Lyn x Tunnel and 1440 Prop

[Tunnelbill]

My Lyn x runs great with a X442AB prop but I want to go faster. Everytime I try to run a AB1440 prop the boat will porpis (SP) . I have tried everything and nothing has worked so far, I had the prop up and down, posi and 0 and Neg trim and I have changed the C/G, No Luck. I'm looking for some info from someone that is running an 1440 prop on there boat. Will this prop work on this boat or is it just me?

Regards,

Bill

 

[shoboat]

Bill,

How much of a backcut is in the trailing edge?

The leading edge needs to be trimmed just a little bit,and

the trailing edge needs aprox. a 3mm backcut, with a milling

machine like our 1440 B/C's have. We are now puting a 1/8th"

radius on ours so the blades don't rip off the hub when we

thin them. The cup is CRITICAL on this propeller,we have

reduced our cupping so the motors will spin great RPM.

We have found through a lot of testing and different propellers

that less load on our motors will allow them to spin up and go

very quick. Example, on one of the Lynx's that has an O.S. motor

on it,and one of our 1440's,it will go 57 MPH in stock form. This motor

revs like a Dremel at full speed. You are going to need a very high

motor depth on a Lynx,so it can spin up easy. Is Andy running tunnel

hulls now?

Good Luck Testing,

Mark Sholund

 

[waltr]

Bill,

I'm running a Mod Novarossi SS /Lawless combo.

The fastest prop I've had on my "Lynx" is a ABC 40X53. Reduced to 38.63mm and 3.1" of cup. Serious RPM! I've tried no less than 30 props on it.

It double stages and will drop your jaw. Anyone who's seen it will agree. It's a rocket, but a finicky race boat.

And Mark did the prop.

 

[Jerry Wyss]

Howdy Bill,

Generally the Lynnx will porpoise if your not pushing it fast enough,, it took me quite a while to find the weight

and weight where, deal, They're a sensitive hull to a correct CG,, balance point is a better word.

Most of the guys that are successful over here don't try to get all the speed that they can outa them, they get

the BP right and prop them to run the inside lane. Great handling boat on the smoother water,, getting them

Really fast and running over some wakes or bumpy water is where their bad habits show up.

I run a heavier O/B than most everybody else so my BP might not be any good for you. I run a vertical pin at

a right angle to the last 4 inches of the sponson bottom (thats really no help for you either, I have angle adjustment

behind the pin)

Neutral thust,, bottom of the propshaft "bullet bulge" 1/16th above the sponson bottoms, most others are higher.

You likely have the L/S NR, yeah? I saw you searching all over the place for one,, TimD or MJ in Oz can prolly

tell ya some things about that combo,, and it ain't all good,,

$.02

JW

 

[Tim_Duggan]

You likely have the L/S NR, yeah? I saw you searching all over the place for one,, TimD or MJ in Oz can prollytell ya some things about that combo,, and it ain't all good,,

JW

VERY fast combo - but a very hard boat to heat race in Oz conditions without DNF's. In the end we put the Nova L/S on a Shaman to make it more reliable as a heat racer, but if you are after a SAW boat the L y n x is faster.

I'm with Walt on the prop choice for racing too. The ABC 40x53 is a lot more forgiving than the 1440 on a L y n x - mostly in the turns.

 

[Joe_Knesek]

I'd agree that the 1440 is not the best heat racing prop unless you just like chasing the boat setup. Once you get a LynxCK set up correctly with a 40x53 it will be just as fast as the 1440 in most conditions and a lot more forgiving.

It's just not worth the trouble if you ask me.

 

[Mike Larson]

Surely some of the fast southern guys can tell Bill what the balance point measurement is theyre runnin on theirs ... saw alot of 'em at the champs.....

Having the boat "slam" was in my thinking the fight between the lift of the front and rear fighting against each other until the forces equalize......

Bill, I'd throw the '40 in the lake, I told ya I hadnt much luck with 'em either..... they do have to be run grossly higher than anything, whether its slip, or to reduce the lift, who knows.....

My Leecraft had the exact same sickness, and I was down to using split shot to trim the hull the balance being that razor edge..... 'course, coming down the front just on the prop is my idea of the edge....... I LIKE rowing after flipped hulls....

