MAC Motors are the bomb

[Anthony Pendeho]

You're right....back on Topic

I have just one Mac at the moment and I love it......Too bad parts arent available for it.

By the way...

Rule #1 for me:

nothing wrong with toy boats as long as everyone remembers they are toys and this is fun

Rule #2

things get out of hand people start getting out of hand when people forget rule #1

I cant get any girls to pose with my boats.....even the ugly ones know that my boats are ugly and wont make them look better.

I've seen the girl holding the boat in your profile.........

I'll bet if you shave her, grow her hair out a little, put her on a diet and she'll be much easier on the eyes......and you'll be happy you did

 

[RaceCraftBearings]

Anthony,

:lol: :lol: :lol: :lol: :lol:

Cant stop laughing, my sides are killin me!!!!!!! You got me real good on that one!

As far as parts for your Mac, I have been running them along time and I just havent needed any parts except a piston and sleeve to refresh a motor that had served me quite well over the years. Like I stated they are bullet proof. What kind of parts do you need?

I agree 100% that it is toy boats and we must all remember that which I have told many that same exact thing when they argue a call I or any other CD has made.

I didn't qoute your post because I didnt want that uglyness holding my boat showing up again

Actualy I had to take that pic for our District Scale Director when I registered the boat to race.

Sorry bout that but they twisted my arms and I refuse to lose which I would have done had I not taken the pic as without it, no racing that boat.

Now where is 3000 Miles ENE of Live Oak? I know its across the big pond but being a dimb country boy from the good ole US of A I cant figure that one out so here is my guess........France?? I have a good friend in France who races boats with us here in the US Francios Peilleron. I hope I spelled that right??? But then again France is probably only 1500 miles?? Help me out here will ya?

Later.........Ron

 

[Joe_Knesek]

I'm from about 3000 miles ENE of the bustling metropolis of Live Oak......far far away from the "high Tech" area in Live-Oak where the men sell toy engines and the all the under age girls pose for pictures holding some old farts toy boat :lol:

well I thought it was funny....please dont try to kick me off guys!

all in fun

Maybe you would rather have these two model your motors?

 

[Krusty 181]

i would love to comment on this thread ...

now i just need to be given a MAC , and ill write what ever you want when you want

 

[SayMikey]

I'm from about 3000 miles ENE of the bustling metropolis of Live Oak......far far away from the "high Tech" area in Live-Oak where the men sell toy engines and the all the under age girls pose for pictures holding some old farts toy boat :lol:

well I thought it was funny....please dont try to kick me off guys!

all in fun

Maybe you would rather have these two model your motors?

NO doubt Joe has spent a nite or two at the local barz lol nice pic Mike

 

[Joe_Knesek]

I'm from about 3000 miles ENE of the bustling metropolis of Live Oak......far far away from the "high Tech" area in Live-Oak where the men sell toy engines and the all the under age girls pose for pictures holding some old farts toy boat :lol:

well I thought it was funny....please dont try to kick me off guys!

all in fun

Maybe you would rather have these two model your motors?

NO doubt Joe has spent a nite or two at the local barz lol nice pic Mike

Let's be clear, I am neither one of these characters! I don't even drink but if I did, I'm sure I'd keep my shirt on.

 

[RaceCraftBearings]

I'm from about 3000 miles ENE of the bustling metropolis of Live Oak......far far away from the "high Tech" area in Live-Oak where the men sell toy engines and the all the under age girls pose for pictures holding some old farts toy boat :lol:

well I thought it was funny....please dont try to kick me off guys!

all in fun

Maybe you would rather have these two model your motors?

Picture left out for obvious reasons!

NO doubt Joe has spent a nite or two at the local barz lol nice pic Mike

Let's be clear, I am neither one of these characters! I don't even drink but if I did, I'm sure I'd keep my shirt on.

Come on Joe that sure looks like you on the left there........... :blink:

JK see you in Atlanta

 

[rmprecision]

Hi

I have a brand new Mac 67

How do i run this motor in?

