WORNBOOTS

My Feedback: (33)

If any of you are interested in a 28 cc trimmer engine new & complete, check out this site I use for axels and tranny's

[link=http://www.surpluscenter.com/item.asp?UID=2004070810060454&item=28-1486&catname=engines]Surplus Sales[/link]

Antique

My Feedback: (4)

WORNBOOTS, Thanks for the lead on these 28cc engines. Mine arrived today. Do you know what engine is in these ? When I saw "McCulloch" for some reason I thought it would be based on a Echo/Kioritz engine. I haven't opened it up yet but from from what I can see it's not an Echo/Kioritz. Any ideas ?

Willdo

I have 4 of these engines ( second hand ) - they are entirely different to the smaller 21cc McCullochs, ( which I have 1 of) - these have a double sided crank and steel conrod.

The 28cc and 32 cc models are virtually identical, and have single sided "cantilever cranks", supported by 2 ball bearings, and aluminium alloy conrods, - they look very easy to convert for aircraft, and are reasonably light.

- Good cheap answer for gas powered planes!

w8ye

My Feedback: (16)

I converted a 28 to a 32 by changing the cylinder and piston. The rest is the same.

Enjoy,

Jim

Antique

My Feedback: (4)

This is the engine that came out of the "surplus 28cc McCulloch string trimmer". Is this a Poulan?

- Front casting un-bolts and leaves what looks like an airplane engine with beam mounts. The magneto ignition coil is bolted to the front casting so it goes away with the casting ,,,,, no cutting. OK for electronic ignition.

- Muffler held on with one spring,,, don't think I like that very much.

- Cylinder fins look really thick & heavy.

What do you think,, worth messing with ?

Willdo

Don't know if it is a Poulan.

Just cut down the frame and keep it attached to hold the coil.

The fins may be a little thick, - I believe that the 32cc version is a little lighter (because it has the same cylinder with a larger bore.

If the exhaust stays on the trimmer ok, why is it no good on an aircraft? - Racing 2 stroke motorcycles used the spring system to hold on the pipes in the past, with 100% success.

This engine has been used successfully a lot, but it all depends whether you want a powerful beast or not.

w8ye

My Feedback: (16)

The engine in the pictures is of a standard late model McCulloch weed whacker right before they quit making them. I have several 32's that look like this.

Enjoy,

Jim

Antique

My Feedback: (4)

Thanks for all the info boys !

bdtsr

My Feedback: (5)

Well has anyone got theirs running yet? Any performance numbers? I just ordered mine and am waiting for it too arrive. I have a Cermark Pitts that's looking for a gasser.

dirtypool

My Feedback: (6)

I have a 28 with a ch ignition and a 32 magneto, both converted. I havent flown either one yet though. One is on an ultra stick (not lite) and the other is going on a version of a Big Pink.

I'll let you know what the numbers are.

bdtsr

My Feedback: (5)

That would be great. I'd like to know if my $45 was worth it!

blohmvoss

ANTIQUE: What are your progress with the surplus MacCulloch engine conversion? I would like to know the shaft-head height and the weight also if you plan to install an electronic ignition. I'm planing to get one.

kiv

I have a couple of the 32cc versions of this motor. Reasonably light, fairly powerful and the block design lends itself well to easy mounting options.

Changing out or modifying the muffler, however, is a PITA! [:@] http://www.abellrc.com/lgear.html is the only source for an aftermarket muffler that I know of. Call and ask for Clay.

The 32cc version is also available in the McCulloch backpack blower that you sometimes find available surplus. The advantage to this version is that the muffler manifold design is different and the muffler is held on with screws instead of springs.

Kiv

Cat 1

My Feedback: (1)

Hi All,

I have converted a few of these 28's and they seem to run very nicely. They are not powerhouses and are on the heavy side but they are stone cold reliable. I have included pics of my latest - electronic ign - fixed timing - custom backplate with mount and a weight loss program.

I can't remember what it ended up weighing but it pulls a 14lb high wing sporter of my own design around in a scale like manner. (no 3d stuff)

Chris

p.s. the plane in the pics is the one the mac-28 pulls around - the 28 was not on this plane when the pic was taken.

bdtsr

My Feedback: (5)

Engine looks nice. Where did you get your prop hub? I need to finish tearing mine down, but would like to get the parts together to finish it.

