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Search: Posts Made By: Jazzy
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04-30-2012, 07:30 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Sweet!! The thrill never goes away...

Whatever info you can share would be great.

Thanks,
Jeff
04-28-2012, 06:54 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Yeah, that's what I was figuring on using.

I considered modifying the piston crown but that would affect CR. It seems to be the one thing that is just about perfect so I don't want to mess with...
04-28-2012, 07:33 AM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

AV8TOR,

Thanks for the tips. I haven't figured out yet how I intend to get a tool to the top of the transfer ports.
04-26-2012, 08:26 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

The porting for this engine is as follows:

Exhaust Port:
-open @ 114 deg
-close @ 254 deg
-duration = 140 deg
-ideal range: 140 - 150 deg

Transfer Ports:
- open @ 132 deg
04-24-2012, 04:54 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Ran it without the muffler today after work.

IT IS IMPERATIVE THAT HEARING PROTECTION IS WORN!!!

I actually had foam plugs in as well as my shooting muffs. It was bearable.

Well, I...
04-23-2012, 07:37 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

I took the spark plug out and the muffler off.

The top of the piston, after about a tank and a half of 40:1 mix, is already caking with crud.

The exhaust port and side of the piston are...
04-22-2012, 06:25 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Ah, yes. Finally had some time to tinker more.
Unfortunately, the remote primer bulb bought the farm while trying to start the engine yesterday... Or was it the day before?
Anyway, I ended up...
04-15-2012, 09:02 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Spaceworm,
I tried just slipping the catch off the throttle lever but it was not conducive to what I deemed acceptable "spring" behavior. There IS some lateral play in the throttle arm so I may...
04-15-2012, 05:28 AM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Okay. Time for another installment.
The resistor spark plug, prop hub, velocity stack, and mounting plate came in from Carr Precision. Very nice!

Cleaning up the flywheel was a time...
03-20-2012, 04:03 AM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Got around to doing some more measuring.

I put the piston at TDC and slowly filled the combustion chamber through the spark plug hole with 2-stroke oil.
I used a syringe-type dispenser that...
03-18-2012, 05:27 AM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

tkg,

I haven't yet done the measuring to see how much room I have to play with as far as exposing the piston skirt in either opening. Those will come soon.

The direction I go in with the...
03-16-2012, 01:52 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

av8tor1977,

I just got a good look at the image you posted! Very nice!

Had I seen it sooner I wouldn't have had to make one at work. I used A-cad so it turned out nicely.
I sized it so...
03-15-2012, 03:09 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

w8ye,

you know, I've been tossing that idea around for a few weeks now. Any pointers for such an undertaking?
I'll consider this in more depth when I see what the actual timing and exhaust...
03-13-2012, 08:53 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Thanks for the tips!
I kinda figured the restriction in the intake port was there to keep the ring concentric. I'll leave that nub alone.

The exhaust port has a similar center "column" in...
03-12-2012, 08:45 PM
Replies: 9
Views: 1,097
Posted By Jazzy

RE: Walbro experts needed

Are you using a velocity stack? Without one it is not uncommon to get erratic operation.

I wouldn't mess with the pump/metering needle fork but someone with more knowledge may say otherwise. ...
03-12-2012, 08:37 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Another mod is the back plate and possibly the back surface of the crack case. The back place WILL need to be trimmed. See silver outline on the back plate. A common mod to the case is to take...
03-12-2012, 07:07 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Using Outers Crud Cutter, Mass Air Flow Cleaner, and Scotchbrite the crank case cleaned up nicely. The piston took well to the scotchbrite. I got a little over zealous on the piston crown but I'm...
03-12-2012, 06:57 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Finally had time for more tinkering. Sorry for the long pause but 'work' does pay the bills! LOL

I ordered a prop hub, velocity stack, and resistor spark plug from Carr.
In the meantime I...
02-28-2012, 08:53 AM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Gents,

I thought I had a link to find a prop hub adapter but now I can't find it. I tried searching but didn't have much luck.

Can someone post or send me some links please?

Thanks,
...
02-11-2012, 01:19 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Ranger,

Interestingly enough, the crank threads are 5/16-24 on this engine.

The rolling-thread screws used to hold pretty much everything else together are 10-32. This will make for an...
02-11-2012, 12:49 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

More tinkering:

The first thing I need to do was remove the drive shaft adapter. As it is a CCWSE rotating crankshaft, the threads are standard: "Lefty-Loosy."
A screwdriver and curve-jawed...
02-04-2012, 06:29 AM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

Thanks w8ye!

I wonder if changing the head and piston could make this one a 32cc engine...
I don't know if the cranks or connecting rods are the same for the two different displacements...
02-03-2012, 09:01 PM
Replies: 47
Views: 3,884
Posted By Jazzy

RE: Mac 2815 Weedie Conversion

I finally had some time to tinker a little more.

I wanted to get an all-up weight of the engine-muffler-carb-magneto combination before I started cutting metal and plastic.
To do this I had to...
01-17-2012, 08:09 PM
Replies: 47
Views: 3,884
Posted By Jazzy

Mac 2815 Weedie Conversion

I am going to be converting a Mac 2815, gas, 2 stroke weedie into an aircraft engine.
The plan is to do a step by step walk through to show those that my be daunted by such an endeavor that it...
01-02-2012, 08:30 AM
Replies: 6
Views: 700
Posted By Jazzy

RE: What should my dishcarge rate be?

This basically depends on what size the cells are (i.e. AA, C, SC, etc.), what size the wires are, and what the pack's intended use is.
For cycling battery packs, modelers often use rates ranging...
Showing results 1 to 25 of 500
 


 
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