It will end up in either a 1/8 scale (lawyers bill pending) or a rigger i already have

Want to do it right as its the only mac i have.

Already blown up th K&B outboards i have

 

[Tom Foley]

Running in the Mac should not differ from any other motor . If you have the skills , disassemble and clean all chips and debris out as well as any loose chrome flashing etc . Then go to the pond with fuel with 18 - 20 percent oil open up your needle valve enough so the motor is obviously way rich to the point of being hard to start and get it running . Right now there is so much fuel going through the motor on the stand that you should be able to make a few needle leanings so as to enable the motor to take throttle and run richly and it will not overheat . Now refill and once you are happy with reliable starting characteristics , get on the water and run several tanks through checking your plug condition and fuel filter each time to ensure slightly rich running . These are great motors that are not subject to the problems of bushing motors in terms of lean running . The needle bearing rods although not a Mac development make these motors near bulletproof , I have all but a 21 now and especially like the 84 ' s in my twin . The combination of the carb and spraybar size seems to be conducive to easy starting , running , and the" carb - up" configuration is not sucepyible to water ingestion due to trace water in the boats . Now with that said I hope exact replacement parts are available soon along with some new motors , even though I haven't needed more than a header ring for these motors . Time to get my 67 hydro back on the water .

 

[rmprecision]

Thanks Tom

I normally run 18 to 20% oil is this the normal range(15 %klotz 5%castor)

Also how much nitro should i use?

 

[rmprecision]

Greg would you like to run in the engine for me?

 

[RaceCraftBearings]

There are many therories on breaking in a new motor.

First: Macs are the cleanest inside and right out of the box than anything else I have delt with so taking them apart is more times than not a breif look and put it back together without having to do anything at all inside.

Second: the run in proceedure that makes the most sense is to run it rich but not overly rich. Launch the boat and do a few slow to med laps then start doing the front half of the lap full speed and the back half of the lap off pipe. This way you are building heat when WOT in the front and cooling when OT in the back. Do this throughout the tank. Repeat as needed which is not all that many tanks maybe (4). You may even be able to start leaning it down somewhere around the third or fourth tank. After that you should be able to fill it up and lean it right to the sweat spot and make some good runs. You have to have a good idea where the sweat spot is, I am one of those that would rather be a shade rich than run it on the ragged edge.

If you run it in sloppy rich and never build any heat all you are really doing is wasting fuel, without heat in the motor you wont be breaking it in.

If I were in Oz I would love to be there to help you , its alway been a place I wanted to visit and just haven't had the chance.

18% oil is plenty and I prefer abit more nitro but if you wont be racing then stick with the mild stuff.

Good Luck!

Ron

 

[Tom Foley]

All good advice on break in . I view the rich running in as a "wash cycle " so to speak, to easily allow initial ultra fine particles of metal that exist to exit the exhaust pipe !! You should be ready for battle after a few tanks of fuel . My 84's still have a touch on top of the stroke after aprox. 20 gallons of 60 %, they are just right now . Can't wait for Brandon in two weeks !

 

[Mike Byer]

All good advice on break in . I view the rich running in as a "wash cycle " so to speak, to easily allow initial ultra fine particles of metal that exist to exit the exhaust pipe !! You should be ready for battle after a few tanks of fuel . My 84's still have a touch on top of the stroke after aprox. 20 gallons of 60 %, they are just right now . Can't wait for Brandon in two weeks !

Tom, Have you put the twin that you got from me in service yet?

Mike B

 

[SayMikey]

All good advice on break in . I view the rich running in as a "wash cycle " so to speak, to easily allow initial ultra fine particles of metal that exist to exit the exhaust pipe !! You should be ready for battle after a few tanks of fuel . My 84's still have a touch on top of the stroke after aprox. 20 gallons of 60 %, they are just right now . Can't wait for Brandon in two weeks !

Tom, Have you put the twin that you got from me in service yet?

