compression
 

ok here a noobish question i just bought my first gass motor a dm 55 i had a used quadra q52 that ran fine but i wanted more power so here is my question will the compression increase as the rings and head seat ? ATM i have just a few tanks into this motor it's wenter so no flying ( dam snow) just trying to get a peace of mind on this subject this is my first new gasser so im not 100% sure how the seating affects the compression. ATM the motor turns easy and dont seem to have the high presser kick that my quadraq52 has if anyone can shead some light on this subject please let me know

RE: compression
 

If you have already run it a few tanks, I doubt you will see much more increase in compression feel.

RE: compression
 

only been ground ran the motor is easy to start in all just sems the compression is lacking i just pulled the head off and looked and the ring is barly showing any sings of ware aka it's still has 98% of it's black coatng on it and the celender walls have no sing od wear on them aka you can still see the honing mars from when it was made just asking i was told that it will take a cupple gallans of fuel befor it will get fully seated is this true

RE: compression
 

Save tme & fuel...get a Frank Bowman custom piston ring. Capt,n

RE: compression
 

ya i checkedbowman out they do not list a ring for my motor inwitch as the same pistion as a dle 55 so i sent a email in a few days ago no reply yet just trying to find out if the motor will get better as they seat togher i have not yet sput this motor threw the stress of flying my 1/4 scale laser 200 around yet

RE: compression
 

The Chinese rings are typically very hard and it may be a year or so before you see a full wear pattern on that ring.

It is easier to look in the exhaust port for ring wear indications.

When you remove the jusg from the ring, the seating of the ring has to start all over again.

RE: compression
 

o well as i said im new to this lear from your mistakes :) the motor has a ton of power + im useing belray 40:1 mix so that will make it take some time to fully seat </p>

RE: compression
 

If you are pleased with the way it runs, do not worry about it.

RE: compression
 

ATM with a vess 23b prop befor i took the head off it was running at 6800 rpm and it's running rich wating to lean it out more tell it's gets at least a full gallon throw it im scaired to lean it out anymore i dont want to ruin this motor

RE: compression
 

That's pretty good for pulling a 23 X 10 prop.

If you continue to run it rich, you will be making more carbon on the piston and rings.

Best you just tune it up for best running.

RE: compression
 

ATM?

The compression will increase as the ring seats. Anticipate the ring will not seat until the engine has about 15-18 gallons of gas through it.

RE: compression
 

atm (at the moment)? dang 18 gallons is a lot, i would have to dedicate a lot of time to only one plane to get that much fuel burnt

RE: compression
 

FWIW and IMHO (LMAO),

TWISI (The way I see it) You have been given some excellent advice by some pretty experienced people.

In no particular order that excellent advice includes:

If you are happy with how it runs - don't worry about it

If you are worried about the time taken to get a good ring seal, Get a Frank Bowman Ring

It will take a long time before the Chinese Ring fully beds in

All the above is excellent advice But some of the best advice is

DO NOT Run the engine excessively rich.

Tune it for best top end RPM and decent transition. IF you feel uncomfortable with the needles at the best RPM setting and really want it to be a little richer, open up the high speed needle by about 1/16th of a turn (about a screwdriver blade width) for your peace of mind.

The DM 55 is actually not a bad engine for the price but they do have the "Classic" Chinese rings in them that never want to wear in fully, especially on the flame chromed bore it runs against.

RE: compression
 

not real easy to tune do to the 20 degree weather out side but in the spring i have a flying buddy that been flying gassers for 15 years he going to tune this motor for me and teach me how to tune it for max proformance ty for all the info