Surely some of you tunnel mafia guys, Drake or even Ernie, would share a little info with a freind struggling?

Bill, i aint got that boat, was impressed with it, I'd still stick with the '42's..... there work to be had from the prop, Clegg could possibly make you a nice range to try.... or possibly the 53's..... I had results also with pitched/cupped 437/3's Mark did for me, with a little 640 mixed in.....

Hopefully you'll get a balance point first, and we'll take it from there... good luck man... mike

 

[Tunnelbill]

:huh: Mark, Walt, Jerry, Tim, Joe, Mike,

Thank you for the info, I got some very good ideas from you all. I guess I need to head to the pond and test, test, test.

Thank you to All,

Bill

 

[topfuel443]

Bill I can do a good X442 for you, or you could always sell the lyn x and get an HTB....LOL

~James

BTW, Don just won the SC State Championships last weekend in 20 mod with your old kodak HTB hull, the boat looked good! Just thought you would like to know its still making laps around the pond, althought it now has a few battle scars

 

[Tunnelbill]

James,

That is Cool, the old HTB 290 lives on. Don has done well with it this year but I did not know he was still running my old 290. I have several X442 props already that work very well. I want to make the 1440 prop work on my boat, I like to Row, Row, Row.... I hope you had a great vacation in the state, it is always great to come home after being overseas.

Thanks,

Bill

 

[theringwah2002]

James,
That is Cool, the old HTB 290 lives on. Don has done well with it this year but I did not know he was still running my old 290. I have several X442 props already that work very well. I want to make the 1440 prop work on my boat, I like to Row, Row, Row.... I hope you had a great vacation in the state, it is always great to come home after being overseas.

Thanks,

Bill

Hi Bill,

I have tried all th props you mentioned. my combo is Nova LS, Lawless, SPP NR21OB. I think the 442 supplied to me from Carl was the most reliable, it was fast and seemed to keep the boat planted. I have a heap of 1440's up to 3.85 cup. 1440's are definitely the fastest, but you do need to tighten the belt and hang on for the ride!

I have reverted back to the 40x53 now as I have smashed up the good 442.

Have you fitted the cannister for the trim weight?

regards

Mark

 

[Jerry Wyss]

:huh: Mark, Walt, Jerry, Tim, Joe, Mike,
Thank you for the info, I got some very good ideas from you all. I guess I need to head to the pond and test, test, test.

Thank you to All,

Bill

Just another note, its better to use a prop that the engine will turn easy and not make the boat wild,, It makes

getting to the "set-up" much faster. I have even put on a smaller bore carb on my larger bore O/B's, O.S.30VG

and the RB Concepts 728 on the Lyn x so I don't have to fight getting the bigger carbs dialed in at the same time.

Nothing worse that trying to trim a tunnel with a heavy explosive power delivery from the engine on a boat that small.

JW

 

[K-ZAM]

Hey Bill

I am running a 1440 3.2 cup on my Lyn x with no problem.

C/G at 7.75.

1 - 1.5 deg negative on the prop

1/8 above the rear

21 nova rossi

I got this set up from Mitch aka Jaxracer.

Might be worth a try

Kentley Porter

 

[Tunnelbill]

Guys,

Thank you, I have some new ideas to work with. Back to the pond :lol: :lol:

Bill

 

[Eric Bourlet]

Hey Bill
I am running a 1440 3.2 cup on my Lyn x with no problem.

C/G at 7.75.

1 - 1.5 deg negative on the prop

1/8 above the rear

21 nova rossi

I got this set up from Mitch aka Jaxracer.

Might be worth a try

Kentley Porter

"""DITTO""" on the setup

Close to what won the NAMBA Nationals with in both Stock and Mod. I run the exact setups in both just swap the OS power head for the MAC no change in prop location. The 1440 is the best all out heat racing prop for the Ly x if you want to win at a National level. the 442 is OK for club racing and is much easier to get a usable ride but a good running 1440 that is thinned out and back cut right will kick anything else off the pond. The ABC props are fine for speed in a strait line but if they have to cross a wake in the comer they are done. I prefer the thrust angle flat but that is an individual thing. This setup will get you very close then, it's up to you to learn the language of your Ly x and give it what needs to suit your driving style.