine piston liner fit, taper amount, cylinder crankshft squareness & alignment, bearing fits, metallurgy, etc. are a few of the things that must be carefully controlled to enable the production of engines that are the same within 500 RPM.

Jim Allen

 

[anthony_marquart]

I put my set up back,.. with the AB pipe.. got some fresh fuel from John Otto.. Ran a few tanks and I have the stability back in the motor...

Don't want to say it's back up to speed but it appears so..

THe fresh fuel does seem to run better!!1