Do they really cost more???
 

I recently took a job as a small engine mechanic and am in charge of the weeders, chainsaws, and all other 2-cycle powerplants. One day before clocking out I got on the computer to check the cost of a Poulan 46. I wanted to see if a Shortblock (complete engine without carburetor, igniton, muffler). From what I can see it is not available that way, but the components to build it are all available. You can buy a cylinder assembly(with piston), crank assembly(with rod and bearings), a wrist pin bearing. This should be all you need to start building an engine, minus ignition of coarse. The cost for all the above mentioned parts are about $100.00 retail.

Now let's say you bought a CH Ignition conversion kit for this engine which retails for $208.00.

We are up to $308.00.

But we forgot the muffler and carburetor. I think another $100.00 will buy both, which brings us up to $408.00.

Is that too much for a brand new engine?

For those that want to say you will "still have a conversion" need to look around, because most engines we fly have a far different background. Most are originally from saws and such. Yes DA, 3W, and the such are not from that arena, but were not talking about that much money either. The average DA-50R set-up will cost you $600.00 without stand-offs, unless you buy somebody's used engine. Used engine.

RE: Do they really cost more???
 

If you go out and buy everything the way you are suggesting, a conversion is no deal. I built a 45 CC homelite conversion with a CH ignition. I also have a DA-50 and a ZDZ-80. The conversion is a nice project and I had fun with it, but it is not in the same league as the DA-50 or the ZDZ-80. A conversion works because you get a good deal on the core engine, or because it gives you satisfaction to build it, or because you want to connect the world of general purpose 2-cycle engines to the world of model aircraft engines. In my case it was all three. If you're trying to make a killing in the engine market, you are in for a disappointment, I beleive. Conversions also require tinkering. The muffler I bought from a well-known vendor uses thread-in pipes. These quickly vibrated out, despite my using engineering cement to hold them in. I had to go get them aluminum welded, and I am still nervous about them. Additionally, conversions often have lower standards than the top engines do. For example, my Homelite has a single stud mounting the prop. My DA-50 has a threaded crankshaft plus four cap screws. The DA-50 is ported to run at low RPMs and high torque. The Homelite is not. The one place you can do well is to buy the engine cheaply, and then keep the conversion cost low, by leaving the magneto in place, etc. Cheaper airplane engines like Zenoah are set up this way, and our conversions do tend to resemble them more. I went the "whole route" because I wanted to see what I could do on my own, and I wanted to understand the relationship between a chainsaw engine and a model airplane engine at a higher level than most of the guys at the field do. BTW, one of the better pilots where I fly is a mechanic in a shop like yours. He keeps talking about building a conversion, but he flies a DA-100. I like my conversion and I am glad I did it, but I have no illusions about it. Finally, if you like the idea, get busy and build one. Then tell us about it!

RE: Do they really cost more???
 

well thats if you buy the engine new :) i got one homey for free from my future father in law who has an electric now. the other homey i got on ebay for 22 bucks. i dont plan on getting a CH ignition but rather sticking with the magneto's that came on them. the mount and prop hub i make with my dad's help(because he has access to the tools since he is a tool maker). now i might get on ebay and get a walbro carb or two that has a bigger opening for 15 to 20 dollars. now at the most for one engine i have 40 dollars spent when the zenoah is 299 or 399 i forget. it has the magneto as well. i will still have a reliable engine however spent alot less. i have a used cap 232 i bought for 125 bucks that is the right size for the homelite. i wont get unlimited verticle but i am not a good enough pilot to take advantage of that anyhow. secondly i learn alot about how small 2 cycle engines work. its all based on the individual choice i feel i have more to gain by converting in the long run than buying a 400 dollar engine.

RE: Do they really cost more???
 

While I will agree doing conversions are fun, I will disagree on the statements that have been made here regarding cost and viability of conversions -VS- "airplane" engines. CH Ignitions cost at least $50.00 less than stated. Bought 6 of them now for my conversions. Why buy all the parts for a Poulan? You can buy the whole saw for less than that at times brand new, sell the leftovers. Heck I got 30 bucks for the bar and chain! Paid $70 dollars for the whole saw from sears. Poulan makes Craftsman. Sure the Poulan 42 may be a tad heavier than my true BME 50 but in my sons Sig Extra 300 it has unlimited verticle. Total cost breakdown: Saw $70, hub and sensor bracket $39.00, muffler $28.00 all welded, CH Ignition $145 with Bosch cap. Grand total of $282.00. Less than half of the cost of a so called airplane engine. Remember that BME singles are right out of the Echo chainsaw line. Have a BME 50 in my Wildhare Extra 300LX. Had to invest $650 or so in it. Just started 2 new projects based on the Echo short blocks. CS4400 = BME 44 and a CS510 = BME 50. Paid $350 for both short blocks. Hubs, mufflers, and ignitions will cost me another $250 or so to buy, but I am making everything but the ignitions. Carbs are all over RCU and Ebay for way less than one may think. Get some G10 board for the carb spacer, a 2" by 2' bar will make blocks for at least 20 engines. Paid 22 bucks for mine. By the way BME uses a single prop shaft. Never had an issue with mine. Just my experience.

