VS1 prop selection

[Grimracer]

One more thing...

Walk into any hobby shop that’s not that stocked on boats (most are not) and ask them for a prop for a 21 tunnel.. Let them know you want Octura or ABC... then ask for a Grimracer.. let me know what one is easer for them to get.

One of the best things about Grimracer props is you local retailer can get them through his or her NORMAL ordering system. No mid day phone calls or odd dealer discounts.

You want em.. they can get em.. FAST and EASY.

Grim

 

[FloridaScaleBoater]

Rick,

Most important is center bore.. that is the TRUE differance.. the dia and pitch are the same.. having said this the 36x55 is our own design. (more to come)

Grimracer

Thank you for the honest answer, I do have an ABC 40X53, I think I will touch it up, check the balance, and see how it works

Rick

 

[JimmyDuncan]

I have not tried the 40X53 ABC, but I had a 40X52/3 ABC sharpened and ballanced by CMDi racing. It was a great prop, but the pond monster has it now.

 

[Grimracer]

Rick,

OS.. VS1... 40X53 = 50MPH

Just keep tuning.. you will get it..

Grim

 

[byron westman]

hi grim ,how sharp do you make your prop ? sharp or razor sharp. also do you play with back cut and cupping or just stock?. I'm playing with one for my stock os 21 outboard. I have it pritty close to sharp buy didn't want to make it weak.

thanks

 

[Grimracer]

Typically on a tunnel boat you want it razor sharp.. not so important on a hydro..

the sharper the prop the less lift it makes.

I have done it all with props.. if the boat is not handling right I mess with the prop.. anything I can do to avoid it however is best.

Grim

 

[Stefan Adolfsson]

Hi, another questin to Grim. Whats the best way to sharpen the prop??

Stefan

 

[Grimracer]

I have a way I do it.. Bob has a way he does it and so does George..

I have an arbor I got from Micro-mark.. it uses a flat pad and sticky back sand paper.

using a dust mask, have at it until its sharp... then finish with 400 wet.

This has nothing to do with profiling the prop or back cutting it.. just sharpen and balance.

I know its not much of an answer but there so no best way..

One can go to AquaCraft models to learn some basics.

http://www.aquacraftmodels.com/accessories/propellers.html

Keep us posted and welcome to I waters.

Grim

 

[Stefan Adolfsson]

Thanks for the quick reply, Grim. Now i know what to do before the ice leaves our lakes, i have run the Grimracer 40X53 from the box this season on my VS1. In Sweden we dont have a mod class so we run everything stock. I think the VS1 with OS 3.5 and Grimracer 40X53 prop is a wery competitiv combination on calm waters.

Thanks for the welcome

Stefan

 

[Moparbarn Jr]

Rick,

OS.. VS1... 40X53 = 50MPH

Just keep tuning.. you will get it..

Grim

I WILL HAVE SOME PROP NOTES TO SHARE AND HAVE CRITIQUED h34r: , ON THE VS1 W/K&B, AT THE WTC'S.

SEE YOU SOON!

 

[byron westman]

i run a 40x53 and was wondering what the differance in performance is with a 40x52 3.

 

[DeanJohnson]

Thanks to all that have replied. There's some very good info said and I appreciate the feedback. Looks like my best bet without having to do much work may be the Grim 40x53.

Thanks again,

Dean

 

[shoboat]

Dean,

Reduce the cup on the trailing edge at .7 radi and it will

work much better at 2.57" of cup, this will allow the motor

to rev up and it may let the cannister muffler two stage.

The O.S. XM-21 OB does not like to be loaded heavy with the

propeller.

Have Fun Testing,

Mark Sholund

 

[mikehoffman]

I run a 1440 from Mark Anderson runs sweet.

 

[Tim leyde]

i run a 40x53 and was wondering what the differance in performance is with a 40x52 3.

I am not sure on the grim props, but I run either a 440 ( 3 blade ) or a 438 ( 2 blade ) on a VS1 with a k&b sx. I can tell the 438 is a bit faster however the 440 is more stabile and we all now what happens if you dont finish a race. I mostly run the 440.

 

[moparbarn]

ALL the props mentioned here run well. i personally run a mark sholund 1440. but, on MY k&b's i have found that the common thought process of running .006" squish clearance is too tight. i've had more than a few motors that just wouldn't turn up, no matter what prop i tried. i have found that opening up the head clearance to .008" or even .010" will let the motor unload, & find another gear. i run 50% nitro & 14% oil. worked for me. a x-640 cut down to 37-38 mm, tongue cut & back cut works well also. a x-442 with similar cuts is good, also. but, both of these are way too much to start with, they have to be cut WAAAAY down. on the os motors the 40x53 seems to work best, from what i've seen at the races. there is a racer here in impba d-12 that has a cut he puts on them that absolutely wakes the os/villain combo up. but, i would have to ask him before i mention his name. i'm reasonably sure that sharing the prop isn't the issue, just don't know if he wants that much prop work to do. sorry, but it's only fair that i ask him first, since he ain't advertising for prop work............

 

[Kris Flynn]

From Memory Geraghty sets them to around .012 to .013 to get extra tourque

 

[shoboat]

Guys,

Way too much cup in a stock ABC 40 x 53, so I am sure a backcut

will take that out also. I just repitch the propeller where it needs to

be in the first place. The 40 x 52/3 works very well and it is much

better than the X-440/3. Diameter and cup is very important on these

tunnel hulls, it also affects the handling and acceleration a great deal.

We are bringing out a few newer profiles here shortly, that are working

very well on some fast test boats across the world. Stay tuned!!!

Have Fun,

Mark Sholund

 

[moparbarn]

From Memory Geraghty sets them to around .012 to .013 to get extra tourque

i talked to rod about this a few times when i was having these issues. he suggested .010" B) . i both trust & respect his knowledge of k&b's ( & all other nitro motors) a lot, & talk to him frequently. rod is a wonderful man to know & is willing to share anything he can with you.