Cat 1

My Feedback: (1)

I built the hub for this engine. As far as I can remember it was fairly straight foreward.( it was a while ago) I remember having to re-thread and cut off some of the long extension. I think Carr precision sells a hub(and other parts) for these for the magneto.

http://home.att.net/~carrprecision/Page3.html

b717doc

I was told that the engine given to me from a neighbor was a 32cc McCulloch "eager beaver"
chainsaw engine, and looks nothing like the pictures here. The exhaust "deflector" is on the back side of the cylinder, and the intake is on the front, just behind the flywheel. I was able to mount the engine for a short while, and fly it on a 120 size stick, the entire airplane w/engine installed weighs in at just over 17 pounds. Turning a 18x10 prop, the airplane has unlimited vertical, and pulls the stick around effortlessly. I am having ALOT of problems keeping the engine on the airplane due to vibration (I guess). The engine does have a small pump coming off the crankcase that I was told pressurized the oil tank for lubricating the chain for the saw, and believe me, It pressurizes very well!!!! I had it pressurizing the fuel tank, but it was actually overpressurizing it, flooding the carb (has a Zama carb), so I disconnected pump, but left it on the engine (it just clips on). There are absolutely no identification marks on the engine that I can find, but it does have dual bearings, and a ringed piston, as described above. Any ideas on taming this puppy down, so it will stay on the firewall would be appreciated.....thanks

tatolazo

Hi:
try to use the pump to presurize a smoke tank and you will have great smoke time on the air using a flow control valve in the line to muffler.

Rodolfo

MattyC-130

My Feedback: (5)

I got one of these engines from surplus sales. Mine said 32 on the cover so I think I lucked out and got a 32cc instead of the 28cc.
Cut off all excess material put on a larger bore carb and crushed inside exhaust tube (in muffler) and JB welded to 1/2 OD aluminum stack pipes on top of muffler.
RPMs zinger 18x8 6950, MA 16x8 7980, OK numbers but I was hoping to get over 7k with the 18x8 and over 8k with the 16x8
I am mounting it on a Big Spad Ultra Stick total weight should be about 15 lbs.

w8ye

My Feedback: (16)

Looking at the way a Mac is made, it appears that it would be more powerful than a Homelite 30. But the timing must be very mild on the Mac. I have two 32's. One is stock except for C-H ignition and a 1/2" carb and turns a 18-8 at 7400. The other has been worked over by one of the guys on here and it turns a 18-8 at 7,600 with the same size carb and ignition.

Enjoy,

Jim

markus1971

My Feedback: (28)

I'll tell you guys what.... I have a 32cc Mac and flying it on a 14 lb 4 star 120. It's got plenty of power! It's pretty much stock except for the larger bore (7/16") carb. When I first converted it, I was upset about the muffler situation. I didn't like the spring either. Macs are the easiest conversion engine ever in my opinion. All you have to do it trim the plastic backplate on the back of the case, cut the long crankshaft off with a cutoff wheel, Cut the Mag bracket down to only the two left bolts holding it, turn the flywheel (i turned both sides) and make a mounting plate and prop adapter. Mine engine weighs right on 4 lbs.

IF ANY OF YOU ARE LOOKING FOR A VERY STURDY LIGHTWEIGHT ALLUMINUM MUFFLER for a mac.......

Locate Ken Lambert right here on RCU or find him at www.lambertsrc.com. He makes a perfect muffler for the Macs. I also got my first Prop adapter from him.

mac28-32

I have 2 32cc mcculloch engines. I tried to put the engines together In a boxer style and connected both pistons to one pin on the crank so while one piston is doing a comp cycle the other is doing intake. The problem is I don't have pressure in the crank case so I don't think it will work, but Iv'e seen r/c engines just like that at tower hobbys what should I do? Any suggestions?

av8tor1977

My Feedback: (6)

The only way a two stroke engine can work in this manner is if the crankcase is sealed between the two cylinders.

AV8TOR

Ralphbf

My Feedback: (27)

TURBO CHARGED

KenLambert

My Feedback: (107)

make it a 4 stroke