RE: Do they really cost more???
 

Add to this the fact that you can always move the CH ignition from plane to plane! It's nice to have each plane all flight ready, but not necessary. For the cost of the sensor, ($7.50 I think), the engine can be flight ready and all you do is plug in the ignition unit.

I would NEVER cough up $400.00 or more for a gas engine. 90% of my conversion engines I got for free or a few bucks. Make all the parts yourself, buy the ignition, and have a blast. Thats what I do. (You don't even have to buy the ignition but I always do to save some weight and make for easier starting.)

AV8TOR

RE: Do they really cost more???
 

Don't forget the bragging rights about how you made a model airplane engine from a chainsaw or whacker?

Enjoy,

Jim

RE: Do they really cost more???
 

And that truly is priceless. People can hardly believe it!!

AV8TOR

RE: Do they really cost more???
 

RE: Do they really cost more???
 

New Echo 58cc short block; everything but the carb and exhaust for our applications, $200.00 more or less. Carb out of the junk box, homemade exhaust and prop hub, ignition off one of my other engines. Still just a whole lot cheaper than $400 to $600 bucks!

Yep, conversions are cool!

AV8TOR

RE: Do they really cost more???
 

Guys I'm really torn.

I have a 45cc Echo blower, runs perfect.
I am thinking seriously about converting it.

There ia a guy selling 50cc Homelites converted for RC inclides everything.... $250.00

There ia a guy selling 46cc Pouland converted for RC inclides everything.... $240.00

Both have flywheels and apear to have been done right, especially the Homelite.

Should I convert, or should I buy a conversion. And which conversion should I get?

Will the Echo be the best of the bunch?

What do you think?????

RE: Do they really cost more???
 

Hi av8tor,
Do you have the part number for that 58cc shortblock or saw model number? I have 44cc and would like to build a larger Kioritz engine.

Thanks Dave

RE: Do they really cost more???
 

Add to my original post that the Echos are very powerful. That is whay Keith at BME does them. I have also converted a 23.6cc from a blower. Flying my Balsa USA Eindecker very scale and turns a cheap Master Airscrew 18/6 at better than 7500 RPM all day with ease. Got 3 string trimmers from a landscaper for free for more projects. By the way Dave, I will let you know when I get them apart if you are still interested in the "left overs".

RE: Do they really cost more???
 

Still interested, thanks Tim

RE: Do they really cost more???
 

Echo 58cc "Short Block" (complete engine without accessories) #SB1020

http://www.smallenginepartswarehouse.com/parts.asp

On the "What to do" question, if you don't need the blower, I would convert it. You will have the satisfaction of doing it yourself, and use the money you would have spent on the other motors for airplanes or accessories! I think the power levels would be fairly close, with the Echo having a possible edge.

AV8TOR

RE: Do they really cost more???
 

for me the conversions vs. ready-made topic is pretty close to kit/scratch vs. ARF debate. the ARF will many times come out cheaper especially if you consider you time worth something but you simply won't get the same satisfaction out of it! depends what you want out of the hobby.

even though i get most of my engines for free the end result would be expensive if i tallied up all the time and running around i do to get them converted. sure i could just buy a ready made hub and mount but that would take alll the fun out of it...for me anyways


dave

RE: Do they really cost more???
 

Where are you guys getting the G10 board from?

RE: Do they really cost more???
 

http://www.mcmaster.com/

http://www.jjorly.com/g10_fr4_sheets_fabricator.htm

or maybe ook up G10 on Google?

Enjoy,

Jim

RE: Do they really cost more???
 

I had looked on Google and only found sheets that were way too big and way to expensive. The McMaster site has a piece 5/8" thick by 4"x6" for $9.36. That looks like what I will get. Is 5/8" a good thickness to get?

RE: Do they really cost more???
 

[link=http://www.jjorly.com/g10_fr4_sheets_fabricator.htm]http://www.jjorly.com/g10_fr4_sheets_fabricator.htm[/link] has a competitive price, they just sell in 3ft x 4ft sheets...
Plus I called the company (JJ Orly) today and they said that they also custom cut parts and special sizes out of G10 for the RC community.

