mac 45

[aaron alberico]

how can i tell what the newest version of the mac 45 is. and how do they go out of the box.

 

[AndyBrown]

I will post some pics here today.

 

[Chris Attebery]

Aaron,

I have had a MAC45 since they came out. To be honest, the first year or so I liked my Picco blackhead better. Once Andy told me to drill the stinger out on the pipe it became my favorite. The newest version of the P/S made the motor really come alive though. I'm running in the mid 70's and I could probably go faster if I spend some time at the pond. I literally bolted this motor in the boat, threw on the prop Andy sent, and within a couple tanks the motor was screaming.

What are you going to run it in? Hydro or Mono?

Chris

 

[Anders_Martinelle]

Aaron, the newest version i have the head cap is not dark blue.

It`s just blue.

There is "small" adjustments between batches so i think only Andy can give you a correct answer of witch is the newest or what changes there is inside......

I agree that right out of the box they run super!!

Anders

 

[AndyBrown]

The newest MAC 45 now has the "4" written correctly on the case.

In the last few weeks we started delivering the lastest improvements which include a ramped drum.

All in all there are small improvements to nearly every part, to include: Crankcase, Drum, Drum housing, Carb, piston/liner. I am happy with the out of box performance. Good power through the entire range.

Will upload pics shortly.

 

[Eric Gadoury]

Andy,

What do you mean by a ramp drum rotor?

Is it like they show on the preswitch web site for the .20?

Thanks,

Eric

 

[AndyBrown]

Hope this helps.

 

[nitrotoys]

MACs Run awesome out of the box.

I have had one, and it ran flawless.

Never a problem and loved to rev out.

Real nice ports in that motor

Andy, All these hot little .12 riggers, Think MAC could come out with a hot little motor for them?

Tom

 

[tracerbob]

Andy,

Will these new parts fit the earlier engines especially the piston/sleeve and the new drum rotor?

 

[aaron alberico]

thanks guys i will b running it in a hydro 45sg. what kind of mods are u doing to the mac 45 Andy to get them to go even harder.

 

[AndyBrown]

Robert,

All the MAC 45 parts are interchangable.

Aaron, John Finch has an older SG 45. Just put this New MAC 45 in it said it runs 79mph.

There is always room for improvement, I just do some extra port flow work.

Likes a pipe that can breath. Meaning .435" Stinger I.D.

Sport Hydro's are running 60-63 mph with this thing straight out of the box.

 

[Eric Gadoury]

Andy,

When you say the stinger is .435, does this mean that you changed the design of you parabolic pipes?

Would it be possible to make a Delrin piece for the drum that would be pressed fit in the drum in order to have a ramp?

Could you post a large pic of the new drum please?

Thanks,

Eric

 

[Chris Attebery]

Eric,

I made an aluminum plug for my MACs. Turn it for a interference fit so it doesn't distort the rotor and use red locktite to hold it in place.

Chris

 

[Eric Gadoury]

Chris,

Is it a true cone or more of an offset cone?

Thanks for the info!!!!

Eric

 

[Chris Attebery]

Eric,

I just turned a cylinder and then milled it off at a 45 degree angle. Drill a small (.032") hole through the plug to relieve air pressure between the drum and backplate.

Chris

 

[Don Ferrette]

Robert,All the MAC 45 parts are interchangable.

Aaron, John Finch has an older SG 45. Just put this New MAC 45 in it said it runs 79mph.

There is always room for improvement, I just do some extra port flow work.

Likes a pipe that can breath. Meaning .435" Stinger I.D.

Sport Hydro's are running 60-63 mph with this thing straight out of the box.

John's & my MAC45's are both stone stock. He's running 79 with his 45SG & my sport 40 is running 61 in heat race trim. Both are running with the parabolic pipe drilled to .435".

 

[aaron alberico]

Andy

what about the mac21 im running one with a p-21s pipe for s.a.w what kind of mods should i do, what pipe length should i run, running on 70% got one of your props 2047. also should i run standard head or turbo head at what clearance. thanks

 

[ClayGlover]

When you say the stinger is .435, does this mean that you changed the design of you parabolic pipes?

I measured my 45 parabolic pipe's stinger, and the I.D. is .375". I drilled the baffle out, but didn't open up the stinger any, that's the diameter it came with. The O.D. of the stinger is only .445". I measured 3 times . If I opened this one to .435", that would leave the stinger wall just .010" thick.

What's the O.D. of the stingers that y'all have drilled to .435" I.D.? Thanks

 

[AndyBrown]

The original Brown 45 parabolic pipes had a .375" stinger. I was boring them to .390" which works well. The new pipes are .435".

I'm sure some guys are wondering why I continue to build the pipes with the stinger baffle when most everyone is being told to drill them out.

The reason is, drilling out the the baffle doesn't work for Every engine and combination. Some set ups run better with extra resrtiction.

Gary Pruesse holds the IMPBA 1/3 mi Oval record and the SAW recor in 1/8 scale with a MAC 67 and the Stock Brown 67 parabolic pipe. When he drills out the baffle the boat slows down.

Aaron,

I would start with the Std. plug. Set the head at about .006". Bore the stinger baffle out. Keep the stinger at .315"

 

[Jay Stone]

Andy,

You have us all BAFFLED.