Re: Vintage engines

That engine is a Merco .61. It is an excellent engine as far as I am concerned. I have a Merco .35, a .49 and a .61 that I bought new in the
early 1960s That were used heavily during the 60s and early 70s until I moved to where there was not much active modeling. I retired a few years ago and moved to a farm in central Wisconsin and started building and flying models again as I now have my own model airport and lots of room. I dug out my old RC Models and found my old Aeromaster Biplane with the .61 still in it. The plane is only good for hanging in the barn but even though the Merco .61 was seized up with congealed castor oil and other gunk I removed it and soaked it in Lacquer thinner and then transmission fluid and dismantled it and it cleaned up good as new. I am flying it now in a Thunder Tiger Trainer and building an old Kwik-Fli 2 kit that I have had for years for the next plane. It runs great and really pulls the trainer around. I fly it here on the farm without a muffler as it was meant to be run but I have a muffler I bought back in the 70s and it fits ok to so if I ever fly at a club site or in town I can put it on.
That Merco should be a great old engine but you must break it in slow and rich, it gets very hot if you lean it out to soon. Break it in easy and it will run for 30 years.
Dave Carr Wisconsin P. S. My engines are older then yours and have only one plug. The twin plug came along later.

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
About ten years ago, Merco .40 plain bearing engines were being sold nationwide in the USA. They quickly developed a bad reputation of being cantankerous and dying in flight.
As it turned out, the engines were fine, but the typical short duration break-in that most OS users tried to use was nowhere near long enough. Also, the Merco engines did not like fuel with much more than 5% nitromethane. Using more nitro would lead to overheating and quitting.
A friend gave me his Merco .40 after becoming frustrated with it. I quickly mounted it on my break-in stand and then broke it in using 5% Sig all castor fuel. It was a sweet engine. No, it was not a powerhouse, which is what my friend wanted, but it was a good engine that was going to have a long, pleasant lifespan in the hands of someone that appreciated its good points.
Ed Cregger

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Thanks for the precious info.
Any idea of the today's value of it on the market ?
Ed Cregger a ιcrit :

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Sorry, I only know that I paid about 35 dollars for the .61 when I bought it new. I suspect it is worth that today if not more. I don't plan to sell mine so I am no help.
Dave Carr

engine
port.
screws
help
marks
value?
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I don't keep up with such things, Sylvain, but there is a group whose name I butcher every time I try to pass it on to someone. <G>
It is something like, the Model Engine Collectors of America. I'm sure someone will graciously be so kind as to provide you with the correct name. Come on fellows.
Ed Cregger

engine
port.
screws
help
marks
value?
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Well you've had your answer on the Merco (lovely engine) but the other one is an OS Max 19 and most likely a Max III (it'll have the mark cast into the transfer port). They were very good engines in their day but it won't be worth very much. If you want to use it then make sure you have about 25% castor in the fuel, don't even try to run it on a modern synthetic.
Sylvain Blanchard wrote:

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Here is a link to a used 61, $54. http://www.theengineersemporium.co.uk/catalogue-pages/modpetreng.html# I saw another one nib for $75 but not sure if it was a twin plug. If yours was new in a box you could get maybe $80. Don,t know if it looks used. Maybe someone collects them and would be willing to pay more but there were quite a few made, they still make basically the same engine and the ST 61 was based on this motor in single plug config. The os could be worth from $5 to $50 depending on its condition and what people are willing to spend. Good Luck Paul
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Okay, Brian, I confess that you have me intrigued. Why should the engine be run only with castor oil, and not a synthetic oil? I just spent several hundred dollars on a metal working lathe, in order to build internal combustion engines, and this is exactly the type of information which I will be needing to know, if I am going to be successful in this endeavor.
Michael
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

should
them
will
the
the
A
reason
toast.
iron
old
I always add a few oz. of castor to my fuel; ALL engines run cooler, less rust when left for a while. -- Jim in NC--
Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mainly, castor oil has better protection against 'needle tweakers' who end up with lean runs. A 'properly' adjusted - meaning slightly rich - engine does not need the excess lube, whether castor or synthetic. I agree that castor has better rust preventative storage capabilities if an engine is NOT treated with after-run oil.
David
wrote:

Add pictures here
βœ–
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.