When I looked on Mcmaster Carr, I couldn't find a 4" x 6" piece anywhere...and I use Mcmaster all the time. The only size they had that was close to 4 x 6 was 6 x 6 x .625 and it was $31.25, almost 3 times the cost per square foot of the 3' x 4' sheets mentioned above. I also buy G10 board quite frequently would question the true integrity of the material at $9.00 per 4x6" block.

What catalog page on Mcmaster was it on?

RE: Do they really cost more???
 

How come a person can't completely delete his own post ? Looks kinda dumb with just a period in a big otherwise empty box..:D

RE: Do they really cost more???
 

G10 from MSC Industrial supply is $106 for 4 square feet, 3/8 thick...
www.mscdirect.com
$38 for one square foot, $66 for 2 square feet....
The 3/8 thickness is perfect for carb blocks..I have used it for many years...It can be machined just like aluminum, but is more abrasive and is very hard on common high speed steel end mills and drills..I use cobalt drill bits and carbide end mills for longer life....It's best cut with a Makita 4 inch disc grinder, it eats bandsaw blades....

RE: Do they really cost more???
 

RCIGN1:

What RPMs are you running to mill the G10, I use a 45,000 CNC router...

RE: Do they really cost more???
 

Some guys have all the toys...;)
I have an old Webb manual mill...2720 rpm with a 4 flute 1/2" solid carbide end mill.....
Definitely not high tech, just like my ignition systems :D
And me :eek:

RE: Do they really cost more???
 

I bought it for cheap on EBAY. I use TiCN Coated carbide tools for milling, flood it with soapy water...extends the life of the tools. For cutting blocks, I use a boron coated blade because the G10 FR4 is so abrasive.

I contacted the company above [link=http://www.jjorly.com]www.jjorly.com[/link] and they mentioned that sell smaller pieces and packages of 25 random sizes for carb block applications, probably from over runs of machined parts.

I do a lot of custom work for RC Hot Rods, some planes / helicopters. As far as actually even driving an RC, I rarely get into the "fun" side. I'm more into the design, concept and customization of the mechanical structures of the vehicle and have a lot of friends who are born enthusiasts with RC racing. I'm also a stand in crew chief for races to help people get their cars back in the race if the damage isn't too extensive. I really enjoy it.

RE: Do they really cost more???
 

It is on catalog page 3350 and Part Number 6842K11

RE: Do they really cost more???
 

AnthonyH

I see what your talking about now...that item (on Mcmater) is actually an linen based phenolic material...which is similar in mechanical strengths to the G10, but is not the same material. The G10-FR4 is an epoxy impregnated fiberglass material. The "Garolite LE" is a continuous cotton woven cloth impregnated with a Phenolic resin binder and is always much cheaper, but doesn't maintain the same chemical resistance and temperature ratings as the G10/FR4 material. The company I mentioned above doesn't sell sheets or blocks of the Garolite LE, but they appear to machine it : [link=http://www.jjorly.com/phenolic_machining_fabrication.htm]http://www.jjorly.com/phenolic_machining_fabrication.htm[/link]

Now I understand why it was so cheap....thanks for the clarification.[8D]

RE: Do they really cost more???
 

On page 3351 is listed the G10/FR4 type Garolite with prices. I've used it a lot in the past and it is G10 and not the red linen fibre or phenoly you mention that is on page 3350.

Enjoy,

Jim

RE: Do they really cost more???
 

Getting back on Topic;

Yes commercial engines do cost more. In my case, much, much more. I have a 34cc Briggs and Stratton Four stroke Gas engine. I converted it from a Sears weedeater. The wacker (used from Ebay) was 100.00 with shipping. I paid Wackerenngines 18.00 with shipping for a hub. A buddy of mine made the 1/4 inch back plate and my band saw took care of the rest. I have a great running, dependable, (and oh boy does it sound good) engine for 118.00. Fuji, the only commercially availible four stroke engine that I know of for RC, has a wopping 799.00 on thiers. This engine does include an Electronic Ignition, but for 189.00 I could have that to. Even with the extra cost of EI, I would still only have 307.00 into the motor. Now,a savings of 490.00 is somewhat profound.
I do however agree with a comment that was posted way up there someplace, the real difference is how you feel about doing the conversion yourself. Its a great fun to play with these suckers and end up with something "I" built. And of course you can brag to friends how cheap it was. I have a feeling it really isnt about saving money to most of those that look down on conversions, I have a feeling it is all about bragging about how much they paid. To each thier own. Just go out and have fun.

RE: Do they really cost more???
 

By the way, I have been told that P-Tex (those cheap cutting boards you see at the department store) makes a darn good material for carb spacers. Any comments? I havent made one yet, but I would like to make a smaller one for my four stroke gasser. What are the dangers of reducing the size of those things? Why are some so long? (to make it easier to get at?) Thanks for the help.

RE: Do they really cost more???
 

.

