Showboat Help !!

[waterbug]

Mark

I'm running a Mac/Lawless on a Magnum and a X640 @ 2.8 it is a screamer !! too much !!! Any suggestions on props to replace the 640 ??

Butch

 

[Jerry Dunlap]

I've had good luck with my MAC running X438 and X640 reduced to 37 mm diameter. Another prop that worked well was a M440 Mark did for me.

JD

 

[dave roach]

Try the ABC 40/53 two blade.

 

[shoboat]

Butch,

All the above are great propellers. The Y-536 would be another that I would

try Butch. If it screams, then what is wrong with the X-640 that you are currently

running? If you want to try something totally different, the Grim 1440 B/C @ 38mm

would be a nice propeller also.

Thanks,

Mark Sholund

 

[waterbug]

Sorry !!! I think I need more prop..... I'm turning some serious RPM's with the X640 @ 2.8 heat treated ...

I have a Grim 1440 BC/SB and a base 1440 BC/SB, X438, stock X442 and X437/3, X440/3

Do I get another X640 and keep pitching up or go to a different prop ??? Is the question I should have asked....

Butch

 

[shoboat]

Butch,

2.8" of cup is not that much,I would probably cup it up a little more and see how

it performs if it was me. If you like the cornering and the punch out of the turns

I would work on it very carefully. Butch we have found under 3.46" of cup is really

working well on most tunnel boats with modified engines. Now the diameter is the

real critical thing to find on your set up,once you find this you will be much faster.

Good Luck Testing,

Mark Sholund

 

[Tunnelbill]

"I think I need more prop..... I'm turning some serious RPM's"

Let it Rev :lol:

Do you want to go faster? Try a Mod X442 or 1440 3.4 or 3.6 cup..

 

[waterbug]

Hi Bill,

Yep !! Kevin sure knows how to build a screamer for sure !!!! It's when the screaming goes to the high pitched " HUM " !!!! that worry's me :lol: :lol:

I hate to see when the Mac gets broke in !!!

Butch :lol:

 

[Richie R]

:huh: Who did your mac.I have and not impressed at all with it. any help would be great. Thanks RICH

Yep !! Kevin sure knows how to build a screamer for sure !!!! It's when the screaming goes to the high pitched " HUM " !!!! that worry's me :lol: :lol:

I hate to see when the Mac gets broke in !!!

Butch :lol:

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[waterbug]

Kevin Bulifant is (izitbrokeyet?) on this forum .... Smart man !!!! Good engine builder...

 

[MarkScott]

Waterbug,

I've got one of Mark's cut down x442. I'll get back to that prop on my next test day. Had issues with my mechanic to work out :lol:

Ritchie,

I had my MAC done at CMDi, heat racing mods. I too was disappointed with the initial performance of the motor. But it came down to my id10t mechanic had the motor to high After raising the motor more, it's starting to scream..

Mark..

 

[Precision Boats]

If you got a Mac that turns r's it will be the first I have seen on a outboard. Good luck with it.

Tim

 

[Bob Kensill]

My Mac has no problem revvvvvving. I will be running it at the IMPBA Internats.

 

[Jerry Wyss]

There's several Mac OB's over here in District 8 that run Real strong, very impressive nee-ner,nee-ner,,neee-nerr :lol:

 

[topfuel443]

If you got a Mac that turns r's it will be the first I have seen on a outboard. Good luck with it.

Tim

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Weve got one in district 13 (an OvalExpress team member, no less) that will turn more R's than Ive ever heard on any other outboard by far. Bob K. had his hands (and a dremel) inside the case on this one to I believe (Steve Hansel'sSp? old motor). Most pleasing sound youve ever heard when that puppy turns on. Great running motor.

~ my $.02

James

 

[VansRacing]

James,

Have you run yourself out of time?

-Carl,

 

[topfuel443]

Hey Carl! Sorry for not getting back to you the other day, Ive been busier than a (insert cliche' here). I am done. I started at 12:00 pm Monday after getting back from the hobby shop for supplies and I finished it 9:00 pm that night. A boat, start to finish in nine hours, isnt too bad and it looks great!!!

Thanks again, seee ya this weekend.

~James