Mike B

I have a mac67 in my scale boat,i ran iton the beach till warm and let it cool ten minutes.I went through 3 of these cycles then ran the boat ib the water no more than half throttle enough times to consume a half gallon of fuel after that let it rip. Be assured you want the motor a little on the rich side lean slightly till speed is achieved NEVER RUN TOO LEAN. Mines great getting ready to slip it in a RR67 for some quick laps...Mike

 

[Tom Foley]

Mike , I have not put the boat together yet , I have my other twin which is the same model but a little more battle weary !! I am trying to decide to put 80's or 67 's in it . With the orlando race and work etc haven't been able to do much other than admire the boat I got from you , nice piece . Thanks , Tom .

 

[Marty Davis]

Engine Break-in is a topic that you will get 100 different answers for. Consider my method and the reasons for this system.

Just running the engine rich AND cool, will do 2 things. It will start to wear the engine out without doing much to get the engine to seal well and you will get some driving time.

Consider this method (ONLY if you use mixture control): REMOVE the water line from the engine, run around the course driving a tight line and lean the engine in the turns and richen the engine on the SAW's. This will keep the engine nice and hot in the turns and cool it off in the SAW. Heat cycling will create a great seal (the little shinny line on the liner right at TDC) in less than 5 tankfuls of fuel. You will have an engine that will run superb, have great compression seal and not be worn out from just running around. The reason for breaking in an engine this way, is to get this seal line, make the rod bushing shinny and fitting well, get the bearings happy and polish any place where the crank touches the front housing.

You will find that your engine will run better than any other that you have using this method.

Would welcome comments.....

Marty Davis

 

[Tom Foley]

WOW , now that is an interesting way to "break " a motor in ! While an accomplished vet of the nitro wars like you might successfully complete that process , I would never reccomend that to anyone , especially with a bushing rod . While running a motor stupidly rich for extended periods accomplishes little , running a little rich is always better than anything lean . I have seen more people lose races and just plain screw up their day with an adjustable needle setup . While third channel needle can be a tool , it seems to cause more harm than good for a novice boater . I firmly believe in working carefully toward a good needle and logging flow results , then purposely scramblig the needle and flowi t by the meter the same day to see if it can be replicated . I still have alot to learn from people in this hobby but sound basics have helped me alot . Marty , thank you very much for all the information that you have shared in your writings and site as well . Bobby Caudill turned me on to your chronicles years ago and it has been a major contribution to the advancement of this hobby . I only wish I had more time to focus on more of it !!

 

[Jim Allen]

Engine Break-in is a topic that you will get 100 different answers for. Consider my method and the reasons for this system.

Just running the engine rich AND cool, will do 2 things. It will start to wear the engine out without doing much to get the engine to seal well and you will get some driving time.

Consider this method (ONLY if you use mixture control): REMOVE the water line from the engine, run around the course driving a tight line and lean the engine in the turns and richen the engine on the SAW's. This will keep the engine nice and hot in the turns and cool it off in the SAW. Heat cycling will create a great seal (the little shinny line on the liner right at TDC) in less than 5 tankfuls of fuel. You will have an engine that will run superb, have great compression seal and not be worn out from just running around. The reason for breaking in an engine this way, is to get this seal line, make the rod bushing shinny and fitting well, get the bearings happy and polish any place where the crank touches the front housing.

You will find that your engine will run better than any other that you have using this method.

Would welcome comments.....

Marty Davis

Marty,

I agree, that without those clearly visible wear bands at TDC on the liner & down from the piston crown, a motor will not have a good seal. Also, the bands should be very even all the way around the ID of the liner & the OD of the piston. This indicates the two parts are remaining round when heated under running conditions. Maybe this is a valid reason to use heavier walled liners, with large diameter thick lips in this critical area??? I have also found that piston, liner break-in time can be greatly reduced when using very fine finishes on both.

Jim

 

[Piston1]

Marty,

The breakin procedure (no cooling, lean on turns, rich on strightaway). Is it Ok for big motors also (80s, 90s etc). How many cycles you recommend.

Thanks,

JOSE