RE: Do they really cost more???
 

Ralph,
You have to quit doing that "edit" thing. We all know you had something to say, we just know what it is when you do that. Just let it go Ralph......


Prop Nut,

I think you are right about those who bad mouth conversions, not because of how they run or look, it's more about how much they didn't cost. And also the fact that the engines aren't really "airplane engines", therefore there must be something wrong with them....somewhere or at sometime.

RE: Do they really cost more???
 

Prop :

The PTEX ( AKA SRB) material is a UHMW (Ultra High Molecular Weight) based plastic, that is primarily used on skis and snow boards. The UHNW, as the name implies, is a very dense material such as the G10 and phenolic.

Never used it for Carb blocks but I will get a chunk and let you know. I see that the PTEX also comes with a graphite binder...how cool. Don't know why some blocks are longer than others, can't imagine it would improve performance...maybe longer is for a slide carb?

RE: Do they really cost more???
 

On the question of the cost of conversion of
a Ryobi 31 cc. For my part, I have done this conversion and I have a great
engine for less than $150.00 (less than half than comparable "model
airplane" gas engines). With that said, I just read a review of the Zenoah
G26 in an issue of Fly RC mag. Guess what? My weed cutter Ryobi
conversion turns a 16x10 prop at a higher RPM (8,100 vs. 7,260) and idles
lower (1,400 vs. 1,860) than the G26. And my tests are at 5,500 ft altitude
with 15% thinner altitude, which knocks the crap out of engine horsepower.

As for weight my Ryobi is almost 1/2 pound lighter (51.1 vs. 58.3 oz.). I
should add that I added a homebuilt electronic ignition and dumped the stock
one pound flywheel/coil assembly.

Granted my $150 total cost doesn't include some of my labor and my friends
machining (I owe him a lunch). I should add that I pulled the Ryobi out of a
new, reconditioned weed cutter from Harbor Freight. Cost $49.95.
Also my 31cc is 22% larger displacement that
the G26 @ 25.4cc which slants the comparrison in the direction of the Ryobi.

Therefore my observation is that the engine conversions are at least
comparable to other gas engines in their displacement class and cost less.
What's wrong with this logic?

RE: Do they really cost more???
 

Absolutely nothing!

:)

AV8TOR

RE: Do they really cost more???
 

Other than itreally peepee's off the OEM guys. [:@] Also the people who need to feel good about spending BIG dollars for the motors in their planes!! :D

RE: Do they really cost more???
 

Let's see. My first conversion (I'm brand new in that 'business':D:

Engine: Poulan 25cc Weed eater head (new) $25 plus $10 S&H (no tax) from ebay.
Prop hub: 1 dollar worth piece of T6 rod Plus 20 cents for prop screw plus 5 cents prop nut.
Motor mount: 1 dollar worth of T6 plate plus 40 cents 4 screws.
Pleasure working with metal: priceless:D

Now I doubled the value of my engine by adding aluminum muffler from Wackerengines. Includng muffler and mount it weights 3lb 8 oz (8 oz more than MVVS that size with muffler, mount, ignition and battery for over 450 bucks). Even with magneto and stock carb the engine turns MA 16x8 7200 rpm (on 1:30 fuel) and idles 1800+ rpm. I was surprised with transition as it goes from idle to full without hesitation like any 'brand name' 3D engine.

Anyway this is the cheapes engine ever I bought (it's cheper than any glow engine) and entire conversion took me about a day.
Remember, I never did it before. The next one will be even easier.;)

RysiuM

RE: Do they really cost more???
 

RysiuM,

What are you putting that 25cc engine on? Or have you already flown it. Tell us about it.

RE: Do they really cost more???
 

You may have already seen that thread [link=http://www.rcuniverse.com/forum/m_3082557/tm.htm]Poulan 25 from FL trimmer[/link] where I described entire conversion.

http://www.rcuniverse.com/forum/upfi...22/Oi14904.jpg

The truth is, that first I had and idea to build 1/4 scale PZL1-9 Wilga 35/80, next I got plans from UK. Now when building the fuselage I had to stop at the firewall to make sure the engine will fit right. As it is not a high performance plane I thought that cheap weed whacker will do just fine. Actually it does much better than I expected.
I estimated the weight of this 1000 sq inch plane will be 13-15 lb including 4 lb engine, and because it has very short nose Poulan fits just fine. I had to scale original plans to 90% as I wanted to fit the fuselage in my truck with 6ft bed. So it is about 68 inch long and 98 inch wingspan.

Anyway the engine is finished now, ready to run so I'm going back to the plane. It is fun as original plans sucks and I use them mostly as a general view coming up with my own engineering solutions. I'm just so happy I could get away with 50 dollars power-plant (including new muffler).

RysiuM